DwM: Support flat-shaded w/ clay & eevee engines

Needed for sculpt mode drawing w/ engines, see: T51497

2 files changed, 12 insertions, 0 deletions

diff --git a/source/blender/draw/engines/eevee/shaders/lit_surface_frag.glsl b/source/blender/draw/engines/eevee/shaders/lit_surface_frag.glsl
index 769d8dcd7bb..fe460e73477 100644
--- a/source/blender/draw/engines/eevee/shaders/lit_surface_frag.glsl
+++ b/source/blender/draw/engines/eevee/shaders/lit_surface_frag.glsl
@@ -27,8 +27,14 @@ layout(std140) uniform shadow_block {
 
 in vec3 worldPosition;
 in vec3 viewPosition;
+
+#ifdef USE_FLAT_NORMAL
+flat in vec3 worldNormal;
+flat in vec3 viewNormal;
+#else
 in vec3 worldNormal;
 in vec3 viewNormal;
+#endif
 
 /* type */
 #define POINT    0.0
diff --git a/source/blender/draw/engines/eevee/shaders/lit_surface_vert.glsl b/source/blender/draw/engines/eevee/shaders/lit_surface_vert.glsl
index 7f1c32c8edf..cf5c8a311f1 100644
--- a/source/blender/draw/engines/eevee/shaders/lit_surface_vert.glsl
+++ b/source/blender/draw/engines/eevee/shaders/lit_surface_vert.glsl
@@ -12,8 +12,14 @@ in vec3 nor;
 
 out vec3 worldPosition;
 out vec3 viewPosition;
+
+#ifdef USE_FLAT_NORMAL
+flat out vec3 worldNormal;
+flat out vec3 viewNormal;
+#else
 out vec3 worldNormal;
 out vec3 viewNormal;
+#endif
 
 void main() {
 	gl_Position = ModelViewProjectionMatrix * vec4(pos, 1.0);