1 files changed, 34 insertions, 0 deletions
diff --git a/source/blender/draw/modes/shaders/overlay_face_wireframe_geom.glsl b/source/blender/draw/modes/shaders/overlay_face_wireframe_geom.glsl
index 1cea418419e..8f5712cca03 100644
--- a/source/blender/draw/modes/shaders/overlay_face_wireframe_geom.glsl
+++ b/source/blender/draw/modes/shaders/overlay_face_wireframe_geom.glsl
@@ -1,7 +1,12 @@
 
+/* This shader is only used for intel GPU where the Geom shader is faster
+ * than doing everything thrice in the vertex shader. */
+
 layout(triangles) in;
 layout(triangle_strip, max_vertices = 3) out;
 
+uniform vec2 wireStepParam;
+
 in vec2 ssPos[];
 in float facingOut[];
 
@@ -10,8 +15,16 @@ flat out vec3 ssVec1;
 flat out vec3 ssVec2;
 out float facing;
 
+#ifdef LIGHT_EDGES
+in vec3 obPos[];
+in vec3 edgeAdj[];
+
+flat out vec3 edgeSharpness;
+#endif
+
 #define NO_EDGE vec3(10000.0);
 
+/* TODO(fclem) remove code duplication. */
 vec3 compute_vec(vec2 v0, vec2 v1)
 {
 	vec2 v = normalize(v1 - v0);
@@ -19,6 +32,13 @@ vec3 compute_vec(vec2 v0, vec2 v1)
 	return vec3(v, -dot(v, v0));
 }
 
+float get_edge_sharpness(vec3 e0, vec3 e1, vec3 e2)
+{
+	vec3 n0 = normalize(cross(e0, e1));
+	vec3 n1 = normalize(cross(e1, e2));
+	return dot(n0, n1);
+}
+
 void main(void)
 {
 	vec3 facings = vec3(facingOut[0], facingOut[1], facingOut[2]);
@@ -29,6 +49,20 @@ void main(void)
 	ssVec1 = do_edge.y ? compute_vec(ssPos[1], ssPos[2]) : NO_EDGE;
 	ssVec2 = do_edge.z ? compute_vec(ssPos[2], ssPos[0]) : NO_EDGE;
 
+#ifdef LIGHT_EDGES
+	vec3 edges[3];
+	edges[0] = obPos[1] - obPos[0];
+	edges[1] = obPos[2] - obPos[1];
+	edges[2] = obPos[0] - obPos[2];
+
+	edgeSharpness.x = get_edge_sharpness(edgeAdj[0] - obPos[0], edges[0], -edges[2]);
+	edgeSharpness.y = get_edge_sharpness(edgeAdj[1] - obPos[1], edges[1], -edges[0]);
+	edgeSharpness.z = get_edge_sharpness(edgeAdj[2] - obPos[2], edges[2], -edges[1]);
+
+	/* Easy to adjust parameters. */
+	edgeSharpness = smoothstep(wireStepParam.xxx, wireStepParam.yyy, edgeSharpness);
+#endif
+
 	gl_Position = gl_in[0].gl_Position;
 	facing = facings.x;
 	EmitVertex();