DRW: Add `DRW_shgroup_call_procedural_indirect()`

Replaces `DRW_shgroup_call_procedural_triangles_indirect`.
This makes the indirect drawing more flexible.
Not all primitive types are supported but it is just a matter of adding
them.

4 files changed, 46 insertions, 8 deletions

diff --git a/source/blender/draw/intern/DRW_render.h b/source/blender/draw/intern/DRW_render.h
index 701b395e0d7..2b2288f23cd 100644
--- a/source/blender/draw/intern/DRW_render.h
+++ b/source/blender/draw/intern/DRW_render.h
@@ -454,9 +454,10 @@ void DRW_shgroup_call_compute_indirect(DRWShadingGroup *shgroup, GPUStorageBuf *
 void DRW_shgroup_call_procedural_points(DRWShadingGroup *sh, Object *ob, uint point_count);
 void DRW_shgroup_call_procedural_lines(DRWShadingGroup *sh, Object *ob, uint line_count);
 void DRW_shgroup_call_procedural_triangles(DRWShadingGroup *sh, Object *ob, uint tri_count);
-void DRW_shgroup_call_procedural_triangles_indirect(DRWShadingGroup *shgroup,
-                                                    Object *ob,
-                                                    GPUStorageBuf *indirect_buf);
+void DRW_shgroup_call_procedural_indirect(DRWShadingGroup *shgroup,
+                                          GPUPrimType primitive_type,
+                                          Object *ob,
+                                          GPUStorageBuf *indirect_buf);
 /**
  * \warning Only use with Shaders that have `IN_PLACE_INSTANCES` defined.
  * TODO: Should be removed.
diff --git a/source/blender/draw/intern/draw_cache.c b/source/blender/draw/intern/draw_cache.c
index f846251c66b..4c0f025e934 100644
--- a/source/blender/draw/intern/draw_cache.c
+++ b/source/blender/draw/intern/draw_cache.c
@@ -90,6 +90,7 @@ static struct DRWShapeCache {
   GPUBatch *drw_procedural_verts;
   GPUBatch *drw_procedural_lines;
   GPUBatch *drw_procedural_tris;
+  GPUBatch *drw_procedural_tri_strips;
   GPUBatch *drw_cursor;
   GPUBatch *drw_cursor_only_circle;
   GPUBatch *drw_fullscreen_quad;
@@ -208,6 +209,21 @@ GPUBatch *drw_cache_procedural_triangles_get(void)
   return SHC.drw_procedural_tris;
 }
 
+GPUBatch *drw_cache_procedural_triangle_strips_get()
+{
+  if (!SHC.drw_procedural_tri_strips) {
+    /* TODO(fclem): get rid of this dummy VBO. */
+    GPUVertFormat format = {0};
+    GPU_vertformat_attr_add(&format, "dummy", GPU_COMP_F32, 1, GPU_FETCH_FLOAT);
+    GPUVertBuf *vbo = GPU_vertbuf_create_with_format(&format);
+    GPU_vertbuf_data_alloc(vbo, 1);
+
+    SHC.drw_procedural_tri_strips = GPU_batch_create_ex(
+        GPU_PRIM_TRI_STRIP, vbo, NULL, GPU_BATCH_OWNS_VBO);
+  }
+  return SHC.drw_procedural_tri_strips;
+}
+
 /** \} */
 
 /* -------------------------------------------------------------------- */
diff --git a/source/blender/draw/intern/draw_manager.h b/source/blender/draw/intern/draw_manager.h
index 9e28169dcc4..411123f00bf 100644
--- a/source/blender/draw/intern/draw_manager.h
+++ b/source/blender/draw/intern/draw_manager.h
@@ -693,6 +693,7 @@ void drw_resource_buffer_finish(DRWData *vmempool);
 GPUBatch *drw_cache_procedural_points_get(void);
 GPUBatch *drw_cache_procedural_lines_get(void);
 GPUBatch *drw_cache_procedural_triangles_get(void);
+GPUBatch *drw_cache_procedural_triangle_strips_get(void);
 
 void drw_uniform_attrs_pool_update(struct GHash *table,
                                    struct GPUUniformAttrList *key,
diff --git a/source/blender/draw/intern/draw_manager_data.c b/source/blender/draw/intern/draw_manager_data.c
index 0535273d144..9392efcf92b 100644
--- a/source/blender/draw/intern/draw_manager_data.c
+++ b/source/blender/draw/intern/draw_manager_data.c
@@ -1056,11 +1056,31 @@ void DRW_shgroup_call_procedural_triangles(DRWShadingGroup *shgroup, Object *ob,
   drw_shgroup_call_procedural_add_ex(shgroup, geom, ob, tri_count * 3);
 }
 
-void DRW_shgroup_call_procedural_triangles_indirect(DRWShadingGroup *shgroup,
-                                                    Object *ob,
-                                                    GPUStorageBuf *indirect_buf)
-{
-  struct GPUBatch *geom = drw_cache_procedural_triangles_get();
+void DRW_shgroup_call_procedural_indirect(DRWShadingGroup *shgroup,
+                                          GPUPrimType primitive_type,
+                                          Object *ob,
+                                          GPUStorageBuf *indirect_buf)
+{
+  struct GPUBatch *geom = NULL;
+  switch (primitive_type) {
+    case GPU_PRIM_POINTS:
+      geom = drw_cache_procedural_points_get();
+      break;
+    case GPU_PRIM_LINES:
+      geom = drw_cache_procedural_lines_get();
+      break;
+    case GPU_PRIM_TRIS:
+      geom = drw_cache_procedural_triangles_get();
+      break;
+    case GPU_PRIM_TRI_STRIP:
+      geom = drw_cache_procedural_triangle_strips_get();
+      break;
+    default:
+      BLI_assert_msg(0,
+                     "Unsupported primitive type in DRW_shgroup_call_procedural_indirect. Add new "
+                     "one as needed.");
+      break;
+  }
   if (G.f & G_FLAG_PICKSEL) {
     drw_command_set_select_id(shgroup, NULL, DST.select_id);
   }