Cleanup: Split image engine into ImageEngine, SpaceAccessor and DrawingMode.

Image engine is used to draw an image into a space. The current
structure wasn't clear and couldn't be easilly extended. This refactor
spliced the image draw engine into 3 main components.

- Space accessors: contains an interface to communicate with space data
  (Image editor, UV Editor, Node Editor) in a common way. This reduced
  the branching in the code base.
- DrawingMode: contains an interface to the used tactic to draw an image
  inside the space framebuffer. Currently only one mode is implemented;
  in the future there could be a separate drawing mode for huge images.
- ImageEngine: the core that connects the draw manager with the space
  data and drawing mode.

6 files changed, 676 insertions, 342 deletions

diff --git a/source/blender/draw/engines/image/image_drawing_mode.hh b/source/blender/draw/engines/image/image_drawing_mode.hh
new file mode 100644
index 00000000000..f2f5bbe554c
--- /dev/null
+++ b/source/blender/draw/engines/image/image_drawing_mode.hh
@@ -0,0 +1,154 @@
+/*
+ * 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
+ */
+
+#pragma once
+
+#include "image_private.hh"
+
+namespace blender::draw::image_engine {
+
+class DefaultDrawingMode : public AbstractDrawingMode {
+ private:
+  DRWPass *create_image_pass() const
+  {
+    /* Write depth is needed for background overlay rendering. Near depth is used for
+     * transparency checker and Far depth is used for indicating the image size. */
+    DRWState state = static_cast<DRWState>(DRW_STATE_WRITE_COLOR | DRW_STATE_WRITE_DEPTH |
+                                           DRW_STATE_DEPTH_ALWAYS | DRW_STATE_BLEND_ALPHA_PREMUL);
+    return DRW_pass_create("Image", state);
+  }
+
+  void add_to_shgroup(AbstractSpaceAccessor *space,
+                      DRWShadingGroup *grp,
+                      const Image *image,
+                      const ImBuf *image_buffer) const
+  {
+    float image_mat[4][4];
+
+    const DRWContextState *draw_ctx = DRW_context_state_get();
+    const ARegion *region = draw_ctx->region;
+    space->get_image_mat(image_buffer, region, image_mat);
+
+    GPUBatch *geom = DRW_cache_quad_get();
+
+    const bool is_tiled_texture = image && image->source == IMA_SRC_TILED;
+    if (is_tiled_texture) {
+      const float translate_x = image_mat[3][0];
+      const float translate_y = image_mat[3][1];
+      LISTBASE_FOREACH (ImageTile *, tile, &image->tiles) {
+        const int tile_x = ((tile->tile_number - 1001) % 10);
+        const int tile_y = ((tile->tile_number - 1001) / 10);
+        image_mat[3][0] = (float)tile_x + translate_x;
+        image_mat[3][1] = (float)tile_y + translate_y;
+        DRW_shgroup_call_obmat(grp, geom, image_mat);
+      }
+    }
+    else {
+      DRW_shgroup_call_obmat(grp, geom, image_mat);
+    }
+  }
+
+ public:
+  void cache_init(IMAGE_Data *vedata) const override
+  {
+    IMAGE_PassList *psl = vedata->psl;
+
+    psl->image_pass = create_image_pass();
+  }
+
+  void cache_image(AbstractSpaceAccessor *space,
+                   IMAGE_Data *vedata,
+                   Image *image,
+                   ImageUser *iuser,
+                   ImBuf *image_buffer) const override
+  {
+    IMAGE_PassList *psl = vedata->psl;
+    IMAGE_StorageList *stl = vedata->stl;
+    IMAGE_PrivateData *pd = stl->pd;
+
+    GPUTexture *tex_tile_data = nullptr;
+    space->get_gpu_textures(
+        image, iuser, image_buffer, &pd->texture, &pd->owns_texture, &tex_tile_data);
+    if (pd->texture == nullptr) {
+      return;
+    }
+    const bool is_tiled_texture = tex_tile_data != nullptr;
+
+    ShaderParameters sh_params;
+    sh_params.use_premul_alpha = BKE_image_has_gpu_texture_premultiplied_alpha(image,
+                                                                               image_buffer);
+    const DRWContextState *draw_ctx = DRW_context_state_get();
+    const Scene *scene = draw_ctx->scene;
+    if (scene->camera && scene->camera->type == OB_CAMERA) {
+      Camera *camera = static_cast<Camera *>(scene->camera->data);
+      copy_v2_fl2(sh_params.far_near, camera->clip_end, camera->clip_start);
+    }
+    space->get_shader_parameters(sh_params, image_buffer, is_tiled_texture);
+
+    GPUShader *shader = IMAGE_shader_image_get(is_tiled_texture);
+    DRWShadingGroup *shgrp = DRW_shgroup_create(shader, psl->image_pass);
+    if (is_tiled_texture) {
+      DRW_shgroup_uniform_texture_ex(shgrp, "imageTileArray", pd->texture, GPU_SAMPLER_DEFAULT);
+      DRW_shgroup_uniform_texture(shgrp, "imageTileData", tex_tile_data);
+    }
+    else {
+      DRW_shgroup_uniform_texture_ex(shgrp, "imageTexture", pd->texture, GPU_SAMPLER_DEFAULT);
+    }
+    DRW_shgroup_uniform_vec2_copy(shgrp, "farNearDistances", sh_params.far_near);
+    DRW_shgroup_uniform_vec4_copy(shgrp, "color", ShaderParameters::color);
+    DRW_shgroup_uniform_vec4_copy(shgrp, "shuffle", sh_params.shuffle);
+    DRW_shgroup_uniform_int_copy(shgrp, "drawFlags", sh_params.flags);
+    DRW_shgroup_uniform_bool_copy(shgrp, "imgPremultiplied", sh_params.use_premul_alpha);
+
+    add_to_shgroup(space, shgrp, image, image_buffer);
+  }
+
+  void draw_finish(IMAGE_Data *vedata) const override
+  {
+    IMAGE_StorageList *stl = vedata->stl;
+    IMAGE_PrivateData *pd = stl->pd;
+
+    if (pd->texture && pd->owns_texture) {
+      GPU_texture_free(pd->texture);
+      pd->owns_texture = false;
+    }
+    pd->texture = nullptr;
+  }
+
+  void draw_scene(IMAGE_Data *vedata) const override
+  {
+    IMAGE_PassList *psl = vedata->psl;
+    IMAGE_PrivateData *pd = vedata->stl->pd;
+
+    DefaultFramebufferList *dfbl = DRW_viewport_framebuffer_list_get();
+    GPU_framebuffer_bind(dfbl->default_fb);
+    static float clear_col[4] = {0.0f, 0.0f, 0.0f, 0.0f};
+    GPU_framebuffer_clear_color_depth(dfbl->default_fb, clear_col, 1.0);
+
+    DRW_view_set_active(pd->view);
+    DRW_draw_pass(psl->image_pass);
+    DRW_view_set_active(nullptr);
+  }
+};
+
+}  // namespace blender::draw::image_engine
+
diff --git a/source/blender/draw/engines/image/image_engine.cc b/source/blender/draw/engines/image/image_engine.cc
index 776639f5224..6ccf20ab339 100644
--- a/source/blender/draw/engines/image/image_engine.cc
+++ b/source/blender/draw/engines/image/image_engine.cc
@@ -17,13 +17,16 @@
  */
 
