Redoing the blur filters for composit;

http://www.blender.org/bf/filters/

I found out current blur actually doesn't do gauss, but more did regular
quadratic. Now you can choose common filter types, but more specifically;

- set gamma on, to emphasize bright parts in blur more than darker parts
- use the bokeh option for (current circlular only) blur based on true
  area filters (meaning, for each pixel it samples the entire surrounding).
  This enables more effects, but is also much slower. Have to check on
  optimization for this still... use with care!

2 files changed, 37 insertions, 2 deletions

diff --git a/source/blender/render/extern/include/RE_pipeline.h b/source/blender/render/extern/include/RE_pipeline.h
index 1afce546791..07d0b0a1315 100644
--- a/source/blender/render/extern/include/RE_pipeline.h
+++ b/source/blender/render/extern/include/RE_pipeline.h
@@ -171,8 +171,8 @@ void RE_test_break_cb	(struct Render *re, int (*f)(void));
 void RE_test_return_cb	(struct Render *re, int (*f)(void));
 void RE_error_cb		(struct Render *re, void (*f)(const char *str));
 
-
-
+/* should move to kernel once... still unsure on how/where */
+float RE_filter_value(int type, float x);
 
 #endif /* RE_PIPELINE_H */
 
diff --git a/source/blender/render/intern/source/initrender.c b/source/blender/render/intern/source/initrender.c
index 9a36cf99e27..19d593a9409 100644
--- a/source/blender/render/intern/source/initrender.c
+++ b/source/blender/render/intern/source/initrender.c
@@ -153,6 +153,41 @@ static float filt_mitchell(float x)	/* Mitchell & Netravali's two-param cubic */
 	return 0.0;
 }
 
+/* x ranges from -1 to 1 */
+float RE_filter_value(int type, float x)
+{
+	float gaussfac= 1.6f;
+	
+	x= ABS(x);
+	
+	switch(type) {
+		case R_FILTER_BOX:
+			if(x>1.0) return 0.0f;
+			return 1.0;
+			
+		case R_FILTER_TENT:
+			if(x>1.0) return 0.0f;
+			return 1.0f-x;
+			
+		case R_FILTER_GAUSS:
+			x*= gaussfac;
+			return (1.0/exp(x*x) - 1.0/exp(gaussfac*gaussfac*2.25));
+			
+		case R_FILTER_MITCH:
+			return filt_mitchell(x*gaussfac);
+			
+		case R_FILTER_QUAD:
+			return filt_quadratic(x*gaussfac);
+			
+		case R_FILTER_CUBIC:
+			return filt_cubic(x*gaussfac);
+			
+		case R_FILTER_CATROM:
+			return filt_catrom(x*gaussfac);
+	}
+	return 0.0f;
+}
+
 static float calc_weight(Render *re, float *weight, int i, int j)
 {
 	float x, y, dist, totw= 0.0;