From cf0f1e9db1d8e0053856c83890511ffd1deec1fd Mon Sep 17 00:00:00 2001
From: Pavel Rojtberg <rojtberg@gmail.com>
Date: Sun, 8 Sep 2024 13:34:08 +0200
Subject: [PATCH] GL3Plus: use global instead of per shader UBOs

as we overwrite all data on binding anyway
---
 .../GL3Plus/include/OgreGL3PlusRenderSystem.h    |  2 ++
 .../GL3Plus/src/GLSL/include/OgreGLSLShader.h    |  5 +----
 .../src/GLSL/src/OgreGLSLSeparableProgram.cpp    |  9 +--------
 .../GL3Plus/src/GLSL/src/OgreGLSLShader.cpp      |  7 +++----
 .../GL3Plus/src/OgreGL3PlusRenderSystem.cpp      | 16 ++++++++++++++++
 5 files changed, 23 insertions(+), 16 deletions(-)

diff --git a/RenderSystems/GL3Plus/include/OgreGL3PlusRenderSystem.h b/RenderSystems/GL3Plus/include/OgreGL3PlusRenderSystem.h
index d2957747acf..7e146bcc67c 100644
--- a/RenderSystems/GL3Plus/include/OgreGL3PlusRenderSystem.h
+++ b/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,
diff --git a/RenderSystems/GL3Plus/src/GLSL/include/OgreGLSLShader.h b/RenderSystems/GL3Plus/src/GLSL/include/OgreGLSLShader.h
index 993b7ee7a75..dcb8bb7acc5 100644
--- a/RenderSystems/GL3Plus/src/GLSL/include/OgreGLSLShader.h
+++ b/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;
     };
 
diff --git a/RenderSystems/GL3Plus/src/GLSL/src/OgreGLSLSeparableProgram.cpp b/RenderSystems/GL3Plus/src/GLSL/src/OgreGLSLSeparableProgram.cpp
index 1d712c2f6fe..fe2578eb334 100644
--- a/RenderSystems/GL3Plus/src/GLSL/src/OgreGLSLSeparableProgram.cpp
+++ b/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)
diff --git a/RenderSystems/GL3Plus/src/GLSL/src/OgreGLSLShader.cpp b/RenderSystems/GL3Plus/src/GLSL/src/OgreGLSLShader.cpp
index 88ea9e2a2c5..2046c11377b 100644
--- a/RenderSystems/GL3Plus/src/GLSL/src/OgreGLSLShader.cpp
+++ b/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;
             }
 
diff --git a/RenderSystems/GL3Plus/src/OgreGL3PlusRenderSystem.cpp b/RenderSystems/GL3Plus/src/OgreGL3PlusRenderSystem.cpp
index 83e25029fae..393280d6821 100644
--- a/RenderSystems/GL3Plus/src/OgreGL3PlusRenderSystem.cpp
+++ b/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);
     }