DRW: Move buffer & temp textures & framebuffer management to DrawManager

This is a necessary step for EEVEE's new arch. This moves more data
to the draw manager. This makes it easier to have the render or draw
engines manage their own data.

This makes more sense and cleans-up what the GPUViewport holds

Also rewrites the Texture pool manager to be in C++.

This also move the DefaultFramebuffer/TextureList and the engine related
data to a new `DRWViewData` struct. This struct manages the per view
(as in stereo view) engine data.

There is a bit of cleanup in the way the draw manager is setup.
We now use a temporary DRWData instead of creating a dummy viewport.

Development: fclem, jbakker

Differential Revision: https://developer.blender.org/D11966

19 files changed, 1109 insertions, 1060 deletions

diff --git a/.clang-format b/.clang-format
index bf20a4e4c4a..91df22f4d5b 100644
--- a/.clang-format
+++ b/.clang-format
@@ -180,6 +180,7 @@ ForEachMacros:
   - CTX_DATA_BEGIN_WITH_ID
   - DEG_OBJECT_ITER_BEGIN
   - DEG_OBJECT_ITER_FOR_RENDER_ENGINE_BEGIN
+  - DRW_ENABLED_ENGINE_ITER
   - DRIVER_TARGETS_LOOPER_BEGIN
   - DRIVER_TARGETS_USED_LOOPER_BEGIN
   - FOREACH_BASE_IN_EDIT_MODE_BEGIN
diff --git a/source/blender/draw/CMakeLists.txt b/source/blender/draw/CMakeLists.txt
index 71115c5ceb9..dd4aa1747e5 100644
--- a/source/blender/draw/CMakeLists.txt
+++ b/source/blender/draw/CMakeLists.txt
@@ -94,6 +94,7 @@ set(SRC
   intern/draw_color_management.cc
   intern/draw_common.c
   intern/draw_debug.c
+  intern/draw_view_data.cc
   intern/draw_fluid.c
   intern/draw_hair.c
   intern/draw_instance_data.c
@@ -105,6 +106,7 @@ set(SRC
   intern/draw_manager_text.c
   intern/draw_manager_texture.c
   intern/draw_select_buffer.c
+  intern/draw_texture_pool.cc
   intern/draw_shader.c
   intern/draw_view.c
   engines/basic/basic_engine.c
@@ -188,7 +190,6 @@ set(SRC
   engines/overlay/overlay_wireframe.c
 
   DRW_engine.h
-  DRW_engine_types.h
   DRW_select_buffer.h
   intern/DRW_render.h
   intern/draw_cache.h
@@ -198,12 +199,14 @@ set(SRC
   intern/draw_color_management.h
   intern/draw_common.h
   intern/draw_debug.h
+  intern/draw_view_data.h
   intern/draw_hair_private.h
   intern/draw_instance_data.h
   intern/draw_manager.h
   intern/draw_manager_profiling.h
   intern/draw_manager_testing.h
   intern/draw_manager_text.h
+  intern/draw_texture_pool.h
   intern/draw_shader.h
   intern/draw_view.h
   intern/mesh_extractors/extract_mesh.h
diff --git a/source/blender/draw/DRW_engine.h b/source/blender/draw/DRW_engine.h
index 5e7b812c37b..927a29ed6b6 100644
--- a/source/blender/draw/DRW_engine.h
+++ b/source/blender/draw/DRW_engine.h
@@ -26,13 +26,12 @@
 
 #include "DNA_object_enums.h"
 
-#include "DRW_engine_types.h"
-
 #ifdef __cplusplus
 extern "C" {
 #endif
 
 struct ARegion;
+struct DRWData;
 struct DRWInstanceDataList;
 struct Depsgraph;
 struct DrawEngineType;
@@ -57,8 +56,6 @@ void DRW_engines_free(void);
 
 bool DRW_engine_render_support(struct DrawEngineType *draw_engine_type);
 void DRW_engine_register(struct DrawEngineType *draw_engine_type);
-void DRW_engine_viewport_data_size_get(
-    const void *engine_type, int *r_fbl_len, int *r_txl_len, int *r_psl_len, int *r_stl_len);
 
 typedef struct DRWUpdateContext {
   struct Main *bmain;
@@ -176,6 +173,9 @@ void DRW_deferred_shader_remove(struct GPUMaterial *mat);
 struct DrawDataList *DRW_drawdatalist_from_id(struct ID *id);
 void DRW_drawdata_free(struct ID *id);
 
+struct DRWData *DRW_viewport_data_create(void);
+void DRW_viewport_data_free(struct DRWData *drw_data);
+
 bool DRW_opengl_context_release(void);
 void DRW_opengl_context_activate(bool drw_state);
 
diff --git a/source/blender/draw/intern/DRW_render.h b/source/blender/draw/intern/DRW_render.h
index fb8b8536897..c1cab931f6a 100644
--- a/source/blender/draw/intern/DRW_render.h
+++ b/source/blender/draw/intern/DRW_render.h
@@ -24,8 +24,6 @@
 
 #pragma once
 
-#include "DRW_engine_types.h"
-
 #include "BLI_listbase.h"
 #include "BLI_math_matrix.h"
 #include "BLI_math_vector.h"
@@ -56,6 +54,7 @@
 
 #include "draw_debug.h"
 #include "draw_manager_profiling.h"
+#include "draw_view_data.h"
 
 #include "MEM_guardedalloc.h"
 
diff --git a/source/blender/draw/intern/draw_instance_data.c b/source/blender/draw/intern/draw_instance_data.c
index e055192eb21..29112ee4788 100644
--- a/source/blender/draw/intern/draw_instance_data.c
+++ b/source/blender/draw/intern/draw_instance_data.c
@@ -364,6 +364,8 @@ void DRW_instance_data_list_free(DRWInstanceDataList *idatalist)
   BLI_memblock_destroy(idatalist->pool_batching, (MemblockValFreeFP)temp_batch_free);
 
   BLI_remlink(&g_idatalists, idatalist);
+
+  MEM_freeN(idatalist);
 }
 
 void DRW_instance_data_list_reset(DRWInstanceDataList *idatalist)
diff --git a/source/blender/draw/intern/draw_manager.c b/source/blender/draw/intern/draw_manager.c
index e65fdce5f2e..7a41142b177 100644
--- a/source/blender/draw/intern/draw_manager.c
+++ b/source/blender/draw/intern/draw_manager.c
@@ -84,10 +84,12 @@
 #include "wm_window.h"
 
 #include "draw_color_management.h"
+#include "draw_manager.h"
 #include "draw_manager_profiling.h"
 #include "draw_manager_testing.h"
 #include "draw_manager_text.h"
 #include "draw_shader.h"
+#include "draw_texture_pool.h"
 
 /* only for callbacks */
 #include "draw_cache_impl.h"
@@ -111,7 +113,10 @@
 /** Render State: No persistent data between draw calls. */
 DRWManager DST = {NULL};
 
-static ListBase DRW_engines = {NULL, NULL};
+static struct {
+  ListBase /*DRWRegisteredDrawEngine*/ engines;
+  int len;
+} g_registered_engines = {{NULL}};
 
 static void drw_state_prepare_clean_for_draw(DRWManager *dst)
 {
@@ -315,35 +320,6 @@ struct DupliObject *DRW_object_get_dupli(const Object *UNUSED(ob))
 /** \name Viewport (DRW_viewport)
  * \{ */
 
-void *drw_viewport_engine_data_ensure(void *engine_type)
-{
-  void *data = GPU_viewport_engine_data_get(DST.viewport, engine_type);
-
-  if (data == NULL) {
-    data = GPU_viewport_engine_data_create(DST.viewport, engine_type);
-  }
-  return data;
-}
-
-void DRW_engine_viewport_data_size_get(
-    const void *engine_type_v, int *r_fbl_len, int *r_txl_len, int *r_psl_len, int *r_stl_len)
-{
-  const DrawEngineType *engine_type = engine_type_v;
-
-  if (r_fbl_len) {
-    *r_fbl_len = engine_type->vedata_size->fbl_len;
-  }
-  if (r_txl_len) {
-    *r_txl_len = engine_type->vedata_size->txl_len;
-  }
-  if (r_psl_len) {
-    *r_psl_len = engine_type->vedata_size->psl_len;
-  }
-  if (r_stl_len) {
-    *r_stl_len = engine_type->vedata_size->stl_len;
-  }
-}
-
 /* WARNING: only use for custom pipeline. 99% of the time, you don't want to use this. */
 void DRW_render_viewport_size_set(const int size[2])
 {
@@ -373,39 +349,6 @@ const float *DRW_viewport_pixelsize_get(void)
   return &DST.pixsize;
 }
 
-static void drw_viewport_cache_resize(void)
-{
-  /* Release the memiter before clearing the mempools that references them */
-  GPU_viewport_cache_release(DST.viewport);
-
-  if (DST.vmempool != NULL) {
-    /* Release Image textures. */
-    BLI_memblock_iter iter;
-    GPUTexture **tex;
-    BLI_memblock_iternew(DST.vmempool->images, &iter);
-    while ((tex = BLI_memblock_iterstep(&iter))) {
-      GPU_texture_free(*tex);
-    }
-
-    BLI_memblock_clear(DST.vmempool->commands, NULL);
-    BLI_memblock_clear(DST.vmempool->commands_small, NULL);
-    BLI_memblock_clear(DST.vmempool->callbuffers, NULL);
-    BLI_memblock_clear(DST.vmempool->obmats, NULL);
-    BLI_memblock_clear(DST.vmempool->obinfos, NULL);
-    BLI_memblock_clear(DST.vmempool->cullstates, NULL);
-    BLI_memblock_clear(DST.vmempool->shgroups, NULL);
-    BLI_memblock_clear(DST.vmempool->uniforms, NULL);
-    BLI_memblock_clear(DST.vmempool->passes, NULL);
-    BLI_memblock_clear(DST.vmempool->views, NULL);
-    BLI_memblock_clear(DST.vmempool->images, NULL);
-
-    DRW_uniform_attrs_pool_clear_all(DST.vmempool->obattrs_ubo_pool);
-  }
-
-  DRW_instance_data_list_free_unused(DST.idatalist);
-  DRW_instance_data_list_resize(DST.idatalist);
-}
-
 /* Not a viewport variable, we could split this out. */
 static void drw_context_state_init(void)
 {
@@ -465,107 +408,207 @@ static void draw_unit_state_create(void)
   DRW_handle_increment(&DST.resource_handle);
 }
 
-/* It also stores viewport variable to an immutable place: DST
- * This is because a cache uniform only store reference
- * to its value. And we don't want to invalidate the cache
- * if this value change per viewport */
-static void drw_viewport_var_init(void)
+DRWData *DRW_viewport_data_create(void)
 {
-  RegionView3D *rv3d = DST.draw_ctx.rv3d;
-  ARegion *region = DST.draw_ctx.region;
+  DRWData *drw_data = MEM_callocN(sizeof(DRWData), "DRWData");
 
-  /* Refresh DST.size */
-  if (DST.viewport) {
-    int size[2];
-    GPU_viewport_size_get(DST.viewport, size);
-    DST.size[0] = size[0];
-    DST.size[1] = size[1];
-    DST.inv_size[0] = 1.0f / size[0];
-    DST.inv_size[1] = 1.0f / size[1];
+  drw_data->texture_pool = DRW_texture_pool_create();
+
+  drw_data->idatalist = DRW_instance_data_list_create();
 
-    DefaultFramebufferList *fbl = (DefaultFramebufferList *)GPU_viewport_framebuffer_list_get(
-        DST.viewport);
-    DST.default_framebuffer = fbl->default_fb;
+  drw_data->commands = BLI_memblock_create(sizeof(DRWCommandChunk));
+  drw_data->commands_small = BLI_memblock_create(sizeof(DRWCommandSmallChunk));
+  drw_data->callbuffers = BLI_memblock_create(sizeof(DRWCallBuffer));
+  drw_data->shgroups = BLI_memblock_create(sizeof(DRWShadingGroup));
+  drw_data->uniforms = BLI_memblock_create(sizeof(DRWUniformChunk));
+  drw_data->views = BLI_memblock_create(sizeof(DRWView));
+  drw_data->images = BLI_memblock_create(sizeof(GPUTexture *));
+  drw_data->obattrs_ubo_pool = DRW_uniform_attrs_pool_new();
+  {
+    uint chunk_len = sizeof(DRWObjectMatrix) * DRW_RESOURCE_CHUNK_LEN;
+    drw_data->obmats = BLI_memblock_create_ex(sizeof(DRWObjectMatrix), chunk_len);
+  }
+  {
+    uint chunk_len = sizeof(DRWObjectInfos) * DRW_RESOURCE_CHUNK_LEN;
+    drw_data->obinfos = BLI_memblock_create_ex(sizeof(DRWObjectInfos), chunk_len);
+  }
+  {
+    uint chunk_len = sizeof(DRWCullingState) * DRW_RESOURCE_CHUNK_LEN;
+    drw_data->cullstates = BLI_memblock_create_ex(sizeof(DRWCullingState), chunk_len);
+  }
+  {
+    uint chunk_len = sizeof(DRWPass) * DRW_RESOURCE_CHUNK_LEN;
+    drw_data->passes = BLI_memblock_create_ex(sizeof(DRWPass), chunk_len);
+  }
 
-    DST.vmempool = GPU_viewport_mempool_get(DST.viewport);
+  for (int i = 0; i < 2; i++) {
+    drw_data->view_data[i] = DRW_view_data_create(&g_registered_engines.engines);
+  }
+  return drw_data;
+}
 
-    if (DST.vmempool->commands == NULL) {
-      DST.vmempool->commands = BLI_memblock_create(sizeof(DRWCommandChunk));
-    }
-    if (DST.vmempool->commands_small == NULL) {
-      DST.vmempool->commands_small = BLI_memblock_create(sizeof(DRWCommandSmallChunk));
-    }
-    if (DST.vmempool->callbuffers == NULL) {
-      DST.vmempool->callbuffers = BLI_memblock_create(sizeof(DRWCallBuffer));
-    }
-    if (DST.vmempool->obmats == NULL) {
-      uint chunk_len = sizeof(DRWObjectMatrix) * DRW_RESOURCE_CHUNK_LEN;
-      DST.vmempool->obmats = BLI_memblock_create_ex(sizeof(DRWObjectMatrix), chunk_len);
-    }
-    if (DST.vmempool->obinfos == NULL) {
-      uint chunk_len = sizeof(DRWObjectInfos) * DRW_RESOURCE_CHUNK_LEN;
-      DST.vmempool->obinfos = BLI_memblock_create_ex(sizeof(DRWObjectInfos), chunk_len);
-    }
-    if (DST.vmempool->cullstates == NULL) {
-      uint chunk_len = sizeof(DRWCullingState) * DRW_RESOURCE_CHUNK_LEN;
-      DST.vmempool->cullstates = BLI_memblock_create_ex(sizeof(DRWCullingState), chunk_len);
-    }
-    if (DST.vmempool->shgroups == NULL) {
-      DST.vmempool->shgroups = BLI_memblock_create(sizeof(DRWShadingGroup));
-    }
-    if (DST.vmempool->uniforms == NULL) {
-      DST.vmempool->uniforms = BLI_memblock_create(sizeof(DRWUniformChunk));
-    }
-    if (DST.vmempool->views == NULL) {
-      DST.vmempool->views = BLI_memblock_create(sizeof(DRWView));
-    }
-    if (DST.vmempool->passes == NULL) {
-      uint chunk_len = sizeof(DRWPass) * DRW_RESOURCE_CHUNK_LEN;
-      DST.vmempool->passes = BLI_memblock_create_ex(sizeof(DRWPass), chunk_len);
-    }
-    if (DST.vmempool->images == NULL) {
-      DST.vmempool->images = BLI_memblock_create(sizeof(GPUTexture *));
-    }
-    if (DST.vmempool->obattrs_ubo_pool == NULL) {
-      DST.vmempool->obattrs_ubo_pool = DRW_uniform_attrs_pool_new();
+/* Reduce ref count of the textures used by a viewport. */
+static void draw_texture_release(DRWData *drw_data)
+{
+  /* Release Image textures. */
+  BLI_memblock_iter iter;
+  GPUTexture **tex;
+  BLI_memblock_iternew(drw_data->images, &iter);
+  while ((tex = BLI_memblock_iterstep(&iter))) {
+    GPU_texture_free(*tex);
+  }
+}
+
+static void drw_viewport_data_reset(DRWData *drw_data)
+{
+  draw_texture_release(drw_data);
+
+  BLI_memblock_clear(drw_data->commands, NULL);
+  BLI_memblock_clear(drw_data->commands_small, NULL);
+  BLI_memblock_clear(drw_data->callbuffers, NULL);
+  BLI_memblock_clear(drw_data->obmats, NULL);
+  BLI_memblock_clear(drw_data->obinfos, NULL);
+  BLI_memblock_clear(drw_data->cullstates, NULL);
+  BLI_memblock_clear(drw_data->shgroups, NULL);
+  BLI_memblock_clear(drw_data->uniforms, NULL);
+  BLI_memblock_clear(drw_data->passes, NULL);
+  BLI_memblock_clear(drw_data->views, NULL);
+  BLI_memblock_clear(drw_data->images, NULL);
+  DRW_uniform_attrs_pool_clear_all(drw_data->obattrs_ubo_pool);
+  DRW_instance_data_list_free_unused(drw_data->idatalist);
+  DRW_instance_data_list_resize(drw_data->idatalist);
+  DRW_instance_data_list_reset(drw_data->idatalist);
+  DRW_texture_pool_reset(drw_data->texture_pool);
+}
+
+void DRW_viewport_data_free(DRWData *drw_data)
+{
+  draw_texture_release(drw_data);
+
+  BLI_memblock_destroy(drw_data->commands, NULL);
+  BLI_memblock_destroy(drw_data->commands_small, NULL);
+  BLI_memblock_destroy(drw_data->callbuffers, NULL);
+  BLI_memblock_destroy(drw_data->obmats, NULL);
+  BLI_memblock_destroy(drw_data->obinfos, NULL);
+  BLI_memblock_destroy(drw_data->cullstates, NULL);
+  BLI_memblock_destroy(drw_data->shgroups, NULL);
+  BLI_memblock_destroy(drw_data->uniforms, NULL);
+  BLI_memblock_destroy(drw_data->views, NULL);
+  BLI_memblock_destroy(drw_data->passes, NULL);
+  BLI_memblock_destroy(drw_data->images, NULL);
+  DRW_uniform_attrs_pool_free(drw_data->obattrs_ubo_pool);
+  DRW_instance_data_list_free(drw_data->idatalist);
+  DRW_texture_pool_free(drw_data->texture_pool);
+  for (int i = 0; i < 2; i++) {
+    DRW_view_data_free(drw_data->view_data[i]);
+  }
+  if (drw_data->matrices_ubo != NULL) {
+    for (int i = 0; i < drw_data->ubo_len; i++) {
+      GPU_uniformbuf_free(drw_data->matrices_ubo[i]);
+      GPU_uniformbuf_free(drw_data->obinfos_ubo[i]);
     }
+    MEM_freeN(drw_data->matrices_ubo);
+    MEM_freeN(drw_data->obinfos_ubo);
+  }
+  MEM_freeN(drw_data);
+}
 
