Cycles Hair: refactoring to store curves with the index of the first key and the

number of keys in the curve, rather than curve segments with the indices of two
keys. ShaderData.segment now stores the segment number in the curve.

1 files changed, 14 insertions, 12 deletions

diff --git a/intern/cycles/kernel/kernel_light.h b/intern/cycles/kernel/kernel_light.h
index 09ee1f68e12..1561ddc9ddd 100644
--- a/intern/cycles/kernel/kernel_light.h
+++ b/intern/cycles/kernel/kernel_light.h
@@ -329,18 +329,20 @@ __device float triangle_light_pdf(KernelGlobals *kg,
 #ifdef __HAIR__
 /* Strand Light */
 
-__device void curve_seg_light_sample(KernelGlobals *kg, int prim, int object,
-	float randu, float randv, float time, LightSample *ls)
+__device void curve_segment_light_sample(KernelGlobals *kg, int prim, int object,
+	int segment, float randu, float randv, float time, LightSample *ls)
 {
 	/* this strand code needs completion */
-	float4 v00 = kernel_tex_fetch(__curve_segments, prim);
+	float4 v00 = kernel_tex_fetch(__curves, prim);
+
+	int k0 = __float_as_int(v00.x) + segment;
+	int k1 = k0 + 1;
 
-	int v1 = __float_as_int(v00.x);
-	int v2 = __float_as_int(v00.y);
-	float l = v00.w;
+	float4 P1 = kernel_tex_fetch(__curve_keys, k0);
+	float4 P2 = kernel_tex_fetch(__curve_keys, k1);
+
+	float l = len(P2 - P1); // XXX slower
 
-	float4 P1 = kernel_tex_fetch(__curve_keys, v1);
-	float4 P2 = kernel_tex_fetch(__curve_keys, v2);
 	float r1 = P1.w;
 	float r2 = P2.w;
 	float3 tg = float4_to_float3(P2 - P1) / l;
@@ -419,15 +421,15 @@ __device void light_sample(KernelGlobals *kg, float randt, float randu, float ra
 	float4 l = kernel_tex_fetch(__light_distribution, index);
 	int prim = __float_as_int(l.y);
 #ifdef __HAIR__
-/* currently use l.z to indicate is strand sample which isn't ideal */
-	bool is_curve = __float_as_int(l.z) == 0.0f;
+	int segment = __float_as_int(l.z);
 #endif
 
 	if(prim >= 0) {
 		int object = __float_as_int(l.w);
+
 #ifdef __HAIR__
-		if (is_curve)
-			curve_seg_light_sample(kg, prim, object, randu, randv, time, ls);
+		if (segment != ~0)
+			curve_segment_light_sample(kg, prim, object, segment, randu, randv, time, ls);
 		else
 #endif
 			triangle_light_sample(kg, prim, object, randu, randv, time, ls);