Disable GPU subdivision if the maximum number of SSBO binding is reached

Some old platforms and drivers have limited amount of SSBO binding per
compute shader. This disables GPU subdivision if we cannot possibly
bind all required buffers within this limit.

For now the maximum number of buffers used by the GPU code is hardcoded,
but will be programmatically detected when shader creation is automated.

Ref D14337

3 files changed, 100 insertions, 59 deletions

diff --git a/source/blender/blenkernel/BKE_subdiv_modifier.h b/source/blender/blenkernel/BKE_subdiv_modifier.h
index 40e8ee2f999..e9de7d1532e 100644
--- a/source/blender/blenkernel/BKE_subdiv_modifier.h
+++ b/source/blender/blenkernel/BKE_subdiv_modifier.h
@@ -13,6 +13,10 @@
 extern "C" {
 #endif
 
+/* Hardcoded for until GPU shaders are automatically generated, then we will have a more
+ * programmatic way of detecting this. */
+#define MAX_GPU_SUBDIV_SSBOS 12
+
 struct Mesh;
 struct Object;
 struct Scene;
diff --git a/source/blender/blenkernel/intern/subdiv_modifier.c b/source/blender/blenkernel/intern/subdiv_modifier.c
index 34dfdaf7595..83772f153d9 100644
--- a/source/blender/blenkernel/intern/subdiv_modifier.c
+++ b/source/blender/blenkernel/intern/subdiv_modifier.c
@@ -77,6 +77,10 @@ static bool is_subdivision_evaluation_possible_on_gpu(void)
     return false;
   }
 
+  if (GPU_max_shader_storage_buffer_bindings() < MAX_GPU_SUBDIV_SSBOS) {
+    return false;
+  }
+
   const int available_evaluators = openSubdiv_getAvailableEvaluators();
   if ((available_evaluators & OPENSUBDIV_EVALUATOR_GLSL_COMPUTE) == 0) {
     return false;
diff --git a/source/blender/draw/intern/draw_cache_impl_subdivision.cc b/source/blender/draw/intern/draw_cache_impl_subdivision.cc
index 8682a15feba..8aa7ff66d65 100644
--- a/source/blender/draw/intern/draw_cache_impl_subdivision.cc
+++ b/source/blender/draw/intern/draw_cache_impl_subdivision.cc
@@ -1244,15 +1244,17 @@ void draw_subdiv_extract_pos_nor(const DRWSubdivCache *cache, GPUVertBuf *pos_no
   GPUShader *shader = get_patch_evaluation_shader(SHADER_PATCH_EVALUATION);
   GPU_shader_bind(shader);
 
-  GPU_vertbuf_bind_as_ssbo(src_buffer, 0);
-  GPU_vertbuf_bind_as_ssbo(cache->gpu_patch_map.patch_map_handles, 1);
-  GPU_vertbuf_bind_as_ssbo(cache->gpu_patch_map.patch_map_quadtree, 2);
-  GPU_vertbuf_bind_as_ssbo(cache->patch_coords, 3);
-  GPU_vertbuf_bind_as_ssbo(cache->verts_orig_index, 4);
-  GPU_vertbuf_bind_as_ssbo(patch_arrays_buffer, 5);
-  GPU_vertbuf_bind_as_ssbo(patch_index_buffer, 6);
-  GPU_vertbuf_bind_as_ssbo(patch_param_buffer, 7);
-  GPU_vertbuf_bind_as_ssbo(pos_nor, 8);
+  int binding_point = 0;
+  GPU_vertbuf_bind_as_ssbo(src_buffer, binding_point++);
+  GPU_vertbuf_bind_as_ssbo(cache->gpu_patch_map.patch_map_handles, binding_point++);
+  GPU_vertbuf_bind_as_ssbo(cache->gpu_patch_map.patch_map_quadtree, binding_point++);
+  GPU_vertbuf_bind_as_ssbo(cache->patch_coords, binding_point++);
+  GPU_vertbuf_bind_as_ssbo(cache->verts_orig_index, binding_point++);
+  GPU_vertbuf_bind_as_ssbo(patch_arrays_buffer, binding_point++);
+  GPU_vertbuf_bind_as_ssbo(patch_index_buffer, binding_point++);
+  GPU_vertbuf_bind_as_ssbo(patch_param_buffer, binding_point++);
+  GPU_vertbuf_bind_as_ssbo(pos_nor, binding_point++);
+  BLI_assert(binding_point <= MAX_GPU_SUBDIV_SSBOS);
 
   drw_subdiv_compute_dispatch(cache, shader, 0, 0, cache->num_subdiv_quads);
 