-    DST.resource_handle = 0;
-    DST.pass_handle = 0;
+static DRWData *drw_viewport_data_ensure(GPUViewport *viewport)
+{
+  DRWData **vmempool_p = GPU_viewport_data_get(viewport);
+  DRWData *vmempool = *vmempool_p;
 
-    draw_unit_state_create();
+  if (vmempool == NULL) {
+    *vmempool_p = vmempool = DRW_viewport_data_create();
+  }
+  return vmempool;
+}
 
-    DST.idatalist = GPU_viewport_instance_data_list_get(DST.viewport);
-    DRW_instance_data_list_reset(DST.idatalist);
+/**
+ * Sets DST.viewport, DST.size and a lot of other important variables.
+ * Needs to be called before enabling any draw engine.
+ * - viewport can be NULL. In this case the data will not be stored and will be free at
+ *   drw_manager_exit().
+ * - size can be NULL to get it from viewport.
+ * - if viewport and size are NULL, size is set to (1, 1).
+ *
+ * Important: drw_manager_init can be called multiple times before drw_manager_exit.
+ */
+static void drw_manager_init(DRWManager *dst, GPUViewport *viewport, const int size[2])
+{
+  RegionView3D *rv3d = dst->draw_ctx.rv3d;
+  ARegion *region = dst->draw_ctx.region;
+
+  int view = (viewport) ? GPU_viewport_active_view_get(viewport) : 0;
+
+  if (!dst->viewport && dst->vmempool) {
+    /* Manager was init first without a viewport, created DRWData, but is being re-init.
+     * In this case, keep the old data. */
+    /* If it is being re-init with a valid viewport, it means there is something wrong. */
+    BLI_assert(viewport == NULL);
+  }
+  else if (viewport) {
+    /* Use viewport's persistent DRWData. */
+    dst->vmempool = drw_viewport_data_ensure(viewport);
   }
   else {
-    DST.size[0] = 0;
-    DST.size[1] = 0;
+    /* Create temporary DRWData. Freed in drw_manager_exit(). */
+    dst->vmempool = DRW_viewport_data_create();
+  }
 
-    DST.inv_size[0] = 0;
-    DST.inv_size[1] = 0;
+  dst->viewport = viewport;
+  dst->view_data_active = dst->vmempool->view_data[view];
+  dst->resource_handle = 0;
+  dst->pass_handle = 0;
+  dst->primary_view_ct = 0;
 
-    DST.default_framebuffer = NULL;
-    DST.vmempool = NULL;
+  drw_viewport_data_reset(dst->vmempool);
+
+  if (size == NULL && viewport == NULL) {
+    /* Avoid division by 0. Engines will either overide this or not use it. */
+    dst->size[0] = 1.0f;
+    dst->size[1] = 1.0f;
+  }
+  else if (size == NULL) {
+    BLI_assert(viewport);
+    GPUTexture *tex = GPU_viewport_color_texture(viewport, 0);
+    dst->size[0] = GPU_texture_width(tex);
+    dst->size[1] = GPU_texture_height(tex);
   }
+  else {
+    BLI_assert(size);
+    dst->size[0] = size[0];
+    dst->size[1] = size[1];
+  }
+  dst->inv_size[0] = 1.0f / dst->size[0];
+  dst->inv_size[1] = 1.0f / dst->size[1];
+
+  DRW_view_data_texture_list_size_validate(dst->view_data_active, (int[2]){UNPACK2(dst->size)});
+
+  if (viewport) {
+    DRW_view_data_default_lists_from_viewport(dst->view_data_active, viewport);
+  }
+
+  DefaultFramebufferList *dfbl = DRW_view_data_default_framebuffer_list_get(dst->view_data_active);
+  dst->default_framebuffer = dfbl->default_fb;
 
-  DST.primary_view_ct = 0;
+  draw_unit_state_create();
 
   if (rv3d != NULL) {
-    normalize_v3_v3(DST.screenvecs[0], rv3d->viewinv[0]);
-    normalize_v3_v3(DST.screenvecs[1], rv3d->viewinv[1]);
+    normalize_v3_v3(dst->screenvecs[0], rv3d->viewinv[0]);
+    normalize_v3_v3(dst->screenvecs[1], rv3d->viewinv[1]);
 
-    DST.pixsize = rv3d->pixsize;
-    DST.view_default = DRW_view_create(rv3d->viewmat, rv3d->winmat, NULL, NULL, NULL);
-    DRW_view_camtexco_set(DST.view_default, rv3d->viewcamtexcofac);
+    dst->pixsize = rv3d->pixsize;
+    dst->view_default = DRW_view_create(rv3d->viewmat, rv3d->winmat, NULL, NULL, NULL);
+    DRW_view_camtexco_set(dst->view_default, rv3d->viewcamtexcofac);
 
-    if (DST.draw_ctx.sh_cfg == GPU_SHADER_CFG_CLIPPED) {
+    if (dst->draw_ctx.sh_cfg == GPU_SHADER_CFG_CLIPPED) {
       int plane_len = (RV3D_LOCK_FLAGS(rv3d) & RV3D_BOXCLIP) ? 4 : 6;
-      DRW_view_clip_planes_set(DST.view_default, rv3d->clip, plane_len);
+      DRW_view_clip_planes_set(dst->view_default, rv3d->clip, plane_len);
     }
 
-    DST.view_active = DST.view_default;
-    DST.view_previous = NULL;
+    dst->view_active = dst->view_default;
+    dst->view_previous = NULL;
   }
   else if (region) {
     View2D *v2d = &region->v2d;
@@ -581,49 +624,64 @@ static void drw_viewport_var_init(void)
     winmat[3][0] = -1.0f;
     winmat[3][1] = -1.0f;
 
-    DST.view_default = DRW_view_create(viewmat, winmat, NULL, NULL, NULL);
-    DST.view_active = DST.view_default;
-    DST.view_previous = NULL;
+    dst->view_default = DRW_view_create(viewmat, winmat, NULL, NULL, NULL);
+    dst->view_active = dst->view_default;
+    dst->view_previous = NULL;
   }
   else {
-    zero_v3(DST.screenvecs[0]);
-    zero_v3(DST.screenvecs[1]);
+    zero_v3(dst->screenvecs[0]);
+    zero_v3(dst->screenvecs[1]);
 
-    DST.pixsize = 1.0f;
-    DST.view_default = NULL;
-    DST.view_active = NULL;
-    DST.view_previous = NULL;
+    dst->pixsize = 1.0f;
+    dst->view_default = NULL;
+    dst->view_active = NULL;
+    dst->view_previous = NULL;
   }
 
   /* fclem: Is this still needed ? */
-  if (DST.draw_ctx.object_edit && rv3d) {
-    ED_view3d_init_mats_rv3d(DST.draw_ctx.object_edit, rv3d);
+  if (dst->draw_ctx.object_edit && rv3d) {
+    ED_view3d_init_mats_rv3d(dst->draw_ctx.object_edit, rv3d);
   }
 
   if (G_draw.view_ubo == NULL) {
     G_draw.view_ubo = GPU_uniformbuf_create_ex(sizeof(DRWViewUboStorage), NULL, "G_draw.view_ubo");
   }
 
-  if (DST.draw_list == NULL) {
-    DST.draw_list = GPU_draw_list_create(DRW_DRAWLIST_LEN);
+  if (dst->draw_list == NULL) {
+    dst->draw_list = GPU_draw_list_create(DRW_DRAWLIST_LEN);
   }
 
-  memset(DST.object_instance_data, 0x0, sizeof(DST.object_instance_data));
+  memset(dst->object_instance_data, 0x0, sizeof(dst->object_instance_data));
+}
+
+static void drw_manager_exit(DRWManager *dst)
+{
+  if (dst->vmempool != NULL && dst->viewport == NULL) {
+    DRW_viewport_data_free(dst->vmempool);
+  }
+  dst->vmempool = NULL;
+  dst->viewport = NULL;
+#ifdef DEBUG
+  /* Avoid accidental reuse. */
+  drw_state_ensure_not_reused(dst);
+#endif
 }
 
 DefaultFramebufferList *DRW_viewport_framebuffer_list_get(void)
 {
-  return GPU_viewport_framebuffer_list_get(DST.viewport);
+  return DRW_view_data_default_framebuffer_list_get(DST.view_data_active);
 }
 
 DefaultTextureList *DRW_viewport_texture_list_get(void)
 {
-  return GPU_viewport_texture_list_get(DST.viewport);
+  return DRW_view_data_default_texture_list_get(DST.view_data_active);
 }
 
 void DRW_viewport_request_redraw(void)
 {
-  GPU_viewport_tag_update(DST.viewport);
+  if (DST.viewport) {
+    GPU_viewport_tag_update(DST.viewport);
+  }
 }
 
 /** \} */
@@ -671,7 +729,7 @@ static void drw_duplidata_load(Object *ob)
 
   void **value;
   if (!BLI_ghash_ensure_p(DST.dupli_ghash, key, &value)) {
-    *value = MEM_callocN(sizeof(void *) * DST.enabled_engine_count, __func__);
+    *value = MEM_callocN(sizeof(void *) * g_registered_engines.len, __func__);
 
     /* TODO: Meh a bit out of place but this is nice as it is
      * only done once per instance type. */
@@ -686,7 +744,7 @@ static void drw_duplidata_load(Object *ob)
 static void duplidata_value_free(void *val)
 {
   void **dupli_datas = val;
-  for (int i = 0; i < DST.enabled_engine_count; i++) {
+  for (int i = 0; i < g_registered_engines.len; i++) {
     MEM_SAFE_FREE(dupli_datas[i]);
   }
   MEM_freeN(val);
@@ -720,13 +778,9 @@ void **DRW_duplidata_get(void *vedata)
   if (DST.dupli_source == NULL) {
     return NULL;
   }
-  /* XXX Search engine index by using vedata array */
-  for (int i = 0; i < DST.enabled_engine_count; i++) {
-    if (DST.vedata_array[i] == vedata) {
-      return &DST.dupli_datas[i];
-    }
-  }
-  return NULL;
+  ViewportEngineData *ved = (ViewportEngineData *)vedata;
+  DRWRegisteredDrawEngine *engine_type = (DRWRegisteredDrawEngine *)ved->engine_type;
+  return &DST.dupli_datas[engine_type->index];
 }
 
 /** \} */
@@ -873,7 +927,7 @@ DrawData *DRW_drawdata_ensure(ID *id,
     size_t fsize = size / sizeof(float);
     BLI_assert(fsize < MAX_INSTANCE_DATA_SIZE);
     if (DST.object_instance_data[fsize] == NULL) {
-      DST.object_instance_data[fsize] = DRW_instance_data_request(DST.idatalist, fsize);
+      DST.object_instance_data[fsize] = DRW_instance_data_request(DST.vmempool->idatalist, fsize);
     }
     dd = (DrawData *)DRW_instance_data_next(DST.object_instance_data[fsize]);
     memset(dd, 0, size);
@@ -967,11 +1021,12 @@ void DRW_cache_free_old_batches(Main *bmain)
 
 static void drw_engines_init(void)
 {
-  LISTBASE_FOREACH (LinkData *, link, &DST.enabled_engines) {
-    DrawEngineType *engine = link->data;
-    ViewportEngineData *data = drw_viewport_engine_data_ensure(engine);
+  DRW_ENABLED_ENGINE_ITER (DST.view_data_active, engine, data) {
     PROFILE_START(stime);
 
+    const DrawEngineDataSize *data_size = engine->vedata_size;
+    memset(data->psl->passes, 0, sizeof(*data->psl->passes) * data_size->psl_len);
+
     if (engine->engine_init) {
       engine->engine_init(data);
     }
@@ -982,15 +1037,7 @@ static void drw_engines_init(void)
 
 static void drw_engines_cache_init(void)
 {
-  DST.enabled_engine_count = BLI_listbase_count(&DST.enabled_engines);
-  DST.vedata_array = MEM_mallocN(sizeof(void *) * DST.enabled_engine_count, __func__);
-
-  int i = 0;
-  for (LinkData *link = DST.enabled_engines.first; link; link = link->next, i++) {
-    DrawEngineType *engine = link->data;
-    ViewportEngineData *data = drw_viewport_engine_data_ensure(engine);
-    DST.vedata_array[i] = data;
-
+  DRW_ENABLED_ENGINE_ITER (DST.view_data_active, engine, data) {
     if (data->text_draw_cache) {
       DRW_text_cache_destroy(data->text_draw_cache);
       data->text_draw_cache = NULL;
@@ -1011,10 +1058,7 @@ static void drw_engines_world_update(Scene *scene)
     return;
   }
 
-  LISTBASE_FOREACH (LinkData *, link, &DST.enabled_engines) {
-    DrawEngineType *engine = link->data;
-    ViewportEngineData *data = drw_viewport_engine_data_ensure(engine);
-
+  DRW_ENABLED_ENGINE_ITER (DST.view_data_active, engine, data) {
     if (engine->id_update) {
       engine->id_update(data, &scene->world->id);
     }
@@ -1036,11 +1080,7 @@ static void drw_engines_cache_populate(Object *ob)
     drw_batch_cache_validate(ob);
   }
 
-  int i = 0;
-  for (LinkData *link = DST.enabled_engines.first; link; link = link->next, i++) {
-    DrawEngineType *engine = link->data;
-    ViewportEngineData *data = DST.vedata_array[i];
-
+  DRW_ENABLED_ENGINE_ITER (DST.view_data_active, engine, data) {
     if (engine->id_update) {
       engine->id_update(data, &ob->id);
     }
@@ -1063,25 +1103,17 @@ static void drw_engines_cache_populate(Object *ob)
 
 static void drw_engines_cache_finish(void)
 {
-  int i = 0;
-  for (LinkData *link = DST.enabled_engines.first; link; link = link->next, i++) {
-    DrawEngineType *engine = link->data;
-    ViewportEngineData *data = DST.vedata_array[i];
-
+  DRW_ENABLED_ENGINE_ITER (DST.view_data_active, engine, data) {
     if (engine->cache_finish) {
       engine->cache_finish(data);
     }
   }
-  MEM_freeN(DST.vedata_array);
 }
 
 static void drw_engines_draw_scene(void)
 {
-  LISTBASE_FOREACH (LinkData *, link, &DST.enabled_engines) {
-    DrawEngineType *engine = link->data;
-    ViewportEngineData *data = drw_viewport_engine_data_ensure(engine);
+  DRW_ENABLED_ENGINE_ITER (DST.view_data_active, engine, data) {
     PROFILE_START(stime);
-
     if (engine->draw_scene) {
       DRW_stats_group_start(engine->idname);
       engine->draw_scene(data);
@@ -1091,7 +1123,6 @@ static void drw_engines_draw_scene(void)
       }
       DRW_stats_group_end();
     }
-
     PROFILE_END_UPDATE(data->render_time, stime);
   }
   /* Reset state after drawing */
@@ -1100,9 +1131,7 @@ static void drw_engines_draw_scene(void)
 
 static void drw_engines_draw_text(void)
 {
-  LISTBASE_FOREACH (LinkData *, link, &DST.enabled_engines) {
-    DrawEngineType *engine = link->data;
-    ViewportEngineData *data = drw_viewport_engine_data_ensure(engine);
+  DRW_ENABLED_ENGINE_ITER (DST.view_data_active, engine, data) {
     PROFILE_START(stime);
 
     if (data->text_draw_cache) {
@@ -1116,10 +1145,7 @@ static void drw_engines_draw_text(void)
 /* Draw render engine info. */
 void DRW_draw_region_engine_info(int xoffset, int *yoffset, int line_height)
 {
-  LISTBASE_FOREACH (LinkData *, link, &DST.enabled_engines) {
-    DrawEngineType *engine = link->data;
-    ViewportEngineData *data = drw_viewport_engine_data_ensure(engine);
-
+  DRW_ENABLED_ENGINE_ITER (DST.view_data_active, engine, data) {
     if (data->info[0] != '\0') {
       char *chr_current = data->info;
       char *chr_start = chr_current;
@@ -1158,12 +1184,10 @@ void DRW_draw_region_engine_info(int xoffset, int *yoffset, int line_height)
 
 static void use_drw_engine(DrawEngineType *engine)
 {
-  LinkData *ld = MEM_callocN(sizeof(LinkData), "enabled engine link data");
-  ld->data = engine;
-  BLI_addtail(&DST.enabled_engines, ld);
+  DRW_view_data_use_engine(DST.view_data_active, engine);
 }
 
