World background working on cycle nodes.

This is added in the spirit of the general cycles GLSL system
which is pretty much WIP still.

This will only work on cycles at the moment but generating for blender
internal is possible too of course though it will be done in a separate
commit.

This hasn't been tested with all and every node in cycles, but
environment and regular textures with texture coordinates work.

There is some difference between the way cycles treats some coordinates,
which is in world space and the way GLSL treats them, which is in view
space.
We might want to explore and improve this further in the future.

...also </drumroll>

4 files changed, 39 insertions, 8 deletions

diff --git a/source/blender/nodes/shader/nodes/node_shader_background.c b/source/blender/nodes/shader/nodes/node_shader_background.c
index 2478fb4d38c..b387529e456 100644
--- a/source/blender/nodes/shader/nodes/node_shader_background.c
+++ b/source/blender/nodes/shader/nodes/node_shader_background.c
@@ -40,6 +40,11 @@ static bNodeSocketTemplate sh_node_background_out[] = {
 	{	-1, 0, ""	}
 };
 
+static int node_shader_gpu_background(GPUMaterial *mat, bNode *UNUSED(node), bNodeExecData *UNUSED(execdata), GPUNodeStack *in, GPUNodeStack *out)
+{
+	return GPU_stack_link(mat, "node_background", in, out, GPU_builtin(GPU_VIEW_NORMAL));
+}
+
 /* node type definition */
 void register_node_type_sh_background(void)
 {
@@ -50,6 +55,7 @@ void register_node_type_sh_background(void)
 	node_type_socket_templates(&ntype, sh_node_background_in, sh_node_background_out);
 	node_type_init(&ntype, NULL);
 	node_type_storage(&ntype, "", NULL, NULL);
+	node_type_gpu(&ntype, node_shader_gpu_background);
 
 	nodeRegisterType(&ntype);
 }
diff --git a/source/blender/nodes/shader/nodes/node_shader_output_world.c b/source/blender/nodes/shader/nodes/node_shader_output_world.c
index c8e47c47c5f..ad7389fd56e 100644
--- a/source/blender/nodes/shader/nodes/node_shader_output_world.c
+++ b/source/blender/nodes/shader/nodes/node_shader_output_world.c
@@ -35,6 +35,16 @@ static bNodeSocketTemplate sh_node_output_world_in[] = {
 	{	-1, 0, ""	}
 };
 
+static int node_shader_gpu_output_world(GPUMaterial *mat, bNode *UNUSED(node), bNodeExecData *UNUSED(execdata), GPUNodeStack *in, GPUNodeStack *out)
+{
+	GPUNodeLink *outlink;
+
+	GPU_stack_link(mat, "node_output_world", in, out, &outlink);
+	GPU_material_output_link(mat, outlink);
+
+	return 1;
+}
+
 /* node type definition */
 void register_node_type_sh_output_world(void)
 {
@@ -45,7 +55,8 @@ void register_node_type_sh_output_world(void)
 	node_type_socket_templates(&ntype, sh_node_output_world_in, NULL);
 	node_type_init(&ntype, NULL);
 	node_type_storage(&ntype, "", NULL, NULL);
-
+	node_type_gpu(&ntype, node_shader_gpu_output_world);
+	
 	/* Do not allow muting output node. */
 	node_type_internal_links(&ntype, NULL);
 
diff --git a/source/blender/nodes/shader/nodes/node_shader_tex_coord.c b/source/blender/nodes/shader/nodes/node_shader_tex_coord.c
index 781b1bb5a93..85eca6ae990 100644
--- a/source/blender/nodes/shader/nodes/node_shader_tex_coord.c
+++ b/source/blender/nodes/shader/nodes/node_shader_tex_coord.c
@@ -46,10 +46,18 @@ static int node_shader_gpu_tex_coord(GPUMaterial *mat, bNode *UNUSED(node), bNod
 {
 	GPUNodeLink *orco = GPU_attribute(CD_ORCO, "");
 	GPUNodeLink *mtface = GPU_attribute(CD_MTFACE, "");
-
-	return GPU_stack_link(mat, "node_tex_coord", in, out,
-	                      GPU_builtin(GPU_VIEW_POSITION), GPU_builtin(GPU_VIEW_NORMAL),
-	                      GPU_builtin(GPU_INVERSE_VIEW_MATRIX), GPU_builtin(GPU_INVERSE_OBJECT_MATRIX), orco, mtface);
+	GPUMatType type = GPU_Material_get_type(mat);
+	
+	if (type == GPU_MATERIAL_TYPE_MESH) {
+		return GPU_stack_link(mat, "node_tex_coord", in, out,
+		                      GPU_builtin(GPU_VIEW_POSITION), GPU_builtin(GPU_VIEW_NORMAL),
+		                      GPU_builtin(GPU_INVERSE_VIEW_MATRIX), GPU_builtin(GPU_INVERSE_OBJECT_MATRIX), orco, mtface);
+	}
+	else {
+		return GPU_stack_link(mat, "node_tex_coord_background", in, out,
+		                      GPU_builtin(GPU_VIEW_POSITION), GPU_builtin(GPU_VIEW_NORMAL),
+		                      GPU_builtin(GPU_INVERSE_VIEW_MATRIX), GPU_builtin(GPU_INVERSE_OBJECT_MATRIX), orco, mtface);		
+	}
 }
 
 /* node type definition */
diff --git a/source/blender/nodes/shader/nodes/node_shader_tex_environment.c b/source/blender/nodes/shader/nodes/node_shader_tex_environment.c
index 56db9dd3b44..f6361331741 100644
--- a/source/blender/nodes/shader/nodes/node_shader_tex_environment.c
+++ b/source/blender/nodes/shader/nodes/node_shader_tex_environment.c
@@ -67,9 +67,15 @@ static int node_shader_gpu_tex_environment(GPUMaterial *mat, bNode *node, bNodeE
 	if (!ima)
 		return GPU_stack_link(mat, "node_tex_environment_empty", in, out);
 
-	if (!in[0].link)
-		in[0].link = GPU_builtin(GPU_VIEW_POSITION);
-
+	if (!in[0].link) {
+		GPUMatType type = GPU_Material_get_type(mat);
+		
+		if (type == GPU_MATERIAL_TYPE_MESH)
+			in[0].link = GPU_builtin(GPU_VIEW_POSITION);
+		else
+			GPU_link(mat, "background_transform_to_world", GPU_builtin(GPU_VIEW_POSITION), &in[0].link);
+	}
+	
 	node_shader_gpu_tex_mapping(mat, node, in, out);
 
 	if (tex->projection == SHD_PROJ_EQUIRECTANGULAR)