 /** \file
- * \ingroup draw_editors
+ * \ingroup draw_engine
  *
  * Draw engine to draw the Image/UV editor
  */
 
 #include "DRW_render.h"
 
+#include <memory>
+#include <optional>
+
 #include "BKE_image.h"
 #include "BKE_main.h"
 #include "BKE_object.h"
@@ -38,291 +41,89 @@
 
 #include "GPU_batch.h"
 
+#include "image_drawing_mode.hh"
 #include "image_engine.h"
 #include "image_private.hh"
+#include "image_space_image.hh"
+#include "image_space_node.hh"
 
 namespace blender::draw::image_engine {
 
-#define IMAGE_DRAW_FLAG_SHOW_ALPHA (1 << 0)
-#define IMAGE_DRAW_FLAG_APPLY_ALPHA (1 << 1)
-#define IMAGE_DRAW_FLAG_SHUFFLING (1 << 2)
-#define IMAGE_DRAW_FLAG_DEPTH (1 << 3)
-#define IMAGE_DRAW_FLAG_DO_REPEAT (1 << 4)
-#define IMAGE_DRAW_FLAG_USE_WORLD_POS (1 << 5)
-
-static void image_cache_image_add(DRWShadingGroup *grp, Image *image, ImBuf *ibuf)
+static std::unique_ptr<AbstractSpaceAccessor> space_accessor_from_context(
+    const DRWContextState *draw_ctx)
 {
-  const DRWContextState *draw_ctx = DRW_context_state_get();
-  const ARegion *region = draw_ctx->region;
   const char space_type = draw_ctx->space_data->spacetype;
-
-  float zoom_x = 1.0f;
-  float zoom_y = 1.0f;
-  float translate_x = 0.0f;
-  float translate_y = 0.0f;
-
-  /* User can freely move the backdrop in the space of the node editor */
-  if (space_type == SPACE_NODE) {
-    SpaceNode *snode = (SpaceNode *)draw_ctx->space_data;
-    const float ibuf_width = ibuf->x;
-    const float ibuf_height = ibuf->y;
-    const float x = (region->winx - snode->zoom * ibuf_width) / 2 + snode->xof;
-    const float y = (region->winy - snode->zoom * ibuf_height) / 2 + snode->yof;
-
-    zoom_x = ibuf_width * snode->zoom;
-    zoom_y = ibuf_height * snode->zoom;
-    translate_x = x;
-    translate_y = y;
-  }
-
-  const bool is_tiled_texture = image && image->source == IMA_SRC_TILED;
-  float obmat[4][4];
-  unit_m4(obmat);
-
-  GPUBatch *geom = DRW_cache_quad_get();
-
-  obmat[0][0] = zoom_x;
-  obmat[1][1] = zoom_y;
-  obmat[3][1] = translate_y;
-  obmat[3][0] = translate_x;
-
-  if (is_tiled_texture) {
-    LISTBASE_FOREACH (ImageTile *, tile, &image->tiles) {
-      const int tile_x = ((tile->tile_number - 1001) % 10);
-      const int tile_y = ((tile->tile_number - 1001) / 10);
-      obmat[3][1] = (float)tile_y + translate_y;
-      obmat[3][0] = (float)tile_x + translate_x;
-      DRW_shgroup_call_obmat(grp, geom, obmat);
-    }
+  if (space_type == SPACE_IMAGE) {
+    return std::make_unique<SpaceImageAccessor>((SpaceImage *)draw_ctx->space_data);
   }
-  else {
-    DRW_shgroup_call_obmat(grp, geom, obmat);
+  if (space_type == SPACE_NODE) {
+    return std::make_unique<SpaceNodeAccessor>((SpaceNode *)draw_ctx->space_data);
   }
+  BLI_assert_unreachable();
+  return nullptr;
 }
 
-static void space_image_gpu_texture_get(Image *image,
-                                        ImageUser *iuser,
-                                        ImBuf *ibuf,
-                                        GPUTexture **r_gpu_texture,
-                                        bool *r_owns_texture,
-                                        GPUTexture **r_tex_tile_data)
-{
-  const DRWContextState *draw_ctx = DRW_context_state_get();
-  SpaceImage *sima = (SpaceImage *)draw_ctx->space_data;
-  if (image->rr != nullptr) {
-    /* Update multi-index and pass for the current eye. */
-    BKE_image_multilayer_index(image->rr, &sima->iuser);
-  }
-  else {
-    BKE_image_multiview_index(image, &sima->iuser);
-  }
+class ImageEngine {
+ private:
+  const DRWContextState *draw_ctx;
+  IMAGE_Data *vedata;
+  std::unique_ptr<AbstractSpaceAccessor> space;
+  DefaultDrawingMode drawing_mode;
 
-  if (ibuf == nullptr) {
-    return;
+ public:
+  ImageEngine(const DRWContextState *draw_ctx, IMAGE_Data *vedata)
+      : draw_ctx(draw_ctx), vedata(vedata), space(space_accessor_from_context(draw_ctx))
+  {
   }
 
