Enable the color blending for the skybox

libraries/model/src/model/Skybox.cpp

@@ -52,6 +52,8 @@ void Skybox::render(gpu::Batch& batch, const ViewFrustum& viewFrustum, const Sky
         static gpu::PipelinePointer thePipeline;
         static gpu::BufferPointer theBuffer;
         static gpu::Stream::FormatPointer theFormat;
+        static gpu::BufferPointer theConstants;
+        const int SKYBOX_CONSTANTS_SLOT = 3;
         if (!thePipeline) {
             auto skyVS = gpu::ShaderPointer(gpu::Shader::createVertex(std::string(Skybox_vert)));
             auto skyFS = gpu::ShaderPointer(gpu::Shader::createPixel(std::string(Skybox_frag)));
@@ -59,7 +61,8 @@ void Skybox::render(gpu::Batch& batch, const ViewFrustum& viewFrustum, const Sky
 
             gpu::Shader::BindingSet bindings;
             bindings.insert(gpu::Shader::Binding(std::string("cubeMap"), 0));
-
+            bindings.insert(gpu::Shader::Binding(std::string("skyboxBuffer"), SKYBOX_CONSTANTS_SLOT));
+            
             if (!gpu::Shader::makeProgram(*skyShader, bindings)) {
 
             }
@@ -74,6 +77,9 @@ void Skybox::render(gpu::Batch& batch, const ViewFrustum& viewFrustum, const Sky
         
             theFormat.reset(new gpu::Stream::Format());
             theFormat->setAttribute(gpu::Stream::POSITION, gpu::Stream::POSITION, gpu::Element(gpu::VEC2, gpu::FLOAT, gpu::XYZ));
+        
+            auto color = glm::vec4(1.0f);
+            theConstants.reset(new gpu::Buffer(sizeof(color), (const gpu::Byte*) &color));
         }
 
         glm::mat4 projMat;
@@ -82,11 +88,19 @@ void Skybox::render(gpu::Batch& batch, const ViewFrustum& viewFrustum, const Sky
         Transform viewTransform;
         viewFrustum.evalViewTransform(viewTransform);
 
+        if (glm::all(glm::equal(skybox.getColor(), glm::vec3(0.0f)))) { 
+            auto color = glm::vec4(1.0f);
+            theConstants->setSubData(0, sizeof(color), (const gpu::Byte*) &color);
+        } else {
+            theConstants->setSubData(0, sizeof(Color), (const gpu::Byte*) &skybox.getColor());
+        }
+
         batch.setProjectionTransform(projMat);
         batch.setViewTransform(viewTransform);
         batch.setModelTransform(Transform()); // only for Mac
         batch.setPipeline(thePipeline);
         batch.setInputBuffer(gpu::Stream::POSITION, theBuffer, 0, 8);
+        batch.setUniformBuffer(SKYBOX_CONSTANTS_SLOT, theConstants, 0, theConstants->getSize());
         batch.setInputFormat(theFormat);
         batch.setUniformTexture(0, skybox.getCubemap());
         batch.draw(gpu::TRIANGLE_STRIP, 4);

libraries/model/src/model/Skybox.h

@@ -38,6 +38,7 @@ public:
 
 protected:
     gpu::TexturePointer _cubemap;
+ 
     Color _color{1.0f, 1.0f, 1.0f};
 };
 typedef std::shared_ptr< Skybox > SkyboxPointer;

libraries/model/src/model/Skybox.slv

@@ -15,6 +15,27 @@
 
 <$declareStandardTransform()$>
 
+struct Skybox {
+    vec4 _color;
+};
+
+<@if GPU_FEATURE_PROFILE == GPU_CORE @>
+uniform skyboxBuffer {
+    Skybox _skybox;
+};
+Skybox getSkybox() {
+    return _skybox;
+}
+<@else@>
+uniform vec4 skyboxBuffer[1];
+Skybox getSkybox() {
+    Skybox _skybox;
+    _skybox._color =  skyboxBuffer[0];
+
+    return _skybox;
+}
+<@endif@>
+
 varying vec3 normal;
 varying vec2 texcoord;
 varying vec3 color;
@@ -22,7 +43,8 @@ varying vec3 color;
 void main(void) {
     texcoord = gl_Vertex.xy;
 
-    color = vec3(1.0, 1.0, 1.0);
+    Skybox skybox = getSkybox();
+    color = skybox._color.xyz;
 
     // standard transform
     TransformCamera cam = getTransformCamera();