FIxing the gamma correction for Quest, intoducing simple gpu lib conversion shaders

libraries/display-plugins/src/display-plugins/OpenGLDisplayPlugin.cpp

@@ -380,16 +380,26 @@ void OpenGLDisplayPlugin::customizeContext() {
         scissorState->setScissorEnable(true);
 
         {
+#ifdef Q_OS_ANDROID
+            gpu::ShaderPointer program = gpu::Shader::createProgram(shader::gpu::program::DrawTextureGammaLinearToSRGB);
+#else
             gpu::ShaderPointer program = gpu::Shader::createProgram(shader::gpu::program::DrawTexture);
-            _simplePipeline = gpu::Pipeline::create(program, scissorState);
+#endif 
-            _hudPipeline = gpu::Pipeline::create(program, blendState);
+           _simplePipeline = gpu::Pipeline::create(program, scissorState);
         }
-
         {
-            gpu::ShaderPointer program = gpu::Shader::createProgram(shader::display_plugins::program::SrgbToLinear);
+#ifdef Q_OS_ANDROID
+            gpu::ShaderPointer program = gpu::Shader::createProgram(shader::gpu::program::DrawTextureGammaLinearToSRGB);
+#else
+            gpu::ShaderPointer program = gpu::Shader::createProgram(shader::gpu::program::DrawTextureGammaSRGBToLinear);
+#endif
             _presentPipeline = gpu::Pipeline::create(program, scissorState);
         }
 
+        {
+            gpu::ShaderPointer program = gpu::Shader::createProgram(shader::gpu::program::DrawTexture);
+            _hudPipeline = gpu::Pipeline::create(program, blendState);
+        }
         {
             gpu::ShaderPointer program = gpu::Shader::createProgram(shader::gpu::program::DrawTextureMirroredX);
             _mirrorHUDPipeline = gpu::Pipeline::create(program, blendState);
@@ -516,7 +526,6 @@ void OpenGLDisplayPlugin::renderFromTexture(gpu::Batch& batch, const gpu::Textur
 #ifndef USE_GLES
     batch.setPipeline(_presentPipeline);
 #else
-    //batch.setPipeline(_presentPipeline);
     batch.setPipeline(_simplePipeline);
 #endif
     batch.draw(gpu::TRIANGLE_STRIP, 4);
@@ -631,8 +640,7 @@ void OpenGLDisplayPlugin::compositeScene() {
         batch.setStateScissorRect(ivec4(uvec2(), _compositeFramebuffer->getSize()));
         batch.resetViewTransform();
         batch.setProjectionTransform(mat4());
-       // batch.setPipeline(_simplePipeline);
+        batch.setPipeline(_simplePipeline);
-        batch.setPipeline(_presentPipeline);
         batch.setResourceTexture(0, _currentFrame->framebuffer->getRenderBuffer(0));
         batch.draw(gpu::TRIANGLE_STRIP, 4);
     });

libraries/gpu/src/gpu/Color.slh

@@ -16,10 +16,10 @@
 // YCoCg =====> Luma (Y) chrominance green (Cg) and chrominance orange (Co)
 // https://software.intel.com/en-us/node/503873
 
+// sRGB ====> Linear
 float color_scalar_sRGBToLinear(float value) {
-    const float SRGB_ELBOW = 0.04045;
+    // Same as pow(value, 2.2)
-
+    return mix(pow((value + 0.055) / 1.055, 2.4), value / 12.92, float(value <= 0.04045));
-    return mix(pow((value + 0.055) / 1.055, 2.4), value / 12.92, float(value <= SRGB_ELBOW));
 }
 
 vec3 color_sRGBToLinear(vec3 srgb) {
@@ -30,6 +30,21 @@ vec4 color_sRGBAToLinear(vec4 srgba) {
     return vec4(color_sRGBToLinear(srgba.xyz), srgba.w);
 }
 
