DRW: Refactor: Use DRWCall to accumulate per instance attributes

This is a big change that cleanup a lot of confusing code.
- The instancing/batching data buffer distribution in draw_instance_data.c.
- The selection & drawing code in draw_manager_exec.c
- Prety much every non-meshes object drawing (object_mode.c).

Most of the changes are just renaming but there still a chance a typo might
have sneek through.

The Batching/Instancing Shading groups are replace by DRWCallBuffers. This
is cleaner and conceptually more in line with what a DRWShadingGroup should
be.

There is still some little confusion in draw_common.c where some function
takes shgroup as input and some don't.

1 files changed, 110 insertions, 222 deletions

diff --git a/source/blender/draw/intern/draw_manager_data.c b/source/blender/draw/intern/draw_manager_data.c
index 3a10543c8ef..151ab469e59 100644
--- a/source/blender/draw/intern/draw_manager_data.c
+++ b/source/blender/draw/intern/draw_manager_data.c
@@ -43,8 +43,6 @@
 
 #include "intern/gpu_codegen.h"
 
-struct GPUVertFormat *g_pos_format = NULL;
-
 /* -------------------------------------------------------------------- */
 /** \name Uniform Buffer Object (DRW_uniformbuffer)
  * \{ */
@@ -453,7 +451,6 @@ static DRWCallState *drw_call_state_object(DRWShadingGroup *shgroup, float (*obm
 void DRW_shgroup_call_add(DRWShadingGroup *shgroup, GPUBatch *geom, float (*obmat)[4])
 {
   BLI_assert(geom != NULL);
-  BLI_assert(ELEM(shgroup->type, DRW_SHG_NORMAL, DRW_SHG_FEEDBACK_TRANSFORM));
 
   DRWCall *call = BLI_memblock_alloc(DST.vmempool->calls);
   BLI_LINKS_APPEND(&shgroup->calls, call);
@@ -465,6 +462,7 @@ void DRW_shgroup_call_add(DRWShadingGroup *shgroup, GPUBatch *geom, float (*obma
   call->inst_count = 0;
 #ifdef USE_GPU_SELECT
   call->select_id = DST.select_id;
+  call->inst_selectid = NULL;
 #endif
 }
 
@@ -472,7 +470,6 @@ void DRW_shgroup_call_range_add(
     DRWShadingGroup *shgroup, GPUBatch *geom, float (*obmat)[4], uint v_sta, uint v_count)
 {
   BLI_assert(geom != NULL);
-  BLI_assert(ELEM(shgroup->type, DRW_SHG_NORMAL, DRW_SHG_FEEDBACK_TRANSFORM));
   BLI_assert(v_count);
 
   DRWCall *call = BLI_memblock_alloc(DST.vmempool->calls);
@@ -485,6 +482,7 @@ void DRW_shgroup_call_range_add(
   call->inst_count = 0;
 #ifdef USE_GPU_SELECT
   call->select_id = DST.select_id;
+  call->inst_selectid = NULL;
 #endif
 }
 
@@ -493,7 +491,6 @@ static void drw_shgroup_call_procedural_add_ex(DRWShadingGroup *shgroup,
                                                uint vert_count,
                                                float (*obmat)[4])
 {
-  BLI_assert(ELEM(shgroup->type, DRW_SHG_NORMAL, DRW_SHG_FEEDBACK_TRANSFORM));
 
   DRWCall *call = BLI_memblock_alloc(DST.vmempool->calls);
   BLI_LINKS_APPEND(&shgroup->calls, call);
@@ -505,6 +502,7 @@ static void drw_shgroup_call_procedural_add_ex(DRWShadingGroup *shgroup,
   call->inst_count = 0;
 #ifdef USE_GPU_SELECT
   call->select_id = DST.select_id;
+  call->inst_selectid = NULL;
 #endif
 }
 
@@ -539,7 +537,6 @@ void DRW_shgroup_call_object_add_ex(DRWShadingGroup *shgroup,
                                     bool bypass_culling)
 {
   BLI_assert(geom != NULL);
-  BLI_assert(ELEM(shgroup->type, DRW_SHG_NORMAL, DRW_SHG_FEEDBACK_TRANSFORM));
 