@@ -1308,15 +1310,17 @@ void draw_subdiv_extract_uvs(const DRWSubdivCache *cache,
   GPUShader *shader = get_patch_evaluation_shader(SHADER_PATCH_EVALUATION_FVAR);
   GPU_shader_bind(shader);
 
-  GPU_vertbuf_bind_as_ssbo(src_buffer, 0);
-  GPU_vertbuf_bind_as_ssbo(cache->gpu_patch_map.patch_map_handles, 1);
-  GPU_vertbuf_bind_as_ssbo(cache->gpu_patch_map.patch_map_quadtree, 2);
-  GPU_vertbuf_bind_as_ssbo(cache->patch_coords, 3);
-  GPU_vertbuf_bind_as_ssbo(cache->verts_orig_index, 4);
-  GPU_vertbuf_bind_as_ssbo(patch_arrays_buffer, 5);
-  GPU_vertbuf_bind_as_ssbo(patch_index_buffer, 6);
-  GPU_vertbuf_bind_as_ssbo(patch_param_buffer, 7);
-  GPU_vertbuf_bind_as_ssbo(uvs, 8);
+  int binding_point = 0;
+  GPU_vertbuf_bind_as_ssbo(src_buffer, binding_point++);
+  GPU_vertbuf_bind_as_ssbo(cache->gpu_patch_map.patch_map_handles, binding_point++);
+  GPU_vertbuf_bind_as_ssbo(cache->gpu_patch_map.patch_map_quadtree, binding_point++);
+  GPU_vertbuf_bind_as_ssbo(cache->patch_coords, binding_point++);
+  GPU_vertbuf_bind_as_ssbo(cache->verts_orig_index, binding_point++);
+  GPU_vertbuf_bind_as_ssbo(patch_arrays_buffer, binding_point++);
+  GPU_vertbuf_bind_as_ssbo(patch_index_buffer, binding_point++);
+  GPU_vertbuf_bind_as_ssbo(patch_param_buffer, binding_point++);
+  GPU_vertbuf_bind_as_ssbo(uvs, binding_point++);
+  BLI_assert(binding_point <= MAX_GPU_SUBDIV_SSBOS);
 
   /* The buffer offset has the stride baked in (which is 2 as we have UVs) so remove the stride by
    * dividing by 2 */
@@ -1380,13 +1384,15 @@ void draw_subdiv_interp_custom_data(const DRWSubdivCache *cache,
 
   GPU_shader_bind(shader);
 
+  int binding_point = 0;
   /* subdiv_polygon_offset is always at binding point 0 for each shader using it. */
-  GPU_vertbuf_bind_as_ssbo(cache->subdiv_polygon_offset_buffer, 0);
-  GPU_vertbuf_bind_as_ssbo(src_data, 1);
-  GPU_vertbuf_bind_as_ssbo(cache->face_ptex_offset_buffer, 2);
-  GPU_vertbuf_bind_as_ssbo(cache->patch_coords, 3);
-  GPU_vertbuf_bind_as_ssbo(cache->extra_coarse_face_data, 4);
-  GPU_vertbuf_bind_as_ssbo(dst_data, 5);
+  GPU_vertbuf_bind_as_ssbo(cache->subdiv_polygon_offset_buffer, binding_point++);
+  GPU_vertbuf_bind_as_ssbo(src_data, binding_point++);
+  GPU_vertbuf_bind_as_ssbo(cache->face_ptex_offset_buffer, binding_point++);
+  GPU_vertbuf_bind_as_ssbo(cache->patch_coords, binding_point++);
+  GPU_vertbuf_bind_as_ssbo(cache->extra_coarse_face_data, binding_point++);
+  GPU_vertbuf_bind_as_ssbo(dst_data, binding_point++);
+  BLI_assert(binding_point <= MAX_GPU_SUBDIV_SSBOS);
 
   drw_subdiv_compute_dispatch(cache, shader, 0, dst_offset, cache->num_subdiv_quads);
 
@@ -1406,12 +1412,15 @@ void draw_subdiv_build_sculpt_data_buffer(const DRWSubdivCache *cache,
   GPUShader *shader = get_subdiv_shader(SHADER_BUFFER_SCULPT_DATA, nullptr);
   GPU_shader_bind(shader);
 
