examples/opengl/framebufferobject/glwidget.cpp
changeset 0 1918ee327afb
child 4 3b1da2848fc7
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/examples/opengl/framebufferobject/glwidget.cpp	Mon Jan 11 14:00:40 2010 +0000
@@ -0,0 +1,330 @@
+/****************************************************************************
+**
+** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
+** All rights reserved.
+** Contact: Nokia Corporation (qt-info@nokia.com)
+**
+** This file is part of the examples of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** No Commercial Usage
+** This file contains pre-release code and may not be distributed.
+** You may use this file in accordance with the terms and conditions
+** contained in the Technology Preview License Agreement accompanying
+** this package.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 2.1 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU Lesser General Public License version 2.1 requirements
+** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Nokia gives you certain additional
+** rights.  These rights are described in the Nokia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** If you have questions regarding the use of this file, please contact
+** Nokia at qt-info@nokia.com.
+**
+**
+**
+**
+**
+**
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include <QtGui/QImage>
+#include "glwidget.h"
+
+#include <math.h>
+
+#ifndef GL_MULTISAMPLE
+#define GL_MULTISAMPLE  0x809D
+#endif
+
+GLWidget::GLWidget(QWidget *parent)
+    : QGLWidget(QGLFormat(QGL::SampleBuffers|QGL::AlphaChannel), parent)
+{
+    setWindowTitle(tr("OpenGL framebuffer objects"));
+    makeCurrent();
+
+    if (QGLFramebufferObject::hasOpenGLFramebufferBlit()) {
+        QGLFramebufferObjectFormat format;
+        format.setSamples(4);
+        format.setAttachment(QGLFramebufferObject::CombinedDepthStencil);
+
+        render_fbo = new QGLFramebufferObject(512, 512, format);
+        texture_fbo = new QGLFramebufferObject(512, 512);
+    } else {
+        render_fbo = new QGLFramebufferObject(1024, 1024);
+        texture_fbo = render_fbo;
+    }
+
+    rot_x = rot_y = rot_z = 0.0f;
+    scale = 0.1f;
+    anim = new QTimeLine(750, this);
+    anim->setUpdateInterval(20);
+    connect(anim, SIGNAL(valueChanged(qreal)), SLOT(animate(qreal)));
+    connect(anim, SIGNAL(finished()), SLOT(animFinished()));
+
+    svg_renderer = new QSvgRenderer(QLatin1String(":/res/bubbles.svg"), this);
+    connect(svg_renderer, SIGNAL(repaintNeeded()), this, SLOT(draw()));
+
+    logo = QImage(":/res/designer.png");
+    logo = logo.convertToFormat(QImage::Format_ARGB32);
+
+    tile_list = glGenLists(1);
+    glNewList(tile_list, GL_COMPILE);
+    glBegin(GL_QUADS);
+    {
+        glTexCoord2f(0.0f, 0.0f); glVertex3f(-1.0f, -1.0f,  1.0f);
+        glTexCoord2f(1.0f, 0.0f); glVertex3f( 1.0f, -1.0f,  1.0f);
+        glTexCoord2f(1.0f, 1.0f); glVertex3f( 1.0f,  1.0f,  1.0f);
+        glTexCoord2f(0.0f, 1.0f); glVertex3f(-1.0f,  1.0f,  1.0f);
+
+        glTexCoord2f(1.0f, 0.0f); glVertex3f(-1.0f, -1.0f, -1.0f);
+        glTexCoord2f(1.0f, 1.0f); glVertex3f(-1.0f,  1.0f, -1.0f);
+        glTexCoord2f(0.0f, 1.0f); glVertex3f( 1.0f,  1.0f, -1.0f);
+        glTexCoord2f(0.0f, 0.0f); glVertex3f( 1.0f, -1.0f, -1.0f);
+
+        glTexCoord2f(0.0f, 1.0f); glVertex3f(-1.0f,  1.0f, -1.0f);
