New shadow feature: Irregular Shadow Buffers

Full log:
http://www.blender3d.org/cms/Irregular_Shadow_Buffe.785.0.html

In short: this is a shadow buffer approach that always results in crispy
shadows, independent of lamp buffer size or zoom level. This shadow buffer
system also supports transparent shadow.

This is part of work on refreshing Shadow Buffers in Blender. You now can
choose of two types (Classical, Irregular). More types will follow. Also
quality issues for Classical shadow buffers are going to be reviewed,
especially to solve the lousy Biasing.

For the CVS log record; it is based on articles:
Gregory Johnson et al, University of Texas, Austin. (Regular grid method).
Timo Aila and Samuli Laine, Helsinki University of Technology. (BSP method).

1 files changed, 44 insertions, 0 deletions

diff --git a/source/blender/render/intern/include/shadbuf.h b/source/blender/render/intern/include/shadbuf.h
index 8258dea466f..8b786c6e098 100644
--- a/source/blender/render/intern/include/shadbuf.h
+++ b/source/blender/render/intern/include/shadbuf.h
@@ -61,6 +61,50 @@ float testshadowbuf(struct ShadBuf *shb, float *rco, float *dxco, float *dyco, f
  */
 float shadow_halo(LampRen *lar, float *p1, float *p2);
 
+/**
+ * Irregular shadowbuffer
+ */
+
+struct MemArena;
+struct APixstr;
+
+void ISB_create(RenderPart *pa, struct APixstr *apixbuf);
+void ISB_free(RenderPart *pa);
+float ISB_getshadow(ShadeInput *shi, ShadBuf *shb);
+
+/* data structures have to be accessible both in camview(x, y) as in lampview(x, y) */
+/* since they're created per tile rendered, speed goes over memory requirements */
+
+
+/* buffer samples, allocated in camera buffer and pointed to in lampbuffer nodes */
+typedef struct ISBSample {
+	float zco[3];			/* coordinate in lampview projection */
+	short *shadfac;			/* initialized zero = full lighted */
+	int facenr;				/* index in faces list */	
+} ISBSample;
+
+/* transparent version of buffer sample */
+typedef struct ISBSampleA {
+	float zco[3];				/* coordinate in lampview projection */
+	short *shadfac;				/* NULL = full lighted */
+	int facenr;					/* index in faces list */	
+	struct ISBSampleA *next;	/* in end, we want the first items to align with ISBSample */
+} ISBSampleA;
+
+/* used for transparent storage only */
+typedef struct ISBShadfacA {
+	struct ISBShadfacA *next;
+	int facenr;
+	float shadfac;
+} ISBShadfacA;
+
+/* What needs to be stored to evaluate shadow, for each thread in ShadBuf */
+typedef struct ISBData {
+	short *shadfacs;				/* simple storage for solid only */
+	ISBShadfacA **shadfaca;
+	struct MemArena *memarena;
+	int minx, miny, rectx, recty;	/* copy from part disprect */
+} ISBData;
 
 #endif /* SHADBUF_EXT_H */