add shader path for mygui (#6162)

CHANGELOG.md

@@ -25,6 +25,7 @@
     Feature #5489: MCP: Telekinesis fix for activators
     Feature #5996: Support Lua scripts in OpenMW
     Feature #6017: Separate persistent and temporary cell references when saving
+    Feature #6162: Refactor GUI to use shaders and to be GLES and GL3+ friendly
 
 0.47.0
 ------

apps/openmw/engine.cpp

@@ -753,6 +753,12 @@ void OMW::Engine::prepareEngine (Settings::Manager & settings)
     else
         gameControllerdb = ""; //if it doesn't exist, pass in an empty string
 
+    // gui needs our shaders path before everything else
+    mResourceSystem->getSceneManager()->setShaderPath((mResDir / "shaders").string());
+
+    osg::ref_ptr<osg::GLExtensions> exts = osg::GLExtensions::Get(0, false);
+    bool shadersSupported = exts && (exts->glslLanguageVersion >= 1.2f);
+
     std::string myguiResources = (mResDir / "mygui").string();
     osg::ref_ptr<osg::Group> guiRoot = new osg::Group;
     guiRoot->setName("GUI Root");
@@ -761,7 +767,7 @@ void OMW::Engine::prepareEngine (Settings::Manager & settings)
     MWGui::WindowManager* window = new MWGui::WindowManager(mWindow, mViewer, guiRoot, mResourceSystem.get(), mWorkQueue.get(),
                 mCfgMgr.getLogPath().string() + std::string("/"), myguiResources,
                 mScriptConsoleMode, mTranslationDataStorage, mEncoding, mExportFonts,
-                Version::getOpenmwVersionDescription(mResDir.string()), mCfgMgr.getUserConfigPath().string());
+                Version::getOpenmwVersionDescription(mResDir.string()), mCfgMgr.getUserConfigPath().string(), shadersSupported);
     mEnvironment.setWindowManager (window);
 
     MWInput::InputManager* input = new MWInput::InputManager (mWindow, mViewer, mScreenCaptureHandler, mScreenCaptureOperation, keybinderUser, keybinderUserExists, userGameControllerdb, gameControllerdb, mGrab);

apps/openmw/mwgui/windowmanagerimp.cpp

@@ -35,6 +35,7 @@
 
 #include <components/resource/resourcesystem.hpp>
 #include <components/resource/imagemanager.hpp>
+#include <components/resource/scenemanager.hpp>
 
 #include <components/sceneutil/workqueue.hpp>
 
@@ -124,7 +125,7 @@ namespace MWGui
     WindowManager::WindowManager(
             SDL_Window* window, osgViewer::Viewer* viewer, osg::Group* guiRoot, Resource::ResourceSystem* resourceSystem, SceneUtil::WorkQueue* workQueue,
             const std::string& logpath, const std::string& resourcePath, bool consoleOnlyScripts, Translation::Storage& translationDataStorage,
-            ToUTF8::FromType encoding, bool exportFonts, const std::string& versionDescription, const std::string& userDataPath)
+            ToUTF8::FromType encoding, bool exportFonts, const std::string& versionDescription, const std::string& userDataPath, bool useShaders)
       : mOldUpdateMask(0)
       , mOldCullMask(0)
       , mStore(nullptr)
@@ -275,6 +276,9 @@ namespace MWGui
         mVideoWrapper->setGammaContrast(Settings::Manager::getFloat("gamma", "Video"),
                                         Settings::Manager::getFloat("contrast", "Video"));
 
+        if (useShaders)
+            mGuiPlatform->getRenderManagerPtr()->enableShaders(mResourceSystem->getSceneManager()->getShaderManager());
+
         mStatsWatcher.reset(new StatsWatcher());
     }
 

apps/openmw/mwgui/windowmanagerimp.hpp

@@ -135,7 +135,7 @@ namespace MWGui
 
     WindowManager(SDL_Window* window, osgViewer::Viewer* viewer, osg::Group* guiRoot, Resource::ResourceSystem* resourceSystem, SceneUtil::WorkQueue* workQueue,
                   const std::string& logpath, const std::string& cacheDir, bool consoleOnlyScripts, Translation::Storage& translationDataStorage,
-                  ToUTF8::FromType encoding, bool exportFonts, const std::string& versionDescription, const std::string& localPath);
+                  ToUTF8::FromType encoding, bool exportFonts, const std::string& versionDescription, const std::string& localPath, bool useShaders);
     virtual ~WindowManager();
 
     /// Set the ESMStore to use for retrieving of GUI-related strings.

apps/openmw/mwrender/renderingmanager.cpp

@@ -201,7 +201,6 @@ namespace MWRender
         auto lightingMethod = SceneUtil::LightManager::getLightingMethodFromString(Settings::Manager::getString("lighting method", "Shaders"));
 
         resourceSystem->getSceneManager()->setParticleSystemMask(MWRender::Mask_ParticleSystem);
-        resourceSystem->getSceneManager()->setShaderPath(resourcePath + "/shaders");
         // Shadows and radial fog have problems with fixed-function mode
         bool forceShaders = Settings::Manager::getBool("radial fog", "Shaders")
                             || Settings::Manager::getBool("force shaders", "Shaders")

components/myguiplatform/myguirendermanager.cpp

@@ -14,6 +14,7 @@
 #include <osgGA/GUIEventHandler>
 
 #include <components/resource/imagemanager.hpp>
+#include <components/shader/shadermanager.hpp>
 