-  if (ibuf->rect == nullptr && ibuf->rect_float == nullptr) {
-    /* This code-path is only supposed to happen when drawing a lazily-allocatable render result.
-     * In all the other cases the `ED_space_image_acquire_buffer()` is expected to return nullptr
-     * as an image buffer when it has no pixels. */
-
-    BLI_assert(image->type == IMA_TYPE_R_RESULT);
-
-    float zero[4] = {0, 0, 0, 0};
-    *r_gpu_texture = GPU_texture_create_2d(__func__, 1, 1, 0, GPU_RGBA16F, zero);
-    *r_owns_texture = true;
-    return;
-  }
+  virtual ~ImageEngine() = default;
 
-  const int sima_flag = sima->flag & ED_space_image_get_display_channel_mask(ibuf);
-  if (sima_flag & SI_SHOW_ZBUF && (ibuf->zbuf || ibuf->zbuf_float || (ibuf->channels == 1))) {
-    if (ibuf->zbuf) {
-      BLI_assert_msg(0, "Integer based depth buffers not supported");
-    }
-    else if (ibuf->zbuf_float) {
-      *r_gpu_texture = GPU_texture_create_2d(
-          __func__, ibuf->x, ibuf->y, 0, GPU_R16F, ibuf->zbuf_float);
-      *r_owns_texture = true;
-    }
-    else if (ibuf->rect_float && ibuf->channels == 1) {
-      *r_gpu_texture = GPU_texture_create_2d(
-          __func__, ibuf->x, ibuf->y, 0, GPU_R16F, ibuf->rect_float);
-      *r_owns_texture = true;
+ private:
+ public:
+  void cache_init()
+  {
+    IMAGE_StorageList *stl = vedata->stl;
+    IMAGE_PrivateData *pd = stl->pd;
+
+    drawing_mode.cache_init(vedata);
+    pd->view = nullptr;
+    if (space->has_view_override()) {
+      const ARegion *region = draw_ctx->region;
+      pd->view = space->create_view_override(region);
     }
   }
-  else if (image->source == IMA_SRC_TILED) {
-    *r_gpu_texture = BKE_image_get_gpu_tiles(image, iuser, ibuf);
-    *r_tex_tile_data = BKE_image_get_gpu_tilemap(image, iuser, nullptr);
-    *r_owns_texture = false;
-  }
-  else {
-    *r_gpu_texture = BKE_image_get_gpu_texture(image, iuser, ibuf);
-    *r_owns_texture = false;
-  }
-}
 
-static void space_node_gpu_texture_get(Image *image,
-                                       ImageUser *iuser,
-                                       ImBuf *ibuf,
-                                       GPUTexture **r_gpu_texture,
-                                       bool *r_owns_texture,
-                                       GPUTexture **r_tex_tile_data)
-{
-  *r_gpu_texture = BKE_image_get_gpu_texture(image, iuser, ibuf);
-  *r_owns_texture = false;
-  *r_tex_tile_data = nullptr;
-}
-
-static void image_gpu_texture_get(Image *image,
-                                  ImageUser *iuser,
-                                  ImBuf *ibuf,
-                                  GPUTexture **r_gpu_texture,
-                                  bool *r_owns_texture,
-                                  GPUTexture **r_tex_tile_data)
-{
-  if (!image) {
-    return;
+  void cache_populate()
+  {
+    IMAGE_StorageList *stl = vedata->stl;
+    IMAGE_PrivateData *pd = stl->pd;
+    Main *bmain = CTX_data_main(draw_ctx->evil_C);
+    pd->image = space->get_image(bmain);
+    if (pd->image == nullptr) {
+      /* Early exit, nothing to draw. */
+      return;
+    }
+    pd->ibuf = space->acquire_image_buffer(pd->image, &pd->lock);
+    ImageUser *iuser = space->get_image_user();
+    drawing_mode.cache_image(space.get(), vedata, pd->image, iuser, pd->ibuf);
   }
 
-  const DRWContextState *draw_ctx = DRW_context_state_get();
-  const char space_type = draw_ctx->space_data->spacetype;
+  void draw_finish()
+  {
+    drawing_mode.draw_finish(vedata);
 