-/* Gather all draw engines needed and store them in DST.enabled_engines
+/* Gather all draw engines needed and store them in DST.view_data_active
  * That also define the rendering order of engines */
 static void drw_engines_enable_from_engine(const RenderEngineType *engine_type, eDrawType drawtype)
 {
@@ -1252,22 +1276,12 @@ static void drw_engines_enable(ViewLayer *UNUSED(view_layer),
 
 static void drw_engines_disable(void)
 {
-  BLI_freelistN(&DST.enabled_engines);
+  DRW_view_data_reset(DST.view_data_active);
 }
 
 static void drw_engines_data_validate(void)
 {
-  int enabled_engines = BLI_listbase_count(&DST.enabled_engines);
-  void **engine_handle_array = BLI_array_alloca(engine_handle_array, enabled_engines + 1);
-  int i = 0;
-
-  LISTBASE_FOREACH (LinkData *, link, &DST.enabled_engines) {
-    DrawEngineType *engine = link->data;
-    engine_handle_array[i++] = engine;
-  }
-  engine_handle_array[i] = NULL;
-
-  GPU_viewport_engines_data_validate(DST.viewport, engine_handle_array);
+  DRW_view_data_free_unused(DST.view_data_active);
 }
 
 /* Fast check to see if gpencil drawing engine is needed.
@@ -1294,55 +1308,57 @@ void DRW_notify_view_update(const DRWUpdateContext *update_ctx)
   Scene *scene = update_ctx->scene;
   ViewLayer *view_layer = update_ctx->view_layer;
 
+  GPUViewport *viewport = WM_draw_region_get_viewport(region);
+  if (!viewport) {
+    return;
+  }
+
   const bool gpencil_engine_needed = drw_gpencil_engine_needed(depsgraph, v3d);
 
-  /* Separate update for each stereo view. */
-  for (int view = 0; view < 2; view++) {
-    GPUViewport *viewport = WM_draw_region_get_viewport(region);
-    if (!viewport) {
-      continue;
-    }
+  /* XXX Really nasty locking. But else this could
+   * be executed by the material previews thread
+   * while rendering a viewport. */
+  BLI_ticket_mutex_lock(DST.gl_context_mutex);
 
-    /* XXX Really nasty locking. But else this could
-     * be executed by the material previews thread
-     * while rendering a viewport. */
-    BLI_ticket_mutex_lock(DST.gl_context_mutex);
+  /* Reset before using it. */
+  drw_state_prepare_clean_for_draw(&DST);
 
-    /* Reset before using it. */
-    drw_state_prepare_clean_for_draw(&DST);
+  DST.draw_ctx = (DRWContextState){
+      .region = region,
+      .rv3d = rv3d,
+      .v3d = v3d,
+      .scene = scene,
+      .view_layer = view_layer,
+      .obact = OBACT(view_layer),
+      .engine_type = engine_type,
+      .depsgraph = depsgraph,
+      .object_mode = OB_MODE_OBJECT,
+  };
 
-    DST.viewport = viewport;
-    GPU_viewport_active_view_set(viewport, view);
-    DST.draw_ctx = (DRWContextState){
-        .region = region,
-        .rv3d = rv3d,
-        .v3d = v3d,
-        .scene = scene,
-        .view_layer = view_layer,
-        .obact = OBACT(view_layer),
-        .engine_type = engine_type,
-        .depsgraph = depsgraph,
-        .object_mode = OB_MODE_OBJECT,
-    };
+  /* Custom lightweight init to avoid reseting the mempools. */
+  DST.viewport = viewport;
+  DST.vmempool = drw_viewport_data_ensure(DST.viewport);
+
+  /* Separate update for each stereo view. */
+  int view_count = GPU_viewport_is_stereo_get(viewport) ? 2 : 1;
+  for (int view = 0; view < view_count; view++) {
+    DST.view_data_active = DST.vmempool->view_data[view];
 
     drw_engines_enable(view_layer, engine_type, gpencil_engine_needed);
     drw_engines_data_validate();
 
-    LISTBASE_FOREACH (LinkData *, link, &DST.enabled_engines) {
-      DrawEngineType *draw_engine = link->data;
-      ViewportEngineData *data = drw_viewport_engine_data_ensure(draw_engine);
-
+    DRW_ENABLED_ENGINE_ITER (DST.view_data_active, draw_engine, data) {
       if (draw_engine->view_update) {
         draw_engine->view_update(data);
       }
     }
 
-    DST.viewport = NULL;
-
     drw_engines_disable();
-
-    BLI_ticket_mutex_unlock(DST.gl_context_mutex);
   }
+
+  drw_manager_exit(&DST);
+
+  BLI_ticket_mutex_unlock(DST.gl_context_mutex);
 }
 
 /** \} */
@@ -1513,8 +1529,6 @@ void DRW_draw_render_loop_ex(struct Depsgraph *depsgraph,
   RegionView3D *rv3d = region->regiondata;
 
   DST.draw_ctx.evil_C = evil_C;
-  DST.viewport = viewport;
-  /* Setup viewport */
   DST.draw_ctx = (DRWContextState){
       .region = region,
       .rv3d = rv3d,
@@ -1531,8 +1545,8 @@ void DRW_draw_render_loop_ex(struct Depsgraph *depsgraph,
   drw_task_graph_init();
   drw_context_state_init();
 
-  drw_viewport_var_init();
-  DRW_viewport_colormanagement_set(DST.viewport);
+  drw_manager_init(&DST, viewport, NULL);
+  DRW_viewport_colormanagement_set(viewport);
 
   const int object_type_exclude_viewport = v3d->object_type_exclude_viewport;
   /* Check if scene needs to perform the populate loop */
@@ -1591,7 +1605,7 @@ void DRW_draw_render_loop_ex(struct Depsgraph *depsgraph,
     DRW_render_instance_buffer_finish();
 
 #ifdef USE_PROFILE
-    double *cache_time = GPU_viewport_cache_time_get(DST.viewport);
+    double *cache_time = DRW_view_data_cache_time_get(DST.view_data_active);
     PROFILE_END_UPDATE(*cache_time, stime);
 #endif
   }
@@ -1631,12 +1645,7 @@ void DRW_draw_render_loop_ex(struct Depsgraph *depsgraph,
   DRW_state_reset();
   drw_engines_disable();
 
-  drw_viewport_cache_resize();
-
-#ifdef DEBUG
-  /* Avoid accidental reuse. */
-  drw_state_ensure_not_reused(&DST);
-#endif
+  drw_manager_exit(&DST);
 }
 
 void DRW_draw_render_loop(struct Depsgraph *depsgraph,
@@ -1674,6 +1683,9 @@ void DRW_draw_render_loop_offscreen(struct Depsgraph *depsgraph,
 
   GPU_viewport_bind_from_offscreen(render_viewport, ofs);
 
+  /* Just here to avoid an assert but shouldn't be required in practice. */
+  GPU_framebuffer_restore();
+
   /* Reset before using it. */
   drw_state_prepare_clean_for_draw(&DST);
   DST.options.is_image_render = is_image_render;
@@ -1735,7 +1747,8 @@ static void DRW_render_gpencil_to_image(RenderEngine *engine,
                                         const rcti *rect)
 {
   if (draw_engine_gpencil_type.render_to_image) {
-    ViewportEngineData *gpdata = drw_viewport_engine_data_ensure(&draw_engine_gpencil_type);
+    ViewportEngineData *gpdata = DRW_view_data_engine_data_get_ensure(DST.view_data_active,
+                                                                      &draw_engine_gpencil_type);
     draw_engine_gpencil_type.render_to_image(gpdata, engine, render_layer, rect);
   }
 }
@@ -1769,11 +1782,9 @@ void DRW_render_gpencil(struct RenderEngine *engine, struct Depsgraph *depsgraph
   };
   drw_context_state_init();
 
-  DST.viewport = GPU_viewport_create();
   const int size[2] = {engine->resolution_x, engine->resolution_y};
-  GPU_viewport_size_set(DST.viewport, size);
 
-  drw_viewport_var_init();
+  drw_manager_init(&DST, NULL, size);
 
   /* Main rendering. */
   rctf view_rect;
@@ -1793,13 +1804,12 @@ void DRW_render_gpencil(struct RenderEngine *engine, struct Depsgraph *depsgraph
     DRW_render_gpencil_to_image(engine, render_layer, &render_rect);
   }
 
-  /* Force cache to reset. */
-  drw_viewport_cache_resize();
-  GPU_viewport_free(DST.viewport);
   DRW_state_reset();
 
   GPU_depth_test(GPU_DEPTH_NONE);
 
+  drw_manager_exit(&DST);
+
   /* Restore Drawing area. */
   GPU_framebuffer_restore();
 
@@ -1848,13 +1858,12 @@ void DRW_render_to_image(RenderEngine *engine, struct Depsgraph *depsgraph)
   };
   drw_context_state_init();
 
-  DST.viewport = GPU_viewport_create();
   const int size[2] = {engine->resolution_x, engine->resolution_y};
-  GPU_viewport_size_set(DST.viewport, size);
 
-  drw_viewport_var_init();
+  drw_manager_init(&DST, NULL, size);
 
-  ViewportEngineData *data = drw_viewport_engine_data_ensure(draw_engine_type);
+  ViewportEngineData *data = DRW_view_data_engine_data_get_ensure(DST.view_data_active,
+                                                                  draw_engine_type);
 
   /* Main rendering. */
   rctf view_rect;
@@ -1898,16 +1907,9 @@ void DRW_render_to_image(RenderEngine *engine, struct Depsgraph *depsgraph)
     engine_type->draw_engine->store_metadata(data, final_render_result);
   }
 
-  /* Force cache to reset. */
-  drw_viewport_cache_resize();
-
-  GPU_viewport_free(DST.viewport);
   GPU_framebuffer_restore();
 
-#ifdef DEBUG
-  /* Avoid accidental reuse. */
-  drw_state_ensure_not_reused(&DST);
-#endif
+  drw_manager_exit(&DST);
 
   /* Reset state after drawing */
   DRW_state_reset();
@@ -1976,21 +1978,17 @@ void DRW_custom_pipeline(DrawEngineType *draw_engine_type,
   };
   drw_context_state_init();
 
-  DST.viewport = GPU_viewport_create();
-  const int size[2] = {1, 1};
-  GPU_viewport_size_set(DST.viewport, size);
-
-  drw_viewport_var_init();
+  drw_manager_init(&DST, NULL, NULL);
 
   DRW_hair_init();
 
-  ViewportEngineData *data = drw_viewport_engine_data_ensure(draw_engine_type);
+  ViewportEngineData *data = DRW_view_data_engine_data_get_ensure(DST.view_data_active,
+                                                                  draw_engine_type);
 
   /* Execute the callback */
   callback(data, user_data);
   DST.buffer_finish_called = false;
 
-  GPU_viewport_free(DST.viewport);
   GPU_framebuffer_restore();
 
   /* The use of custom pipeline in other thread using the same
@@ -1999,33 +1997,18 @@ void DRW_custom_pipeline(DrawEngineType *draw_engine_type,
    * GPU_finish to sync seems to fix the issue. (see T62997) */
   GPU_finish();
 
-#ifdef DEBUG
-  /* Avoid accidental reuse. */
-  drw_state_ensure_not_reused(&DST);
-#endif
+  drw_manager_exit(&DST);
 }
 
 /* Used when the render engine want to redo another cache populate inside the same render frame.
  */
 void DRW_cache_restart(void)
 {
-  /* Save viewport size. */
-  float size[2], inv_size[2];
-  copy_v2_v2(size, DST.size);
-  copy_v2_v2(inv_size, DST.inv_size);
-
-  /* Force cache to reset. */
-  drw_viewport_cache_resize();
-
-  drw_viewport_var_init();
+  drw_manager_init(&DST, DST.viewport, (int[2]){UNPACK2(DST.size)});
 
   DST.buffer_finish_called = false;
 
   DRW_hair_init();
-
-  /* Restore. */
-  copy_v2_v2(DST.size, size);
-  copy_v2_v2(DST.inv_size, inv_size);
 }
 
 void DRW_draw_render_loop_2d_ex(struct Depsgraph *depsgraph,
@@ -2037,9 +2020,6 @@ void DRW_draw_render_loop_2d_ex(struct Depsgraph *depsgraph,
   ViewLayer *view_layer = DEG_get_evaluated_view_layer(depsgraph);
 
   DST.draw_ctx.evil_C = evil_C;
-  DST.viewport = viewport;
-
-  /* Setup viewport */
   DST.draw_ctx = (DRWContextState){
       .region = region,
       .scene = scene,
@@ -2053,8 +2033,8 @@ void DRW_draw_render_loop_2d_ex(struct Depsgraph *depsgraph,
   };
 
   drw_context_state_init();
-  drw_viewport_var_init();
-  DRW_viewport_colormanagement_set(DST.viewport);
+  drw_manager_init(&DST, viewport, NULL);
+  DRW_viewport_colormanagement_set(viewport);
 
   /* TODO(jbakker): Only populate when editor needs to draw object.
    * for the image editor this is when showing UV's. */
@@ -2098,7 +2078,7 @@ void DRW_draw_render_loop_2d_ex(struct Depsgraph *depsgraph,
     DRW_render_instance_buffer_finish();
 
 #ifdef USE_PROFILE
-    double *cache_time = GPU_viewport_cache_time_get(DST.viewport);
+    double *cache_time = DRW_view_data_cache_time_get(DST.view_data_active);
     PROFILE_END_UPDATE(*cache_time, stime);
 #endif
   }
@@ -2180,12 +2160,7 @@ void DRW_draw_render_loop_2d_ex(struct Depsgraph *depsgraph,
   DRW_state_reset();
   drw_engines_disable();
 
-  drw_viewport_cache_resize();
-
-#ifdef DEBUG
-  /* Avoid accidental reuse. */
-  drw_state_ensure_not_reused(&DST);
-#endif
+  drw_manager_exit(&DST);
 }
 
 static struct DRWSelectBuffer {
@@ -2222,7 +2197,7 @@ void DRW_render_instance_buffer_finish(void)
 {
   BLI_assert_msg(!DST.buffer_finish_called, "DRW_render_instance_buffer_finish called twice!");
   DST.buffer_finish_called = true;
-  DRW_instance_buffer_finish(DST.idatalist);
+  DRW_instance_buffer_finish(DST.vmempool->idatalist);
   drw_resource_buffer_finish(DST.vmempool);
 }
 
@@ -2305,11 +2280,22 @@ void DRW_draw_select_loop(struct Depsgraph *depsgraph,
     }
   }
 
+  /* Instead of 'DRW_context_state_init(C, &DST.draw_ctx)', assign from args */
+  DST.draw_ctx = (DRWContextState){
+      .region = region,
+      .rv3d = rv3d,
+      .v3d = v3d,
+      .scene = scene,
+      .view_layer = view_layer,
+      .obact = obact,
+      .engine_type = engine_type,
+      .depsgraph = depsgraph,
+  };
+  drw_context_state_init();
+
   const int viewport_size[2] = {BLI_rcti_size_x(rect), BLI_rcti_size_y(rect)};
-  struct GPUViewport *viewport = GPU_viewport_create();
-  GPU_viewport_size_set(viewport, viewport_size);
+  drw_manager_init(&DST, NULL, viewport_size);
 
-  DST.viewport = viewport;
   DST.options.is_select = true;
   DST.options.is_material_select = do_material_sub_selection;
   drw_task_graph_init();
@@ -2337,22 +2323,6 @@ void DRW_draw_select_loop(struct Depsgraph *depsgraph,
   }
   drw_engines_data_validate();
 
-  /* Setup viewport */
-
-  /* Instead of 'DRW_context_state_init(C, &DST.draw_ctx)', assign from args */
-  DST.draw_ctx = (DRWContextState){
-      .region = region,
-      .rv3d = rv3d,
-      .v3d = v3d,
-      .scene = scene,
-      .view_layer = view_layer,
-      .obact = obact,
-      .engine_type = engine_type,
-      .depsgraph = depsgraph,
-  };
-  drw_context_state_init();
-  drw_viewport_var_init();
-
   /* Update UBO's */
   DRW_globals_update();
 