+  /* Mask VBO is always at binding point 0. */
   if (mask_vbo) {
     GPU_vertbuf_bind_as_ssbo(mask_vbo, 0);
   }
 
-  GPU_vertbuf_bind_as_ssbo(face_set_vbo, 1);
-  GPU_vertbuf_bind_as_ssbo(sculpt_data, 2);
+  int binding_point = 1;
+  GPU_vertbuf_bind_as_ssbo(face_set_vbo, binding_point++);
+  GPU_vertbuf_bind_as_ssbo(sculpt_data, binding_point++);
+  BLI_assert(binding_point <= MAX_GPU_SUBDIV_SSBOS);
 
   drw_subdiv_compute_dispatch(cache, shader, 0, 0, cache->num_subdiv_quads, mask_vbo != nullptr);
 
@@ -1439,6 +1448,7 @@ void draw_subdiv_accumulate_normals(const DRWSubdivCache *cache,
   GPU_vertbuf_bind_as_ssbo(face_adjacency_lists, binding_point++);
   GPU_vertbuf_bind_as_ssbo(vertex_loop_map, binding_point++);
   GPU_vertbuf_bind_as_ssbo(vertex_normals, binding_point++);
+  BLI_assert(binding_point <= MAX_GPU_SUBDIV_SSBOS);
 
   drw_subdiv_compute_dispatch(cache, shader, 0, 0, cache->num_subdiv_verts);
 
@@ -1463,6 +1473,7 @@ void draw_subdiv_finalize_normals(const DRWSubdivCache *cache,
   GPU_vertbuf_bind_as_ssbo(vertex_normals, binding_point++);
   GPU_vertbuf_bind_as_ssbo(subdiv_loop_subdiv_vert_index, binding_point++);
   GPU_vertbuf_bind_as_ssbo(pos_nor, binding_point++);
+  BLI_assert(binding_point <= MAX_GPU_SUBDIV_SSBOS);
 
   drw_subdiv_compute_dispatch(cache, shader, 0, 0, cache->num_subdiv_quads);
 
@@ -1482,9 +1493,12 @@ void draw_subdiv_finalize_custom_normals(const DRWSubdivCache *cache,
   GPUShader *shader = get_subdiv_shader(SHADER_BUFFER_NORMALS_FINALIZE, "#define CUSTOM_NORMALS");
   GPU_shader_bind(shader);
 
-  GPU_vertbuf_bind_as_ssbo(src_custom_normals, 0);
+  int binding_point = 0;
+  GPU_vertbuf_bind_as_ssbo(src_custom_normals, binding_point++);
   /* outputPosNor is bound at index 2 in the base shader. */
-  GPU_vertbuf_bind_as_ssbo(pos_nor, 2);
+  binding_point = 2;
+  GPU_vertbuf_bind_as_ssbo(pos_nor, binding_point++);
+  BLI_assert(binding_point <= MAX_GPU_SUBDIV_SSBOS);
 
   drw_subdiv_compute_dispatch(cache, shader, 0, 0, cache->num_subdiv_quads);
 
@@ -1519,15 +1533,22 @@ void draw_subdiv_build_tris_buffer(const DRWSubdivCache *cache,
       do_single_material ? SHADER_BUFFER_TRIS : SHADER_BUFFER_TRIS_MULTIPLE_MATERIALS, defines);
   GPU_shader_bind(shader);
 
-  /* Outputs */
-  GPU_indexbuf_bind_as_ssbo(subdiv_tris, 1);
-
   if (!do_single_material) {
-    GPU_vertbuf_bind_as_ssbo(cache->polygon_mat_offset, 2);
     /* subdiv_polygon_offset is always at binding point 0 for each shader using it. */
     GPU_vertbuf_bind_as_ssbo(cache->subdiv_polygon_offset_buffer, 0);
   }
 
+  int binding_point = 1;
+
+  /* Outputs */
+  GPU_indexbuf_bind_as_ssbo(subdiv_tris, binding_point++);
+
+  if (!do_single_material) {
+    GPU_vertbuf_bind_as_ssbo(cache->polygon_mat_offset, binding_point++);
+  }
+
+  BLI_assert(binding_point <= MAX_GPU_SUBDIV_SSBOS);
+
   drw_subdiv_compute_dispatch(cache, shader, 0, 0, cache->num_subdiv_quads);
 
