Cycles Hair: refactoring to support generic attributes for hair curves. There

should be no functional changes yet. UV, tangent and intercept are now stored
as attributes, with the intention to add more like multiple uv's, vertex
colors, generated coordinates and motion vectors later.

Things got a bit messy due to having both triangle and curve data in the same
mesh data structure, which also gives us two sets of attributes. This will get
cleaned up when we split the mesh class.

3 files changed, 74 insertions, 145 deletions

diff --git a/intern/cycles/kernel/svm/svm_attribute.h b/intern/cycles/kernel/svm/svm_attribute.h
index 4f9dc4af007..f11b69138d1 100644
--- a/intern/cycles/kernel/svm/svm_attribute.h
+++ b/intern/cycles/kernel/svm/svm_attribute.h
@@ -28,10 +28,13 @@ __device void svm_node_attr_init(KernelGlobals *kg, ShaderData *sd,
 		/* find attribute by unique id */
 		uint id = node.y;
 		uint attr_offset = sd->object*kernel_data.bvh.attributes_map_stride;
+		attr_offset = (sd->curve_seg == ~0)? attr_offset: attr_offset + ATTR_PRIM_CURVE;
 		uint4 attr_map = kernel_tex_fetch(__attributes_map, attr_offset);
-
-		while(attr_map.x != id)
-			attr_map = kernel_tex_fetch(__attributes_map, ++attr_offset);
+		
+		while(attr_map.x != id) {
+			attr_offset += ATTR_PRIM_TYPES;
+			attr_map = kernel_tex_fetch(__attributes_map, attr_offset);
+		}
 
 		/* return result */
 		*elem = (AttributeElement)attr_map.y;
@@ -58,45 +61,27 @@ __device void svm_node_attr(KernelGlobals *kg, ShaderData *sd, float *stack, uin
 
 	svm_node_attr_init(kg, sd, node, &type, &mesh_type, &elem, &offset, &out_offset);
 
-#ifdef __HAIR__
-	if (sd->curve_seg != ~0) {
-		/*currently strand attributes aren't enabled - only exports stored uvs*/
-		if(type == NODE_ATTR_FLOAT)
-			stack_store_float(stack, out_offset, 0.0f);
+	/* fetch and store attribute */
+	if(type == NODE_ATTR_FLOAT) {
+		if(mesh_type == NODE_ATTR_FLOAT) {
+			float f = primitive_attribute_float(kg, sd, elem, offset, NULL, NULL);
+			stack_store_float(stack, out_offset, f);
+		}
 		else {
-			float4 sd2 = kernel_tex_fetch(__tri_woop, sd->prim*3+2);
-			float3 uv =  make_float3(sd2.z,sd2.w,0.0f);
-			stack_store_float3(stack, out_offset, uv);
+			float3 f = primitive_attribute_float3(kg, sd, elem, offset, NULL, NULL);
+			stack_store_float(stack, out_offset, average(f));
 		}
 	}
-	else
-	{
-#endif
-
-		/* fetch and store attribute */
-		if(type == NODE_ATTR_FLOAT) {
-			if(mesh_type == NODE_ATTR_FLOAT) {
-				float f = triangle_attribute_float(kg, sd, elem, offset, NULL, NULL);
-				stack_store_float(stack, out_offset, f);
-			}
-			else {
-				float3 f = triangle_attribute_float3(kg, sd, elem, offset, NULL, NULL);
-				stack_store_float(stack, out_offset, average(f));
-			}
+	else {
+		if(mesh_type == NODE_ATTR_FLOAT3) {
+			float3 f = primitive_attribute_float3(kg, sd, elem, offset, NULL, NULL);
+			stack_store_float3(stack, out_offset, f);
 		}
 		else {
-			if(mesh_type == NODE_ATTR_FLOAT3) {
-				float3 f = triangle_attribute_float3(kg, sd, elem, offset, NULL, NULL);
-				stack_store_float3(stack, out_offset, f);
-			}
-			else {
-				float f = triangle_attribute_float(kg, sd, elem, offset, NULL, NULL);
-				stack_store_float3(stack, out_offset, make_float3(f, f, f));
-			}
+			float f = primitive_attribute_float(kg, sd, elem, offset, NULL, NULL);
+			stack_store_float3(stack, out_offset, make_float3(f, f, f));
 		}
-#ifdef __HAIR__
 	}
-#endif
 }
 
