glwidget.cpp Example File
opengl/framebufferobject/glwidget.cpp/**************************************************************************** ** ** Copyright (C) 2015 The Qt Company Ltd. ** Contact: http://www.qt.io/licensing/ ** ** This file is part of the examples of the Qt Toolkit. ** ** $QT_BEGIN_LICENSE:BSD$ ** You may use this file under the terms of the BSD license as follows: ** ** "Redistribution and use in source and binary forms, with or without ** modification, are permitted provided that the following conditions are ** met: ** * Redistributions of source code must retain the above copyright ** notice, this list of conditions and the following disclaimer. ** * Redistributions in binary form must reproduce the above copyright ** notice, this list of conditions and the following disclaimer in ** the documentation and/or other materials provided with the ** distribution. ** * Neither the name of The Qt Company Ltd nor the names of its ** contributors may be used to endorse or promote products derived ** from this software without specific prior written permission. ** ** ** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS ** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT ** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR ** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT ** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, ** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT ** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, ** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY ** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT ** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE ** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE." ** ** $QT_END_LICENSE$ ** ****************************************************************************/ #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)); } } }
© 2016 The Qt Company Ltd. Documentation contributions included herein are the copyrights of their respective owners. The documentation provided herein is licensed under the terms of the GNU Free Documentation License version 1.3 as published by the Free Software Foundation. Qt and respective logos are trademarks of The Qt Company Ltd. in Finland and/or other countries worldwide. All other trademarks are property of their respective owners.