Bounding box clipping in the render engine.

Now bounding boxes are computed per object, and checked first before
zbuffering objects. For strands, bounding boxes are computed per
original face in the mesh. Overall the speed improvement from this 
is quite small (zbuffering is rarely the bottleneck), but it seems a
sensible thing to do anyway.

3 files changed, 9 insertions, 4 deletions

diff --git a/source/blender/render/intern/include/render_types.h b/source/blender/render/intern/include/render_types.h
index 3a8a491a852..7b68552e5fb 100644
--- a/source/blender/render/intern/include/render_types.h
+++ b/source/blender/render/intern/include/render_types.h
@@ -247,13 +247,15 @@ typedef struct ObjectRen {
 	struct Scene *sce;
 	int index, psysindex, flag, lay;
 
+	float boundbox[2][3];
+
 	int totvert, totvlak, totstrand, tothalo;
 	int vertnodeslen, vlaknodeslen, strandnodeslen, blohalen;
 	struct VertTableNode *vertnodes;
 	struct VlakTableNode *vlaknodes;
 	struct StrandTableNode *strandnodes;
 	struct HaloRen **bloha;
-	ListBase strandbufs;
+	struct StrandBuffer *strandbuf;
 
 	char (*mtface)[32];
 	char (*mcol)[32];
@@ -346,7 +348,7 @@ typedef struct StrandSurface {
 	int (*face)[4];
 	float (*co)[3];
 	/* for occlusion caching */
-	float (*col)[3];					/* for occlusion */
+	float (*col)[3];
 	/* for speedvectors */
 	float (*prevco)[3], (*nextco)[3];
 	int totvert, totface;
@@ -354,13 +356,14 @@ typedef struct StrandSurface {
 
 typedef struct StrandBound {
 	int start, end;
-	float bbox[2][3];
+	float boundbox[2][3];
 } StrandBound;
 
 typedef struct StrandBuffer {
 	struct StrandBuffer *next, *prev;
 	struct StrandVert *vert;
-	int totvert;
+	struct StrandBound *bound;
+	int totvert, totbound;
 
 	struct ObjectRen *obr;
 	struct Material *ma;
diff --git a/source/blender/render/intern/include/renderdatabase.h b/source/blender/render/intern/include/renderdatabase.h
index cfcbb4e7775..a204aa7876b 100644
--- a/source/blender/render/intern/include/renderdatabase.h
+++ b/source/blender/render/intern/include/renderdatabase.h
@@ -85,6 +85,7 @@ void free_renderdata_vlaknodes(struct VlakTableNode *vlaknodes);
 
 void set_normalflags(struct Render *re, struct ObjectRen *obr);
 void project_renderdata(struct Render *re, void (*projectfunc)(float *, float mat[][4], float *),  int do_pano, float xoffs, int do_buckets);
+int clip_render_object(float boundbox[][3], float *bounds, float mat[][4]);
 
 /* functions are not exported... so wrong names */
 
diff --git a/source/blender/render/intern/include/strand.h b/source/blender/render/intern/include/strand.h
index f001bc42112..ebe026e3fec 100644
--- a/source/blender/render/intern/include/strand.h
+++ b/source/blender/render/intern/include/strand.h
@@ -93,6 +93,7 @@ typedef struct StrandShadeCache StrandShadeCache;
 
 void strand_eval_point(StrandSegment *sseg, StrandPoint *spoint);
 void render_strand_segment(struct Render *re, float winmat[][4], struct StrandPart *spart, struct ZSpan *zspan, int totzspan, StrandSegment *sseg);
+void strand_minmax(struct StrandRen *strand, float *min, float *max);
 
 struct StrandSurface *cache_strand_surface(struct Render *re, struct ObjectRen *obr, struct DerivedMesh *dm, float mat[][4], int timeoffset);
 void free_strand_surface(struct Render *re);