 __device void svm_node_attr_bump_dx(KernelGlobals *kg, ShaderData *sd, float *stack, uint4 node)
@@ -109,43 +94,30 @@ __device void svm_node_attr_bump_dx(KernelGlobals *kg, ShaderData *sd, float *st
 	svm_node_attr_init(kg, sd, node, &type, &mesh_type, &elem, &offset, &out_offset);
 
 	/* fetch and store attribute */
-#ifdef __HAIR__
-	if (sd->curve_seg != ~0) {
-		/*currently strand attributes aren't enabled*/
-		if(type == NODE_ATTR_FLOAT)
-			stack_store_float(stack, out_offset, 0.0f);
-		else
-			stack_store_float3(stack, out_offset,  make_float3(0.0f, 0.0f, 0.0f));
+	if(type == NODE_ATTR_FLOAT) {
+		if(mesh_type == NODE_ATTR_FLOAT) {
+			float dx;
+			float f = primitive_attribute_float(kg, sd, elem, offset, &dx, NULL);
+			stack_store_float(stack, out_offset, f+dx);
+		}
+		else {
+			float3 dx;
+			float3 f = primitive_attribute_float3(kg, sd, elem, offset, &dx, NULL);
+			stack_store_float(stack, out_offset, average(f+dx));
+		}
 	}
 	else {
-#endif
-		if(type == NODE_ATTR_FLOAT) {
-			if(mesh_type == NODE_ATTR_FLOAT) {
-				float dx;
-				float f = triangle_attribute_float(kg, sd, elem, offset, &dx, NULL);
-				stack_store_float(stack, out_offset, f+dx);
-			}
-			else {
-				float3 dx;
-				float3 f = triangle_attribute_float3(kg, sd, elem, offset, &dx, NULL);
-				stack_store_float(stack, out_offset, average(f+dx));
-			}
+		if(mesh_type == NODE_ATTR_FLOAT3) {
+			float3 dx;
+			float3 f = primitive_attribute_float3(kg, sd, elem, offset, &dx, NULL);
+			stack_store_float3(stack, out_offset, f+dx);
 		}
 		else {
-			if(mesh_type == NODE_ATTR_FLOAT3) {
-				float3 dx;
-				float3 f = triangle_attribute_float3(kg, sd, elem, offset, &dx, NULL);
-				stack_store_float3(stack, out_offset, f+dx);
-			}
-			else {
-				float dx;
-				float f = triangle_attribute_float(kg, sd, elem, offset, &dx, NULL);
-				stack_store_float3(stack, out_offset, make_float3(f+dx, f+dx, f+dx));
-			}
+			float dx;
+			float f = primitive_attribute_float(kg, sd, elem, offset, &dx, NULL);
+			stack_store_float3(stack, out_offset, make_float3(f+dx, f+dx, f+dx));
 		}
-#ifdef __HAIR__
 	}
-#endif
 }
 
 __device void svm_node_attr_bump_dy(KernelGlobals *kg, ShaderData *sd, float *stack, uint4 node)
@@ -158,43 +130,30 @@ __device void svm_node_attr_bump_dy(KernelGlobals *kg, ShaderData *sd, float *st
 	svm_node_attr_init(kg, sd, node, &type, &mesh_type, &elem, &offset, &out_offset);
 
 	/* fetch and store attribute */
-#ifdef __HAIR__
-	if (sd->curve_seg != ~0) {
-		/*currently strand attributes aren't enabled*/
-		if(type == NODE_ATTR_FLOAT)
-			stack_store_float(stack, out_offset, 0.0f);
-		else 
-			stack_store_float3(stack, out_offset,  make_float3(0.0f, 0.0f, 0.0f));
+	if(type == NODE_ATTR_FLOAT) {
+		if(mesh_type == NODE_ATTR_FLOAT) {
+			float dy;
+			float f = primitive_attribute_float(kg, sd, elem, offset, NULL, &dy);
+			stack_store_float(stack, out_offset, f+dy);
+		}
+		else {
+			float3 dy;
+			float3 f = primitive_attribute_float3(kg, sd, elem, offset, NULL, &dy);
+			stack_store_float(stack, out_offset, average(f+dy));
+		}
 	}
 	else {
-#endif
-		if(type == NODE_ATTR_FLOAT) {
-			if(mesh_type == NODE_ATTR_FLOAT) {
-				float dy;
-				float f = triangle_attribute_float(kg, sd, elem, offset, NULL, &dy);
-				stack_store_float(stack, out_offset, f+dy);
-			}
-			else {
-				float3 dy;
-				float3 f = triangle_attribute_float3(kg, sd, elem, offset, NULL, &dy);
-				stack_store_float(stack, out_offset, average(f+dy));
-			}
+		if(mesh_type == NODE_ATTR_FLOAT3) {
+			float3 dy;
+			float3 f = primitive_attribute_float3(kg, sd, elem, offset, NULL, &dy);
+			stack_store_float3(stack, out_offset, f+dy);
 		}
 		else {
-			if(mesh_type == NODE_ATTR_FLOAT3) {
-				float3 dy;
-				float3 f = triangle_attribute_float3(kg, sd, elem, offset, NULL, &dy);
-				stack_store_float3(stack, out_offset, f+dy);
-			}
-			else {
-				float dy;
-				float f = triangle_attribute_float(kg, sd, elem, offset, NULL, &dy);
-				stack_store_float3(stack, out_offset, make_float3(f+dy, f+dy, f+dy));
-			}
+			float dy;
+			float f = primitive_attribute_float(kg, sd, elem, offset, NULL, &dy);
+			stack_store_float3(stack, out_offset, make_float3(f+dy, f+dy, f+dy));
 		}
-#ifdef __HAIR__
 	}
-#endif
 }
 