   /* This generates an index buffer, so we need to put a barrier on the element array. */
@@ -1574,18 +1595,20 @@ void draw_subdiv_build_fdots_buffers(const DRWSubdivCache *cache,
   GPUShader *shader = get_patch_evaluation_shader(SHADER_PATCH_EVALUATION_FACE_DOTS);
   GPU_shader_bind(shader);
 
-  GPU_vertbuf_bind_as_ssbo(src_buffer, 0);
-  GPU_vertbuf_bind_as_ssbo(cache->gpu_patch_map.patch_map_handles, 1);
-  GPU_vertbuf_bind_as_ssbo(cache->gpu_patch_map.patch_map_quadtree, 2);
-  GPU_vertbuf_bind_as_ssbo(cache->fdots_patch_coords, 3);
-  GPU_vertbuf_bind_as_ssbo(cache->verts_orig_index, 4);
-  GPU_vertbuf_bind_as_ssbo(patch_arrays_buffer, 5);
-  GPU_vertbuf_bind_as_ssbo(patch_index_buffer, 6);
-  GPU_vertbuf_bind_as_ssbo(patch_param_buffer, 7);
-  GPU_vertbuf_bind_as_ssbo(fdots_pos, 8);
-  GPU_vertbuf_bind_as_ssbo(fdots_nor, 9);
-  GPU_indexbuf_bind_as_ssbo(fdots_indices, 10);
-  GPU_vertbuf_bind_as_ssbo(cache->extra_coarse_face_data, 11);
+  int binding_point = 0;
+  GPU_vertbuf_bind_as_ssbo(src_buffer, binding_point++);
+  GPU_vertbuf_bind_as_ssbo(cache->gpu_patch_map.patch_map_handles, binding_point++);
+  GPU_vertbuf_bind_as_ssbo(cache->gpu_patch_map.patch_map_quadtree, binding_point++);
+  GPU_vertbuf_bind_as_ssbo(cache->fdots_patch_coords, binding_point++);
+  GPU_vertbuf_bind_as_ssbo(cache->verts_orig_index, binding_point++);
+  GPU_vertbuf_bind_as_ssbo(patch_arrays_buffer, binding_point++);
+  GPU_vertbuf_bind_as_ssbo(patch_index_buffer, binding_point++);
+  GPU_vertbuf_bind_as_ssbo(patch_param_buffer, binding_point++);
+  GPU_vertbuf_bind_as_ssbo(fdots_pos, binding_point++);
+  GPU_vertbuf_bind_as_ssbo(fdots_nor, binding_point++);
+  GPU_indexbuf_bind_as_ssbo(fdots_indices, binding_point++);
+  GPU_vertbuf_bind_as_ssbo(cache->extra_coarse_face_data, binding_point++);
+  BLI_assert(binding_point <= MAX_GPU_SUBDIV_SSBOS);
 
   drw_subdiv_compute_dispatch(cache, shader, 0, 0, cache->num_coarse_poly);
 
@@ -1607,8 +1630,10 @@ void draw_subdiv_build_lines_buffer(const DRWSubdivCache *cache, GPUIndexBuf *li
   GPUShader *shader = get_subdiv_shader(SHADER_BUFFER_LINES, nullptr);
   GPU_shader_bind(shader);
 
-  GPU_vertbuf_bind_as_ssbo(cache->edges_orig_index, 0);
-  GPU_indexbuf_bind_as_ssbo(lines_indices, 1);
+  int binding_point = 0;
+  GPU_vertbuf_bind_as_ssbo(cache->edges_orig_index, binding_point++);
+  GPU_indexbuf_bind_as_ssbo(lines_indices, binding_point++);
+  BLI_assert(binding_point <= MAX_GPU_SUBDIV_SSBOS);
 
   drw_subdiv_compute_dispatch(cache, shader, 0, 0, cache->num_subdiv_quads);
 
@@ -1648,9 +1673,11 @@ void draw_subdiv_build_edge_fac_buffer(const DRWSubdivCache *cache,
   GPUShader *shader = get_subdiv_shader(SHADER_BUFFER_EDGE_FAC, defines);
   GPU_shader_bind(shader);
 