-  if (space_type == SPACE_IMAGE) {
-    space_image_gpu_texture_get(
-        image, iuser, ibuf, r_gpu_texture, r_owns_texture, r_tex_tile_data);
+    IMAGE_StorageList *stl = vedata->stl;
+    IMAGE_PrivateData *pd = stl->pd;
+    space->release_buffer(pd->image, pd->ibuf, pd->lock);
+    pd->image = nullptr;
+    pd->ibuf = nullptr;
   }
-  else if (space_type == SPACE_NODE) {
-    space_node_gpu_texture_get(image, iuser, ibuf, r_gpu_texture, r_owns_texture, r_tex_tile_data);
-  }
-}
-
-static void image_cache_image(IMAGE_Data *vedata, Image *image, ImageUser *iuser, ImBuf *ibuf)
-{
-  IMAGE_PassList *psl = vedata->psl;
-  IMAGE_StorageList *stl = vedata->stl;
-  IMAGE_PrivateData *pd = stl->pd;
-
-  const DRWContextState *draw_ctx = DRW_context_state_get();
-  const char space_type = draw_ctx->space_data->spacetype;
-  const Scene *scene = draw_ctx->scene;
-
-  GPUTexture *tex_tile_data = nullptr;
-  image_gpu_texture_get(image, iuser, ibuf, &pd->texture, &pd->owns_texture, &tex_tile_data);
-
-  if (pd->texture) {
-    static float color[4] = {1.0f, 1.0f, 1.0f, 1.0f};
-    static float shuffle[4] = {1.0f, 1.0f, 1.0f, 1.0f};
-    static float far_near[2] = {100.0f, 0.0f};
-
-    if (scene->camera && scene->camera->type == OB_CAMERA) {
-      far_near[1] = ((Camera *)scene->camera->data)->clip_start;
-      far_near[0] = ((Camera *)scene->camera->data)->clip_end;
-    }
-
-    const bool use_premul_alpha = BKE_image_has_gpu_texture_premultiplied_alpha(image, ibuf);
-    const bool is_tiled_texture = tex_tile_data != nullptr;
-
-    int draw_flags = 0;
-    if (space_type == SPACE_IMAGE) {
-      SpaceImage *sima = (SpaceImage *)draw_ctx->space_data;
-      const int sima_flag = sima->flag & ED_space_image_get_display_channel_mask(ibuf);
-      const bool do_repeat = (!is_tiled_texture) && ((sima->flag & SI_DRAW_TILE) != 0);
-      SET_FLAG_FROM_TEST(draw_flags, do_repeat, IMAGE_DRAW_FLAG_DO_REPEAT);
-      SET_FLAG_FROM_TEST(draw_flags, is_tiled_texture, IMAGE_DRAW_FLAG_USE_WORLD_POS);
-      if ((sima_flag & SI_USE_ALPHA) != 0) {
-        /* Show RGBA */
-        draw_flags |= IMAGE_DRAW_FLAG_SHOW_ALPHA | IMAGE_DRAW_FLAG_APPLY_ALPHA;
-      }
-      else if ((sima_flag & SI_SHOW_ALPHA) != 0) {
-        draw_flags |= IMAGE_DRAW_FLAG_SHUFFLING;
-        copy_v4_fl4(shuffle, 0.0f, 0.0f, 0.0f, 1.0f);
-      }
-      else if ((sima_flag & SI_SHOW_ZBUF) != 0) {
-        draw_flags |= IMAGE_DRAW_FLAG_DEPTH | IMAGE_DRAW_FLAG_SHUFFLING;
-        copy_v4_fl4(shuffle, 1.0f, 0.0f, 0.0f, 0.0f);
-      }
-      else if ((sima_flag & SI_SHOW_R) != 0) {
-        draw_flags |= IMAGE_DRAW_FLAG_SHUFFLING;
-        if (IMB_alpha_affects_rgb(ibuf)) {
-          draw_flags |= IMAGE_DRAW_FLAG_APPLY_ALPHA;
-        }
-        copy_v4_fl4(shuffle, 1.0f, 0.0f, 0.0f, 0.0f);
-      }
-      else if ((sima_flag & SI_SHOW_G) != 0) {
-        draw_flags |= IMAGE_DRAW_FLAG_SHUFFLING;
-        if (IMB_alpha_affects_rgb(ibuf)) {
-          draw_flags |= IMAGE_DRAW_FLAG_APPLY_ALPHA;
-        }
-        copy_v4_fl4(shuffle, 0.0f, 1.0f, 0.0f, 0.0f);
-      }
-      else if ((sima_flag & SI_SHOW_B) != 0) {
-        draw_flags |= IMAGE_DRAW_FLAG_SHUFFLING;
-        if (IMB_alpha_affects_rgb(ibuf)) {
-          draw_flags |= IMAGE_DRAW_FLAG_APPLY_ALPHA;
-        }
-        copy_v4_fl4(shuffle, 0.0f, 0.0f, 1.0f, 0.0f);
-      }
-      else /* RGB */ {
-        if (IMB_alpha_affects_rgb(ibuf)) {
-          draw_flags |= IMAGE_DRAW_FLAG_APPLY_ALPHA;
-        }
-      }
-    }
-    if (space_type == SPACE_NODE) {
-      SpaceNode *snode = (SpaceNode *)draw_ctx->space_data;
-      if ((snode->flag & SNODE_USE_ALPHA) != 0) {
-        /* Show RGBA */
-        draw_flags |= IMAGE_DRAW_FLAG_SHOW_ALPHA | IMAGE_DRAW_FLAG_APPLY_ALPHA;
-      }
-      else if ((snode->flag & SNODE_SHOW_ALPHA) != 0) {
-        draw_flags |= IMAGE_DRAW_FLAG_SHUFFLING;
-        copy_v4_fl4(shuffle, 0.0f, 0.0f, 0.0f, 1.0f);
-      }
-      else if ((snode->flag & SNODE_SHOW_R) != 0) {
-        draw_flags |= IMAGE_DRAW_FLAG_SHUFFLING;
-        if (IMB_alpha_affects_rgb(ibuf)) {
-          draw_flags |= IMAGE_DRAW_FLAG_APPLY_ALPHA;
-        }
-        copy_v4_fl4(shuffle, 1.0f, 0.0f, 0.0f, 0.0f);
-      }
-      else if ((snode->flag & SNODE_SHOW_G) != 0) {
-        draw_flags |= IMAGE_DRAW_FLAG_SHUFFLING;
-        if (IMB_alpha_affects_rgb(ibuf)) {
-          draw_flags |= IMAGE_DRAW_FLAG_APPLY_ALPHA;
-        }
-        copy_v4_fl4(shuffle, 0.0f, 1.0f, 0.0f, 0.0f);
-      }
-      else if ((snode->flag & SNODE_SHOW_B) != 0) {
-        draw_flags |= IMAGE_DRAW_FLAG_SHUFFLING;
-        if (IMB_alpha_affects_rgb(ibuf)) {
-          draw_flags |= IMAGE_DRAW_FLAG_APPLY_ALPHA;
-        }
-        copy_v4_fl4(shuffle, 0.0f, 0.0f, 1.0f, 0.0f);
-      }
-      else /* RGB */ {
-        if (IMB_alpha_affects_rgb(ibuf)) {
-          draw_flags |= IMAGE_DRAW_FLAG_APPLY_ALPHA;
-        }
-      }
-    }
 
-    GPUShader *shader = IMAGE_shader_image_get(is_tiled_texture);
-    DRWShadingGroup *shgrp = DRW_shgroup_create(shader, psl->image_pass);
-    if (is_tiled_texture) {
-      DRW_shgroup_uniform_texture_ex(shgrp, "imageTileArray", pd->texture, GPU_SAMPLER_DEFAULT);
-      DRW_shgroup_uniform_texture(shgrp, "imageTileData", tex_tile_data);
-    }
-    else {
-      DRW_shgroup_uniform_texture_ex(shgrp, "imageTexture", pd->texture, GPU_SAMPLER_DEFAULT);
-    }
-    DRW_shgroup_uniform_vec2_copy(shgrp, "farNearDistances", far_near);
-    DRW_shgroup_uniform_vec4_copy(shgrp, "color", color);
-    DRW_shgroup_uniform_vec4_copy(shgrp, "shuffle", shuffle);
-    DRW_shgroup_uniform_int_copy(shgrp, "drawFlags", draw_flags);
-    DRW_shgroup_uniform_bool_copy(shgrp, "imgPremultiplied", use_premul_alpha);
-    image_cache_image_add(shgrp, image, ibuf);
+  void draw_scene()
+  {
+    drawing_mode.draw_scene(vedata);
   }
-}
+};
 