   DRWCall *call = BLI_memblock_alloc(DST.vmempool->calls);
   BLI_LINKS_APPEND(&shgroup->calls, call);
@@ -553,6 +550,7 @@ void DRW_shgroup_call_object_add_ex(DRWShadingGroup *shgroup,
   call->inst_count = 0;
 #ifdef USE_GPU_SELECT
   call->select_id = DST.select_id;
+  call->inst_selectid = NULL;
 #endif
 }
 
@@ -563,7 +561,6 @@ void DRW_shgroup_call_object_add_with_callback(DRWShadingGroup *shgroup,
                                                void *user_data)
 {
   BLI_assert(geom != NULL);
-  BLI_assert(ELEM(shgroup->type, DRW_SHG_NORMAL, DRW_SHG_FEEDBACK_TRANSFORM));
 
   DRWCall *call = BLI_memblock_alloc(DST.vmempool->calls);
   BLI_LINKS_APPEND(&shgroup->calls, call);
@@ -577,6 +574,7 @@ void DRW_shgroup_call_object_add_with_callback(DRWShadingGroup *shgroup,
   call->inst_count = 0;
 #ifdef USE_GPU_SELECT
   call->select_id = DST.select_id;
+  call->inst_selectid = NULL;
 #endif
 }
 
@@ -586,7 +584,6 @@ void DRW_shgroup_call_instances_add(DRWShadingGroup *shgroup,
                                     uint count)
 {
   BLI_assert(geom != NULL);
-  BLI_assert(ELEM(shgroup->type, DRW_SHG_NORMAL, DRW_SHG_FEEDBACK_TRANSFORM));
 
   DRWCall *call = BLI_memblock_alloc(DST.vmempool->calls);
   BLI_LINKS_APPEND(&shgroup->calls, call);
@@ -598,6 +595,31 @@ void DRW_shgroup_call_instances_add(DRWShadingGroup *shgroup,
   call->inst_count = count;
 #ifdef USE_GPU_SELECT
   call->select_id = DST.select_id;
+  call->inst_selectid = NULL;
+#endif
+}
+
+void DRW_shgroup_call_instances_with_attribs_add(DRWShadingGroup *shgroup,
+                                                 struct GPUBatch *geom,
+                                                 float (*obmat)[4],
+                                                 struct GPUBatch *inst_attributes)
+{
+  BLI_assert(geom != NULL);
+  BLI_assert(inst_attributes->verts[0] != NULL);
+
+  GPUVertBuf *buf_inst = inst_attributes->verts[0];
+
+  DRWCall *call = BLI_memblock_alloc(DST.vmempool->calls);
+  BLI_LINKS_APPEND(&shgroup->calls, call);
+
+  call->state = drw_call_state_create(shgroup, obmat, NULL);
+  call->batch = DRW_temp_batch_instance_request(DST.idatalist, buf_inst, geom);
+  call->vert_first = 0;
+  call->vert_count = 0; /* Auto from batch. */
+  call->inst_count = buf_inst->vertex_len;
+#ifdef USE_GPU_SELECT
+  call->select_id = DST.select_id;
+  call->inst_selectid = NULL;
 #endif
 }
 
@@ -741,30 +763,95 @@ void DRW_shgroup_call_sculpt_with_materials_add(DRWShadingGroup **shgroups,
   drw_sculpt_generate_calls(&scd, use_vcol);
 }
 