@@ -2456,14 +2426,10 @@ void DRW_draw_select_loop(struct Depsgraph *depsgraph,
   DRW_state_reset();
   drw_engines_disable();
 
-#  ifdef DEBUG
-  /* Avoid accidental reuse. */
-  drw_state_ensure_not_reused(&DST);
-#  endif
+  drw_manager_exit(&DST);
+
   GPU_framebuffer_restore();
 
-  /* Cleanup for selection state */
-  GPU_viewport_free(viewport);
 #endif /* USE_GPU_SELECT */
 }
 
@@ -2485,7 +2451,6 @@ static void drw_draw_depth_loop_impl(struct Depsgraph *depsgraph,
     DRW_opengl_context_enable();
   }
 
-  DST.viewport = viewport;
   DST.options.is_depth = true;
 
   /* Instead of 'DRW_context_state_init(C, &DST.draw_ctx)', assign from args */
@@ -2499,18 +2464,21 @@ static void drw_draw_depth_loop_impl(struct Depsgraph *depsgraph,
       .engine_type = engine_type,
       .depsgraph = depsgraph,
   };
+  drw_context_state_init();
   drw_task_graph_init();
-  drw_engines_data_validate();
 
   /* Setup frame-buffer. */
-  DefaultFramebufferList *fbl = (DefaultFramebufferList *)GPU_viewport_framebuffer_list_get(
-      DST.viewport);
-  GPU_framebuffer_bind(fbl->depth_only_fb);
-  GPU_framebuffer_clear_depth(fbl->depth_only_fb, 1.0f);
+  GPUTexture *depth_tx = GPU_viewport_depth_texture(viewport);
 
-  /* Setup viewport */
-  drw_context_state_init();
-  drw_viewport_var_init();
+  GPUFrameBuffer *depth_fb = NULL;
+  GPU_framebuffer_ensure_config(&depth_fb,
+                                {
+                                    GPU_ATTACHMENT_TEXTURE(depth_tx),
+                                    GPU_ATTACHMENT_NONE,
+                                });
+
+  GPU_framebuffer_bind(depth_fb);
+  GPU_framebuffer_clear_depth(depth_fb, 1.0f);
 
   /* Update UBO's */
   DRW_globals_update();
@@ -2559,15 +2527,11 @@ static void drw_draw_depth_loop_impl(struct Depsgraph *depsgraph,
   /* TODO: Reading depth for operators should be done here. */
 
   GPU_framebuffer_restore();
+  GPU_framebuffer_free(depth_fb);
 
   drw_engines_disable();
 
-  drw_viewport_cache_resize();
-
-#ifdef DEBUG
-  /* Avoid accidental reuse. */
-  drw_state_ensure_not_reused(&DST);
-#endif
+  drw_manager_exit(&DST);
 
   /* Changing context. */
   if (use_opengl_context) {
@@ -2586,6 +2550,11 @@ void DRW_draw_depth_loop(struct Depsgraph *depsgraph,
   /* Reset before using it. */
   drw_state_prepare_clean_for_draw(&DST);
 
+  /* Required by `drw_manager_init()` */
+  DST.draw_ctx.region = region;
+  DST.draw_ctx.rv3d = region->regiondata;
+  drw_manager_init(&DST, viewport, NULL);
+
   /* Get list of enabled engines */
   {
     /* Required by `DRW_state_draw_support()` */
@@ -2611,6 +2580,11 @@ void DRW_draw_depth_loop_gpencil(struct Depsgraph *depsgraph,
   /* Reset before using it. */
   drw_state_prepare_clean_for_draw(&DST);
 
+  /* Required by `drw_manager_init()` */
+  DST.draw_ctx.region = region;
+  DST.draw_ctx.rv3d = region->regiondata;
+  drw_manager_init(&DST, viewport, NULL);
+
   use_drw_engine(&draw_engine_gpencil_type);
 
   drw_draw_depth_loop_impl(depsgraph, region, v3d, viewport, false);
@@ -2648,9 +2622,7 @@ void DRW_draw_select_id(Depsgraph *depsgraph, ARegion *region, View3D *v3d, cons
   drw_task_graph_init();
   drw_context_state_init();
 
-  /* Setup viewport */
-  DST.viewport = viewport;
-  drw_viewport_var_init();
+  drw_manager_init(&DST, viewport, NULL);
 
   /* Update UBO's */
   UI_SetTheme(SPACE_VIEW3D, RGN_TYPE_WINDOW);
@@ -2677,7 +2649,7 @@ void DRW_draw_select_id(Depsgraph *depsgraph, ARegion *region, View3D *v3d, cons
     DRW_render_instance_buffer_finish();
 #else
     DST.buffer_finish_called = true;
-    // DRW_instance_buffer_finish(DST.idatalist);
+    // DRW_instance_buffer_finish(DST.vmempool->idatalist);
     drw_resource_buffer_finish(DST.vmempool);
 #endif
   }
@@ -2689,12 +2661,7 @@ void DRW_draw_select_id(Depsgraph *depsgraph, ARegion *region, View3D *v3d, cons
 
   drw_engines_disable();
 
-  drw_viewport_cache_resize();
-
-#ifdef DEBUG
-  /* Avoid accidental reuse. */
-  drw_state_ensure_not_reused(&DST);
-#endif
+  drw_manager_exit(&DST);
 }
 
 /**
@@ -2710,10 +2677,17 @@ void DRW_draw_depth_object(
   GPU_matrix_mul(object->obmat);
 
   /* Setup frame-buffer. */
-  DefaultFramebufferList *fbl = GPU_viewport_framebuffer_list_get(viewport);
+  GPUTexture *depth_tx = GPU_viewport_depth_texture(viewport);
+
+  GPUFrameBuffer *depth_fb = NULL;
+  GPU_framebuffer_ensure_config(&depth_fb,
+                                {
+                                    GPU_ATTACHMENT_TEXTURE(depth_tx),
+                                    GPU_ATTACHMENT_NONE,
+                                });
 
-  GPU_framebuffer_bind(fbl->depth_only_fb);
-  GPU_framebuffer_clear_depth(fbl->depth_only_fb, 1.0f);
+  GPU_framebuffer_bind(depth_fb);
+  GPU_framebuffer_clear_depth(depth_fb, 1.0f);
   GPU_depth_test(GPU_DEPTH_LESS_EQUAL);
 
   const float(*world_clip_planes)[4] = NULL;
@@ -2763,6 +2737,9 @@ void DRW_draw_depth_object(
   GPU_matrix_set(rv3d->viewmat);
   GPU_depth_test(GPU_DEPTH_NONE);
   GPU_framebuffer_restore();
+
+  GPU_framebuffer_free(depth_fb);
+  DRW_opengl_context_disable();
 }
 
 /** \} */
@@ -2895,7 +2872,12 @@ bool DRW_engine_render_support(DrawEngineType *draw_engine_type)
 
 void DRW_engine_register(DrawEngineType *draw_engine_type)
 {
-  BLI_addtail(&DRW_engines, draw_engine_type);
+  DRWRegisteredDrawEngine *draw_engine = MEM_mallocN(sizeof(DRWRegisteredDrawEngine), __func__);
+  draw_engine->draw_engine = draw_engine_type;
+  draw_engine->index = g_registered_engines.len;
+
+  BLI_addtail(&g_registered_engines.engines, draw_engine);
+  g_registered_engines.len = BLI_listbase_count(&g_registered_engines.engines);
 }
 
 void DRW_engines_register(void)
@@ -2966,14 +2948,15 @@ void DRW_engines_free(void)
   DRW_stats_free();
   DRW_globals_free();
 
-  DrawEngineType *next;
-  for (DrawEngineType *type = DRW_engines.first; type; type = next) {
+  DRWRegisteredDrawEngine *next;
+  for (DRWRegisteredDrawEngine *type = g_registered_engines.engines.first; type; type = next) {
     next = type->next;
     BLI_remlink(&R_engines, type);
 
-    if (type->engine_free) {
-      type->engine_free();
+    if (type->draw_engine->engine_free) {
+      type->draw_engine->engine_free();
     }
+    MEM_freeN(type);
   }
 
   DRW_UBO_FREE_SAFE(G_draw.block_ubo);
diff --git a/source/blender/draw/intern/draw_manager.h b/source/blender/draw/intern/draw_manager.h
index c09126c98ef..1bb1ee06354 100644
--- a/source/blender/draw/intern/draw_manager.h
+++ b/source/blender/draw/intern/draw_manager.h
@@ -98,6 +98,17 @@ struct Object;
 
 /* ------------ Data Structure --------------- */
 /**
+ * Data structure to for registered draw engines that can store draw manager
+ * specific data.
+ */
+typedef struct DRWRegisteredDrawEngine {
+  void /*DRWRegisteredDrawEngine*/ *next, *prev;
+  DrawEngineType *draw_engine;
+  /** Index of the type in the lists. Index is used for dupli data. */
+  int index;
+} DRWRegisteredDrawEngine;
+
+/**
  * Data structure containing all drawcalls organized by passes and materials.
  * DRWPass > DRWShadingGroup > DRWCall > DRWCallState
  *                           > DRWUniform
@@ -495,6 +506,35 @@ typedef struct DRWDebugSphere {
   float color[4];
 } DRWDebugSphere;
 
+/* ------------- Memory Pools ------------ */
+
+/* Contains memory pools information */
+typedef struct DRWData {
+  /** Instance data. */
+  DRWInstanceDataList *idatalist;
+  /** Mempools for drawcalls. */
+  struct BLI_memblock *commands;
+  struct BLI_memblock *commands_small;
+  struct BLI_memblock *callbuffers;
+  struct BLI_memblock *obmats;
+  struct BLI_memblock *obinfos;
+  struct BLI_memblock *cullstates;
+  struct BLI_memblock *shgroups;
+  struct BLI_memblock *uniforms;
+  struct BLI_memblock *views;
+  struct BLI_memblock *passes;
+  struct BLI_memblock *images;
+  struct GPUUniformBuf **matrices_ubo;
+  struct GPUUniformBuf **obinfos_ubo;
+  struct GHash *obattrs_ubo_pool;
+  uint ubo_len;
+  /** Texture pool to reuse temp texture across engines. */
+  /* TODO(fclem) the pool could be shared even between viewports. */
+  struct DRWTexturePool *texture_pool;
+  /** Per stereo view data. Contains engine data and default framebuffers. */
+  struct DRWViewData *view_data[2];
+} DRWData;
+
 /* ------------- DRAW MANAGER ------------ */
 
 typedef struct DupliKey {
@@ -509,8 +549,10 @@ typedef struct DupliKey {
 typedef struct DRWManager {
   /* TODO: clean up this struct a bit. */
   /* Cache generation */
-  ViewportMemoryPool *vmempool;
-  DRWInstanceDataList *idatalist;
+  /* TODO(fclem) Rename to data. */
+  DRWData *vmempool;
+  /** Active view data structure for one of the 2 stereo view. Not related to DRWView. */
+  struct DRWViewData *view_data_active;
   /* State of the object being evaluated if already allocated. */
   DRWResourceHandle ob_handle;
   /** True if current DST.ob_state has its matching DRWObjectInfos init. */
@@ -567,10 +609,6 @@ typedef struct DRWManager {
   /* Convenience pointer to text_store owned by the viewport */
   struct DRWTextStore **text_store_p;
 
-  ListBase enabled_engines; /* RenderEngineType */
-  void **vedata_array;      /* ViewportEngineData */
-  int enabled_engine_count; /* Length of enabled_engines list. */
-
   bool buffer_finish_called; /* Avoid bad usage of DRW_render_instance_buffer_finish */
 
   DRWView *view_default;
@@ -627,7 +665,7 @@ void drw_batch_cache_validate(Object *ob);
 void drw_batch_cache_generate_requested(struct Object *ob);
 void drw_batch_cache_generate_requested_delayed(Object *ob);
 
-void drw_resource_buffer_finish(ViewportMemoryPool *vmempool);
+void drw_resource_buffer_finish(DRWData *vmempool);
 
 /* Procedural Drawing */
 GPUBatch *drw_cache_procedural_points_get(void);
@@ -641,6 +679,13 @@ void drw_uniform_attrs_pool_update(struct GHash *table,
                                    struct Object *dupli_parent,
                                    struct DupliObject *dupli_source);
 
+double *drw_engine_data_cache_time_get(GPUViewport *viewport);
+void *drw_engine_data_engine_data_create(GPUViewport *viewport, void *engine_type);
+void *drw_engine_data_engine_data_get(GPUViewport *viewport, void *engine_handle);
+bool drw_engine_data_engines_data_validate(GPUViewport *viewport, void **engine_handle_array);
+void drw_engine_data_cache_release(GPUViewport *viewport);
+void drw_engine_data_free(GPUViewport *viewport);
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/source/blender/draw/intern/draw_manager_data.c b/source/blender/draw/intern/draw_manager_data.c
index af331c86a8b..f96bd474aec 100644
--- a/source/blender/draw/intern/draw_manager_data.c
+++ b/source/blender/draw/intern/draw_manager_data.c
@@ -87,7 +87,7 @@ static void draw_call_sort(DRWCommand *array, DRWCommand *array_tmp, int array_l
   memcpy(array, array_tmp, sizeof(*array) * array_len);
 }
 
-void drw_resource_buffer_finish(ViewportMemoryPool *vmempool)
+void drw_resource_buffer_finish(DRWData *vmempool)
 {
   int chunk_id = DRW_handle_chunk_get(&DST.resource_handle);
   int elem_id = DRW_handle_id_get(&DST.resource_handle);
@@ -908,7 +908,8 @@ void DRW_shgroup_call_instances_with_attrs(DRWShadingGroup *shgroup,
     drw_command_set_select_id(shgroup, NULL, DST.select_id);
   }
   DRWResourceHandle handle = drw_resource_handle(shgroup, ob ? ob->obmat : NULL, ob);
-  GPUBatch *batch = DRW_temp_batch_instance_request(DST.idatalist, NULL, inst_attributes, geom);
+  GPUBatch *batch = DRW_temp_batch_instance_request(
+      DST.vmempool->idatalist, NULL, inst_attributes, geom);
   drw_command_draw_instance(shgroup, batch, handle, 0, true);
 }
 
@@ -1128,7 +1129,7 @@ DRWCallBuffer *DRW_shgroup_call_buffer(DRWShadingGroup *shgroup,
   BLI_assert(format != NULL);
 
   DRWCallBuffer *callbuf = BLI_memblock_alloc(DST.vmempool->callbuffers);
-  callbuf->buf = DRW_temp_buffer_request(DST.idatalist, format, &callbuf->count);
+  callbuf->buf = DRW_temp_buffer_request(DST.vmempool->idatalist, format, &callbuf->count);
   callbuf->buf_select = NULL;
   callbuf->count = 0;
 
@@ -1138,12 +1139,12 @@ DRWCallBuffer *DRW_shgroup_call_buffer(DRWShadingGroup *shgroup,
       GPU_vertformat_attr_add(&inst_select_format, "selectId", GPU_COMP_I32, 1, GPU_FETCH_INT);
     }
     callbuf->buf_select = DRW_temp_buffer_request(
-        DST.idatalist, &inst_select_format, &callbuf->count);
+        DST.vmempool->idatalist, &inst_select_format, &callbuf->count);
     drw_command_set_select_id(shgroup, callbuf->buf_select, -1);
   }
 
   DRWResourceHandle handle = drw_resource_handle(shgroup, NULL, NULL);
-  GPUBatch *batch = DRW_temp_batch_request(DST.idatalist, callbuf->buf, prim_type);
+  GPUBatch *batch = DRW_temp_batch_request(DST.vmempool->idatalist, callbuf->buf, prim_type);
   drw_command_draw(shgroup, batch, handle);
 
   return callbuf;
@@ -1157,7 +1158,7 @@ DRWCallBuffer *DRW_shgroup_call_buffer_instance(DRWShadingGroup *shgroup,
   BLI_assert(format != NULL);
 
   DRWCallBuffer *callbuf = BLI_memblock_alloc(DST.vmempool->callbuffers);
-  callbuf->buf = DRW_temp_buffer_request(DST.idatalist, format, &callbuf->count);
+  callbuf->buf = DRW_temp_buffer_request(DST.vmempool->idatalist, format, &callbuf->count);
   callbuf->buf_select = NULL;
   callbuf->count = 0;
 
@@ -1167,12 +1168,13 @@ DRWCallBuffer *DRW_shgroup_call_buffer_instance(DRWShadingGroup *shgroup,
       GPU_vertformat_attr_add(&inst_select_format, "selectId", GPU_COMP_I32, 1, GPU_FETCH_INT);
     }
     callbuf->buf_select = DRW_temp_buffer_request(
-        DST.idatalist, &inst_select_format, &callbuf->count);
+        DST.vmempool->idatalist, &inst_select_format, &callbuf->count);
     drw_command_set_select_id(shgroup, callbuf->buf_select, -1);
   }
 