 /* -------------------------------------------------------------------- */
 /** \name Engine Callbacks
@@ -343,49 +144,12 @@ static void IMAGE_engine_init(void *ved)
   pd->texture = nullptr;
 }
 
-static void IMAGE_cache_init(void *ved)
+static void IMAGE_cache_init(void *vedata)
 {
-  IMAGE_Data *vedata = (IMAGE_Data *)ved;
-  IMAGE_StorageList *stl = vedata->stl;
-  IMAGE_PrivateData *pd = stl->pd;
-  IMAGE_PassList *psl = vedata->psl;
   const DRWContextState *draw_ctx = DRW_context_state_get();
-
-  {
-    /* Write depth is needed for background overlay rendering. Near depth is used for
-     * transparency checker and Far depth is used for indicating the image size. */
-    DRWState state = static_cast<DRWState>(DRW_STATE_WRITE_COLOR | DRW_STATE_WRITE_DEPTH |
-                                           DRW_STATE_DEPTH_ALWAYS | DRW_STATE_BLEND_ALPHA_PREMUL);
-    psl->image_pass = DRW_pass_create("Image", state);
-  }
-
-  const SpaceLink *space_link = draw_ctx->space_data;
-  const char space_type = space_link->spacetype;
-  pd->view = nullptr;
-  if (space_type == SPACE_IMAGE) {
-    SpaceImage *sima = (SpaceImage *)draw_ctx->space_data;
-    Image *image = ED_space_image(sima);
-    ImBuf *ibuf = ED_space_image_acquire_buffer(sima, &pd->lock, 0);
-    image_cache_image(vedata, image, &sima->iuser, ibuf);
-    pd->image = image;
-    pd->ibuf = ibuf;
-  }
-  else if (space_type == SPACE_NODE) {
-    ARegion *region = draw_ctx->region;
-    Main *bmain = CTX_data_main(draw_ctx->evil_C);
-    Image *image = BKE_image_ensure_viewer(bmain, IMA_TYPE_COMPOSITE, "Viewer Node");
-    ImBuf *ibuf = BKE_image_acquire_ibuf(image, nullptr, &pd->lock);
-    {
-      /* Setup a screen pixel view. The backdrop of the node editor doesn't follow the region. */
-      float winmat[4][4], viewmat[4][4];
-      orthographic_m4(viewmat, 0.0, region->winx, 0.0, region->winy, 0.0, 1.0);
-      unit_m4(winmat);
-      pd->view = DRW_view_create(viewmat, winmat, nullptr, nullptr, nullptr);
-    }
-    image_cache_image(vedata, image, nullptr, ibuf);
-    pd->image = image;
-    pd->ibuf = ibuf;
-  }
+  ImageEngine image_engine(draw_ctx, static_cast<IMAGE_Data *>(vedata));
+  image_engine.cache_init();
+  image_engine.cache_populate();
 }
 
 static void IMAGE_cache_populate(void *UNUSED(vedata), Object *UNUSED(ob))
@@ -393,45 +157,12 @@ static void IMAGE_cache_populate(void *UNUSED(vedata), Object *UNUSED(ob))
   /* Function intentional left empty. `cache_populate` is required to be implemented. */
 }
 
-static void image_draw_finish(IMAGE_Data *ved)
+static void IMAGE_draw_scene(void *vedata)
 {
-  IMAGE_Data *vedata = (IMAGE_Data *)ved;
-  IMAGE_StorageList *stl = vedata->stl;
-  IMAGE_PrivateData *pd = stl->pd;
   const DRWContextState *draw_ctx = DRW_context_state_get();
-  const char space_type = draw_ctx->space_data->spacetype;
-  if (space_type == SPACE_IMAGE) {
-    SpaceImage *sima = (SpaceImage *)draw_ctx->space_data;
-    ED_space_image_release_buffer(sima, pd->ibuf, pd->lock);
-  }
-  else if (space_type == SPACE_NODE) {
-    BKE_image_release_ibuf(pd->image, pd->ibuf, pd->lock);
-  }
-  pd->image = nullptr;
-  pd->ibuf = nullptr;
-
-  if (pd->texture && pd->owns_texture) {
-    GPU_texture_free(pd->texture);
-    pd->owns_texture = false;
-  }
-  pd->texture = nullptr;
-}
-
-static void IMAGE_draw_scene(void *ved)
-{
-  IMAGE_Data *vedata = (IMAGE_Data *)ved;
-  IMAGE_PassList *psl = vedata->psl;
-  IMAGE_PrivateData *pd = vedata->stl->pd;
-
-  DefaultFramebufferList *dfbl = DRW_viewport_framebuffer_list_get();
-  GPU_framebuffer_bind(dfbl->default_fb);
-  static float clear_col[4] = {0.0f, 0.0f, 0.0f, 0.0f};
-  GPU_framebuffer_clear_color_depth(dfbl->default_fb, clear_col, 1.0);
-
-  DRW_view_set_active(pd->view);
-  DRW_draw_pass(psl->image_pass);
-  DRW_view_set_active(nullptr);
-  image_draw_finish(vedata);
+  ImageEngine image_engine(draw_ctx, static_cast<IMAGE_Data *>(vedata));
+  image_engine.draw_scene();
+  image_engine.draw_finish();
 }
 
 static void IMAGE_engine_free()
@@ -466,4 +197,3 @@ DrawEngineType draw_engine_image_type = {
     nullptr,               /* store_metadata */
 };
 }
-
diff --git a/source/blender/draw/engines/image/image_engine.h b/source/blender/draw/engines/image/image_engine.h
index ba1e87088f1..feee599971e 100644
--- a/source/blender/draw/engines/image/image_engine.h
+++ b/source/blender/draw/engines/image/image_engine.h
@@ -17,7 +17,7 @@
  */
 
