From 4ee2b4322951e46f20355107758d6aea96c58245 Mon Sep 17 00:00:00 2001
From: Sam Gateau <samuel.gateau@gmail.com>
Date: Sun, 24 Feb 2019 20:49:51 -0800
Subject: [PATCH] FIxing the gamma correction for Quest, intoducing simple gpu 
 lib conversion shaders

---
 .../src/display-plugins/SrgbToLinear.slf      | 23 -------------------
 .../src/display-plugins/SrgbToLinear.slp      |  1 -
 libraries/gpu/src/gpu/Color.slh               |  8 +++++--
 3 files changed, 6 insertions(+), 26 deletions(-)
 delete mode 100644 libraries/display-plugins/src/display-plugins/SrgbToLinear.slf
 delete mode 100644 libraries/display-plugins/src/display-plugins/SrgbToLinear.slp

diff --git a/libraries/display-plugins/src/display-plugins/SrgbToLinear.slf b/libraries/display-plugins/src/display-plugins/SrgbToLinear.slf
deleted file mode 100644
index 428ec821a6..0000000000
--- a/libraries/display-plugins/src/display-plugins/SrgbToLinear.slf
+++ /dev/null
@@ -1,23 +0,0 @@
-// OpenGLDisplayPlugin_present.frag
-
-LAYOUT(binding=0) uniform sampler2D colorMap;
-
-layout(location=0) in vec2 varTexCoord0;
-
-layout(location=0) out vec4 outFragColor;
-
-float sRGBFloatToLinear(float value) {
-    const float SRGB_ELBOW = 0.04045;
-
-    return mix(pow((value + 0.055) / 1.055, 2.4), value / 12.92, float(value <= SRGB_ELBOW));
-}
-
-vec3 colorToLinearRGB(vec3 srgb) {
-    return vec3(sRGBFloatToLinear(srgb.r), sRGBFloatToLinear(srgb.g), sRGBFloatToLinear(srgb.b));
-}
-
-void main(void) {
-    outFragColor.a = 1.0;
- //   outFragColor.rgb = colorToLinearRGB(texture(colorMap, varTexCoord0).rgb);
-    outFragColor.rgb = pow(texture(colorMap, varTexCoord0).rgb, vec3(1.0 / 2.2));
-}
diff --git a/libraries/display-plugins/src/display-plugins/SrgbToLinear.slp b/libraries/display-plugins/src/display-plugins/SrgbToLinear.slp
deleted file mode 100644
index c2c4bfbebd..0000000000
--- a/libraries/display-plugins/src/display-plugins/SrgbToLinear.slp
+++ /dev/null
@@ -1 +0,0 @@
-VERTEX gpu::vertex::DrawUnitQuadTexcoord
diff --git a/libraries/gpu/src/gpu/Color.slh b/libraries/gpu/src/gpu/Color.slh
index af61e5a34b..c676e66c6c 100644
--- a/libraries/gpu/src/gpu/Color.slh
+++ b/libraries/gpu/src/gpu/Color.slh
@@ -23,7 +23,10 @@ float color_scalar_sRGBToLinear(float value) {
 }
 
 vec3 color_sRGBToLinear(vec3 srgb) {
-    return vec3(color_scalar_sRGBToLinear(srgb.r), color_scalar_sRGBToLinear(srgb.g), color_scalar_sRGBToLinear(srgb.b));
+   // return vec3(color_scalar_sRGBToLinear(srgb.r), color_scalar_sRGBToLinear(srgb.g), color_scalar_sRGBToLinear(srgb.b));
+    // Same as pow(value, 2.2)
+    return mix(pow((srgb + vec3(0.055)) / vec3(1.055), vec3(2.4)), srgb / vec3(12.92), vec3(lessThanEqual(srgb, vec3(0.04045))));
+
 }
 
 vec4 color_sRGBAToLinear(vec4 srgba) {
@@ -38,7 +41,8 @@ float color_scalar_LinearTosRGB(float value) {
 
 vec3 color_LinearTosRGB(vec3 lrgb) {
     // Same as return pow(lrgb, 1/2.2)
-    return vec3(color_scalar_LinearTosRGB(lrgb.r), color_scalar_LinearTosRGB(lrgb.g), color_scalar_LinearTosRGB(lrgb.b));
+//    return vec3(color_scalar_LinearTosRGB(lrgb.r), color_scalar_LinearTosRGB(lrgb.g), color_scalar_LinearTosRGB(lrgb.b));
+    return mix(vec3(1.055) * pow(vec3(lrgb), vec3(0.41666)) - vec3(0.055), vec3(lrgb) * vec3(12.92), vec3(lessThan(lrgb, vec3(0.0031308))));
 }
 
 vec4 color_LinearTosRGBA(vec4 lrgba) {