Cycles: Refactor how we pass bounce info to light path node.

This commit changes the way how we pass bounce information to the Light
Path node. Instead of manualy copying the bounces into ShaderData, we now
directly pass PathState. This reduces the arguments that we need to pass
around and also makes it easier to extend the feature.

This commit also exposes the Transmission Bounce Depth to the Light Path
node. It works similar to the Transparent Depth Output: Replace a
Transmission lightpath after X bounces with another shader, e.g a Diffuse
one. This can be used to avoid black surfaces, due to low amount of max
bounces.

Reviewed by Sergey and Brecht, thanks for some hlp with this.

I tested compilation and usage on CPU (SVM and OSL), CUDA, OpenCL Split
and Mega kernel. Hopefully this covers all devices. :)

1 files changed, 2 insertions, 2 deletions

diff --git a/intern/cycles/kernel/svm/svm.h b/intern/cycles/kernel/svm/svm.h
index 69b98060c62..633e1edfb19 100644
--- a/intern/cycles/kernel/svm/svm.h
+++ b/intern/cycles/kernel/svm/svm.h
@@ -187,7 +187,7 @@ CCL_NAMESPACE_BEGIN
 #define NODES_FEATURE(feature) ((__NODES_FEATURES__ & (feature)) != 0)
 
 /* Main Interpreter Loop */
-ccl_device_noinline void svm_eval_nodes(KernelGlobals *kg, ShaderData *sd, ShaderType type, int path_flag)
+ccl_device_noinline void svm_eval_nodes(KernelGlobals *kg, ShaderData *sd, ccl_addr_space PathState *state, ShaderType type, int path_flag)
 {
 	float stack[SVM_STACK_SIZE];
 	int offset = ccl_fetch(sd, shader) & SHADER_MASK;
@@ -335,7 +335,7 @@ ccl_device_noinline void svm_eval_nodes(KernelGlobals *kg, ShaderData *sd, Shade
 				svm_node_brightness(sd, stack, node.y, node.z, node.w);
 				break;
 			case NODE_LIGHT_PATH:
-				svm_node_light_path(sd, stack, node.y, node.z, path_flag);
+				svm_node_light_path(sd, state, stack, node.y, node.z, path_flag);
 				break;
 			case NODE_OBJECT_INFO:
 				svm_node_object_info(kg, sd, stack, node.y, node.z);