+        glTexCoord2f(0.0f, 0.0f); glVertex3f(-1.0f,  1.0f,  1.0f);
+        glTexCoord2f(1.0f, 0.0f); glVertex3f( 1.0f,  1.0f,  1.0f);
+        glTexCoord2f(1.0f, 1.0f); glVertex3f( 1.0f,  1.0f, -1.0f);
+
+        glTexCoord2f(1.0f, 1.0f); glVertex3f(-1.0f, -1.0f, -1.0f);
+        glTexCoord2f(0.0f, 1.0f); glVertex3f( 1.0f, -1.0f, -1.0f);
+        glTexCoord2f(0.0f, 0.0f); glVertex3f( 1.0f, -1.0f,  1.0f);
+        glTexCoord2f(1.0f, 0.0f); glVertex3f(-1.0f, -1.0f,  1.0f);
+
+        glTexCoord2f(1.0f, 0.0f); glVertex3f( 1.0f, -1.0f, -1.0f);
+        glTexCoord2f(1.0f, 1.0f); glVertex3f( 1.0f,  1.0f, -1.0f);
+        glTexCoord2f(0.0f, 1.0f); glVertex3f( 1.0f,  1.0f,  1.0f);
+        glTexCoord2f(0.0f, 0.0f); glVertex3f( 1.0f, -1.0f,  1.0f);
+
+        glTexCoord2f(0.0f, 0.0f); glVertex3f(-1.0f, -1.0f, -1.0f);
+        glTexCoord2f(1.0f, 0.0f); glVertex3f(-1.0f, -1.0f,  1.0f);
+        glTexCoord2f(1.0f, 1.0f); glVertex3f(-1.0f,  1.0f,  1.0f);
+        glTexCoord2f(0.0f, 1.0f); glVertex3f(-1.0f,  1.0f, -1.0f);
+    }
+    glEnd();
+    glEndList();
+
+    wave = new GLfloat[logo.width()*logo.height()];
+    memset(wave, 0, logo.width()*logo.height());
+    startTimer(30); // wave timer
+}
+
+GLWidget::~GLWidget()
+{
+    delete[] wave;
+    glDeleteLists(tile_list, 1);
+    delete texture_fbo;
+    if (render_fbo != texture_fbo)
+        delete render_fbo;
+}
+
+void GLWidget::paintEvent(QPaintEvent *)
+{
+    draw();
+}
+
+void GLWidget::draw()
+{
+    QPainter p(this); // used for text overlay
+
+    // save the GL state set for QPainter
+    saveGLState();
+
+    // render the 'bubbles.svg' file into our framebuffer object
+    QPainter fbo_painter(render_fbo);
+    svg_renderer->render(&fbo_painter);
+    fbo_painter.end();
+
+    if (render_fbo != texture_fbo) {
+        QRect rect(0, 0, render_fbo->width(), render_fbo->height());
+        QGLFramebufferObject::blitFramebuffer(texture_fbo, rect,
+                                              render_fbo, rect);
+    }
+
+    // draw into the GL widget
+    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+    glMatrixMode(GL_PROJECTION);
+    glLoadIdentity();
+    glFrustum(-1, 1, -1, 1, 10, 100);
+    glTranslatef(0.0f, 0.0f, -15.0f);
+    glMatrixMode(GL_MODELVIEW);
+    glLoadIdentity();
+    glViewport(0, 0, width(), height());
+    glEnable(GL_BLEND);
+    glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
+
+    glBindTexture(GL_TEXTURE_2D, texture_fbo->texture());
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+    glEnable(GL_TEXTURE_2D);
+    glEnable(GL_MULTISAMPLE);
+    glEnable(GL_CULL_FACE);
+
+    // draw background
+    glPushMatrix();
+    glScalef(1.7f, 1.7f, 1.7f);
+    glColor4f(1.0f, 1.0f, 1.0f, 1.0f);
+    glCallList(tile_list);
+    glPopMatrix();
+
+    const int w = logo.width();
+    const int h = logo.height();
+
+    glRotatef(rot_x, 1.0f, 0.0f, 0.0f);
+    glRotatef(rot_y, 0.0f, 1.0f, 0.0f);
+    glRotatef(rot_z, 0.0f, 0.0f, 1.0f);
+    glScalef(scale/w, scale/w, scale/w);
+
+    glDepthFunc(GL_LESS);
+    glEnable(GL_DEPTH_TEST);
+    // draw the Qt icon
+    glTranslatef(-w+1, -h+1, 0.0f);
+    for (int y=h-1; y>=0; --y) {
+        uint *p = (uint*) logo.scanLine(y);
+        uint *end = p + w;
+        int  x = 0;
+        while (p < end) {
