1 files changed, 30 insertions, 0 deletions
diff --git a/source/blender/draw/intern/shaders/common_colormanagement_lib.glsl b/source/blender/draw/intern/shaders/common_colormanagement_lib.glsl
new file mode 100644
index 00000000000..45f711296f3
--- /dev/null
+++ b/source/blender/draw/intern/shaders/common_colormanagement_lib.glsl
@@ -0,0 +1,30 @@
+float linearrgb_to_srgb(float c)
+{
+  if (c < 0.0031308) {
+    return (c < 0.0) ? 0.0 : c * 12.92;
+  }
+  else {
+    return 1.055 * pow(c, 1.0 / 2.4) - 0.055;
+  }
+}
+
+vec4 texture_read_as_linearrgb(sampler2D tex, bool premultiplied, vec2 co)
+{
+  /* By convention image textures return scene linear colors, but
+   * overlays still assume srgb. */
+  vec4 color = texture(tex, co);
+  /* Unpremultiply if stored multiplied, since straight alpha is expected by shaders. */
+  if (premultiplied && !(color.a == 0.0 || color.a == 1.0)) {
+    color.rgb = color.rgb / color.a;
+  }
+  return color;
+}
+
+vec4 texture_read_as_srgb(sampler2D tex, bool premultiplied, vec2 co)
+{
+  vec4 color = texture_read_as_linearrgb(tex, premultiplied, co);
+  color.r = linearrgb_to_srgb(color.r);
+  color.g = linearrgb_to_srgb(color.g);
+  color.b = linearrgb_to_srgb(color.b);
+  return color;
+}