 /** \file
- * \ingroup draw_editors
+ * \ingroup draw_engine
  */
 
 #pragma once
diff --git a/source/blender/draw/engines/image/image_private.hh b/source/blender/draw/engines/image/image_private.hh
index 434e27eff65..be6f5b78806 100644
--- a/source/blender/draw/engines/image/image_private.hh
+++ b/source/blender/draw/engines/image/image_private.hh
@@ -20,10 +20,16 @@
  * \ingroup draw_engine
  */
 
+#pragma once
+
+#include <optional>
+
 /* Forward declarations */
+extern "C" {
 struct GPUTexture;
 struct ImBuf;
 struct Image;
+}
 
 /* *********** LISTS *********** */
 
@@ -57,6 +63,128 @@ struct IMAGE_Data {
   IMAGE_StorageList *stl;
 };
 
+/* Shader parameters. */
+#define IMAGE_DRAW_FLAG_SHOW_ALPHA (1 << 0)
+#define IMAGE_DRAW_FLAG_APPLY_ALPHA (1 << 1)
+#define IMAGE_DRAW_FLAG_SHUFFLING (1 << 2)
+#define IMAGE_DRAW_FLAG_DEPTH (1 << 3)
+#define IMAGE_DRAW_FLAG_DO_REPEAT (1 << 4)
+#define IMAGE_DRAW_FLAG_USE_WORLD_POS (1 << 5)
+
+struct ShaderParameters {
+  constexpr static float color[4] = {1.0f, 1.0f, 1.0f, 1.0f};
+
+  int flags = 0;
+  float shuffle[4];
+  float far_near[2];
+  bool use_premul_alpha = false;
+
+  ShaderParameters()
+  {
+    copy_v4_fl(shuffle, 1.0f);
+    copy_v2_fl2(far_near, 100.0f, 0.0f);
+  }
+};
+
+/**
+ *  Space accessor.
+ *
+ *  Image engine is used to draw the images inside multiple spaces \see SpaceLink.
+ *  The AbstractSpaceAccessor is an interface to communicate with a space.
+ */
+class AbstractSpaceAccessor {
+ public:
+  /**
+   * Return the active image of the space.
+   *
+   * The returned image will be drawn in the space.
+   *
+   * The return value is optional.
+   */
+  virtual Image *get_image(Main *bmain) = 0;
+
+  /**
+   * Return the #ImageUser of the space.
+   *
+   * The return value is optional.
+   */
+  virtual ImageUser *get_image_user() = 0;
+
+  /**
+   * Acquire the image buffer of the image.
+   *
+   * \param image: Image to get the buffer from. Image is the same as returned from the #get_image
+   * member.
+   * \param lock: pointer to a lock object.
+   * \return Image buffer of the given image.
+   */
+  virtual ImBuf *acquire_image_buffer(Image *image, void **lock) = 0;
+
+  /**
+   * Release a previous locked image from #acquire_image_buffer.
+   */
+  virtual void release_buffer(Image *image, ImBuf *image_buffer, void *lock) = 0;
+
+  /**
+   * Update the r_shader_parameters with space specific settings.
+   *
+   * Only update the #ShaderParameters.flags and #ShaderParameters.shuffle. Other parameters
+   * are updated inside the image engine.
+   */
+  virtual void get_shader_parameters(ShaderParameters &r_shader_parameters,
+                                     ImBuf *image_buffer,
+                                     bool is_tiled) = 0;
+
+  /**
+   * Retrieve the gpu textures to draw.
+   */
+  virtual void get_gpu_textures(Image *image,
+                                ImageUser *iuser,
+                                ImBuf *image_buffer,
+                                GPUTexture **r_gpu_texture,
+                                bool *r_owns_texture,
+                                GPUTexture **r_tex_tile_data) = 0;
+
+  /**
+   * Does this space override the view.
+   * When so this member should return true and the create_view_override must return the view to
+   * use during drawing.
+   */
+  virtual bool has_view_override() const = 0;
+
+  /**
+   * Override the view for drawing.
+   * Should match #has_view_override.
+   */
+  virtual DRWView *create_view_override(const ARegion *UNUSED(region)) = 0;
+
+  /**
+   * Initialize the matrix that will be used to draw the image. The matrix will be send as object
+   * matrix to the drawing pipeline.
+   */
+  virtual void get_image_mat(const ImBuf *image_buffer,
+                             const ARegion *region,
+                             float r_mat[4][4]) const = 0;
+};  // namespace blender::draw::image_engine
+
+/**
+ * Abstract class for a drawing mode of the image engine.
+ *
+ * The drawing mode decides how to draw the image on the screen. Each way how to draw would have
+ * its own subclass. For now there is only a single drawing mode. #DefaultDrawingMode.
+ **/
+class AbstractDrawingMode {
+ public:
+  virtual void cache_init(IMAGE_Data *vedata) const = 0;
+  virtual void cache_image(AbstractSpaceAccessor *space,
+                           IMAGE_Data *vedata,
+                           Image *image,
+                           ImageUser *iuser,
+                           ImBuf *image_buffer) const = 0;
+  virtual void draw_scene(IMAGE_Data *vedata) const = 0;
+  virtual void draw_finish(IMAGE_Data *vedata) const = 0;
+};
+
 /* image_shader.c */
 GPUShader *IMAGE_shader_image_get(bool is_tiled_image);
 void IMAGE_shader_library_ensure(void);
diff --git a/source/blender/draw/engines/image/image_space_image.hh b/source/blender/draw/engines/image/image_space_image.hh
new file mode 100644
index 00000000000..9c868dbcd1a
--- /dev/null
+++ b/source/blender/draw/engines/image/image_space_image.hh