 #include <components/debug/debuglog.hpp>
 
@@ -127,9 +128,13 @@ public:
                 state->apply();
             }
 
+            // A GUI element without an associated texture would be extremely rare.
+            // It is worth it to use a dummy 1x1 black texture sampler instead of either adding a conditional or relinking shaders.
             osg::Texture2D* texture = batch.mTexture;
             if(texture)
                 state->applyTextureAttribute(0, texture);
+            else
+                state->applyTextureAttribute(0, mDummyTexture);
 
             osg::GLBufferObject* bufferobject = state->isVertexBufferObjectSupported() ? vbo->getOrCreateGLBufferObject(state->getContextID()) : nullptr;
             if (bufferobject)
@@ -189,6 +194,10 @@ public:
         mStateSet->setMode(GL_DEPTH_TEST, osg::StateAttribute::OFF);
         mStateSet->setMode(GL_BLEND, osg::StateAttribute::ON);
 
+        mDummyTexture = new osg::Texture2D;
+        mDummyTexture->setInternalFormat(GL_RGB);
+        mDummyTexture->setTextureSize(1,1);
+
         // need to flip tex coords since MyGUI uses DirectX convention of top left image origin
         osg::Matrix flipMat;
         flipMat.preMultTranslate(osg::Vec3f(0,1,0));
@@ -201,6 +210,7 @@ public:
         , mStateSet(copy.mStateSet)
         , mWriteTo(0)
         , mReadFrom(0)
+        , mDummyTexture(copy.mDummyTexture)
     {
     }
 
@@ -231,6 +241,11 @@ public:
         mBatchVector[mWriteTo].clear();
     }
 
+    osg::StateSet* getDrawableStateSet()
+    {
+        return mStateSet;
+    }
+
     META_Object(osgMyGUI, Drawable)
 
 private:
@@ -242,6 +257,8 @@ private:
 
     int mWriteTo;
     mutable int mReadFrom;
+
+    osg::ref_ptr<osg::Texture2D> mDummyTexture;
 };
 
 class OSGVertexBuffer : public MyGUI::IVertexBuffer
@@ -417,6 +434,16 @@ void RenderManager::shutdown()
     mSceneRoot->removeChild(mGuiRoot);
 }
 
+void RenderManager::enableShaders(Shader::ShaderManager& shaderManager)
+{
+    auto vertexShader = shaderManager.getShader("gui_vertex.glsl", {}, osg::Shader::VERTEX);
+    auto fragmentShader = shaderManager.getShader("gui_fragment.glsl", {}, osg::Shader::FRAGMENT);
+    auto program = shaderManager.getProgram(vertexShader, fragmentShader);
+
+    mDrawable->getDrawableStateSet()->setAttributeAndModes(program, osg::StateAttribute::ON);
+    mDrawable->getDrawableStateSet()->addUniform(new osg::Uniform("diffuseMap", 0));
+}
+
 MyGUI::IVertexBuffer* RenderManager::createVertexBuffer()
 {
     return new OSGVertexBuffer();

components/myguiplatform/myguirendermanager.hpp

@@ -12,6 +12,11 @@ namespace Resource
     class ImageManager;
 }
 
+namespace Shader
+{
+    class ShaderManager;
+}
+
 namespace osgViewer
 {
     class Viewer;
@@ -62,6 +67,8 @@ public:
     void initialise();
     void shutdown();
 
+    void enableShaders(Shader::ShaderManager& shaderManager);
+
     void setScalingFactor(float factor);
 
     static RenderManager& getInstance() { return *getInstancePtr(); }

files/shaders/CMakeLists.txt

@@ -31,6 +31,8 @@ set(SHADER_FILES
     nv_default_fragment.glsl
     nv_nolighting_vertex.glsl
     nv_nolighting_fragment.glsl
+    gui_vertex.glsl
+    gui_fragment.glsl
 )
 
 copy_all_resource_files(${CMAKE_CURRENT_SOURCE_DIR} ${OPENMW_SHADERS_ROOT} ${DDIRRELATIVE} "${SHADER_FILES}")

files/shaders/gui_fragment.glsl

@@ -0,0 +1,11 @@
+#version 120
+
+uniform sampler2D diffuseMap;
+
+varying vec2 diffuseMapUV;
+varying vec4 passColor;
+
+void main()
+{
+    gl_FragData[0] = texture2D(diffuseMap, diffuseMapUV) * passColor;
+}

files/shaders/gui_vertex.glsl

@@ -0,0 +1,11 @@
+#version 120
+
+varying vec2 diffuseMapUV;
+varying vec4 passColor;
+
+void main()
+{
+    gl_Position = vec4(gl_Vertex.xyz, 1.0);
+    diffuseMapUV = (gl_TextureMatrix[0] * gl_MultiTexCoord0).xy;
+    passColor = gl_Color;
+}