Fix T62876: Camera Background Images

Migrate old legacy code to the draw mamager/object mode. The old legacy
version did not work with wireframe. By migrating the code
to modern draw manager code we have mode control on the drawing process.

Still background images do not work with OIT, the cause seems to be that the transparent pixels are treated as background pixels.
Also There are some artifacts when working with Holdouts and DoF, this
is because the draw engines do not pass the correct alpha values.

Reviewers: fclem, brecht

Differential Revision: https://developer.blender.org/D4638

1 files changed, 0 insertions, 25 deletions

diff --git a/source/blender/draw/modes/shaders/object_empty_image_frag.glsl b/source/blender/draw/modes/shaders/object_empty_image_frag.glsl
index 88220140aec..7dfbf469adc 100644
--- a/source/blender/draw/modes/shaders/object_empty_image_frag.glsl
+++ b/source/blender/draw/modes/shaders/object_empty_image_frag.glsl
@@ -15,31 +15,6 @@ uniform bool imagePremultiplied;
 uniform int depthMode;
 uniform bool useAlphaTest;
 
-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_srgb(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;
-  }
-  color.r = linearrgb_to_srgb(color.r);
-  color.g = linearrgb_to_srgb(color.g);
-  color.b = linearrgb_to_srgb(color.b);
-  return color;
-}
-
 void main()
 {
 #ifdef USE_WIRE