Mesh Batch Cache: Refactor + Multithread

For clarity sake, the batch cache now uses exclusively per Loop attributes.
While this is a bit of a waste of VRAM (for the few case where per vert
attribs are enough) it reduces the complexity and amount of overall VBO
to update in general situations.

This patch also makes the VertexBuffers filling multithreaded. This make
the update of dense meshes a bit faster. The main bottleneck is the
IndexBuffers update which cannot be multithreaded efficiently (have to
increment a counter and/or do a final sorting pass).

We introduce the concept of "extract" functions/step.
All extract functions are executed in one thread each and if possible,
using multiple thread for looping over all elements.

Reviewed By: brecht

Differential Revision: http://developer.blender.org/D5424

1 files changed, 2 insertions, 1 deletions

diff --git a/source/blender/gpu/GPU_batch.h b/source/blender/gpu/GPU_batch.h
index 365dd89a006..c65ca5d905e 100644
--- a/source/blender/gpu/GPU_batch.h
+++ b/source/blender/gpu/GPU_batch.h
@@ -40,7 +40,7 @@ typedef enum {
   GPU_BATCH_READY_TO_DRAW,
 } GPUBatchPhase;
 
-#define GPU_BATCH_VBO_MAX_LEN 4
+#define GPU_BATCH_VBO_MAX_LEN 5
 #define GPU_BATCH_VAO_STATIC_LEN 3
 #define GPU_BATCH_VAO_DYN_ALLOC_COUNT 16
 
@@ -115,6 +115,7 @@ void GPU_batch_vao_cache_clear(GPUBatch *);
 void GPU_batch_callback_free_set(GPUBatch *, void (*callback)(GPUBatch *, void *), void *);
 
 void GPU_batch_instbuf_set(GPUBatch *, GPUVertBuf *, bool own_vbo); /* Instancing */
+void GPU_batch_elembuf_set(GPUBatch *batch, GPUIndexBuf *elem, bool own_ibo);
 
 int GPU_batch_vertbuf_add_ex(GPUBatch *, GPUVertBuf *, bool own_vbo);