kwin/effects/_test/test_fbo.cpp

/********************************************************************
 KWin - the KDE window manager
 This file is part of the KDE project.

Copyright (C) 2007 Rivo Laks <rivolaks@hot.ee>

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program.  If not, see <http://www.gnu.org/licenses/>.
*********************************************************************/

#include "test_fbo.h"

#include <kwinglutils.h>

#include <assert.h>

namespace KWin
{

KWIN_EFFECT(test_fbo, TestFBOEffect)
KWIN_EFFECT_SUPPORTED(test_fbo, TestFBOEffect::supported())


TestFBOEffect::TestFBOEffect() : Effect()
{
    mRot = 0.0f;

    // Create texture and render target
    mTexture = new GLTexture(displayWidth(), displayHeight());
    mTexture->setFilter(GL_LINEAR_MIPMAP_LINEAR);

    mRenderTarget = new GLRenderTarget(mTexture);

    mValid = mRenderTarget->valid();
}

TestFBOEffect::~TestFBOEffect()
{
    delete mTexture;
    delete mRenderTarget;
}

bool TestFBOEffect::supported()
{
    return GLRenderTarget::supported() && GLTexture::NPOTTextureSupported() &&
           (effects->compositingType() == OpenGLCompositing);
}


void TestFBOEffect::prePaintScreen(ScreenPrePaintData& data, int time)
{
    if (mValid) {
        data.mask |= PAINT_SCREEN_WITH_TRANSFORMED_WINDOWS;
        // Start rendering to texture
        effects->pushRenderTarget(mRenderTarget);
    }

    effects->prePaintScreen(data, time);
}

void TestFBOEffect::postPaintScreen()
{
    // Call the next effect.
    effects->postPaintScreen();

    if (mValid) {
        // Disable render texture
        assert(effects->popRenderTarget() == mRenderTarget);
        mTexture->bind();

        // Render fullscreen quad with screen contents
        glBegin(GL_QUADS);
        glTexCoord2f(0.0, 0.0); glVertex2f(0.0, displayHeight());
        glTexCoord2f(1.0, 0.0); glVertex2f(displayWidth(), displayHeight());
        glTexCoord2f(1.0, 1.0); glVertex2f(displayWidth(), 0.0);
        glTexCoord2f(0.0, 1.0); glVertex2f(0.0, 0.0);
        glEnd();

        // Render rotated screen thumbnail
        mRot += 0.5f;
        glTranslatef(displayWidth() / 2.0f, displayHeight() / 2.0f, 0.0f);
        glRotatef(mRot, 0.0, 0.0, 1.0);
        glScalef(0.2, 0.2, 0.2);
        glTranslatef(-displayWidth() / 2.0f, -displayHeight() / 2.0f, 0.0f);

        glEnable(GL_BLEND);
        glColor4f(1.0, 1.0, 1.0, 0.8);
        glBegin(GL_QUADS);
        glTexCoord2f(0.0, 0.0); glVertex2f(0.0, displayHeight());
        glTexCoord2f(1.0, 0.0); glVertex2f(displayWidth(), displayHeight());
        glTexCoord2f(1.0, 1.0); glVertex2f(displayWidth(), 0.0);
        glTexCoord2f(0.0, 1.0); glVertex2f(0.0, 0.0);
        glEnd();
        glColor4f(1.0, 1.0, 1.0, 1.0);
        glDisable(GL_BLEND);

        // Reset matrix and unbind texture
        glLoadIdentity();

        mTexture->unbind();

        // Make sure the animation continues
        effects->addRepaintFull();
    }

}


} // namespace