-void DRW_shgroup_call_dynamic_add_array(DRWShadingGroup *shgroup,
-                                        const void *attr[],
-                                        uint attr_len)
+static GPUVertFormat inst_select_format = {0};
+
+DRWCallBuffer *DRW_shgroup_call_buffer_add(DRWShadingGroup *shgroup,
+                                           struct GPUVertFormat *format,
+                                           GPUPrimType prim_type)
+{
+  BLI_assert(ELEM(prim_type, GPU_PRIM_POINTS, GPU_PRIM_LINES, GPU_PRIM_TRI_FAN));
+  BLI_assert(format != NULL);
+
+  DRWCall *call = BLI_memblock_alloc(DST.vmempool->calls);
+  BLI_LINKS_APPEND(&shgroup->calls, call);
+
+  call->state = drw_call_state_create(shgroup, NULL, NULL);
+  GPUVertBuf *buf = DRW_temp_buffer_request(DST.idatalist, format, &call->vert_count);
+  call->batch = DRW_temp_batch_request(DST.idatalist, buf, prim_type);
+  call->vert_first = 0;
+  call->vert_count = 0;
+  call->inst_count = 0;
+
+#ifdef USE_GPU_SELECT
+  if (G.f & G_FLAG_PICKSEL) {
+    /* Not actually used for rendering but alloced in one chunk. */
+    if (inst_select_format.attr_len == 0) {
+      GPU_vertformat_attr_add(&inst_select_format, "selectId", GPU_COMP_I32, 1, GPU_FETCH_INT);
+    }
+    call->inst_selectid = DRW_temp_buffer_request(
+        DST.idatalist, &inst_select_format, &call->vert_count);
+  }
+#endif
+  return (DRWCallBuffer *)call;
+}
+
+DRWCallBuffer *DRW_shgroup_call_buffer_instance_add(DRWShadingGroup *shgroup,
+                                                    struct GPUVertFormat *format,
+                                                    GPUBatch *geom)
 {
+  BLI_assert(geom != NULL);
+  BLI_assert(format != NULL);
+
+  DRWCall *call = BLI_memblock_alloc(DST.vmempool->calls);
+  BLI_LINKS_APPEND(&shgroup->calls, call);
+
+  call->state = drw_call_state_create(shgroup, NULL, NULL);
+  GPUVertBuf *buf = DRW_temp_buffer_request(DST.idatalist, format, &call->inst_count);
+  call->batch = DRW_temp_batch_instance_request(DST.idatalist, buf, geom);
+  call->vert_first = 0;
+  call->vert_count = 0; /* Auto from batch. */
+  call->inst_count = 0;
+
 #ifdef USE_GPU_SELECT
   if (G.f & G_FLAG_PICKSEL) {
-    if (shgroup->instance_count == shgroup->inst_selectid->vertex_len) {
-      GPU_vertbuf_data_resize(shgroup->inst_selectid, shgroup->instance_count + 32);
+    /* Not actually used for rendering but alloced in one chunk. */
+    if (inst_select_format.attr_len == 0) {
+      GPU_vertformat_attr_add(&inst_select_format, "selectId", GPU_COMP_I32, 1, GPU_FETCH_INT);
     }
-    GPU_vertbuf_attr_set(shgroup->inst_selectid, 0, shgroup->instance_count, &DST.select_id);
+    call->inst_selectid = DRW_temp_buffer_request(
+        DST.idatalist, &inst_select_format, &call->inst_count);
   }
 #endif
+  return (DRWCallBuffer *)call;
+}
 
-  BLI_assert(attr_len == shgroup->attrs_count);
+void DRW_buffer_add_entry_array(DRWCallBuffer *callbuf, const void *attr[], uint attr_len)
+{
+  DRWCall *call = (DRWCall *)callbuf;
+  const bool is_instance = call->batch->inst != NULL;
+  GPUVertBuf *buf = is_instance ? call->batch->inst : call->batch->verts[0];
+  uint count = is_instance ? call->inst_count++ : call->vert_count++;
+  const bool resize = (count == buf->vertex_alloc);
+
+  BLI_assert(attr_len == buf->format.attr_len);
   UNUSED_VARS_NDEBUG(attr_len);
 
+  if (UNLIKELY(resize)) {
+    GPU_vertbuf_data_resize(buf, count + DRW_BUFFER_VERTS_CHUNK);
+  }
+
   for (int i = 0; i < attr_len; ++i) {
-    if (shgroup->instance_count == shgroup->instance_vbo->vertex_len) {
-      GPU_vertbuf_data_resize(shgroup->instance_vbo, shgroup->instance_count + 32);
-    }
-    GPU_vertbuf_attr_set(shgroup->instance_vbo, i, shgroup->instance_count, attr[i]);
+    GPU_vertbuf_attr_set(buf, i, count, attr[i]);
   }
 
-  shgroup->instance_count += 1;
+#ifdef USE_GPU_SELECT
+  if (G.f & G_FLAG_PICKSEL) {
+    if (UNLIKELY(resize)) {
+      GPU_vertbuf_data_resize(call->inst_selectid, count + DRW_BUFFER_VERTS_CHUNK);
+    }
+    GPU_vertbuf_attr_set(call->inst_selectid, 0, count, &DST.select_id);
+  }
+#endif
 }
 