+            glColor4ub(qRed(*p), qGreen(*p), qBlue(*p), uchar(qAlpha(*p)*.9));
+            glTranslatef(0.0f, 0.0f, wave[y*w+x]);
+            if (qAlpha(*p) > 128)
+                glCallList(tile_list);
+            glTranslatef(0.0f, 0.0f, -wave[y*w+x]);
+            glTranslatef(2.0f, 0.0f, 0.0f);
+            ++x;
+            ++p;
+        }
+        glTranslatef(-w*2.0f, 2.0f, 0.0f);
+    }
+
+    // restore the GL state that QPainter expects
+    restoreGLState();
+
+    // draw the overlayed text using QPainter
+    p.setPen(QColor(197, 197, 197, 157));
+    p.setBrush(QColor(197, 197, 197, 127));
+    p.drawRect(QRect(0, 0, width(), 50));
+    p.setPen(Qt::black);
+    p.setBrush(Qt::NoBrush);
+    const QString str1(tr("A simple OpenGL framebuffer object example."));
+    const QString str2(tr("Use the mouse wheel to zoom, press buttons and move mouse to rotate, double-click to flip."));
+    QFontMetrics fm(p.font());
+    p.drawText(width()/2 - fm.width(str1)/2, 20, str1);
+    p.drawText(width()/2 - fm.width(str2)/2, 20 + fm.lineSpacing(), str2);
+}
+
+void GLWidget::mousePressEvent(QMouseEvent *e)
+{
+    anchor = e->pos();
+}
+
+void GLWidget::mouseMoveEvent(QMouseEvent *e)
+{
+    QPoint diff = e->pos() - anchor;
+    if (e->buttons() & Qt::LeftButton) {
+        rot_x += diff.y()/5.0f;
+        rot_y += diff.x()/5.0f;
+    } else if (e->buttons() & Qt::RightButton) {
+        rot_z += diff.x()/5.0f;
+    }
+
+    anchor = e->pos();
+    draw();
+}
+
+void GLWidget::wheelEvent(QWheelEvent *e)
+{
+    e->delta() > 0 ? scale += scale*0.1f : scale -= scale*0.1f;
+    draw();
+}
+
+void GLWidget::mouseDoubleClickEvent(QMouseEvent *)
+{
+    anim->start();
+}
+
+void GLWidget::animate(qreal val)
+{
+    rot_y = val * 180;
+    draw();
+}
+
+void GLWidget::animFinished()
+{
+    if (anim->direction() == QTimeLine::Forward)
+        anim->setDirection(QTimeLine::Backward);
+    else
+        anim->setDirection(QTimeLine::Forward);
+}
+
+void GLWidget::saveGLState()
+{
+    glPushAttrib(GL_ALL_ATTRIB_BITS);
+    glMatrixMode(GL_PROJECTION);
+    glPushMatrix();
+    glMatrixMode(GL_MODELVIEW);
+    glPushMatrix();
+}
+
+void GLWidget::restoreGLState()
+{
+    glMatrixMode(GL_PROJECTION);
+    glPopMatrix();
+    glMatrixMode(GL_MODELVIEW);
+    glPopMatrix();
+    glPopAttrib();
+}
+
+#define PI 3.14159
+
+void GLWidget::timerEvent(QTimerEvent *)
+{
+    if (QApplication::mouseButtons() != 0)
+        return;
+
+    static bool scale_in = true;
+
+    if (scale_in && scale > 35.0f)
+        scale_in = false;
+    else if (!scale_in && scale < .5f)
+        scale_in = true;
+
+    scale = scale_in ? scale + scale*0.01f : scale-scale*0.01f;
+    rot_z += 0.3f;
+    rot_x += 0.1f;
+
+    int dx, dy; // disturbance point
+    float s, v, W, t;
+    int i, j;
+    static float wt[128][128];
+    const int width = logo.width();
+    const int AMP = 5;
+
+    dx = dy = width >> 1;
+
+    W = .3f;
+    v = -4; // wave speed
+
+    for (i = 0; i < width; ++i) {
+	for ( j = 0; j < width; ++j) {
+	    s = sqrt((double) ((j - dx) * (j - dx) + (i - dy) * (i - dy)));
+	    wt[i][j] += 0.1f;
+	    t = s / v;
+            if (s != 0)
+                wave[i*width + j] = AMP * sin(2 * PI * W * (wt[i][j] + t)) / (0.2*(s + 2));
+            else
+                wave[i*width + j] = AMP * sin(2 * PI * W * (wt[i][j] + t));
+	}
+    }
+}