DRW: Refactor simple instancing.

Instead of creating a new instancing shading group without attrib, we now have instancing calls. The benefits is that they can be culled.
They can be used in conjuction with the standard and generate calls but shader must support it (which is generally not the case).
We store a pointer to the actual count so that the number can be tweaked between redraw.

This will makes multi layer rendering more efficient.

1 files changed, 6 insertions, 2 deletions

diff --git a/source/blender/draw/intern/DRW_render.h b/source/blender/draw/intern/DRW_render.h
index c83b67b00e5..1713960597e 100644
--- a/source/blender/draw/intern/DRW_render.h
+++ b/source/blender/draw/intern/DRW_render.h
@@ -347,6 +347,11 @@ void DRW_shgroup_instance_batch(DRWShadingGroup *shgroup, struct Gwn_Batch *batc
 void DRW_shgroup_free(struct DRWShadingGroup *shgroup);
 void DRW_shgroup_call_add(DRWShadingGroup *shgroup, struct Gwn_Batch *geom, float (*obmat)[4]);
 void DRW_shgroup_call_object_add(DRWShadingGroup *shgroup, struct Gwn_Batch *geom, struct Object *ob);
+/* Used for drawing a batch with instancing without instance attribs. */
+void DRW_shgroup_call_instances_add(
+        DRWShadingGroup *shgroup, struct Gwn_Batch *geom, float (*obmat)[4], unsigned int *count);
+void DRW_shgroup_call_object_instances_add(
+        DRWShadingGroup *shgroup, struct Gwn_Batch *geom, struct Object *ob, unsigned int *count);
 void DRW_shgroup_call_sculpt_add(DRWShadingGroup *shgroup, struct Object *ob, float (*obmat)[4]);
 void DRW_shgroup_call_generate_add(
         DRWShadingGroup *shgroup, DRWCallGenerateFn *geometry_fn, void *user_data, float (*obmat)[4]);
@@ -355,8 +360,7 @@ void DRW_shgroup_call_dynamic_add_array(DRWShadingGroup *shgroup, const void *at
 	const void *array[] = {__VA_ARGS__}; \
 	DRW_shgroup_call_dynamic_add_array(shgroup, array, (sizeof(array) / sizeof(*array))); \
 } while (0)
-/* Use this to set a high number of instances. */
-void DRW_shgroup_set_instance_count(DRWShadingGroup *shgroup, unsigned int count);
+
 unsigned int DRW_shgroup_get_instance_count(const DRWShadingGroup *shgroup);
 
 void DRW_shgroup_state_enable(DRWShadingGroup *shgroup, DRWState state);