   DRWResourceHandle handle = drw_resource_handle(shgroup, NULL, NULL);
-  GPUBatch *batch = DRW_temp_batch_instance_request(DST.idatalist, callbuf->buf, NULL, geom);
+  GPUBatch *batch = DRW_temp_batch_instance_request(
+      DST.vmempool->idatalist, callbuf->buf, NULL, geom);
   drw_command_draw(shgroup, batch, handle);
 
   return callbuf;
diff --git a/source/blender/draw/intern/draw_manager_profiling.c b/source/blender/draw/intern/draw_manager_profiling.c
index d9ba2cbf932..70fe12270f5 100644
--- a/source/blender/draw/intern/draw_manager_profiling.c
+++ b/source/blender/draw/intern/draw_manager_profiling.c
@@ -257,10 +257,9 @@ void DRW_stats_draw(const rcti *rect)
 
   /* Engines rows */
   char time_to_txt[16];
-  LISTBASE_FOREACH (LinkData *, link, &DST.enabled_engines) {
+  DRW_ENABLED_ENGINE_ITER(DST.view_data_active, engine, data)
+  {
     u = 0;
-    DrawEngineType *engine = link->data;
-    ViewportEngineData *data = drw_viewport_engine_data_ensure(engine);
 
     draw_stat_5row(rect, u++, v, engine->idname, sizeof(engine->idname));
 
@@ -297,7 +296,7 @@ void DRW_stats_draw(const rcti *rect)
   v += 2;
 
   u = 0;
-  double *cache_time = GPU_viewport_cache_time_get(DST.viewport);
+  double *cache_time = DRW_view_data_cache_time_get(DST.view_data_active);
   sprintf(col_label, "Cache Time");
   draw_stat_5row(rect, u++, v, col_label, sizeof(col_label));
   sprintf(time_to_txt, "%.2fms", *cache_time);
diff --git a/source/blender/draw/intern/draw_manager_text.h b/source/blender/draw/intern/draw_manager_text.h
index 760259018bb..4f3a6153775 100644
--- a/source/blender/draw/intern/draw_manager_text.h
+++ b/source/blender/draw/intern/draw_manager_text.h
@@ -22,6 +22,10 @@
 
 #pragma once
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 struct ARegion;
 struct DRWTextStore;
 struct Object;
@@ -57,3 +61,7 @@ enum {
 
 /* draw_manager.c */
 struct DRWTextStore *DRW_text_cache_ensure(void);
+
+#ifdef __cplusplus
+}
+#endif
\ No newline at end of file
diff --git a/source/blender/draw/intern/draw_manager_texture.c b/source/blender/draw/intern/draw_manager_texture.c
index 99e8ba968a2..86242468e4a 100644
--- a/source/blender/draw/intern/draw_manager_texture.c
+++ b/source/blender/draw/intern/draw_manager_texture.c
@@ -21,6 +21,7 @@
  */
 
 #include "draw_manager.h"
+#include "draw_texture_pool.h"
 
 #ifndef NDEBUG
 /* Maybe gpu_texture.c is a better place for this. */
@@ -147,7 +148,7 @@ GPUTexture *DRW_texture_pool_query_2d(int w,
                                       DrawEngineType *engine_type)
 {
   BLI_assert(drw_texture_format_supports_framebuffer(format));
-  GPUTexture *tex = GPU_viewport_texture_pool_query(DST.viewport, engine_type, w, h, format);
+  GPUTexture *tex = DRW_texture_pool_query(DST.vmempool->texture_pool, w, h, format, engine_type);
 
   return tex;
 }
diff --git a/source/blender/draw/intern/draw_texture_pool.cc b/source/blender/draw/intern/draw_texture_pool.cc
new file mode 100644
index 00000000000..544a763ddb9
--- /dev/null
+++ b/source/blender/draw/intern/draw_texture_pool.cc
@@ -0,0 +1,140 @@
+/*
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ * Copyright 2021, Blender Foundation.
+ */
+
+/** \file
+ * \ingroup draw
+ */
+
+#include "BKE_global.h"
+
+#include "BLI_vector.hh"
+
+#include "draw_texture_pool.h"
+
+using namespace blender;
+
+typedef struct DRWTexturePoolHandle {
+  uint64_t users_bits;
+  GPUTexture *texture;
+} DRWTexturePoolHandle;
+
+struct DRWTexturePool {
+  Vector<void *, 16> users;
+  Vector<DRWTexturePoolHandle> handles;
+  /* Cache last result to avoid linear search each time. */
+  int last_user_id = -1;
+};
+
+DRWTexturePool *DRW_texture_pool_create(void)
+{
+  return new DRWTexturePool();
+}
+
+void DRW_texture_pool_free(DRWTexturePool *pool)
+{
+  /* Reseting the pool twice will effectively free all textures. */
+  DRW_texture_pool_reset(pool);
+  DRW_texture_pool_reset(pool);
+  delete pool;
+}
+
+/**
+ * Try to find a texture corresponding to params into the texture pool.
+ * If no texture was found, create one and add it to the pool.
+ */
+GPUTexture *DRW_texture_pool_query(
+    DRWTexturePool *pool, int width, int height, eGPUTextureFormat format, void *user)
+{
+  int user_id = pool->last_user_id;
+  /* Try cached value. */
+  if (user_id != -1) {
+    if (pool->users[user_id] != user) {
+      user_id = -1;
+    }
+  }
+  /* Try to find inside previous users. */
+  if (user_id == -1) {
+    user_id = pool->users.first_index_of_try(user);
+  }
+  /* No chance, needs to add it to the user list. */
+  if (user_id == -1) {
+    user_id = pool->users.size();
+    pool->users.append(user);
+    /* If there is more than 63 users, better refactor this system. */
+    BLI_assert(user_id < 64);
+  }
+  pool->last_user_id = user_id;
+
+  uint64_t user_bit = 1llu << user_id;
+  for (DRWTexturePoolHandle &handle : pool->handles) {
+    /* Skip if the user is already using this texture. */
+    if (user_bit & handle.users_bits) {
+      continue;
+    }
+    /* If everthing matches reuse the texture. */
+    if ((GPU_texture_format(handle.texture) == format) &&
+        (GPU_texture_width(handle.texture) == width) &&
+        (GPU_texture_height(handle.texture) == height)) {
+      handle.users_bits |= user_bit;
+      return handle.texture;
+    }
+  }
+
+  char name[16] = "DRW_tex_pool";
+  if (G.debug & G_DEBUG_GPU) {
+    int texture_id = pool->handles.size();
+    SNPRINTF(name, "DRW_tex_pool_%d", texture_id);
+  }
+
+  DRWTexturePoolHandle handle;
+  handle.users_bits = user_bit;
+  handle.texture = GPU_texture_create_2d(name, width, height, 1, format, nullptr);
+  pool->handles.append(handle);
+  /* Doing filtering for depth does not make sense when not doing shadow mapping,
+   * and enabling texture filtering on integer texture make them unreadable. */
+  bool do_filter = !GPU_texture_depth(handle.texture) && !GPU_texture_integer(handle.texture);
+  GPU_texture_filter_mode(handle.texture, do_filter);
+
+  return handle.texture;
+}
+
+/* Resets the user bits for each texture in the pool and delete unused ones. */
+void DRW_texture_pool_reset(DRWTexturePool *pool)
+{
+  pool->last_user_id = -1;
+
+  for (auto it = pool->handles.rbegin(); it != pool->handles.rend(); ++it) {
+    DRWTexturePoolHandle &handle = *it;
+    if (handle.users_bits == 0) {
+      if (handle.texture) {
+        GPU_texture_free(handle.texture);
+        handle.texture = nullptr;
+      }
+    }
+    else {
+      handle.users_bits = 0;
+    }
+  }
+
+  /* Reverse iteration to make sure we only reorder with known good handles. */
+  for (int i = pool->handles.size() - 1; i >= 0; i--) {
+    if (!pool->handles[i].texture) {
+      pool->handles.remove_and_reorder(i);
+    }
+  }
+}
\ No newline at end of file
diff --git a/source/blender/draw/DRW_engine_types.h b/source/blender/draw/intern/draw_texture_pool.h
index 807f654f559..f0b8f775c75 100644
--- a/source/blender/draw/DRW_engine_types.h
+++ b/source/blender/draw/intern/draw_texture_pool.h
@@ -13,38 +13,34 @@
  * along with this program; if not, write to the Free Software Foundation,
  * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  *
- * Copyright 2016, Blender Foundation.
+ * Copyright 2021, Blender Foundation.
  */
 
 /** \file
  * \ingroup draw
+ *
+ * Texture pool
+ * A pool that gives temporary render targets that can be reused through other parts of the
+ * render pipeline.
+ * Expect texture data is garbage when acquiring it.
  */
 
 #pragma once
 
+#include "GPU_texture.h"
+
+typedef struct DRWTexturePool DRWTexturePool;
+
 #ifdef __cplusplus
 extern "C" {
 #endif
 
-/* Buffer and textures used by the viewport by default */
-typedef struct DefaultFramebufferList {
-  struct GPUFrameBuffer *default_fb;
-  struct GPUFrameBuffer *overlay_fb;
-  struct GPUFrameBuffer *in_front_fb;
-  struct GPUFrameBuffer *color_only_fb;
-  struct GPUFrameBuffer *depth_only_fb;
-  struct GPUFrameBuffer *overlay_only_fb;
-  struct GPUFrameBuffer *stereo_comp_fb;
-} DefaultFramebufferList;
-
-typedef struct DefaultTextureList {
-  struct GPUTexture *color;
-  struct GPUTexture *color_overlay;
-  struct GPUTexture *color_stereo;
-  struct GPUTexture *color_overlay_stereo;
-  struct GPUTexture *depth;
-  struct GPUTexture *depth_in_front;
-} DefaultTextureList;
+DRWTexturePool *DRW_texture_pool_create(void);
+void DRW_texture_pool_free(DRWTexturePool *pool);
+
+GPUTexture *DRW_texture_pool_query(
+    DRWTexturePool *pool, int width, int height, eGPUTextureFormat format, void *user);
+void DRW_texture_pool_reset(DRWTexturePool *pool);
 