@@ -0,0 +1,183 @@
+/*
+ * 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
+ */
+
+#pragma once
+
+#include "image_private.hh"
+
+namespace blender::draw::image_engine {
+
+class SpaceImageAccessor : public AbstractSpaceAccessor {
+  SpaceImage *sima;
+
+ public:
+  SpaceImageAccessor(SpaceImage *sima) : sima(sima)
+  {
+  }
+
+  Image *get_image(Main *UNUSED(bmain)) override
+  {
+    return ED_space_image(sima);
+  }
+
+  ImageUser *get_image_user() override
+  {
+    return &sima->iuser;
+  }
+
+  ImBuf *acquire_image_buffer(Image *UNUSED(image), void **lock) override
+  {
+    return ED_space_image_acquire_buffer(sima, lock, 0);
+  }
+
+  void release_buffer(Image *UNUSED(image), ImBuf *image_buffer, void *lock) override
+  {
+    ED_space_image_release_buffer(sima, image_buffer, lock);
+  }
+
+  void get_shader_parameters(ShaderParameters &r_shader_parameters,
+                             ImBuf *image_buffer,
+                             bool is_tiled) override
+  {
+    const int sima_flag = sima->flag & ED_space_image_get_display_channel_mask(image_buffer);
+    const bool do_repeat = (!is_tiled) && ((sima->flag & SI_DRAW_TILE) != 0);
+    SET_FLAG_FROM_TEST(r_shader_parameters.flags, do_repeat, IMAGE_DRAW_FLAG_DO_REPEAT);
+    SET_FLAG_FROM_TEST(r_shader_parameters.flags, is_tiled, IMAGE_DRAW_FLAG_USE_WORLD_POS);
+    if ((sima_flag & SI_USE_ALPHA) != 0) {
+      /* Show RGBA */
+      r_shader_parameters.flags |= IMAGE_DRAW_FLAG_SHOW_ALPHA | IMAGE_DRAW_FLAG_APPLY_ALPHA;
+    }
+    else if ((sima_flag & SI_SHOW_ALPHA) != 0) {
+      r_shader_parameters.flags |= IMAGE_DRAW_FLAG_SHUFFLING;
+      copy_v4_fl4(r_shader_parameters.shuffle, 0.0f, 0.0f, 0.0f, 1.0f);
+    }
+    else if ((sima_flag & SI_SHOW_ZBUF) != 0) {
+      r_shader_parameters.flags |= IMAGE_DRAW_FLAG_DEPTH | IMAGE_DRAW_FLAG_SHUFFLING;
+      copy_v4_fl4(r_shader_parameters.shuffle, 1.0f, 0.0f, 0.0f, 0.0f);
+    }
+    else if ((sima_flag & SI_SHOW_R) != 0) {
+      r_shader_parameters.flags |= IMAGE_DRAW_FLAG_SHUFFLING;
+      if (IMB_alpha_affects_rgb(image_buffer)) {
+        r_shader_parameters.flags |= IMAGE_DRAW_FLAG_APPLY_ALPHA;
+      }
+      copy_v4_fl4(r_shader_parameters.shuffle, 1.0f, 0.0f, 0.0f, 0.0f);
+    }
+    else if ((sima_flag & SI_SHOW_G) != 0) {
+      r_shader_parameters.flags |= IMAGE_DRAW_FLAG_SHUFFLING;
+      if (IMB_alpha_affects_rgb(image_buffer)) {
+        r_shader_parameters.flags |= IMAGE_DRAW_FLAG_APPLY_ALPHA;
+      }
+      copy_v4_fl4(r_shader_parameters.shuffle, 0.0f, 1.0f, 0.0f, 0.0f);
+    }
+    else if ((sima_flag & SI_SHOW_B) != 0) {
+      r_shader_parameters.flags |= IMAGE_DRAW_FLAG_SHUFFLING;
+      if (IMB_alpha_affects_rgb(image_buffer)) {
+        r_shader_parameters.flags |= IMAGE_DRAW_FLAG_APPLY_ALPHA;
+      }
+      copy_v4_fl4(r_shader_parameters.shuffle, 0.0f, 0.0f, 1.0f, 0.0f);
+    }
+    else /* RGB */ {
+      if (IMB_alpha_affects_rgb(image_buffer)) {
+        r_shader_parameters.flags |= IMAGE_DRAW_FLAG_APPLY_ALPHA;
+      }
+    }
+  }
+
+  bool has_view_override() const override
+  {
+    return false;
+  }
+  DRWView *create_view_override(const ARegion *UNUSED(region)) override
+  {
+    return nullptr;
+  }
+
+  void get_gpu_textures(Image *image,
+                        ImageUser *iuser,
+                        ImBuf *image_buffer,
+                        GPUTexture **r_gpu_texture,
+                        bool *r_owns_texture,
+                        GPUTexture **r_tex_tile_data) override
+  {
+    if (image->rr != nullptr) {
+      /* Update multi-index and pass for the current eye. */
+      BKE_image_multilayer_index(image->rr, iuser);
+    }
+    else {
+      BKE_image_multiview_index(image, iuser);
+    }
+
+    if (image_buffer == nullptr) {
+      return;
+    }
+
+    if (image_buffer->rect == nullptr && image_buffer->rect_float == nullptr) {
+      /* This code-path is only supposed to happen when drawing a lazily-allocatable render result.
+       * In all the other cases the `ED_space_image_acquire_buffer()` is expected to return nullptr
+       * as an image buffer when it has no pixels. */
+
+      BLI_assert(image->type == IMA_TYPE_R_RESULT);
+
+      float zero[4] = {0, 0, 0, 0};
+      *r_gpu_texture = GPU_texture_create_2d(__func__, 1, 1, 0, GPU_RGBA16F, zero);
+      *r_owns_texture = true;
+      return;
+    }
+
+    const int sima_flag = sima->flag & ED_space_image_get_display_channel_mask(image_buffer);
+    if (sima_flag & SI_SHOW_ZBUF &&
+        (image_buffer->zbuf || image_buffer->zbuf_float || (image_buffer->channels == 1))) {
+      if (image_buffer->zbuf) {
+        BLI_assert_msg(0, "Integer based depth buffers not supported");
+      }
+      else if (image_buffer->zbuf_float) {
+        *r_gpu_texture = GPU_texture_create_2d(
+            __func__, image_buffer->x, image_buffer->y, 0, GPU_R16F, image_buffer->zbuf_float);
+        *r_owns_texture = true;
+      }
+      else if (image_buffer->rect_float && image_buffer->channels == 1) {
