Eevee: Implement Wireframe Node

This implementation is a bit hacky but match cycles pretty close.

If pixel size is not enabled, it will use the geom shader to
compute distances between vertices. This will have a cost.

Implementation is a bit hacky in gpu_codegen to make the geom shader works
in an optional manner.

1 files changed, 12 insertions, 0 deletions

diff --git a/source/blender/nodes/shader/nodes/node_shader_wireframe.c b/source/blender/nodes/shader/nodes/node_shader_wireframe.c
index 11d889def31..3592f98d81d 100644
--- a/source/blender/nodes/shader/nodes/node_shader_wireframe.c
+++ b/source/blender/nodes/shader/nodes/node_shader_wireframe.c
@@ -38,6 +38,17 @@ static bNodeSocketTemplate sh_node_wireframe_out[] = {
 	{	-1, 0, ""	}
 };
 
+static int node_shader_gpu_wireframe(GPUMaterial *mat, bNode *node, bNodeExecData *UNUSED(execdata), GPUNodeStack *in, GPUNodeStack *out)
+{
+	/* node->custom1 is use_pixel_size */
+	if (node->custom1) {
+		return GPU_stack_link(mat, node, "node_wireframe_screenspace", in, out, GPU_builtin(GPU_BARYCENTRIC_TEXCO));
+	}
+	else {
+		return GPU_stack_link(mat, node, "node_wireframe", in, out, GPU_builtin(GPU_BARYCENTRIC_TEXCO), GPU_builtin(GPU_BARYCENTRIC_DIST));
+	}
+}
+
 /* node type definition */
 void register_node_type_sh_wireframe(void)
 {
@@ -47,6 +58,7 @@ void register_node_type_sh_wireframe(void)
 	node_type_socket_templates(&ntype, sh_node_wireframe_in, sh_node_wireframe_out);
 	node_type_init(&ntype, NULL);
 	node_type_storage(&ntype, "", NULL, NULL);
+	node_type_gpu(&ntype, node_shader_gpu_wireframe);
 
 	nodeRegisterType(&ntype);
 }