Add ShaderEffect class which provides generic support for fullscreen shader effects

svn path=/trunk/KDE/kdebase/workspace/; revision=683160

lib/CMakeLists.txt

@@ -30,6 +30,7 @@ set(kwin_EFFECTSLIB_SRCS
     kwineffects.cpp
     kwinglutils.cpp
     kwinglutils_funcs.cpp
+    kwinshadereffect.cpp
     )
 kde4_automoc(${kwin_EFFECTSLIB_SRCS})
 kde4_add_library(kwineffects SHARED ${kwin_EFFECTSLIB_SRCS})

lib/kwinshadereffect.cpp

@@ -0,0 +1,165 @@
+/*****************************************************************
+ KWin - the KDE window manager
+ This file is part of the KDE project.
+
+Copyright (C) 2006-2007 Rivo Laks <rivolaks@hot.ee>
+
+You can Freely distribute this program under the GNU General Public
+License. See the file "COPYING" for the exact licensing terms.
+******************************************************************/
+
+#include "kwinshadereffect.h"
+
+#include "kwinglutils.h"
+
+#include <kstandarddirs.h>
+#include <kdebug.h>
+
+#include <assert.h>
+
+
+namespace KWin
+{
+
+
+ShaderEffect::ShaderEffect(const QString& shadername) : Effect()
+{
+    mTexture = 0;
+    mRenderTarget = 0;
+    mShader = 0;
+
+    mTime = 0.0f;
+    mValid = loadData(shadername);
+    mEnabled = false;
+}
+
+ShaderEffect::~ShaderEffect()
+{
+    delete mTexture;
+    delete mRenderTarget;
+    delete mShader;
+}
+
+bool ShaderEffect::loadData(const QString& shadername)
+{
+#ifndef HAVE_OPENGL
+    return false;
+#else
+    // If NPOT textures are not supported, use nearest power-of-two sized
+    //  texture. It wastes memory, but it's possible to support systems without
+    //  NPOT textures that way
+    int texw = displayWidth();
+    int texh = displayHeight();
+    if( !GLTexture::NPOTTextureSupported() )
+    {
+        kWarning( 1212 ) << k_funcinfo << "NPOT textures not supported, wasting some memory" << endl;
+        texw = nearestPowerOfTwo(texw);
+        texh = nearestPowerOfTwo(texh);
+    }
+    // Create texture and render target
+    mTexture = new GLTexture(texw, texh);
+    mTexture->setFilter(GL_LINEAR_MIPMAP_LINEAR);
+    mTexture->setWrapMode(GL_CLAMP);
+
+    mRenderTarget = new GLRenderTarget(mTexture);
+    if( !mRenderTarget->valid() )
+        return false;
+
+    QString fragmentshader =  KGlobal::dirs()->findResource("data", "kwin/" + shadername + ".frag");
+    QString vertexshader =  KGlobal::dirs()->findResource("data", "kwin/" + shadername + ".vert");
+    if(fragmentshader.isEmpty() || vertexshader.isEmpty())
+    {
+        kError() << k_funcinfo << "Couldn't locate shader files" << endl;
+        return false;
+    }
+    mShader = new GLShader(vertexshader, fragmentshader);
+    if(!mShader->isValid())
+    {
+        kError() << k_funcinfo << "The shader failed to load!" << endl;
+        return false;
+    }
+    mShader->bind();
+    mShader->setUniform("sceneTex", 0);
+    mShader->setUniform("textureWidth", (float)texw);
+    mShader->setUniform("textureHeight", (float)texh);
+    mShader->unbind();
+
+    return true;
+#endif
+}
+
+bool ShaderEffect::supported()
+{
+#ifndef HAVE_OPENGL
+    return false;
+#else
+    return GLRenderTarget::supported() &&
+            GLShader::fragmentShaderSupported() &&
+            (effects->compositingType() == OpenGLCompositing);
+#endif
+}
+
+bool ShaderEffect::isEnabled() const
+{
+    return mEnabled;
+}
+
+void ShaderEffect::setEnabled(bool enabled)
+{
+    mEnabled = enabled;
+    // Everything needs to be repainted
+    effects->addRepaintFull();
+}
+
+GLShader* ShaderEffect::shader() const
+{
+    return mShader;
+}
+
+void ShaderEffect::prePaintScreen( int* mask, QRegion* region, int time )
+{
+    mTime += time / 1000.0f;
+#ifdef HAVE_OPENGL
+    if( mValid && mEnabled )
+    {
+        *mask |= PAINT_SCREEN_WITH_TRANSFORMED_WINDOWS;
+        // Start rendering to texture
+        effects->pushRenderTarget(mRenderTarget);
+    }
+#endif
+
+    effects->prePaintScreen(mask, region, time);
+}
+
+void ShaderEffect::postPaintScreen()
+{
+    // Call the next effect.
+    effects->postPaintScreen();
+
+#ifdef HAVE_OPENGL
+    if( mValid && mEnabled )
+    {
+        // Disable render texture
+        assert( effects->popRenderTarget() == mRenderTarget );
+        mTexture->bind();
+
+        // Use the shader
+        mShader->bind();
+        mShader->setUniform("time", mTime);
+
+        // Render fullscreen quad with screen contents
+        glBegin(GL_QUADS);
+        glVertex2f(0.0, displayHeight());
+        glVertex2f(displayWidth(), displayHeight());
+        glVertex2f(displayWidth(), 0.0);
+        glVertex2f(0.0, 0.0);
+        glEnd();
+
+        mShader->unbind();
+        mTexture->unbind();
+    }
+#endif
+}
+
+} // namespace
+

lib/kwinshadereffect.h

@@ -0,0 +1,56 @@
+/*****************************************************************
+ KWin - the KDE window manager
+ This file is part of the KDE project.
+
+Copyright (C) 2006-2007 Rivo Laks <rivolaks@hot.ee>
+
+You can Freely distribute this program under the GNU General Public
+License. See the file "COPYING" for the exact licensing terms.
+******************************************************************/
+
+#ifndef KWIN_SHADEREFFECT_H
+#define KWIN_SHADEREFFECT_H
+
+
+#include <kwineffects.h>
+
+
+namespace KWin
+{
+
+class GLTexture;
+class GLRenderTarget;
+class GLShader;
+class KWIN_EXPORT ShaderEffect : public Effect
+{
+    public:
+        ShaderEffect(const QString& shadername);
+        virtual ~ShaderEffect();
+
+        virtual void prePaintScreen( int* mask, QRegion* region, int time );
+        virtual void postPaintScreen();
+
+        static bool supported();
+
+    protected:
+        bool isEnabled() const;
+        void setEnabled(bool enabled);
+
+        GLShader* shader() const;
+
+        bool loadData(const QString& shadername);
+
+    private:
+        GLTexture* mTexture;
+        GLRenderTarget* mRenderTarget;
+        GLShader* mShader;
+        bool mValid;
+
+        float mTime;
+
+        bool mEnabled;
+};
+
+} // namespace
+
+#endif