GP: Refactor drawing engine to single VBO

This is part of T57829.

Reduce the number of batches used to only one by shader type.  This reduces GPU overhead and increase a lot the FPS. As the number of batches is small, the time to allocate and free memory was reduced in 90% or more.

Also the code has been simplified and all batch management has been removed because this is not necessary. Now, all shading groups are created after all vertex buffer data for all strokes has been created using DRW_shgroup_call_range_add().

All batch cache data has been moved to the Object runtime struct and not as before where some parts (derived data) were saved inside GPD datablock.

For particles, now the code is faster and cleaner and gets better FPS.

Thanks to Clément Foucault for his help and advices to improve speed.

1 files changed, 0 insertions, 3 deletions

diff --git a/source/blender/makesdna/DNA_gpencil_types.h b/source/blender/makesdna/DNA_gpencil_types.h
index 503ad2f28d9..8a1bccc6957 100644
--- a/source/blender/makesdna/DNA_gpencil_types.h
+++ b/source/blender/makesdna/DNA_gpencil_types.h
@@ -236,10 +236,7 @@ typedef enum eGPDframe_Flag {
 
 /* Runtime temp data for bGPDlayer */
 typedef struct bGPDlayer_Runtime {
-	struct bGPDframe *derived_array;/* runtime data created by modifiers */
 	int icon_id;                    /* id for dynamic icon used to show annotation color preview for layer */
-	int batch_index;                /* batch used for dupli instances */
-	int len_derived;                /* len of the derived array */
 	char pad_[4];
 } bGPDlayer_Runtime;