From e776b632c095690763bcbc8164834ed92c21ea5b Mon Sep 17 00:00:00 2001 From: Eric Anholt Date: Fri, 1 Feb 2013 14:49:21 +1100 Subject: [PATCH] vbo: Merge GL_QUADS drawing requests in display lists. minecraft apparently has its piles of display lists each contain 6 instances of glBegin(GL_QUADS)/verts/glEnd(), which appear in the compiled list as 6 prims of 4 verts each in one draw call. We can reduce driver overhead even more by making that one prim of 24 verts. Improves minecraft performance by 1.6% +/- .25% (n=446) Reviewed-by: Jordan Justen --- src/mesa/vbo/vbo_save_api.c | 43 +++++++++++++++++++++++++++++++++++++ 1 file changed, 43 insertions(+) diff --git a/src/mesa/vbo/vbo_save_api.c b/src/mesa/vbo/vbo_save_api.c index 789e864677c..74907175375 100644 --- a/src/mesa/vbo/vbo_save_api.c +++ b/src/mesa/vbo/vbo_save_api.c @@ -301,6 +301,47 @@ _save_reset_counters(struct gl_context *ctx) save->dangling_attr_ref = 0; } +/** + * For a list of prims, try merging prims that can just be extensions of the + * previous prim. + */ +static void +vbo_merge_prims(struct gl_context *ctx, + struct _mesa_prim *prim_list, + GLuint *prim_count) +{ + GLuint i; + struct _mesa_prim *prev_prim = prim_list; + + for (i = 1; i < *prim_count; i++) { + struct _mesa_prim *this_prim = prim_list + i; + + if (this_prim->mode == prev_prim->mode && + this_prim->mode == GL_QUADS && + this_prim->count % 4 == 0 && + prev_prim->count % 4 == 0 && + this_prim->start == prev_prim->start + prev_prim->count && + this_prim->basevertex == prev_prim->basevertex && + this_prim->num_instances == prev_prim->num_instances && + this_prim->base_instance == prev_prim->base_instance) { + /* We've found a prim that just extend the previous one. Tack it + * onto the previous one, and let this primitive struct get dropped. + */ + prev_prim->count += this_prim->count; + prev_prim->end = this_prim->end; + continue; + } + + /* If any previous primitives have been dropped, then we need to copy + * this later one into the next available slot. + */ + prev_prim++; + if (prev_prim != this_prim) + *prev_prim = *this_prim; + } + + *prim_count = prev_prim - prim_list + 1; +} /** * Insert the active immediate struct onto the display list currently @@ -380,6 +421,8 @@ _save_compile_vertex_list(struct gl_context *ctx) */ save->copied.nr = _save_copy_vertices(ctx, node, save->buffer); + vbo_merge_prims(ctx, node->prim, &node->prim_count); + /* Deal with GL_COMPILE_AND_EXECUTE: */ if (ctx->ExecuteFlag) { -- 2.30.2