 CCL_NAMESPACE_END
diff --git a/intern/cycles/kernel/svm/svm_geometry.h b/intern/cycles/kernel/svm/svm_geometry.h
index e1b898e9b14..db8bbabe0ec 100644
--- a/intern/cycles/kernel/svm/svm_geometry.h
+++ b/intern/cycles/kernel/svm/svm_geometry.h
@@ -28,26 +28,7 @@ __device void svm_node_geometry(KernelGlobals *kg, ShaderData *sd, float *stack,
 		case NODE_GEOM_P: data = sd->P; break;
 		case NODE_GEOM_N: data = sd->N; break;
 #ifdef __DPDU__
-		case NODE_GEOM_T: {
-			/* try to create spherical tangent from generated coordinates */
-			int attr_offset = (sd->object != ~0)? find_attribute(kg, sd, ATTR_STD_GENERATED): ATTR_STD_NOT_FOUND;
-#ifdef __HAIR__
-			if(attr_offset != ATTR_STD_NOT_FOUND && sd->curve_seg == ~0) {
-#else
-			if(attr_offset != ATTR_STD_NOT_FOUND) {
-#endif
-				data = triangle_attribute_float3(kg, sd, ATTR_ELEMENT_VERTEX, attr_offset, NULL, NULL);
-				data = make_float3(-(data.y - 0.5f), (data.x - 0.5f), 0.0f);
-				object_normal_transform(kg, sd, &data);
-				data = cross(sd->N, normalize(cross(data, sd->N)));;
-			}
-			else {
-				/* otherwise use surface derivatives */
-				data = normalize(sd->dPdu);
-			}
-
-			break;
-		}
+		case NODE_GEOM_T: data = primitive_tangent(kg, sd); break;
 #endif
 		case NODE_GEOM_I: data = sd->I; break;
 		case NODE_GEOM_Ng: data = sd->Ng; break;
@@ -164,6 +145,7 @@ __device void svm_node_particle_info(KernelGlobals *kg, ShaderData *sd, float *s
 }
 
 #ifdef __HAIR__
+
 /* Hair Info */
 
 __device void svm_node_hair_info(KernelGlobals *kg, ShaderData *sd, float *stack, uint type, uint out_offset)
@@ -177,18 +159,15 @@ __device void svm_node_hair_info(KernelGlobals *kg, ShaderData *sd, float *stack
 			stack_store_float(stack, out_offset, data);
 			break;
 		}
-		case NODE_INFO_CURVE_INTERCEPT: {
-			data = intercept(kg, sd->curve_seg, sd->prim, sd->u);
-			stack_store_float(stack, out_offset, data);
-			break;
-		}
+		case NODE_INFO_CURVE_INTERCEPT:
+			break; /* handled as attribute */
 		case NODE_INFO_CURVE_THICKNESS: {
-			data = 2 * hair_radius(kg, sd->curve_seg, sd->u);
+			data = curve_thickness(kg, sd);
 			stack_store_float(stack, out_offset, data);
 			break;
 		}
 		case NODE_INFO_CURVE_TANGENT_NORMAL: {
-			data3 = hair_tangent_normal(kg, sd);
+			data3 = curve_tangent_normal(kg, sd);
 			stack_store_float3(stack, out_offset, data3);
 			break;
 		}
diff --git a/intern/cycles/kernel/svm/svm_tex_coord.h b/intern/cycles/kernel/svm/svm_tex_coord.h
index 5e7c92ba93c..7a1af43b625 100644
--- a/intern/cycles/kernel/svm/svm_tex_coord.h
+++ b/intern/cycles/kernel/svm/svm_tex_coord.h
@@ -242,18 +242,15 @@ __device void svm_node_normal_map(KernelGlobals *kg, ShaderData *sd, float *stac
 
