Devel

Docs/src/high-level-programs.md

@@ -196,6 +196,18 @@ param_named skewMatrix float4 0.5 0 -0.5 1.0
 This means that `mat[0]` is the first column in GLSL, but the first row in HLSL and %Ogre. %Ogre takes care of transposing square matrices before uploading them with GLSL, so matrix-vector multiplication `M*v` just works and `mat[0]` will return the same data.
 However, with non-square matrices transposing would change their GLSL type from e.g. `mat2x4` (two columns, four rows) to `mat4x2` (two rows, four columns) and consequently what `mat[0]` would return. Therefore %Ogre just passes such matrices unchanged and you have to handle this case (notably in skinning) yourself by either transposing the matrix in the shader or column-wise access.
 
+## Uniform Buffers {#Uniform-Buffers}
+
+If supported by the RenderSystem, you can opt-in to use uniform buffers for parameter storage.
+This is done by declaring the parameters in a uniform block named @c OgreUniforms
+
+```cpp
+layout(std140, row_major) uniform OgreUniforms
+{
+    mat4 worldTransform;
+}
+```
+
 ## Transform Feedback Varyings {#Transform-Feedback-Varyings}
 
 Similarly to vertex attributes, the transform feedback varyings are bound by name.

RenderSystems/GL3Plus/include/OgreGL3PlusRenderSystem.h

@@ -102,6 +102,8 @@ namespace Ogre {
 
         std::array<GLSLShader*, GPT_COUNT> mCurrentShader;
 
+        HardwareBufferPtr mUniformBuffer[GPT_COUNT];
+
         GLenum getBlendMode(SceneBlendFactor ogreBlend) const;
 
         void bindVertexElementToGpu(const VertexElement& elem,

RenderSystems/GL3Plus/src/GLSL/include/OgreGLSLShader.h

@@ -52,8 +52,6 @@ namespace Ogre {
         void setSamplerBinding(bool enable) { mHasSamplerBinding = enable; }
         bool getSamplerBinding() const { return mHasSamplerBinding; }
 
-        const HardwareBufferPtr& getDefaultBuffer() const { return mDefaultBuffer; }
-
         /// Overridden from GpuProgram
         const String& getLanguage(void) const override;
     protected:
@@ -68,9 +66,8 @@ namespace Ogre {
 
         /// @param block uniform block to consider. -1 for non-UBO uniforms
         void extractUniforms(int block = -1) const;
-        void extractBufferBlocks(GLenum type) const;
+        void extractBufferBlocks(GLenum type);
 
-        mutable HardwareBufferPtr mDefaultBuffer;
         bool mHasSamplerBinding;
     };
 

RenderSystems/GL3Plus/src/GLSL/src/OgreGLSLSeparableProgram.cpp

@@ -120,14 +120,7 @@ namespace Ogre
         GLuint progID = mShaders[fromProgType]->getGLProgramHandle();
         GLUniformCache* uniformCache = mShaders[fromProgType]->getUniformCache();
 
-        bool usesUBO = false;
-        if(const auto& ubo = static_cast<GLSLShader*>(mShaders[fromProgType])->getDefaultBuffer())
-        {
-            // we ignore ma
-            ubo->writeData(0, ubo->getSizeInBytes(), params->getConstantList().data(), true);
-            static_cast<GL3PlusHardwareBuffer*>(ubo.get())->bind();
-            usesUBO = true;
-        }
+        bool usesUBO = !params->hasLogicalIndexedParameters();
 
         // Iterate through uniform reference list and update uniform values
         for (const auto& it : params->getConstantDefinitions().map)

RenderSystems/GL3Plus/src/GLSL/src/OgreGLSLShader.cpp

@@ -566,7 +566,7 @@ namespace Ogre {
         }
     }
 
-    void GLSLShader::extractBufferBlocks(GLenum type) const
+    void GLSLShader::extractBufferBlocks(GLenum type)
     {
         GLint numBlocks = 0;
         OGRE_CHECK_GL_ERROR(glGetProgramInterfaceiv(mGLProgramHandle, type, GL_ACTIVE_RESOURCES, &numBlocks));
@@ -589,15 +589,14 @@ namespace Ogre {
             if (name == "OgreUniforms") // default buffer
             {
                 extractUniforms(blockIdx);
-                int binding = mType == GPT_COMPUTE_PROGRAM ? 0 : int(mType);
+                int binding = mType == GPT_COMPUTE_PROGRAM ? 0 : (int(mType) % GPT_PIPELINE_COUNT);
                 if (binding > 1)
                     LogManager::getSingleton().logWarning(
                         getResourceLogName() +
                         " - using 'OgreUniforms' in this shader type does alias with shared_params");
 
-                mDefaultBuffer = hbm.createUniformBuffer(values[2]);
-                static_cast<GL3PlusHardwareBuffer*>(mDefaultBuffer.get())->setGLBufferBinding(binding);
                 OGRE_CHECK_GL_ERROR(glUniformBlockBinding(mGLProgramHandle, blockIdx, binding));
+                mLogicalToPhysical.reset();
                 continue;
             }
 

RenderSystems/GL3Plus/src/OgreGL3PlusRenderSystem.cpp

@@ -1648,6 +1648,22 @@ namespace Ogre {
             params->_updateSharedParams();
         }
 
+        auto paramsSize = params->getConstantList().size();
+        if (paramsSize && getCapabilities()->hasCapability(RSC_SEPARATE_SHADER_OBJECTS) &&
+            !params->hasLogicalIndexedParameters())
+        {
+            auto& ubo = mUniformBuffer[gptype];
+            if(!ubo || ubo->getSizeInBytes() < paramsSize)
+            {
+                ubo = mHardwareBufferManager->createUniformBuffer(paramsSize);
+            }
+
+            ubo->writeData(0, ubo->getSizeInBytes(), params->getConstantList().data(), true);
+
+            int binding = gptype == GPT_COMPUTE_PROGRAM ? 0 : (int(gptype) % GPT_PIPELINE_COUNT);
+            static_cast<GL3PlusHardwareBuffer*>(ubo.get())->setGLBufferBinding(binding);
+        }
+
         // Pass on parameters from params to program object uniforms.
         program->updateUniforms(params, mask, gptype);
     }