+// Linear ====> sRGB
+float color_scalar_LinearTosRGB(float value) {
+    // Same as return pow(value, 1/2.2)
+    return mix(1.055 * pow(value, 0.41666) - 0.055, value * 12.92, float(value < 0.0031308));
+}
+
+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));
+}
+
+vec4 color_LinearTosRGBA(vec4 lrgba) {
+    return vec4(color_LinearTosRGB(lrgba.xyz), lrgba.w);
+}
+
 vec3 color_LinearToYCoCg(vec3 rgb) {
     // Y = R/4 + G/2 + B/4
     // Co = R/2 - B/2

libraries/gpu/src/gpu/DrawTextureGammaLinearToSRGB.slf

@@ -0,0 +1,26 @@
+<@include gpu/Config.slh@>
+<$VERSION_HEADER$>
+//  Generated on <$_SCRIBE_DATE$>
+//
+//  DrawTexture.frag
+//
+//  Draw texture 0 fetched at texcoord.xy
+//
+//  Created by Sam Gateau on 6/22/2015
+//  Copyright 2015 High Fidelity, Inc.
+//
+//  Distributed under the Apache License, Version 2.0.
+//  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html
+//
+
+<@include gpu/Color.slh@>
+
+
+LAYOUT(binding=0) uniform sampler2D colorMap;
+
+layout(location=0) in vec2 varTexCoord0;
+layout(location=0) out vec4 outFragColor;
+
+void main(void) {
+    outFragColor = color_LinearTosRGBA(texture(colorMap, varTexCoord0));
+}

libraries/gpu/src/gpu/DrawTextureGammaLinearToSRGB.slp

@@ -0,0 +1 @@
+VERTEX DrawUnitQuadTexcoord

libraries/gpu/src/gpu/DrawTextureGammaSRGBToLinear.slf

@@ -0,0 +1,26 @@
+<@include gpu/Config.slh@>
+<$VERSION_HEADER$>
+//  Generated on <$_SCRIBE_DATE$>
+//
+//  DrawTexture.frag
+//
+//  Draw texture 0 fetched at texcoord.xy
+//
+//  Created by Sam Gateau on 6/22/2015
+//  Copyright 2015 High Fidelity, Inc.
+//
+//  Distributed under the Apache License, Version 2.0.
+//  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html
+//
+
+<@include gpu/Color.slh@>
+
+
+LAYOUT(binding=0) uniform sampler2D colorMap;
+
+layout(location=0) in vec2 varTexCoord0;
+layout(location=0) out vec4 outFragColor;
+
+void main(void) {
+    outFragColor = color_sRGBAToLinear(texture(colorMap, varTexCoord0));
+}

libraries/gpu/src/gpu/DrawTextureGammaSRGBToLinear.slp

@@ -0,0 +1 @@
+VERTEX DrawUnitQuadTexcoord

libraries/oculusMobile/src/ovr/Framebuffer.cpp

@@ -32,18 +32,19 @@ void Framebuffer::create(const glm::uvec2& size) {
     _validTexture = false;
 
     // Depth renderbuffer
-    glGenRenderbuffers(1, &_depth);
+  /*  glGenRenderbuffers(1, &_depth);
     glBindRenderbuffer(GL_RENDERBUFFER, _depth);
     glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH_COMPONENT24, _size.x, _size.y);
     glBindRenderbuffer(GL_RENDERBUFFER, 0);
-
+*/
     // Framebuffer
     glGenFramebuffers(1, &_fbo);
-    glBindFramebuffer(GL_DRAW_FRAMEBUFFER, _fbo);
+  //  glBindFramebuffer(GL_DRAW_FRAMEBUFFER, _fbo);
-    glFramebufferRenderbuffer(GL_DRAW_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_RENDERBUFFER, _depth);
+  //  glFramebufferRenderbuffer(GL_DRAW_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_RENDERBUFFER, _depth);
-    glBindFramebuffer(GL_FRAMEBUFFER, 0);
+  //  glBindFramebuffer(GL_FRAMEBUFFER, 0);
 
     _swapChain = vrapi_CreateTextureSwapChain3(VRAPI_TEXTURE_TYPE_2D, GL_RGBA8, _size.x, _size.y, 1, 3);
+
     _length = vrapi_GetTextureSwapChainLength(_swapChain);
     if (!_length) {
         __android_log_write(ANDROID_LOG_WARN, "QQQ_OVR", "Unable to count swap chain textures");