 /** \} */
@@ -775,17 +862,7 @@ void DRW_shgroup_call_dynamic_add_array(DRWShadingGroup *shgroup,
 
 static void drw_shgroup_init(DRWShadingGroup *shgroup, GPUShader *shader)
 {
-  shgroup->instance_geom = NULL;
-  shgroup->instance_vbo = NULL;
-  shgroup->instance_count = 0;
   shgroup->uniforms = NULL;
-#ifdef USE_GPU_SELECT
-  shgroup->inst_selectid = NULL;
-  shgroup->override_selectid = -1;
-#endif
-#ifndef NDEBUG
-  shgroup->attrs_count = 0;
-#endif
 
   int view_ubo_location = GPU_shader_get_uniform_block(shader, "viewBlock");
 
@@ -817,6 +894,7 @@ static void drw_shgroup_init(DRWShadingGroup *shgroup, GPUShader *shader)
   /* Not supported. */
   BLI_assert(GPU_shader_get_builtin_uniform(shader, GPU_UNIFORM_MODELVIEW_INV) == -1);
   BLI_assert(GPU_shader_get_builtin_uniform(shader, GPU_UNIFORM_MODELVIEW) == -1);
+  BLI_assert(GPU_shader_get_builtin_uniform(shader, GPU_UNIFORM_NORMAL) == -1);
 
   shgroup->model = GPU_shader_get_builtin_uniform(shader, GPU_UNIFORM_MODEL);
   shgroup->modelinverse = GPU_shader_get_builtin_uniform(shader, GPU_UNIFORM_MODEL_INV);
@@ -825,9 +903,6 @@ static void drw_shgroup_init(DRWShadingGroup *shgroup, GPUShader *shader)
   shgroup->objectinfo = GPU_shader_get_builtin_uniform(shader, GPU_UNIFORM_OBJECT_INFO);
   shgroup->callid = GPU_shader_get_builtin_uniform(shader, GPU_UNIFORM_CALLID);
 
-  /* We do not support normal matrix anymore. */
-  BLI_assert(GPU_shader_get_builtin_uniform(shader, GPU_UNIFORM_NORMAL) == -1);
-
   shgroup->matflag = 0;
   if (shgroup->modelinverse > -1) {
     shgroup->matflag |= DRW_CALL_MODELINVERSE;
@@ -843,113 +918,19 @@ static void drw_shgroup_init(DRWShadingGroup *shgroup, GPUShader *shader)
   }
 }
 
