Viewport Rendering: Don't clamp when overlays are disabled.

During viewport rendering the color values were clamped in order to
apply the overlay on top of it. This clamping would show the scene
colors washed out.

This patch adds a work around to skip the clamping when the overlays are
turned off.

Parial fix for {T77909}

1 files changed, 6 insertions, 4 deletions

diff --git a/source/blender/gpu/shaders/gpu_shader_image_overlays_merge_frag.glsl b/source/blender/gpu/shaders/gpu_shader_image_overlays_merge_frag.glsl
index 73f40c693ae..7f3fe2f5252 100644
--- a/source/blender/gpu/shaders/gpu_shader_image_overlays_merge_frag.glsl
+++ b/source/blender/gpu/shaders/gpu_shader_image_overlays_merge_frag.glsl
@@ -4,6 +4,7 @@
 uniform sampler2D image_texture;
 uniform sampler2D overlays_texture;
 uniform bool display_transform;
+uniform bool overlay;
 
 in vec2 texCoord_interp;
 
@@ -30,12 +31,13 @@ void linearrgb_to_srgb(vec4 col_from, out vec4 col_to)
 void main()
 {
   fragColor = texture(image_texture, texCoord_interp.st);
-
   vec4 overlay_col = texture(overlays_texture, texCoord_interp.st);
 
-  fragColor = clamp(fragColor, 0.0, 1.0);
-  fragColor *= 1.0 - overlay_col.a;
-  fragColor += overlay_col;
+  if (overlay) {
+    fragColor = clamp(fragColor, 0.0, 1.0);
+    fragColor *= 1.0 - overlay_col.a;
+    fragColor += overlay_col;
+  }
 
   if (display_transform) {
     linearrgb_to_srgb(fragColor, fragColor);