 #ifdef __cplusplus
 }
diff --git a/source/blender/draw/intern/draw_view_data.cc b/source/blender/draw/intern/draw_view_data.cc
new file mode 100644
index 00000000000..55ebbf82c29
--- /dev/null
+++ b/source/blender/draw/intern/draw_view_data.cc
@@ -0,0 +1,243 @@
+/*
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ * Copyright 2021, Blender Foundation.
+ */
+
+/** \file
+ * \ingroup draw
+ */
+
+#include "BLI_vector.hh"
+
+#include "GPU_viewport.h"
+
+#include "DRW_render.h"
+
+#include "draw_instance_data.h"
+
+#include "draw_manager_text.h"
+
+#include "draw_manager.h"
+#include "draw_view_data.h"
+
+using namespace blender;
+
+struct DRWViewData {
+  DefaultFramebufferList dfbl = {};
+  DefaultTextureList dtxl = {};
+  /** True indicates the textures inside dtxl are from the viewport and should not be freed. */
+  bool from_viewport = false;
+  /** Common size for texture in the engines texture list.
+   * We free all texture lists if it changes. */
+  int texture_list_size[2] = {0, 0};
+
+  double cache_time = 0.0;
+
+  Vector<ViewportEngineData> engines;
+  Vector<ViewportEngineData *> enabled_engines;
+};
+
+/**
+ * Creates a view data with all possible engines type for this view.
+ *
+ * `engine_types` contains `DRWRegisteredDrawEngine`.
+ * */
+DRWViewData *DRW_view_data_create(ListBase *engine_types)
+{
+  DRWViewData *view_data = new DRWViewData();
+  LISTBASE_FOREACH (DRWRegisteredDrawEngine *, type, engine_types) {
+    ViewportEngineData engine = {};
+    engine.engine_type = type;
+    view_data->engines.append(engine);
+  }
+  return view_data;
+}
+
+void DRW_view_data_default_lists_from_viewport(DRWViewData *view_data, GPUViewport *viewport)
+{
+  int active_view = GPU_viewport_active_view_get(viewport);
+  view_data->from_viewport = true;
+
+  DefaultFramebufferList *dfbl = &view_data->dfbl;
+  DefaultTextureList *dtxl = &view_data->dtxl;
+  /* Depth texture is shared between both stereo views. */
+  dtxl->depth = GPU_viewport_depth_texture(viewport);
+  dtxl->color = GPU_viewport_color_texture(viewport, active_view);
+  dtxl->color_overlay = GPU_viewport_overlay_texture(viewport, active_view);
+
+  GPU_framebuffer_ensure_config(&dfbl->default_fb,
+                                {
+                                    GPU_ATTACHMENT_TEXTURE(dtxl->depth),
+                                    GPU_ATTACHMENT_TEXTURE(dtxl->color),
+                                });
+  GPU_framebuffer_ensure_config(&dfbl->overlay_fb,
+                                {
+                                    GPU_ATTACHMENT_TEXTURE(dtxl->depth),
+                                    GPU_ATTACHMENT_TEXTURE(dtxl->color_overlay),
+                                });
+  GPU_framebuffer_ensure_config(&dfbl->depth_only_fb,
+                                {
+                                    GPU_ATTACHMENT_TEXTURE(dtxl->depth),
+                                    GPU_ATTACHMENT_NONE,
+                                });
+  GPU_framebuffer_ensure_config(&dfbl->color_only_fb,
+                                {
+                                    GPU_ATTACHMENT_NONE,
+                                    GPU_ATTACHMENT_TEXTURE(dtxl->color),
+                                });
+  GPU_framebuffer_ensure_config(&dfbl->overlay_only_fb,
+                                {
+                                    GPU_ATTACHMENT_NONE,
+                                    GPU_ATTACHMENT_TEXTURE(dtxl->color_overlay),
+                                });
+}
+
+static void draw_viewport_engines_data_clear(ViewportEngineData *data)
+{
+  DrawEngineType *engine_type = data->engine_type->draw_engine;
+  const DrawEngineDataSize *data_size = engine_type->vedata_size;
+
+  for (int i = 0; data->fbl && i < data_size->fbl_len; i++) {
+    GPU_FRAMEBUFFER_FREE_SAFE(data->fbl->framebuffers[i]);
+  }
+  for (int i = 0; data->txl && i < data_size->txl_len; i++) {
+    GPU_TEXTURE_FREE_SAFE(data->txl->textures[i]);
+  }
+  for (int i = 0; data->stl && i < data_size->stl_len; i++) {
+    MEM_SAFE_FREE(data->stl->storage[i]);
+  }
+
+  MEM_SAFE_FREE(data->fbl);
+  MEM_SAFE_FREE(data->txl);
+  MEM_SAFE_FREE(data->psl);
+  MEM_SAFE_FREE(data->stl);
+
+  if (data->text_draw_cache) {
+    DRW_text_cache_destroy(data->text_draw_cache);
+    data->text_draw_cache = nullptr;
+  }
+}
+
+static void draw_view_data_clear(DRWViewData *view_data)
+{
+  GPU_FRAMEBUFFER_FREE_SAFE(view_data->dfbl.default_fb);
+  GPU_FRAMEBUFFER_FREE_SAFE(view_data->dfbl.overlay_fb);
+  GPU_FRAMEBUFFER_FREE_SAFE(view_data->dfbl.in_front_fb);
+  GPU_FRAMEBUFFER_FREE_SAFE(view_data->dfbl.color_only_fb);
+  GPU_FRAMEBUFFER_FREE_SAFE(view_data->dfbl.depth_only_fb);
+  GPU_FRAMEBUFFER_FREE_SAFE(view_data->dfbl.overlay_only_fb);
+
+  if (!view_data->from_viewport) {
+    GPU_TEXTURE_FREE_SAFE(view_data->dtxl.color);
+    GPU_TEXTURE_FREE_SAFE(view_data->dtxl.color_overlay);
+    GPU_TEXTURE_FREE_SAFE(view_data->dtxl.depth);
+  }
+  GPU_TEXTURE_FREE_SAFE(view_data->dtxl.depth_in_front);
+
+  for (ViewportEngineData &engine : view_data->engines) {
+    draw_viewport_engines_data_clear(&engine);
+  }
+
+  view_data->texture_list_size[0] = view_data->texture_list_size[1] = 0;
+  view_data->cache_time = 0.0f;
+}
+
+void DRW_view_data_free(DRWViewData *view_data)
+{
+  draw_view_data_clear(view_data);
+  delete view_data;
+}
+
+void DRW_view_data_texture_list_size_validate(DRWViewData *view_data, const int size[2])
+{
+  if (!equals_v2v2_int(view_data->texture_list_size, size)) {
+    draw_view_data_clear(view_data);
+    copy_v2_v2_int(view_data->texture_list_size, size);
+  }
+}
+
+ViewportEngineData *DRW_view_data_engine_data_get_ensure(DRWViewData *view_data,
+                                                         DrawEngineType *engine_type)
+{
+  for (ViewportEngineData &engine : view_data->engines) {
+    if (engine.engine_type->draw_engine == engine_type) {
+      if (engine.fbl == nullptr) {
+        const DrawEngineDataSize *data_size = engine_type->vedata_size;
+        engine.fbl = (FramebufferList *)MEM_calloc_arrayN(
+            data_size->fbl_len, sizeof(GPUFrameBuffer *), "FramebufferList");
+        engine.txl = (TextureList *)MEM_calloc_arrayN(
+            data_size->txl_len, sizeof(GPUTexture *), "TextureList");
+        engine.psl = (PassList *)MEM_calloc_arrayN(
+            data_size->psl_len, sizeof(DRWPass *), "PassList");
+        engine.stl = (StorageList *)MEM_calloc_arrayN(
+            data_size->stl_len, sizeof(void *), "StorageList");
+      }
+      return &engine;
+    }
+  }
+  return nullptr;
+}
+
+void DRW_view_data_use_engine(DRWViewData *view_data, DrawEngineType *engine_type)
+{
+  ViewportEngineData *engine = DRW_view_data_engine_data_get_ensure(view_data, engine_type);
+  view_data->enabled_engines.append(engine);
+}
+
+void DRW_view_data_reset(DRWViewData *view_data)
+{
+  view_data->enabled_engines.clear();
+}
+
+void DRW_view_data_free_unused(DRWViewData *view_data)
+{
+  for (ViewportEngineData &engine : view_data->engines) {
+    if (view_data->enabled_engines.first_index_of_try(&engine) == -1) {
+      draw_viewport_engines_data_clear(&engine);
+    }
+  }
+}
+
+double *DRW_view_data_cache_time_get(DRWViewData *view_data)
+{
+  return &view_data->cache_time;
+}
+
+DefaultFramebufferList *DRW_view_data_default_framebuffer_list_get(DRWViewData *view_data)
+{
+  return &view_data->dfbl;
+}
+
+DefaultTextureList *DRW_view_data_default_texture_list_get(DRWViewData *view_data)
+{
+  return &view_data->dtxl;
+}
+
+void DRW_view_data_enabled_engine_iter_begin(DRWEngineIterator *iterator, DRWViewData *view_data)
+{
+  iterator->id = 0;
+  iterator->end = view_data->enabled_engines.size();
+  iterator->engines = view_data->enabled_engines.data();
+}
+
+ViewportEngineData *DRW_view_data_enabled_engine_iter_step(DRWEngineIterator *iterator)
+{
+  if (iterator->id >= iterator->end) {
+    return nullptr;
+  }
+  ViewportEngineData *engine = iterator->engines[iterator->id++];
+  return engine;
+}
diff --git a/source/blender/draw/intern/draw_view_data.h b/source/blender/draw/intern/draw_view_data.h
new file mode 100644
index 00000000000..c8176170a61
--- /dev/null
+++ b/source/blender/draw/intern/draw_view_data.h
@@ -0,0 +1,139 @@
+/*
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ * Copyright 2021, Blender Foundation.
+ */
+
+/** \file
+ * \ingroup draw
+ *
+ * Engine data
+ * Structure containing each draw engine instance data.
+ */
+
+#pragma once
+
+#define GPU_INFO_SIZE 512 /* IMA_MAX_RENDER_TEXT */
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+struct GPUViewport;
+struct DrawEngineType;
+struct DRWRegisteredDrawEngine;
+
+/* NOTE these structs are only here for reading the actual lists from the engine.
+ * The actual length of them is stored in a ViewportEngineData_Info.
+ * The length of 1 is just here to avoid compiler warning. */
+typedef struct FramebufferList {
+  struct GPUFrameBuffer *framebuffers[1];
+} FramebufferList;
+
+typedef struct TextureList {
+  struct GPUTexture *textures[1];
+} TextureList;
+
+typedef struct PassList {
+  struct DRWPass *passes[1];
+} PassList;
+
+/* Stores custom structs from the engine that have been MEM_(m/c)allocN'ed. */
+typedef struct StorageList {
+  void *storage[1];
+} StorageList;
+
+typedef struct ViewportEngineData {
+  /* Not owning pointer to the draw engine. */
+  struct DRWRegisteredDrawEngine *engine_type;
+
+  FramebufferList *fbl;
+  TextureList *txl;
+  PassList *psl;
+  StorageList *stl;
+  char info[GPU_INFO_SIZE];
+
+  /* we may want to put this elsewhere */
+  struct DRWTextStore *text_draw_cache;
+
+  /* Profiling data */
+  double init_time;
+  double render_time;
+  double background_time;
+} ViewportEngineData;
+
+typedef struct ViewportEngineData_Info {
+  int fbl_len;
+  int txl_len;
+  int psl_len;
+  int stl_len;
+} ViewportEngineData_Info;
+
+/* Buffer and textures used by the viewport by default */
+typedef struct DefaultFramebufferList {
+  struct GPUFrameBuffer *default_fb;
+  struct GPUFrameBuffer *overlay_fb;
+  struct GPUFrameBuffer *in_front_fb;
+  struct GPUFrameBuffer *color_only_fb;
+  struct GPUFrameBuffer *depth_only_fb;
+  struct GPUFrameBuffer *overlay_only_fb;
+} DefaultFramebufferList;
+
+typedef struct DefaultTextureList {
+  struct GPUTexture *color;
+  struct GPUTexture *color_overlay;
+  struct GPUTexture *depth;
+  struct GPUTexture *depth_in_front;
+} DefaultTextureList;
+
+typedef struct DRWViewData DRWViewData;
+
+DRWViewData *DRW_view_data_create(ListBase *engine_types);
+void DRW_view_data_free(DRWViewData *view_data);
+
+void DRW_view_data_default_lists_from_viewport(DRWViewData *view_data,
+                                               struct GPUViewport *viewport);
+void DRW_view_data_texture_list_size_validate(DRWViewData *view_data, const int size[2]);
+ViewportEngineData *DRW_view_data_engine_data_get_ensure(DRWViewData *view_data,
+                                                         struct DrawEngineType *engine_type_);
+void DRW_view_data_use_engine(DRWViewData *view_data, struct DrawEngineType *engine_type);
+void DRW_view_data_reset(DRWViewData *view_data);
+void DRW_view_data_free_unused(DRWViewData *view_data);
+double *DRW_view_data_cache_time_get(DRWViewData *view_data);
+DefaultFramebufferList *DRW_view_data_default_framebuffer_list_get(DRWViewData *view_data);
+DefaultTextureList *DRW_view_data_default_texture_list_get(DRWViewData *view_data);
+
+typedef struct DRWEngineIterator {
+  int id, end;
+  ViewportEngineData **engines;
+} DRWEngineIterator;
+
+/* Iterate over used engines of this view_data. */
+void DRW_view_data_enabled_engine_iter_begin(DRWEngineIterator *iterator, DRWViewData *view_data);
+ViewportEngineData *DRW_view_data_enabled_engine_iter_step(DRWEngineIterator *iterator);
+
+#define DRW_ENABLED_ENGINE_ITER(view_data_, engine_, data_) \
+  DRWEngineIterator iterator; \
+  ViewportEngineData *data_; \
+  struct DrawEngineType *engine_; \
+  DRW_view_data_enabled_engine_iter_begin(&iterator, view_data_); \
+  /* WATCH Comma operator trickery ahead! This tests engine_ == NULL. */ \
+  while ((data_ = DRW_view_data_enabled_engine_iter_step(&iterator), \
+          engine_ = (data_ != NULL) ? (struct DrawEngineType *)data_->engine_type->draw_engine : \
+                                      NULL))
+
+#ifdef __cplusplus
+}
+#endif
diff --git a/source/blender/editors/space_view3d/view3d_draw.c b/source/blender/editors/space_view3d/view3d_draw.c
index 79148035a25..1cfd83c503e 100644
--- a/source/blender/editors/space_view3d/view3d_draw.c
+++ b/source/blender/editors/space_view3d/view3d_draw.c
@@ -2180,13 +2180,17 @@ static void validate_object_select_id(struct Depsgraph *depsgraph,
  *       Calling this function should be avoided during interactive drawing. */
 static void view3d_opengl_read_Z_pixels(GPUViewport *viewport, rcti *rect, void *data)
 {
-  DefaultTextureList *dtxl = (DefaultTextureList *)GPU_viewport_texture_list_get(viewport);
+  GPUTexture *depth_tx = GPU_viewport_depth_texture(viewport);
 
-  GPUFrameBuffer *tmp_fb = GPU_framebuffer_create(__func__);
-  GPU_framebuffer_texture_attach(tmp_fb, dtxl->depth, 0, 0);
-  GPU_framebuffer_bind(tmp_fb);
+  GPUFrameBuffer *depth_read_fb = NULL;
+  GPU_framebuffer_ensure_config(&depth_read_fb,
+                                {
+                                    GPU_ATTACHMENT_TEXTURE(depth_tx),
+                                    GPU_ATTACHMENT_NONE,
+                                });
 
-  GPU_framebuffer_read_depth(tmp_fb,
+  GPU_framebuffer_bind(depth_read_fb);
+  GPU_framebuffer_read_depth(depth_read_fb,
                              rect->xmin,
                              rect->ymin,
                              BLI_rcti_size_x(rect),
@@ -2195,7 +2199,7 @@ static void view3d_opengl_read_Z_pixels(GPUViewport *viewport, rcti *rect, void
                              data);
 
   GPU_framebuffer_restore();
-  GPU_framebuffer_free(tmp_fb);
+  GPU_framebuffer_free(depth_read_fb);
 }
 
 void ED_view3d_select_id_validate(ViewContext *vc)
@@ -2265,12 +2269,11 @@ static ViewDepths *view3d_depths_create(ARegion *region)
   ViewDepths *d = MEM_callocN(sizeof(ViewDepths), "ViewDepths");
   d->w = region->winx;
   d->h = region->winy;
-  d->depths = MEM_mallocN(sizeof(float) * d->w * d->h, "View depths");
 
   {
     GPUViewport *viewport = WM_draw_region_get_viewport(region);
-    DefaultFramebufferList *fbl = GPU_viewport_framebuffer_list_get(viewport);
-    GPU_framebuffer_read_depth(fbl->depth_only_fb, 0, 0, d->w, d->h, GPU_DATA_FLOAT, d->depths);
+    GPUTexture *depth_tx = GPU_viewport_depth_texture(viewport);
+    d->depths = GPU_texture_read(depth_tx, GPU_DATA_FLOAT, 0);
 
     /* Assumed to be this as they are never changed. */
     d->depth_range[0] = 0.0;
diff --git a/source/blender/gpu/GPU_texture.h b/source/blender/gpu/GPU_texture.h
index 9a1885160b6..deff9e47871 100644
--- a/source/blender/gpu/GPU_texture.h
+++ b/source/blender/gpu/GPU_texture.h
@@ -52,6 +52,14 @@ typedef enum eGPUSamplerState {
   GPU_SAMPLER_REPEAT = (GPU_SAMPLER_REPEAT_S | GPU_SAMPLER_REPEAT_T | GPU_SAMPLER_REPEAT_R),
 } eGPUSamplerState;
 
+#define GPU_TEXTURE_FREE_SAFE(texture) \
+  do { \
+    if (texture != NULL) { \
+      GPU_texture_free(texture); \
+      texture = NULL; \
+    } \
+  } while (0)
+
 /* `GPU_SAMPLER_MAX` is not a valid enum value, but only a limit.
  * It also creates a bad mask for the `NOT` operator in `ENUM_OPERATORS`.
  */
diff --git a/source/blender/gpu/GPU_viewport.h b/source/blender/gpu/GPU_viewport.h
index 0ecd5f3eb7b..4d9970dac90 100644
--- a/source/blender/gpu/GPU_viewport.h
+++ b/source/blender/gpu/GPU_viewport.h
@@ -35,76 +35,15 @@
 extern "C" {
 #endif
 
-#define GPU_INFO_SIZE 512 /* IMA_MAX_RENDER_TEXT */
 #define GLA_PIXEL_OFS 0.375f
 
 typedef struct GHash GHash;
 typedef struct GPUViewport GPUViewport;
 
 struct GPUFrameBuffer;
-
-/* Contains memory pools information. */
-typedef struct ViewportMemoryPool {
-  struct BLI_memblock *commands;
-  struct BLI_memblock *commands_small;
-  struct BLI_memblock *callbuffers;
-  struct BLI_memblock *obmats;
-  struct BLI_memblock *obinfos;
-  struct BLI_memblock *cullstates;
-  struct BLI_memblock *shgroups;
-  struct BLI_memblock *uniforms;
-  struct BLI_memblock *views;
-  struct BLI_memblock *passes;
-  struct BLI_memblock *images;
-  struct GPUUniformBuf **matrices_ubo;
-  struct GPUUniformBuf **obinfos_ubo;
-  struct GHash *obattrs_ubo_pool;
-  uint ubo_len;
-} ViewportMemoryPool;
-
-/* All FramebufferLists are just the same pointers with different names. */
-typedef struct FramebufferList {
-  struct GPUFrameBuffer *framebuffers[1];
-} FramebufferList;
-
-typedef struct TextureList {
-  struct GPUTexture *textures[1];
-} TextureList;
-
-typedef struct PassList {
-  struct DRWPass *passes[1];
-} PassList;
-
-typedef struct StorageList {
-  void *storage[1]; /* Custom structs from the engine. */
-} StorageList;
-
-typedef struct ViewportEngineData {
-  void *engine_type;
-
-  FramebufferList *fbl;
-  TextureList *txl;
-  PassList *psl;
-  StorageList *stl;
-  char info[GPU_INFO_SIZE];
-
-  TextureList *txl_stereo;
-  StorageList *stl_stereo;
-  /* We may want to put this elsewhere. */
-  struct DRWTextStore *text_draw_cache;
-
-  /* Profiling data. */
-  double init_time;
-  double render_time;
-  double background_time;
-} ViewportEngineData;
-
-typedef struct ViewportEngineData_Info {
-  int fbl_len;
-  int txl_len;
-  int psl_len;
-  int stl_len;
-} ViewportEngineData_Info;
+struct DefaultFramebufferList;
+struct DefaultTextureList;
+struct DRWData;
 
 GPUViewport *GPU_viewport_create(void);
 GPUViewport *GPU_viewport_stereo_create(void);
@@ -129,35 +68,21 @@ void GPU_viewport_unbind_from_offscreen(GPUViewport *viewport,
                                         bool display_colorspace,
                                         bool do_overlay_merge);
 
-ViewportMemoryPool *GPU_viewport_mempool_get(GPUViewport *viewport);
-struct DRWInstanceDataList *GPU_viewport_instance_data_list_get(GPUViewport *viewport);
+struct DRWData **GPU_viewport_data_get(GPUViewport *viewport);
 
-void *GPU_viewport_engine_data_create(GPUViewport *viewport, void *engine_type);
-void *GPU_viewport_engine_data_get(GPUViewport *viewport, void *engine_handle);
-void *GPU_viewport_framebuffer_list_get(GPUViewport *viewport);
 void GPU_viewport_stereo_composite(GPUViewport *viewport, Stereo3dFormat *stereo_format);
-void *GPU_viewport_texture_list_get(GPUViewport *viewport);
-void GPU_viewport_size_get(const GPUViewport *viewport, int size[2]);
-void GPU_viewport_size_set(GPUViewport *viewport, const int size[2]);
-void GPU_viewport_active_view_set(GPUViewport *viewport, int view);
-
-/* Profiling. */
-double *GPU_viewport_cache_time_get(GPUViewport *viewport);
 
 void GPU_viewport_tag_update(GPUViewport *viewport);
 bool GPU_viewport_do_update(GPUViewport *viewport);
 
-GPUTexture *GPU_viewport_color_texture(GPUViewport *viewport, int view);
+int GPU_viewport_active_view_get(GPUViewport *viewport);
+bool GPU_viewport_is_stereo_get(GPUViewport *viewport);
 
-/* Texture pool. */
-GPUTexture *GPU_viewport_texture_pool_query(
-    GPUViewport *viewport, void *engine, int width, int height, int format);
-
-bool GPU_viewport_engines_data_validate(GPUViewport *viewport, void **engine_handle_array);
-void GPU_viewport_cache_release(GPUViewport *viewport);
+GPUTexture *GPU_viewport_color_texture(GPUViewport *viewport, int view);
+GPUTexture *GPU_viewport_overlay_texture(GPUViewport *viewport, int view);
+GPUTexture *GPU_viewport_depth_texture(GPUViewport *viewport);
 
-struct GPUFrameBuffer *GPU_viewport_framebuffer_default_get(GPUViewport *viewport);
-struct GPUFrameBuffer *GPU_viewport_framebuffer_overlay_get(GPUViewport *viewport);
+GPUFrameBuffer *GPU_viewport_framebuffer_overlay_get(GPUViewport *viewport);
 
 #ifdef __cplusplus
 }
diff --git a/source/blender/gpu/intern/gpu_viewport.c b/source/blender/gpu/intern/gpu_viewport.c
index dd63edea0db..ccd9a4c061b 100644
--- a/source/blender/gpu/intern/gpu_viewport.c
+++ b/source/blender/gpu/intern/gpu_viewport.c
@@ -48,22 +48,6 @@
 
 #include "MEM_guardedalloc.h"
 