+        *r_gpu_texture = GPU_texture_create_2d(
+            __func__, image_buffer->x, image_buffer->y, 0, GPU_R16F, image_buffer->rect_float);
+        *r_owns_texture = true;
+      }
+    }
+    else if (image->source == IMA_SRC_TILED) {
+      *r_gpu_texture = BKE_image_get_gpu_tiles(image, iuser, image_buffer);
+      *r_tex_tile_data = BKE_image_get_gpu_tilemap(image, iuser, nullptr);
+      *r_owns_texture = false;
+    }
+    else {
+      *r_gpu_texture = BKE_image_get_gpu_texture(image, iuser, image_buffer);
+      *r_owns_texture = false;
+    }
+  }
+
+  void get_image_mat(const ImBuf *UNUSED(image_buffer),
+                     const ARegion *UNUSED(region),
+                     float r_mat[4][4]) const override
+  {
+    unit_m4(r_mat);
+  }
+};
+
+}  // namespace blender::draw::image_engine
+
diff --git a/source/blender/draw/engines/image/image_space_node.hh b/source/blender/draw/engines/image/image_space_node.hh
new file mode 100644
index 00000000000..e70aaaebf84
--- /dev/null
+++ b/source/blender/draw/engines/image/image_space_node.hh
@@ -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
+ */
+
+#pragma once
+
+#include "image_private.hh"
+
+namespace blender::draw::image_engine {
+
+class SpaceNodeAccessor : public AbstractSpaceAccessor {
+  SpaceNode *snode;
+
+ public:
+  SpaceNodeAccessor(SpaceNode *snode) : snode(snode)
+  {
+  }
+
+  Image *get_image(Main *bmain) override
+  {
+    return BKE_image_ensure_viewer(bmain, IMA_TYPE_COMPOSITE, "Viewer Node");
+  }
+
+  ImageUser *get_image_user() override
+  {
+    return nullptr;
+  }
+
+  ImBuf *acquire_image_buffer(Image *image, void **lock) override
+  {
+    return BKE_image_acquire_ibuf(image, nullptr, lock);
+  }
+
+  void release_buffer(Image *image, ImBuf *ibuf, void *lock) override
+  {
+    BKE_image_release_ibuf(image, ibuf, lock);
+  }
+
+  bool has_view_override() const override
+  {
+    return true;
+  }
+
+  DRWView *create_view_override(const ARegion *region) override
+  {
+    /* Setup a screen pixel view. The backdrop of the node editor doesn't follow the region. */
+    float winmat[4][4], viewmat[4][4];
+    orthographic_m4(viewmat, 0.0, region->winx, 0.0, region->winy, 0.0, 1.0);
+    unit_m4(winmat);
+    return DRW_view_create(viewmat, winmat, nullptr, nullptr, nullptr);
+  }
+
+  void get_shader_parameters(ShaderParameters &r_shader_parameters,
+                             ImBuf *ibuf,
+                             bool UNUSED(is_tiled)) override
+  {
+    if ((snode->flag & SNODE_USE_ALPHA) != 0) {
+      /* Show RGBA */
+      r_shader_parameters.flags |= IMAGE_DRAW_FLAG_SHOW_ALPHA | IMAGE_DRAW_FLAG_APPLY_ALPHA;
+    }
+    else if ((snode->flag & SNODE_SHOW_ALPHA) != 0) {
+      r_shader_parameters.flags |= IMAGE_DRAW_FLAG_SHUFFLING;
+      copy_v4_fl4(r_shader_parameters.shuffle, 0.0f, 0.0f, 0.0f, 1.0f);
+    }
+    else if ((snode->flag & SNODE_SHOW_R) != 0) {
+      r_shader_parameters.flags |= IMAGE_DRAW_FLAG_SHUFFLING;
+      if (IMB_alpha_affects_rgb(ibuf)) {
+        r_shader_parameters.flags |= IMAGE_DRAW_FLAG_APPLY_ALPHA;
+      }
+      copy_v4_fl4(r_shader_parameters.shuffle, 1.0f, 0.0f, 0.0f, 0.0f);
+    }
+    else if ((snode->flag & SNODE_SHOW_G) != 0) {
+      r_shader_parameters.flags |= IMAGE_DRAW_FLAG_SHUFFLING;
+      if (IMB_alpha_affects_rgb(ibuf)) {
+        r_shader_parameters.flags |= IMAGE_DRAW_FLAG_APPLY_ALPHA;
+      }
+      copy_v4_fl4(r_shader_parameters.shuffle, 0.0f, 1.0f, 0.0f, 0.0f);
+    }
+    else if ((snode->flag & SNODE_SHOW_B) != 0) {
+      r_shader_parameters.flags |= IMAGE_DRAW_FLAG_SHUFFLING;
+      if (IMB_alpha_affects_rgb(ibuf)) {
+        r_shader_parameters.flags |= IMAGE_DRAW_FLAG_APPLY_ALPHA;
+      }
+      copy_v4_fl4(r_shader_parameters.shuffle, 0.0f, 0.0f, 1.0f, 0.0f);
+    }
+    else /* RGB */ {
+      if (IMB_alpha_affects_rgb(ibuf)) {
+        r_shader_parameters.flags |= IMAGE_DRAW_FLAG_APPLY_ALPHA;
+      }
+    }
+  }
+
+  void get_gpu_textures(Image *image,
+                        ImageUser *iuser,
+                        ImBuf *ibuf,
+                        GPUTexture **r_gpu_texture,
+                        bool *r_owns_texture,
+                        GPUTexture **r_tex_tile_data) override
+  {
+    *r_gpu_texture = BKE_image_get_gpu_texture(image, iuser, ibuf);
+    *r_owns_texture = false;
+    *r_tex_tile_data = nullptr;
+  }
+
+  void get_image_mat(const ImBuf *image_buffer,
+                     const ARegion *region,
+                     float r_mat[4][4]) const override
+  {
+    unit_m4(r_mat);
+    const float ibuf_width = image_buffer->x;
+    const float ibuf_height = image_buffer->y;
+
+    r_mat[0][0] = ibuf_width * snode->zoom;
+    r_mat[1][1] = ibuf_height * snode->zoom;
+    r_mat[3][0] = (region->winx - snode->zoom * ibuf_width) / 2 + snode->xof;
+    r_mat[3][1] = (region->winy - snode->zoom * ibuf_height) / 2 + snode->yof;
+  }
+};
+
+}  // namespace blender::draw::image_engine
+