-static void drw_shgroup_instance_init(DRWShadingGroup *shgroup,
-                                      GPUShader *shader,
-                                      GPUBatch *batch,
-                                      GPUVertFormat *format)
-{
-  BLI_assert(shgroup->type == DRW_SHG_INSTANCE);
-  BLI_assert(batch != NULL);
-  BLI_assert(format != NULL);
-
-  drw_shgroup_init(shgroup, shader);
-
-  shgroup->instance_geom = batch;
-#ifndef NDEBUG
-  shgroup->attrs_count = format->attr_len;
-#endif
-
-  DRW_instancing_buffer_request(
-      DST.idatalist, format, batch, shgroup, &shgroup->instance_geom, &shgroup->instance_vbo);
-
-#ifdef USE_GPU_SELECT
-  if (G.f & G_FLAG_PICKSEL) {
-    /* Not actually used for rendering but alloced in one chunk.
-     * Plus we don't have to care about ownership. */
-    static GPUVertFormat inst_select_format = {0};
-    if (inst_select_format.attr_len == 0) {
-      GPU_vertformat_attr_add(&inst_select_format, "selectId", GPU_COMP_I32, 1, GPU_FETCH_INT);
-    }
-    GPUBatch *batch_dummy; /* Not used */
-    DRW_batching_buffer_request(DST.idatalist,
-                                &inst_select_format,
-                                GPU_PRIM_POINTS,
-                                shgroup,
-                                &batch_dummy,
-                                &shgroup->inst_selectid);
-  }
-#endif
-}
-
-static void drw_shgroup_batching_init(DRWShadingGroup *shgroup,
-                                      GPUShader *shader,
-                                      GPUVertFormat *format)
-{
-  drw_shgroup_init(shgroup, shader);
-
-#ifndef NDEBUG
-  shgroup->attrs_count = (format != NULL) ? format->attr_len : 0;
-#endif
-  BLI_assert(format != NULL);
-
-  GPUPrimType type;
-  switch (shgroup->type) {
-    case DRW_SHG_POINT_BATCH:
-      type = GPU_PRIM_POINTS;
-      break;
-    case DRW_SHG_LINE_BATCH:
-      type = GPU_PRIM_LINES;
-      break;
-    case DRW_SHG_TRIANGLE_BATCH:
-      type = GPU_PRIM_TRIS;
-      break;
-    default:
-      type = GPU_PRIM_NONE;
-      BLI_assert(0);
-      break;
-  }
-
-  DRW_batching_buffer_request(
-      DST.idatalist, format, type, shgroup, &shgroup->batch_geom, &shgroup->batch_vbo);
-
-#ifdef USE_GPU_SELECT
-  if (G.f & G_FLAG_PICKSEL) {
-    /* Not actually used for rendering but alloced in one chunk. */
-    static GPUVertFormat inst_select_format = {0};
-    if (inst_select_format.attr_len == 0) {
-      GPU_vertformat_attr_add(&inst_select_format, "selectId", GPU_COMP_I32, 1, GPU_FETCH_INT);
-    }
-    GPUBatch *batch; /* Not used */
-    DRW_batching_buffer_request(DST.idatalist,
-                                &inst_select_format,
-                                GPU_PRIM_POINTS,
-                                shgroup,
-                                &batch,
-                                &shgroup->inst_selectid);
-  }
-#endif
-}
-
 static DRWShadingGroup *drw_shgroup_create_ex(struct GPUShader *shader, DRWPass *pass)
 {
   DRWShadingGroup *shgroup = BLI_memblock_alloc(DST.vmempool->shgroups);
 
   BLI_LINKS_APPEND(&pass->shgroups, shgroup);
 
-  shgroup->type = DRW_SHG_NORMAL;
   shgroup->shader = shader;
   shgroup->state_extra = 0;
   shgroup->state_extra_disable = ~0x0;
   shgroup->stencil_mask = 0;
   shgroup->calls.first = NULL;
   shgroup->calls.last = NULL;
-#if 0 /* All the same in the union! */
-  shgroup->batch_geom = NULL;
-  shgroup->batch_vbo = NULL;
-
-  shgroup->instance_geom = NULL;
-  shgroup->instance_vbo = NULL;
-#endif
+  shgroup->tfeedback_target = NULL;
   shgroup->pass_parent = pass;
 
   return shgroup;
@@ -1034,7 +1015,6 @@ DRWShadingGroup *DRW_shgroup_material_create(struct GPUMaterial *material, DRWPa
     drw_shgroup_init(shgroup, GPU_pass_shader_get(gpupass));
     drw_shgroup_material_inputs(shgroup, material);
   }
-
   return shgroup;
 }
 
@@ -1045,96 +1025,18 @@ DRWShadingGroup *DRW_shgroup_create(struct GPUShader *shader, DRWPass *pass)
   return shgroup;
 }
 
