new cvar: r_sortentities to sort render edicts.

This is not as good as real surface batching across entities, but often about
equally good. Tends to gain about 1% on space maps or other "unvisable stuff".

Not active by default yet.

git-svn-id: svn://svn.icculus.org/twilight/trunk/darkplaces@11290 d7cf8633-e32d-0410-b094-e92efae38249
::stable-branch::merge=5fe8348f930d33cde9e0ae1c428a7d4cf0e12249

diff --git a/gl_rmain.c b/gl_rmain.c
index 435cefe566289a665eefe3492695b77b1bf378ca..80458225256a7ce26518da56d47c711efd3cf255 100644 (file)
--- a/gl_rmain.c
+++ b/gl_rmain.c
@@ -99,6 +99,7 @@ cvar_t r_cullentities_trace_samples = {0, "r_cullentities_trace_samples", "2", "
 cvar_t r_cullentities_trace_tempentitysamples = {0, "r_cullentities_trace_tempentitysamples", "-1", "number of samples to test for entity culling of temp entities (including all CSQC entities), -1 disables trace culling on these entities to prevent flicker (pvs still applies)"};
 cvar_t r_cullentities_trace_enlarge = {0, "r_cullentities_trace_enlarge", "0", "box enlargement for entity culling"};
 cvar_t r_cullentities_trace_delay = {0, "r_cullentities_trace_delay", "1", "number of seconds until the entity gets actually culled"};
+cvar_t r_sortentities = {0, "r_sortentities", "0", "sort entities before drawing (might be faster)"};
 cvar_t r_speeds = {0, "r_speeds","0", "displays rendering statistics and per-subsystem timings"};
 cvar_t r_fullbright = {0, "r_fullbright","0", "makes map very bright and renders faster"};
 
@@ -4213,6 +4214,7 @@ void GL_Main_Init(void)
        Cvar_RegisterVariable(&r_cullentities_trace_tempentitysamples);
        Cvar_RegisterVariable(&r_cullentities_trace_enlarge);
        Cvar_RegisterVariable(&r_cullentities_trace_delay);
+       Cvar_RegisterVariable(&r_sortentities);
        Cvar_RegisterVariable(&r_drawviewmodel);
        Cvar_RegisterVariable(&r_drawexteriormodel);
        Cvar_RegisterVariable(&r_speeds);
@@ -6734,6 +6736,37 @@ r_refdef_scene_t * R_GetScenePointer( r_refdef_scene_type_t scenetype )
        }
 }
 
+int R_SortEntities_Compare(const void *ap, const void *bp)
+{
+       const entity_render_t *a = *(const entity_render_t **)ap;
+       const entity_render_t *b = *(const entity_render_t **)bp;
+
+       // 1. compare model
+       if(a->model < b->model)
+               return -1;
+       if(a->model > b->model)
+               return +1;
+
+       // 2. compare skin
+       // TODO possibly calculate the REAL skinnum here first using
+       // skinscenes?
+       if(a->skinnum < b->skinnum)
+               return -1;
+       if(a->skinnum > b->skinnum)
+               return +1;
+
+       // everything we compared is equal
+       return 0;
+}
+void R_SortEntities(void)
+{
+       // below or equal 2 ents, sorting never gains anything
+       if(r_refdef.scene.numentities <= 2)
+               return;
+       // sort
+       qsort(r_refdef.scene.entities, r_refdef.scene.numentities, sizeof(*r_refdef.scene.entities), R_SortEntities_Compare);
+}
+
 /*
 ================
 R_RenderView
@@ -6758,6 +6791,8 @@ void R_RenderView(void)
 
        if (!r_drawentities.integer)
                r_refdef.scene.numentities = 0;
+       else if (r_sortentities.integer)
+               R_SortEntities();
 
        R_AnimCache_ClearCache();
        R_FrameData_NewFrame();