-static const int default_fbl_len = (sizeof(DefaultFramebufferList)) / sizeof(void *);
-static const int default_txl_len = (sizeof(DefaultTextureList)) / sizeof(void *);
-
-#define MAX_ENABLE_ENGINE 8
-
-/* Maximum number of simultaneous engine enabled at the same time.
- * Setting it lower than the real number will do lead to
- * higher VRAM usage due to sub-efficient buffer reuse. */
-#define MAX_ENGINE_BUFFER_SHARING 5
-
-typedef struct ViewportTempTexture {
-  struct ViewportTempTexture *next, *prev;
-  void *user[MAX_ENGINE_BUFFER_SHARING];
-  GPUTexture *texture;
-} ViewportTempTexture;
-
 /* Struct storing a viewport specific GPUBatch.
  * The end-goal is to have a single batch shared across viewport and use a model matrix to place
  * the batch. Due to OCIO and Image/UV editor we are not able to use an model matrix yet. */
@@ -89,23 +73,17 @@ struct GPUViewport {
   /* Set the active view (for stereoscopic viewport rendering). */
   int active_view;
 
-  /* If engine_handles mismatch we free all #ViewportEngineData in this viewport. */
-  struct {
-    void *handle;
-    ViewportEngineData *data;
-  } engine_data[MAX_ENABLE_ENGINE];
-
-  DefaultFramebufferList *fbl;
-  DefaultTextureList *txl;
-
-  ViewportMemoryPool vmempool;           /* Used for rendering data structure. */
-  struct DRWInstanceDataList *idatalist; /* Used for rendering data structure. */
-
-  ListBase
-      tex_pool; /* ViewportTempTexture list : Temporary textures shared across draw engines. */
-
-  /* Profiling data. */
-  double cache_time;
+  /* Viewport Resources. */
+  struct DRWData *draw_data;
+  /** Color buffers, one for each stereo view. Only one if not stereo viewport. */
+  GPUTexture *color_render_tx[2];
+  GPUTexture *color_overlay_tx[2];
+  /** Depth buffer. Can be shared with GPUOffscreen. */
+  GPUTexture *depth_tx;
+  /** Compositing framebuffer for stereo viewport. */
+  GPUFrameBuffer *stereo_comp_fb;
+  /** Overlay framebuffer for drawing outside of DRW module. */
+  GPUFrameBuffer *overlay_fb;
 
   /* Color management. */
   ColorManagedViewSettings view_settings;
@@ -123,12 +101,6 @@ enum {
   GPU_VIEWPORT_STEREO = (1 << 1),
 };
 
-static void gpu_viewport_buffers_free(
-    FramebufferList *fbl, int fbl_len, TextureList *txl, TextureList *txl_stereo, int txl_len);
-static void gpu_viewport_storage_free(StorageList *stl, int stl_len);
-static void gpu_viewport_passes_free(PassList *psl, int psl_len);
-static void gpu_viewport_texture_pool_free(GPUViewport *viewport);
-
 void GPU_viewport_tag_update(GPUViewport *viewport)
 {
   viewport->flag |= DO_UPDATE;
@@ -144,12 +116,9 @@ bool GPU_viewport_do_update(GPUViewport *viewport)
 GPUViewport *GPU_viewport_create(void)
 {
   GPUViewport *viewport = MEM_callocN(sizeof(GPUViewport), "GPUViewport");
-  viewport->fbl = MEM_callocN(sizeof(DefaultFramebufferList), "FramebufferList");
-  viewport->txl = MEM_callocN(sizeof(DefaultTextureList), "TextureList");
-  viewport->idatalist = DRW_instance_data_list_create();
   viewport->do_color_management = false;
   viewport->size[0] = viewport->size[1] = -1;
-  viewport->active_view = -1;
+  viewport->active_view = 0;
   return viewport;
 }
 
@@ -160,343 +129,55 @@ GPUViewport *GPU_viewport_stereo_create(void)
   return viewport;
 }
 
-static void gpu_viewport_framebuffer_view_set(GPUViewport *viewport, int view)
-{
-  /* Early check if the view is the latest requested. */
-  if (viewport->active_view == view) {
-    return;
-  }
-  DefaultFramebufferList *dfbl = viewport->fbl;
-  DefaultTextureList *dtxl = viewport->txl;
-
-  /* Only swap the texture when this is a Stereo Viewport. */
-  if (((viewport->flag & GPU_VIEWPORT_STEREO) != 0)) {
-    SWAP(GPUTexture *, dtxl->color, dtxl->color_stereo);
-    SWAP(GPUTexture *, dtxl->color_overlay, dtxl->color_overlay_stereo);
-
-    for (int i = 0; i < MAX_ENABLE_ENGINE; i++) {
-      if (viewport->engine_data[i].handle != NULL) {
-        ViewportEngineData *data = viewport->engine_data[i].data;
-        SWAP(StorageList *, data->stl, data->stl_stereo);
-        SWAP(TextureList *, data->txl, data->txl_stereo);
-      }
-      else {
-        break;
-      }
-    }
-  }
-
-  GPU_framebuffer_ensure_config(&dfbl->default_fb,
-                                {
-                                    GPU_ATTACHMENT_TEXTURE(dtxl->depth),
-                                    GPU_ATTACHMENT_TEXTURE(dtxl->color),
-                                });
-
-  GPU_framebuffer_ensure_config(&dfbl->overlay_fb,
-                                {
-                                    GPU_ATTACHMENT_TEXTURE(dtxl->depth),
-                                    GPU_ATTACHMENT_TEXTURE(dtxl->color_overlay),
-                                });
-
-  GPU_framebuffer_ensure_config(&dfbl->depth_only_fb,
-                                {
-                                    GPU_ATTACHMENT_TEXTURE(dtxl->depth),
-                                    GPU_ATTACHMENT_NONE,
-                                });
-
-  GPU_framebuffer_ensure_config(&dfbl->color_only_fb,
-                                {
-                                    GPU_ATTACHMENT_NONE,
-                                    GPU_ATTACHMENT_TEXTURE(dtxl->color),
-                                });
-
-  GPU_framebuffer_ensure_config(&dfbl->overlay_only_fb,
-                                {
-                                    GPU_ATTACHMENT_NONE,
-                                    GPU_ATTACHMENT_TEXTURE(dtxl->color_overlay),
-                                });
-
-  viewport->active_view = view;
-}
-
-void *GPU_viewport_engine_data_create(GPUViewport *viewport, void *engine_type)
-{
-  ViewportEngineData *data = MEM_callocN(sizeof(ViewportEngineData), "ViewportEngineData");
-  int fbl_len, txl_len, psl_len, stl_len;
-
-  DRW_engine_viewport_data_size_get(engine_type, &fbl_len, &txl_len, &psl_len, &stl_len);
-
-  data->engine_type = engine_type;
-
-  data->fbl = MEM_callocN((sizeof(void *) * fbl_len) + sizeof(FramebufferList), "FramebufferList");
-  data->txl = MEM_callocN((sizeof(void *) * txl_len) + sizeof(TextureList), "TextureList");
-  data->psl = MEM_callocN((sizeof(void *) * psl_len) + sizeof(PassList), "PassList");
-  data->stl = MEM_callocN((sizeof(void *) * stl_len) + sizeof(StorageList), "StorageList");
-
-  if ((viewport->flag & GPU_VIEWPORT_STEREO) != 0) {
-    data->txl_stereo = MEM_callocN((sizeof(void *) * txl_len) + sizeof(TextureList),
-                                   "TextureList");
-    data->stl_stereo = MEM_callocN((sizeof(void *) * stl_len) + sizeof(StorageList),
-                                   "StorageList");
-  }
-
-  for (int i = 0; i < MAX_ENABLE_ENGINE; i++) {
-    if (viewport->engine_data[i].handle == NULL) {
-      viewport->engine_data[i].handle = engine_type;
-      viewport->engine_data[i].data = data;
-      return data;
-    }
-  }
-
-  BLI_assert_msg(0, "Too many draw engines enabled at the same time");
-  return NULL;
-}
-
-static void gpu_viewport_engines_data_free(GPUViewport *viewport)
+struct DRWData **GPU_viewport_data_get(GPUViewport *viewport)
 {
-  int fbl_len, txl_len, psl_len, stl_len;
-
-  for (int i = 0; i < MAX_ENABLE_ENGINE && viewport->engine_data[i].handle; i++) {
-    ViewportEngineData *data = viewport->engine_data[i].data;
-
-    DRW_engine_viewport_data_size_get(data->engine_type, &fbl_len, &txl_len, &psl_len, &stl_len);
-
-    gpu_viewport_buffers_free(data->fbl, fbl_len, data->txl, data->txl_stereo, txl_len);
-    gpu_viewport_passes_free(data->psl, psl_len);
-    gpu_viewport_storage_free(data->stl, stl_len);
-
-    MEM_freeN(data->fbl);
-    MEM_freeN(data->txl);
-    MEM_freeN(data->psl);
-    MEM_freeN(data->stl);
-
-    if ((viewport->flag & GPU_VIEWPORT_STEREO) != 0) {
-      gpu_viewport_storage_free(data->stl_stereo, stl_len);
-      MEM_freeN(data->txl_stereo);
-      MEM_freeN(data->stl_stereo);
-    }
-    /* We could handle this in the DRW module */
-    if (data->text_draw_cache) {
-      extern void DRW_text_cache_destroy(struct DRWTextStore * dt);
-      DRW_text_cache_destroy(data->text_draw_cache);
-      data->text_draw_cache = NULL;
-    }
-
-    MEM_freeN(data);
-
-    /* Mark as unused. */
-    viewport->engine_data[i].handle = NULL;
-  }
-
-  gpu_viewport_texture_pool_free(viewport);
-}
-
-void *GPU_viewport_engine_data_get(GPUViewport *viewport, void *engine_handle)
-{
-  BLI_assert(engine_handle != NULL);
-
-  for (int i = 0; i < MAX_ENABLE_ENGINE; i++) {
-    if (viewport->engine_data[i].handle == engine_handle) {
-      return viewport->engine_data[i].data;
-    }
-  }
-  return NULL;
-}
-
-ViewportMemoryPool *GPU_viewport_mempool_get(GPUViewport *viewport)
-{
-  return &viewport->vmempool;
+  return &viewport->draw_data;
 }
 
-struct DRWInstanceDataList *GPU_viewport_instance_data_list_get(GPUViewport *viewport)
-{
-  return viewport->idatalist;
-}
-
-/* Note this function is only allowed to be called from `DRW_notify_view_update`. The rest
- * should bind the correct viewport.
- *
- * The reason is that DRW_notify_view_update can be called from a different thread, but needs
- * access to the engine data. */
-void GPU_viewport_active_view_set(GPUViewport *viewport, int view)
-{
-  gpu_viewport_framebuffer_view_set(viewport, view);
-}
-
-void *GPU_viewport_framebuffer_list_get(GPUViewport *viewport)
-{
-  return viewport->fbl;
-}
-
-void *GPU_viewport_texture_list_get(GPUViewport *viewport)
-{
-  return viewport->txl;
-}
-
-void GPU_viewport_size_get(const GPUViewport *viewport, int size[2])
-{
-  copy_v2_v2_int(size, viewport->size);
-}
-
-/**
- * Special case, this is needed for when we have a viewport without a frame-buffer output
- * (occlusion queries for eg)
- * but still need to set the size since it may be used for other calculations.
- */
-void GPU_viewport_size_set(GPUViewport *viewport, const int size[2])
-{
-  copy_v2_v2_int(viewport->size, size);
-}
-
-double *GPU_viewport_cache_time_get(GPUViewport *viewport)
-{
-  return &viewport->cache_time;
-}
-
-/**
- * Try to find a texture corresponding to params into the texture pool.
- * If no texture was found, create one and add it to the pool.
- */
-GPUTexture *GPU_viewport_texture_pool_query(
-    GPUViewport *viewport, void *engine, int width, int height, int format)
+static void gpu_viewport_textures_create(GPUViewport *viewport)
 {
-  GPUTexture *tex;
-
-  LISTBASE_FOREACH (ViewportTempTexture *, tmp_tex, &viewport->tex_pool) {
-    if ((GPU_texture_format(tmp_tex->texture) == format) &&
-        (GPU_texture_width(tmp_tex->texture) == width) &&
-        (GPU_texture_height(tmp_tex->texture) == height)) {
-      /* Search if the engine is not already using this texture */
-      for (int i = 0; i < MAX_ENGINE_BUFFER_SHARING; i++) {
-        if (tmp_tex->user[i] == engine) {
-          break;
-        }
-
-        if (tmp_tex->user[i] == NULL) {
-          tmp_tex->user[i] = engine;
-          return tmp_tex->texture;
-        }
-      }
-    }
-  }
-
-  tex = GPU_texture_create_2d("temp_from_pool", width, height, 1, format, NULL);
-  /* Doing filtering for depth does not make sense when not doing shadow mapping,
-   * and enabling texture filtering on integer texture make them unreadable. */
-  bool do_filter = !GPU_texture_depth(tex) && !GPU_texture_integer(tex);
-  GPU_texture_filter_mode(tex, do_filter);
-
-  ViewportTempTexture *tmp_tex = MEM_callocN(sizeof(ViewportTempTexture), "ViewportTempTexture");
-  tmp_tex->texture = tex;
-  tmp_tex->user[0] = engine;
-  BLI_addtail(&viewport->tex_pool, tmp_tex);
-
-  return tex;
-}
-
-static void gpu_viewport_texture_pool_clear_users(GPUViewport *viewport)
-{
-  ViewportTempTexture *tmp_tex_next;
-
-  for (ViewportTempTexture *tmp_tex = viewport->tex_pool.first; tmp_tex; tmp_tex = tmp_tex_next) {
-    tmp_tex_next = tmp_tex->next;
-    bool no_user = true;
-    for (int i = 0; i < MAX_ENGINE_BUFFER_SHARING; i++) {
-      if (tmp_tex->user[i] != NULL) {
-        tmp_tex->user[i] = NULL;
-        no_user = false;
-      }
-    }
-
-    if (no_user) {
-      GPU_texture_free(tmp_tex->texture);
-      BLI_freelinkN(&viewport->tex_pool, tmp_tex);
-    }
-  }
-}
-
-static void gpu_viewport_texture_pool_free(GPUViewport *viewport)
-{
-  LISTBASE_FOREACH (ViewportTempTexture *, tmp_tex, &viewport->tex_pool) {
-    GPU_texture_free(tmp_tex->texture);
-  }
-
-  BLI_freelistN(&viewport->tex_pool);
-}
-
-/* Takes an NULL terminated array of engine_handle. Returns true is data is still valid. */
-bool GPU_viewport_engines_data_validate(GPUViewport *viewport, void **engine_handle_array)
-{
-  for (int i = 0; i < MAX_ENABLE_ENGINE && engine_handle_array[i]; i++) {
-    if (viewport->engine_data[i].handle != engine_handle_array[i]) {
-      gpu_viewport_engines_data_free(viewport);
-      return false;
-    }
-  }
-  return true;
-}
-
-void GPU_viewport_cache_release(GPUViewport *viewport)
-{
-  for (int i = 0; i < MAX_ENABLE_ENGINE && viewport->engine_data[i].handle; i++) {
-    ViewportEngineData *data = viewport->engine_data[i].data;
-    int psl_len;
-    DRW_engine_viewport_data_size_get(data->engine_type, NULL, NULL, &psl_len, NULL);
-    gpu_viewport_passes_free(data->psl, psl_len);
-  }
-}
-
-static void gpu_viewport_default_fb_create(GPUViewport *viewport)
-{
-  DefaultFramebufferList *dfbl = viewport->fbl;
-  DefaultTextureList *dtxl = viewport->txl;
   int *size = viewport->size;
-  bool ok = true;
 
-  dtxl->color = GPU_texture_create_2d("dtxl_color", UNPACK2(size), 1, GPU_RGBA16F, NULL);
-  dtxl->color_overlay = GPU_texture_create_2d(
-      "dtxl_color_overlay", UNPACK2(size), 1, GPU_SRGB8_A8, NULL);
+  if (viewport->color_render_tx[0] == NULL) {
+    viewport->color_render_tx[0] = GPU_texture_create_2d(
+        "dtxl_color", UNPACK2(size), 1, GPU_RGBA16F, NULL);
+    viewport->color_overlay_tx[0] = GPU_texture_create_2d(
+        "dtxl_color_overlay", UNPACK2(size), 1, GPU_SRGB8_A8, NULL);
+  }
 
-  if (viewport->flag & GPU_VIEWPORT_STEREO) {
-    dtxl->color_stereo = GPU_texture_create_2d(
+  if ((viewport->flag & GPU_VIEWPORT_STEREO) != 0 && viewport->color_render_tx[1] == NULL) {
+    viewport->color_render_tx[1] = GPU_texture_create_2d(
         "dtxl_color_stereo", UNPACK2(size), 1, GPU_RGBA16F, NULL);
-    dtxl->color_overlay_stereo = GPU_texture_create_2d(
+    viewport->color_overlay_tx[1] = GPU_texture_create_2d(
         "dtxl_color_overlay_stereo", UNPACK2(size), 1, GPU_SRGB8_A8, NULL);
   }
 
   /* Can be shared with GPUOffscreen. */
-  if (dtxl->depth == NULL) {
-    dtxl->depth = GPU_texture_create_2d(
+  if (viewport->depth_tx == NULL) {
+    viewport->depth_tx = GPU_texture_create_2d(
         "dtxl_depth", UNPACK2(size), 1, GPU_DEPTH24_STENCIL8, NULL);
   }
 
