1 files changed, 11 insertions, 3 deletions
diff --git a/source/blender/draw/modes/shaders/object_outline_prepass_frag.glsl b/source/blender/draw/modes/shaders/object_outline_prepass_frag.glsl
index c3447456ea6..5d6c4881b5b 100644
--- a/source/blender/draw/modes/shaders/object_outline_prepass_frag.glsl
+++ b/source/blender/draw/modes/shaders/object_outline_prepass_frag.glsl
@@ -1,10 +1,18 @@
-uniform int callId;
-uniform int baseId;
+
+/* Should be 2 bits only [0..3]. */
+uniform int outlineId;
+
+flat in int objectId;
 
 /* using uint because 16bit uint can contain more ids than int. */
 out uint outId;
 
+/* 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()
 {
-  outId = uint(baseId + callId);
+  outId = (uint(outlineId) << 14u) | ((uint(objectId) << SHIFT) >> SHIFT);
 }