converting material and mesh from srgb to linear in pipeline

libraries/model/src/model/Material.cpp

@@ -13,6 +13,18 @@
 using namespace model;
 using namespace gpu;
 
+float componentSRGBToLinear(float cs) {
+    if (cs >  0.04045) {
+        return pow(((cs + 0.055)/1.055), 2.4);
+    } else {
+        return cs / 12.92;
+    }
+}
+
+glm::vec3 convertSRGBToLinear(const glm::vec3& srgb) {
+    return glm::vec3(componentSRGBToLinear(srgb.x), componentSRGBToLinear(srgb.y), componentSRGBToLinear(srgb.z));
+}
+
 Material::Material() :
     _key(0),
     _schemaBuffer(),

libraries/model/src/model/Material.h

@@ -23,6 +23,10 @@
 
 namespace model {
 
+static glm::vec3 convertSRGBToLinear(const glm::vec3& srgb);
+
+
+
 // Material Key is a coarse trait description of a material used to classify the materials
 class MaterialKey {
 public:

libraries/model/src/model/Material.slh

@@ -26,8 +26,38 @@ Material getMaterial() {
     return _mat;
 }
 
+float componentSRGBToLinear(float cs) {
+    /* sRGB to linear conversion
+         {  cs / 12.92,                 cs <= 0.04045
+    cl = {
+         {  ((cs + 0.055)/1.055)^2.4,   cs >  0.04045
+
+    constants:
+    T = 0.04045
+    A = 1 / 1.055 = 0.94786729857
+    B = 0.055 * A = 0.05213270142
+    C = 1 / 12.92 = 0.0773993808
+    G = 2.4
+    */
+    const float T = 0.04045;
+    const float A = 0.947867;
+    const float B = 0.052132;
+    const float C = 0.077399;
+    const float G = 2.4;
+
+    if (cs > T) {
+        return pow((cs * A + B), G);
+    } else {
+        return cs * C;
+    }
+}
+
+vec3 SRGBToLinear(vec3 srgb) {
+    return vec3(componentSRGBToLinear(srgb.x),componentSRGBToLinear(srgb.y),componentSRGBToLinear(srgb.z));
+}
+
 float getMaterialOpacity(Material m) { return m._diffuse.a; }
-vec3 getMaterialDiffuse(Material m) { return m._diffuse.rgb; }
+vec3 getMaterialDiffuse(Material m) { return (gl_FragCoord.x > 800 ? SRGBToLinear(m._diffuse.rgb) : m._diffuse.rgb); }
 vec3 getMaterialSpecular(Material m) { return m._specular.rgb; }
 float getMaterialShininess(Material m) { return m._specular.a; }
 

libraries/render-utils/src/model.slf

@@ -28,12 +28,14 @@ void main(void) {
     // Fetch diffuse map
     vec4 diffuse = texture(diffuseMap, _texCoord0);
 
+    vec3 vertexColor = (gl_FragCoord.y > 400 ? SRGBToLinear(_color.rgb) : _color.rgb);
+
     Material mat = getMaterial();
 
     packDeferredFragment(
         normalize(_normal.xyz), 
         evalOpaqueFinalAlpha(getMaterialOpacity(mat), diffuse.a),
-        getMaterialDiffuse(mat) * diffuse.rgb * _color,
+        getMaterialDiffuse(mat) * diffuse.rgb * vertexColor,
         getMaterialSpecular(mat),
         getMaterialShininess(mat));
 }