-  GPU_vertbuf_bind_as_ssbo(pos_nor, 0);
-  GPU_vertbuf_bind_as_ssbo(edge_idx, 1);
-  GPU_vertbuf_bind_as_ssbo(edge_fac, 2);
+  int binding_point = 0;
+  GPU_vertbuf_bind_as_ssbo(pos_nor, binding_point++);
+  GPU_vertbuf_bind_as_ssbo(edge_idx, binding_point++);
+  GPU_vertbuf_bind_as_ssbo(edge_fac, binding_point++);
+  BLI_assert(binding_point <= MAX_GPU_SUBDIV_SSBOS);
 
   drw_subdiv_compute_dispatch(cache, shader, 0, 0, cache->num_subdiv_quads);
 
@@ -1673,14 +1700,16 @@ void draw_subdiv_build_lnor_buffer(const DRWSubdivCache *cache,
   GPUShader *shader = get_subdiv_shader(SHADER_BUFFER_LNOR, "#define SUBDIV_POLYGON_OFFSET\n");
   GPU_shader_bind(shader);
 
+  int binding_point = 0;
   /* Inputs */
-  GPU_vertbuf_bind_as_ssbo(pos_nor, 1);
-  GPU_vertbuf_bind_as_ssbo(cache->extra_coarse_face_data, 2);
   /* subdiv_polygon_offset is always at binding point 0 for each shader using it. */
-  GPU_vertbuf_bind_as_ssbo(cache->subdiv_polygon_offset_buffer, 0);
+  GPU_vertbuf_bind_as_ssbo(cache->subdiv_polygon_offset_buffer, binding_point++);
+  GPU_vertbuf_bind_as_ssbo(pos_nor, binding_point++);
+  GPU_vertbuf_bind_as_ssbo(cache->extra_coarse_face_data, binding_point++);
 
   /* Outputs */
-  GPU_vertbuf_bind_as_ssbo(lnor, 3);
+  GPU_vertbuf_bind_as_ssbo(lnor, binding_point++);
+  BLI_assert(binding_point <= MAX_GPU_SUBDIV_SSBOS);
 
   drw_subdiv_compute_dispatch(cache, shader, 0, 0, cache->num_subdiv_quads);
 
@@ -1699,13 +1728,15 @@ void draw_subdiv_build_edituv_stretch_area_buffer(const DRWSubdivCache *cache,
                                         "#define SUBDIV_POLYGON_OFFSET\n");
   GPU_shader_bind(shader);
 
+  int binding_point = 0;
   /* Inputs */
-  GPU_vertbuf_bind_as_ssbo(coarse_data, 1);
   /* subdiv_polygon_offset is always at binding point 0 for each shader using it. */
-  GPU_vertbuf_bind_as_ssbo(cache->subdiv_polygon_offset_buffer, 0);
+  GPU_vertbuf_bind_as_ssbo(cache->subdiv_polygon_offset_buffer, binding_point++);
+  GPU_vertbuf_bind_as_ssbo(coarse_data, binding_point++);
 
   /* Outputs */
-  GPU_vertbuf_bind_as_ssbo(subdiv_data, 2);
+  GPU_vertbuf_bind_as_ssbo(subdiv_data, binding_point++);
+  BLI_assert(binding_point <= MAX_GPU_SUBDIV_SSBOS);
 
   drw_subdiv_compute_dispatch(cache, shader, 0, 0, cache->num_subdiv_quads);
 
@@ -1725,12 +1756,14 @@ void draw_subdiv_build_edituv_stretch_angle_buffer(const DRWSubdivCache *cache,
   GPUShader *shader = get_subdiv_shader(SHADER_BUFFER_UV_STRETCH_ANGLE, nullptr);
   GPU_shader_bind(shader);
 
+  int binding_point = 0;
   /* Inputs */
-  GPU_vertbuf_bind_as_ssbo(pos_nor, 0);
-  GPU_vertbuf_bind_as_ssbo(uvs, 1);
+  GPU_vertbuf_bind_as_ssbo(pos_nor, binding_point++);
+  GPU_vertbuf_bind_as_ssbo(uvs, binding_point++);
 
   /* Outputs */
-  GPU_vertbuf_bind_as_ssbo(stretch_angles, 2);
+  GPU_vertbuf_bind_as_ssbo(stretch_angles, binding_point++);
+  BLI_assert(binding_point <= MAX_GPU_SUBDIV_SSBOS);
 
   drw_subdiv_compute_dispatch(cache, shader, uvs_offset, 0, cache->num_subdiv_quads);