 	if(space == NODE_NORMAL_MAP_TANGENT) {
 		/* tangent space */
-#ifdef __HAIR__
-			if(sd->object == ~0 || sd->curve_seg != ~0) {
-#else
-			if(sd->object == ~0) {
-#endif
+		if(sd->object == ~0) {
 			stack_store_float3(stack, normal_offset, make_float3(0.0f, 0.0f, 0.0f));
 			return;
 		}
 
 		/* first try to get tangent attribute */
-		int attr_offset = find_attribute(kg, sd, node.z);
-		int attr_sign_offset = find_attribute(kg, sd, node.w);
+		AttributeElement attr_elem, attr_sign_elem;
+		int attr_offset = find_attribute(kg, sd, node.z, &attr_elem);
+		int attr_sign_offset = find_attribute(kg, sd, node.w, &attr_sign_elem);
 
 		if(attr_offset == ATTR_STD_NOT_FOUND || attr_sign_offset == ATTR_STD_NOT_FOUND) {
 			stack_store_float3(stack, normal_offset, make_float3(0.0f, 0.0f, 0.0f));
@@ -261,8 +258,8 @@ __device void svm_node_normal_map(KernelGlobals *kg, ShaderData *sd, float *stac
 		}
 
 		/* ensure orthogonal and normalized (interpolation breaks it) */
-		float3 tangent = triangle_attribute_float3(kg, sd, ATTR_ELEMENT_CORNER, attr_offset, NULL, NULL);
-		float sign = triangle_attribute_float(kg, sd, ATTR_ELEMENT_CORNER, attr_sign_offset, NULL, NULL);
+		float3 tangent = primitive_attribute_float3(kg, sd, attr_elem, attr_offset, NULL, NULL);
+		float sign = primitive_attribute_float(kg, sd, attr_sign_elem, attr_sign_offset, NULL, NULL);
 
 		object_normal_transform(kg, sd, &tangent);
 		tangent = cross(sd->N, normalize(cross(tangent, sd->N)));;
@@ -299,30 +296,24 @@ __device void svm_node_tangent(KernelGlobals *kg, ShaderData *sd, float *stack,
 
 	if(direction_type == NODE_TANGENT_UVMAP) {
 		/* UV map */
-		int attr_offset = find_attribute(kg, sd, node.z);
+		AttributeElement attr_elem;
+		int attr_offset = find_attribute(kg, sd, node.z, &attr_elem);
 
-#ifdef __HAIR__
-		if(attr_offset == ATTR_STD_NOT_FOUND || sd->curve_seg != ~0)
-#else
 		if(attr_offset == ATTR_STD_NOT_FOUND)
-#endif
 			tangent = make_float3(0.0f, 0.0f, 0.0f);
 		else
-			tangent = triangle_attribute_float3(kg, sd, ATTR_ELEMENT_CORNER, attr_offset, NULL, NULL);
+			tangent = primitive_attribute_float3(kg, sd, attr_elem, attr_offset, NULL, NULL);
 	}
 	else {
 		/* radial */
-		int attr_offset = find_attribute(kg, sd, node.z);
+		AttributeElement attr_elem;
+		int attr_offset = find_attribute(kg, sd, node.z, &attr_elem);
 		float3 generated;
 
-#ifdef __HAIR__
-		if(attr_offset == ATTR_STD_NOT_FOUND || sd->curve_seg != ~0)
-#else
 		if(attr_offset == ATTR_STD_NOT_FOUND)
-#endif
 			generated = sd->P;
 		else
-			generated = triangle_attribute_float3(kg, sd, ATTR_ELEMENT_VERTEX, attr_offset, NULL, NULL);
+			generated = primitive_attribute_float3(kg, sd, attr_elem, attr_offset, NULL, NULL);
 
 		if(axis == NODE_TANGENT_AXIS_X)
 			tangent = make_float3(0.0f, -(generated.z - 0.5f), (generated.y - 0.5f));