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<pre> /****************************************************************************
**
** Copyright (C) 2005-2006 Trolltech ASA. All rights reserved.
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** This file is part of the example classes of the Qt Toolkit.
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#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), parent)
{
setWindowTitle(tr("OpenGL pbuffers 2"));
pbuffer = new QGLPixelBuffer(512, 512, format(), this);
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/qt4-logo.png");
logo = logo.convertToFormat(QImage::Format_ARGB32);
makeCurrent(); <span class="comment">// need a current context to create the display list</span>
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); <span class="comment">// wave timer</span>
pbuffer->makeCurrent();
dynamicTexture = pbuffer->generateDynamicTexture();
<span class="comment">// bind the dynamic texture to the pbuffer - this is a no-op under X11</span>
pbuffer->bindToDynamicTexture(dynamicTexture);
}
GLWidget::~GLWidget()
{
delete[] wave;
glDeleteLists(tile_list, 1);
pbuffer->releaseFromDynamicTexture();
glDeleteTextures(1, &dynamicTexture);
delete pbuffer;
}
void GLWidget::paintEvent(QPaintEvent *)
{
draw();
}
void GLWidget::draw()
{
QPainter p(this); <span class="comment">// used for text overlay</span>
<span class="comment">// save the GL state set for QPainter</span>
saveGLState();
<span class="comment">// render the 'bubbles.svg' file into our pbuffer</span>
QPainter pbuffer_painter(pbuffer);
svg_renderer->render(&pbuffer_painter);
pbuffer_painter.end();
glFlush();
#if defined(Q_WS_X11)
<span class="comment">// rendering directly to a texture is not supported on X11, unfortunately</span>
pbuffer->updateDynamicTexture(dynamicTexture);
#endif
makeCurrent();
<span class="comment">// draw into the GL widget</span>
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());
glBindTexture(GL_TEXTURE_2D, dynamicTexture);
glEnable(GL_TEXTURE_2D);
glEnable(GL_MULTISAMPLE);
glEnable(GL_CULL_FACE);
glEnable(GL_BLEND);
glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
<span class="comment">// draw background</span>
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);
<span class="comment">// draw the Qt icon</span>
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);
}
<span class="comment">// restore the GL state that QPainter expects</span>
restoreGLState();
<span class="comment">// draw the overlayed text using QPainter</span>
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 pbuffer 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; <span class="comment">// disturbance point</span>
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; <span class="comment">// wave speed</span>
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));
}
}
}</pre>
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