-  if (!dtxl->depth || !dtxl->color) {
-    ok = false;
-    goto cleanup;
+  if (!viewport->depth_tx || !viewport->color_render_tx[0] || !viewport->color_overlay_tx[0]) {
+    GPU_viewport_free(viewport);
   }
+}
 
-  gpu_viewport_framebuffer_view_set(viewport, 0);
+static void gpu_viewport_textures_free(GPUViewport *viewport)
+{
+  GPU_FRAMEBUFFER_FREE_SAFE(viewport->stereo_comp_fb);
+  GPU_FRAMEBUFFER_FREE_SAFE(viewport->overlay_fb);
 
-  ok = ok && GPU_framebuffer_check_valid(dfbl->default_fb, NULL);
-  ok = ok && GPU_framebuffer_check_valid(dfbl->overlay_fb, NULL);
-  ok = ok && GPU_framebuffer_check_valid(dfbl->color_only_fb, NULL);
-  ok = ok && GPU_framebuffer_check_valid(dfbl->depth_only_fb, NULL);
-  ok = ok && GPU_framebuffer_check_valid(dfbl->overlay_only_fb, NULL);
-cleanup:
-  if (!ok) {
-    GPU_viewport_free(viewport);
-    DRW_opengl_context_disable();
-    return;
+  for (int i = 0; i < 2; i++) {
+    GPU_TEXTURE_FREE_SAFE(viewport->color_render_tx[i]);
+    GPU_TEXTURE_FREE_SAFE(viewport->color_overlay_tx[i]);
   }
 
-  GPU_framebuffer_restore();
+  GPU_TEXTURE_FREE_SAFE(viewport->depth_tx);
 }
 
 void GPU_viewport_bind(GPUViewport *viewport, int view, const rcti *rect)
 {
-  DefaultFramebufferList *dfbl = viewport->fbl;
-  int fbl_len, txl_len;
-
   int rect_size[2];
   /* add one pixel because of scissor test */
   rect_size[0] = BLI_rcti_size_x(rect) + 1;
@@ -504,39 +185,18 @@ void GPU_viewport_bind(GPUViewport *viewport, int view, const rcti *rect)
 
   DRW_opengl_context_enable();
 
-  if (dfbl->default_fb) {
-    if (!equals_v2v2_int(viewport->size, rect_size)) {
-      gpu_viewport_buffers_free((FramebufferList *)viewport->fbl,
-                                default_fbl_len,
-                                (TextureList *)viewport->txl,
-                                NULL,
-                                default_txl_len);
-
-      for (int i = 0; i < MAX_ENABLE_ENGINE && viewport->engine_data[i].handle; i++) {
-        ViewportEngineData *data = viewport->engine_data[i].data;
-        DRW_engine_viewport_data_size_get(data->engine_type, &fbl_len, &txl_len, NULL, NULL);
-        gpu_viewport_buffers_free(data->fbl, fbl_len, data->txl, data->txl_stereo, txl_len);
-      }
-
-      gpu_viewport_texture_pool_free(viewport);
-      viewport->active_view = -1;
-    }
+  if (!equals_v2v2_int(viewport->size, rect_size)) {
+    copy_v2_v2_int(viewport->size, rect_size);
+    gpu_viewport_textures_free(viewport);
+    gpu_viewport_textures_create(viewport);
   }
 
-  copy_v2_v2_int(viewport->size, rect_size);
-
-  gpu_viewport_texture_pool_clear_users(viewport);
-
-  if (!dfbl->default_fb) {
-    gpu_viewport_default_fb_create(viewport);
-  }
-  gpu_viewport_framebuffer_view_set(viewport, view);
+  viewport->active_view = view;
 }
 
+/* Should be called from DRW after DRW_opengl_context_enable. */
 void GPU_viewport_bind_from_offscreen(GPUViewport *viewport, struct GPUOffScreen *ofs)
 {
-  DefaultFramebufferList *dfbl = viewport->fbl;
-  DefaultTextureList *dtxl = viewport->txl;
   GPUTexture *color, *depth;
   GPUFrameBuffer *fb;
   viewport->size[0] = GPU_offscreen_width(ofs);
@@ -544,14 +204,12 @@ void GPU_viewport_bind_from_offscreen(GPUViewport *viewport, struct GPUOffScreen
 
   GPU_offscreen_viewport_data_get(ofs, &fb, &color, &depth);
 
-  /* This is the only texture we can share. */
-  dtxl->depth = depth;
+  gpu_viewport_textures_free(viewport);
 
-  gpu_viewport_texture_pool_clear_users(viewport);
+  /* This is the only texture we can share. */
+  viewport->depth_tx = depth;
 
-  if (!dfbl->default_fb) {
-    gpu_viewport_default_fb_create(viewport);
-  }
+  gpu_viewport_textures_create(viewport);
 }
 
 void GPU_viewport_colorspace_set(GPUViewport *viewport,
@@ -608,21 +266,17 @@ void GPU_viewport_stereo_composite(GPUViewport *viewport, Stereo3dFormat *stereo
      * done from a single viewport. See `wm_stereo.c` */
     return;
   }
-  gpu_viewport_framebuffer_view_set(viewport, 0);
-  DefaultTextureList *dtxl = viewport->txl;
-  DefaultFramebufferList *dfbl = viewport->fbl;
-
   /* The composite framebuffer object needs to be created in the window context. */
-  GPU_framebuffer_ensure_config(&dfbl->stereo_comp_fb,
+  GPU_framebuffer_ensure_config(&viewport->stereo_comp_fb,
                                 {
                                     GPU_ATTACHMENT_NONE,
-                                    GPU_ATTACHMENT_TEXTURE(dtxl->color_overlay),
-                                    GPU_ATTACHMENT_TEXTURE(dtxl->color),
+                                    GPU_ATTACHMENT_TEXTURE(viewport->color_overlay_tx[0]),
+                                    GPU_ATTACHMENT_TEXTURE(viewport->color_render_tx[0]),
                                 });
 
   GPUVertFormat *vert_format = immVertexFormat();
   uint pos = GPU_vertformat_attr_add(vert_format, "pos", GPU_COMP_F32, 2, GPU_FETCH_FLOAT);
-  GPU_framebuffer_bind(dfbl->stereo_comp_fb);
+  GPU_framebuffer_bind(viewport->stereo_comp_fb);
   GPU_matrix_push();
   GPU_matrix_push_projection();
   GPU_matrix_identity_set();
@@ -650,8 +304,8 @@ void GPU_viewport_stereo_composite(GPUViewport *viewport, Stereo3dFormat *stereo
   }
   immUniform1i("stereoDisplaySettings", settings);
 
-  GPU_texture_bind(dtxl->color_stereo, 0);
-  GPU_texture_bind(dtxl->color_overlay_stereo, 1);
+  GPU_texture_bind(viewport->color_render_tx[1], 0);
+  GPU_texture_bind(viewport->color_overlay_tx[1], 1);
 
   immBegin(GPU_PRIM_TRI_STRIP, 4);
 
@@ -662,8 +316,8 @@ void GPU_viewport_stereo_composite(GPUViewport *viewport, Stereo3dFormat *stereo
 
   immEnd();
 
-  GPU_texture_unbind(dtxl->color_stereo);
-  GPU_texture_unbind(dtxl->color_overlay_stereo);
+  GPU_texture_unbind(viewport->color_render_tx[1]);
+  GPU_texture_unbind(viewport->color_overlay_tx[1]);
 
   immUnbindProgram();
   GPU_matrix_pop_projection();
@@ -747,14 +401,14 @@ static void gpu_viewport_batch_free(GPUViewport *viewport)
 /** \} */
 
 static void gpu_viewport_draw_colormanaged(GPUViewport *viewport,
+                                           int view,
                                            const rctf *rect_pos,
                                            const rctf *rect_uv,
                                            bool display_colorspace,
                                            bool do_overlay_merge)
 {
-  DefaultTextureList *dtxl = viewport->txl;
-  GPUTexture *color = dtxl->color;
-  GPUTexture *color_overlay = dtxl->color_overlay;
+  GPUTexture *color = viewport->color_render_tx[view];
+  GPUTexture *color_overlay = viewport->color_overlay_tx[view];
 
   bool use_ocio = false;
 
@@ -808,12 +462,9 @@ void GPU_viewport_draw_to_screen_ex(GPUViewport *viewport,
                                     bool display_colorspace,
                                     bool do_overlay_merge)
 {
-  gpu_viewport_framebuffer_view_set(viewport, view);
-  DefaultFramebufferList *dfbl = viewport->fbl;
-  DefaultTextureList *dtxl = viewport->txl;
-  GPUTexture *color = dtxl->color;
+  GPUTexture *color = viewport->color_render_tx[view];
 
-  if (dfbl->default_fb == NULL) {
+  if (color == NULL) {
     return;
   }
 
@@ -854,7 +505,7 @@ void GPU_viewport_draw_to_screen_ex(GPUViewport *viewport,
   }
 
   gpu_viewport_draw_colormanaged(
-      viewport, &pos_rect, &uv_rect, display_colorspace, do_overlay_merge);
+      viewport, view, &pos_rect, &uv_rect, display_colorspace, do_overlay_merge);
 }
 
 /**
@@ -877,10 +528,7 @@ void GPU_viewport_unbind_from_offscreen(GPUViewport *viewport,
                                         bool display_colorspace,
                                         bool do_overlay_merge)
 {
-  DefaultFramebufferList *dfbl = viewport->fbl;
-  DefaultTextureList *dtxl = viewport->txl;
-
-  if (dfbl->default_fb == NULL) {
+  if (viewport->color_render_tx == NULL) {
     return;
   }
 
@@ -902,10 +550,10 @@ void GPU_viewport_unbind_from_offscreen(GPUViewport *viewport,
   };
 
   gpu_viewport_draw_colormanaged(
-      viewport, &pos_rect, &uv_rect, display_colorspace, do_overlay_merge);
+      viewport, 0, &pos_rect, &uv_rect, display_colorspace, do_overlay_merge);
 
   /* This one is from the offscreen. Don't free it with the viewport. */
-  dtxl->depth = NULL;
+  viewport->depth_tx = NULL;
 }
 
 void GPU_viewport_unbind(GPUViewport *UNUSED(viewport))
@@ -914,149 +562,53 @@ void GPU_viewport_unbind(GPUViewport *UNUSED(viewport))
   DRW_opengl_context_disable();
 }
 
-GPUTexture *GPU_viewport_color_texture(GPUViewport *viewport, int view)
+int GPU_viewport_active_view_get(GPUViewport *viewport)
 {
-  DefaultFramebufferList *dfbl = viewport->fbl;
-
-  if (dfbl->default_fb) {
-    DefaultTextureList *dtxl = viewport->txl;
-    if (viewport->active_view == view) {
-      return dtxl->color;
-    }
+  return viewport->active_view;
+}
 
-    return dtxl->color_stereo;
-  }
+bool GPU_viewport_is_stereo_get(GPUViewport *viewport)
+{
+  return (viewport->flag & GPU_VIEWPORT_STEREO) != 0;
+}
 
-  return NULL;
+GPUTexture *GPU_viewport_color_texture(GPUViewport *viewport, int view)
+{
+  return viewport->color_render_tx[view];
 }
 
-static void gpu_viewport_buffers_free(
-    FramebufferList *fbl, int fbl_len, TextureList *txl, TextureList *txl_stereo, int txl_len)
+GPUTexture *GPU_viewport_overlay_texture(GPUViewport *viewport, int view)
 {
-  for (int i = 0; i < fbl_len; i++) {
-    GPUFrameBuffer *fb = fbl->framebuffers[i];
-    if (fb) {
-      GPU_framebuffer_free(fb);
-      fbl->framebuffers[i] = NULL;
-    }
-  }
-  for (int i = 0; i < txl_len; i++) {
-    GPUTexture *tex = txl->textures[i];
-    if (tex) {
-      GPU_texture_free(tex);
-      txl->textures[i] = NULL;
-    }
-  }
-  if (txl_stereo != NULL) {
-    for (int i = 0; i < txl_len; i++) {
-      GPUTexture *tex = txl_stereo->textures[i];
-      if (tex) {
-        GPU_texture_free(tex);
-        txl_stereo->textures[i] = NULL;
-      }
-    }
-  }
+  return viewport->color_overlay_tx[view];
 }
 
-static void gpu_viewport_storage_free(StorageList *stl, int stl_len)
+GPUTexture *GPU_viewport_depth_texture(GPUViewport *viewport)
 {
-  for (int i = 0; i < stl_len; i++) {
-    void *storage = stl->storage[i];
-    if (storage) {
-      MEM_freeN(storage);
-      stl->storage[i] = NULL;
-    }
-  }
+  return viewport->depth_tx;
 }
 
-static void gpu_viewport_passes_free(PassList *psl, int psl_len)
+/* Overlay framebuffer for drawing outside of DRW module. */
+GPUFrameBuffer *GPU_viewport_framebuffer_overlay_get(GPUViewport *viewport)
 {
-  memset(psl->passes, 0, sizeof(*psl->passes) * psl_len);
+  GPU_framebuffer_ensure_config(&viewport->overlay_fb,
+                                {
+                                    GPU_ATTACHMENT_TEXTURE(viewport->depth_tx),
+                                    GPU_ATTACHMENT_TEXTURE(viewport->color_overlay_tx[0]),
+                                });
+  return viewport->overlay_fb;
 }
 
 /* Must be executed inside Draw-manager OpenGL Context. */
 void GPU_viewport_free(GPUViewport *viewport)
 {
-  gpu_viewport_engines_data_free(viewport);
-
-  gpu_viewport_buffers_free((FramebufferList *)viewport->fbl,
-                            default_fbl_len,
-                            (TextureList *)viewport->txl,
-                            NULL,
-                            default_txl_len);
-
-  gpu_viewport_texture_pool_free(viewport);
-
-  MEM_freeN(viewport->fbl);
-  MEM_freeN(viewport->txl);
-
-  if (viewport->vmempool.commands != NULL) {
-    BLI_memblock_destroy(viewport->vmempool.commands, NULL);
-  }
-  if (viewport->vmempool.commands_small != NULL) {
-    BLI_memblock_destroy(viewport->vmempool.commands_small, NULL);
-  }
-  if (viewport->vmempool.callbuffers != NULL) {
-    BLI_memblock_destroy(viewport->vmempool.callbuffers, NULL);
-  }
-  if (viewport->vmempool.obmats != NULL) {
-    BLI_memblock_destroy(viewport->vmempool.obmats, NULL);
-  }
-  if (viewport->vmempool.obinfos != NULL) {
-    BLI_memblock_destroy(viewport->vmempool.obinfos, NULL);
-  }
-  if (viewport->vmempool.cullstates != NULL) {
-    BLI_memblock_destroy(viewport->vmempool.cullstates, NULL);
-  }
-  if (viewport->vmempool.shgroups != NULL) {
-    BLI_memblock_destroy(viewport->vmempool.shgroups, NULL);
-  }
-  if (viewport->vmempool.uniforms != NULL) {
-    BLI_memblock_destroy(viewport->vmempool.uniforms, NULL);
-  }
-  if (viewport->vmempool.views != NULL) {
-    BLI_memblock_destroy(viewport->vmempool.views, NULL);
-  }
-  if (viewport->vmempool.passes != NULL) {
-    BLI_memblock_destroy(viewport->vmempool.passes, NULL);
-  }
-  if (viewport->vmempool.images != NULL) {
-    BLI_memblock_iter iter;
-    GPUTexture **tex;
-    BLI_memblock_iternew(viewport->vmempool.images, &iter);
-    while ((tex = BLI_memblock_iterstep(&iter))) {
-      GPU_texture_free(*tex);
-    }
-    BLI_memblock_destroy(viewport->vmempool.images, NULL);
-  }
-  if (viewport->vmempool.obattrs_ubo_pool != NULL) {
-    DRW_uniform_attrs_pool_free(viewport->vmempool.obattrs_ubo_pool);
+  if (viewport->draw_data) {
+    DRW_viewport_data_free(viewport->draw_data);
   }
 
-  for (int i = 0; i < viewport->vmempool.ubo_len; i++) {
-    GPU_uniformbuf_free(viewport->vmempool.matrices_ubo[i]);
-    GPU_uniformbuf_free(viewport->vmempool.obinfos_ubo[i]);
-  }
-  MEM_SAFE_FREE(viewport->vmempool.matrices_ubo);
-  MEM_SAFE_FREE(viewport->vmempool.obinfos_ubo);
-
-  DRW_instance_data_list_free(viewport->idatalist);
-  MEM_freeN(viewport->idatalist);
+  gpu_viewport_textures_free(viewport);
 
   BKE_color_managed_view_settings_free(&viewport->view_settings);
   gpu_viewport_batch_free(viewport);
 
   MEM_freeN(viewport);
 }
-
-GPUFrameBuffer *GPU_viewport_framebuffer_default_get(GPUViewport *viewport)
-{
-  DefaultFramebufferList *fbl = GPU_viewport_framebuffer_list_get(viewport);
-  return fbl->default_fb;
-}
-
-GPUFrameBuffer *GPU_viewport_framebuffer_overlay_get(GPUViewport *viewport)
-{
-  DefaultFramebufferList *fbl = GPU_viewport_framebuffer_list_get(viewport);
-  return fbl->overlay_fb;
-}