-DRWShadingGroup *DRW_shgroup_instance_create(struct GPUShader *shader,
-                                             DRWPass *pass,
-                                             GPUBatch *geom,
-                                             GPUVertFormat *format)
-{
-  DRWShadingGroup *shgroup = drw_shgroup_create_ex(shader, pass);
-  shgroup->type = DRW_SHG_INSTANCE;
-  shgroup->instance_geom = geom;
-  drw_call_calc_orco(NULL, shgroup->instance_orcofac);
-  drw_shgroup_instance_init(shgroup, shader, geom, format);
-
-  return shgroup;
-}
-
-DRWShadingGroup *DRW_shgroup_point_batch_create(struct GPUShader *shader, DRWPass *pass)
-{
-  DRW_shgroup_instance_format(g_pos_format, {{"pos", DRW_ATTR_FLOAT, 3}});
-
-  DRWShadingGroup *shgroup = drw_shgroup_create_ex(shader, pass);
-  shgroup->type = DRW_SHG_POINT_BATCH;
-
-  drw_shgroup_batching_init(shgroup, shader, g_pos_format);
-
-  return shgroup;
-}
-
-DRWShadingGroup *DRW_shgroup_line_batch_create_with_format(struct GPUShader *shader,
-                                                           DRWPass *pass,
-                                                           GPUVertFormat *format)
-{
-  DRWShadingGroup *shgroup = drw_shgroup_create_ex(shader, pass);
-  shgroup->type = DRW_SHG_LINE_BATCH;
-
-  drw_shgroup_batching_init(shgroup, shader, format);
-
-  return shgroup;
-}
-
-DRWShadingGroup *DRW_shgroup_line_batch_create(struct GPUShader *shader, DRWPass *pass)
-{
-  DRW_shgroup_instance_format(g_pos_format, {{"pos", DRW_ATTR_FLOAT, 3}});
-
-  return DRW_shgroup_line_batch_create_with_format(shader, pass, g_pos_format);
-}
-
 DRWShadingGroup *DRW_shgroup_transform_feedback_create(struct GPUShader *shader,
                                                        DRWPass *pass,
                                                        GPUVertBuf *tf_target)
 {
   BLI_assert(tf_target != NULL);
   DRWShadingGroup *shgroup = drw_shgroup_create_ex(shader, pass);
-  shgroup->type = DRW_SHG_FEEDBACK_TRANSFORM;
-
   drw_shgroup_init(shgroup, shader);
-
   shgroup->tfeedback_target = tf_target;
-
   return shgroup;
 }
 
 /**
- * Specify an external batch instead of adding each attribute one by one.
- */
-void DRW_shgroup_instance_batch(DRWShadingGroup *shgroup, struct GPUBatch *batch)
-{
-  BLI_assert(shgroup->type == DRW_SHG_INSTANCE);
-  BLI_assert(shgroup->instance_count == 0);
-  /* You cannot use external instancing batch without a dummy format. */
-  BLI_assert(shgroup->attrs_count != 0);
-
-  shgroup->type = DRW_SHG_INSTANCE_EXTERNAL;
-  drw_call_calc_orco(NULL, shgroup->instance_orcofac);
-  /* PERF : This destroys the vaos cache so better check if it's necessary. */
-  /* Note: This WILL break if batch->verts[0] is destroyed and reallocated
-   * at the same address. Bindings/VAOs would remain obsolete. */
-  // if (shgroup->instancing_geom->inst != batch->verts[0])
-  /* XXX FIXME: THIS IS BROKEN BECAUSE OVEWRITTEN BY DRW_instance_buffer_finish(). */
-  GPU_batch_instbuf_set(shgroup->instance_geom, batch->verts[0], false);
-
-#ifdef USE_GPU_SELECT
-  shgroup->override_selectid = DST.select_id;
-#endif
-}
-
-uint DRW_shgroup_get_instance_count(const DRWShadingGroup *shgroup)
-{
-  return shgroup->instance_count;
-}
-
-/**
  * State is added to #Pass.state while drawing.
  * Use to temporarily enable draw options.
  */
@@ -1156,26 +1058,12 @@ void DRW_shgroup_stencil_mask(DRWShadingGroup *shgroup, uint mask)
 
 bool DRW_shgroup_is_empty(DRWShadingGroup *shgroup)
 {
-  switch (shgroup->type) {
-    case DRW_SHG_NORMAL:
-    case DRW_SHG_FEEDBACK_TRANSFORM:
-      return shgroup->calls.first == NULL;
-    case DRW_SHG_POINT_BATCH:
-    case DRW_SHG_LINE_BATCH:
-    case DRW_SHG_TRIANGLE_BATCH:
-    case DRW_SHG_INSTANCE:
-    case DRW_SHG_INSTANCE_EXTERNAL:
-      return shgroup->instance_count == 0;
-  }
-  BLI_assert(!"Shading Group type not supported");
-  return true;
+  return shgroup->calls.first == NULL;
 }
 
 DRWShadingGroup *DRW_shgroup_create_sub(DRWShadingGroup *shgroup)
 {
   /* Remove this assertion if needed but implement the other cases first! */
-  BLI_assert(shgroup->type == DRW_SHG_NORMAL);
-
   DRWShadingGroup *shgroup_new = BLI_memblock_alloc(DST.vmempool->shgroups);
 
   *shgroup_new = *shgroup;