1 files changed, 74 insertions, 0 deletions
diff --git a/source/blender/draw/engines/overlay/shaders/overlay_outline_prepass_gpencil_vert.glsl b/source/blender/draw/engines/overlay/shaders/overlay_outline_prepass_gpencil_vert.glsl
new file mode 100644
index 00000000000..4b1470e5723
--- /dev/null
+++ b/source/blender/draw/engines/overlay/shaders/overlay_outline_prepass_gpencil_vert.glsl
@@ -0,0 +1,74 @@
+
+#pragma BLENDER_REQUIRE(common_view_clipping_lib.glsl)
+#pragma BLENDER_REQUIRE(common_view_lib.glsl)
+#pragma BLENDER_REQUIRE(common_gpencil_lib.glsl)
+
+uint outline_colorid_get(void)
+{
+  int flag = int(abs(ObjectInfo.w));
+  bool is_active = (flag & DRW_BASE_ACTIVE) != 0;
+
+  if (isTransform) {
+    return 0u; /* colorTransform */
+  }
+  else if (is_active) {
+    return 3u; /* colorActive */
+  }
+  else {
+    return 1u; /* colorSelect */
+  }
+
+  return 0u;
+}
+
+/* Replace top 2 bits (of the 16bit output) by outlineId.
+ * This leaves 16K different IDs to create outlines between objects.
+ * SHIFT = (32 - (16 - 2)) */
+#define SHIFT 18u
+
+void main()
+{
+  vec3 world_pos;
+  vec3 unused_N;
+  vec4 unused_color;
+  float unused_strength;
+  vec2 unused_uv;
+
+  gl_Position = gpencil_vertex(ma,
+                               ma1,
+                               ma2,
+                               ma3,
+                               pos,
+                               pos1,
+                               pos2,
+                               pos3,
+                               uv1,
+                               uv2,
+                               col1,
+                               col2,
+                               fcol1,
+                               vec4(drw_view.viewport_size, drw_view.viewport_size_inverse),
+                               world_pos,
+                               unused_N,
+                               unused_color,
+                               unused_strength,
+                               unused_uv,
+                               gp_interp.sspos,
+                               gp_interp.aspect,
+                               gp_interp.thickness,
+                               gp_interp.hardness);
+
+  /* Small bias to always be on top of the geom. */
+  gl_Position.z -= 1e-3;
+
+  /* ID 0 is nothing (background) */
+  interp.ob_id = uint(resource_handle + 1);
+
+  /* Should be 2 bits only [0..3]. */
+  uint outline_id = outline_colorid_get();
+
+  /* Combine for 16bit uint target. */
+  interp.ob_id = (outline_id << 14u) | ((interp.ob_id << SHIFT) >> SHIFT);
+
+  view_clipping_distances(world_pos);
+}