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    41 

    42 #include <QtGui/QImage>

    43 #include "glwidget.h"

    44 

    45 #include <math.h>

    46 

    47 #ifndef GL_MULTISAMPLE

    48 #define GL_MULTISAMPLE  0x809D

    49 #endif

    50 

    51 GLWidget::GLWidget(QWidget *parent)

    52     : QGLWidget(QGLFormat(QGL::SampleBuffers|QGL::AlphaChannel), parent)

    53 {

    54     setWindowTitle(tr("OpenGL framebuffer objects"));

    55     makeCurrent();

    56 

    57     if (QGLFramebufferObject::hasOpenGLFramebufferBlit()) {

    58         QGLFramebufferObjectFormat format;

    59         format.setSamples(4);

    60         format.setAttachment(QGLFramebufferObject::CombinedDepthStencil);

    61 

    62         render_fbo = new QGLFramebufferObject(512, 512, format);

    63         texture_fbo = new QGLFramebufferObject(512, 512);

    64     } else {

    65         render_fbo = new QGLFramebufferObject(1024, 1024);

    66         texture_fbo = render_fbo;

    67     }

    68 

    69     rot_x = rot_y = rot_z = 0.0f;

    70     scale = 0.1f;

    71     anim = new QTimeLine(750, this);

    72     anim->setUpdateInterval(20);

    73     connect(anim, SIGNAL(valueChanged(qreal)), SLOT(animate(qreal)));

    74     connect(anim, SIGNAL(finished()), SLOT(animFinished()));

    75 

    76     svg_renderer = new QSvgRenderer(QLatin1String(":/res/bubbles.svg"), this);

    77     connect(svg_renderer, SIGNAL(repaintNeeded()), this, SLOT(draw()));

    78 

    79     logo = QImage(":/res/designer.png");

    80     logo = logo.convertToFormat(QImage::Format_ARGB32);

    81 

    82     tile_list = glGenLists(1);

    83     glNewList(tile_list, GL_COMPILE);

    84     glBegin(GL_QUADS);

    85     {

    86         glTexCoord2f(0.0f, 0.0f); glVertex3f(-1.0f, -1.0f,  1.0f);

    87         glTexCoord2f(1.0f, 0.0f); glVertex3f( 1.0f, -1.0f,  1.0f);

    88         glTexCoord2f(1.0f, 1.0f); glVertex3f( 1.0f,  1.0f,  1.0f);

    89         glTexCoord2f(0.0f, 1.0f); glVertex3f(-1.0f,  1.0f,  1.0f);

    90 

    91         glTexCoord2f(1.0f, 0.0f); glVertex3f(-1.0f, -1.0f, -1.0f);

    92         glTexCoord2f(1.0f, 1.0f); glVertex3f(-1.0f,  1.0f, -1.0f);

    93         glTexCoord2f(0.0f, 1.0f); glVertex3f( 1.0f,  1.0f, -1.0f);

    94         glTexCoord2f(0.0f, 0.0f); glVertex3f( 1.0f, -1.0f, -1.0f);

    95 

    96         glTexCoord2f(0.0f, 1.0f); glVertex3f(-1.0f,  1.0f, -1.0f);

    97         glTexCoord2f(0.0f, 0.0f); glVertex3f(-1.0f,  1.0f,  1.0f);

    98         glTexCoord2f(1.0f, 0.0f); glVertex3f( 1.0f,  1.0f,  1.0f);

    99         glTexCoord2f(1.0f, 1.0f); glVertex3f( 1.0f,  1.0f, -1.0f);

   100 

   101         glTexCoord2f(1.0f, 1.0f); glVertex3f(-1.0f, -1.0f, -1.0f);

   102         glTexCoord2f(0.0f, 1.0f); glVertex3f( 1.0f, -1.0f, -1.0f);

   103         glTexCoord2f(0.0f, 0.0f); glVertex3f( 1.0f, -1.0f,  1.0f);

   104         glTexCoord2f(1.0f, 0.0f); glVertex3f(-1.0f, -1.0f,  1.0f);

   105 

   106         glTexCoord2f(1.0f, 0.0f); glVertex3f( 1.0f, -1.0f, -1.0f);

   107         glTexCoord2f(1.0f, 1.0f); glVertex3f( 1.0f,  1.0f, -1.0f);

   108         glTexCoord2f(0.0f, 1.0f); glVertex3f( 1.0f,  1.0f,  1.0f);

   109         glTexCoord2f(0.0f, 0.0f); glVertex3f( 1.0f, -1.0f,  1.0f);

   110 

   111         glTexCoord2f(0.0f, 0.0f); glVertex3f(-1.0f, -1.0f, -1.0f);

   112         glTexCoord2f(1.0f, 0.0f); glVertex3f(-1.0f, -1.0f,  1.0f);

   113         glTexCoord2f(1.0f, 1.0f); glVertex3f(-1.0f,  1.0f,  1.0f);

   114         glTexCoord2f(0.0f, 1.0f); glVertex3f(-1.0f,  1.0f, -1.0f);

   115     }

   116     glEnd();

   117     glEndList();

   118 

   119     wave = new GLfloat[logo.width()*logo.height()];

   120     memset(wave, 0, logo.width()*logo.height());

   121     startTimer(30); // wave timer

   122 }

   123 

   124 GLWidget::~GLWidget()

   125 {

   126     delete[] wave;

   127     glDeleteLists(tile_list, 1);

   128     delete texture_fbo;

   129     if (render_fbo != texture_fbo)

   130         delete render_fbo;

   131 }

   132 

   133 void GLWidget::paintEvent(QPaintEvent *)

   134 {

   135     draw();

   136 }

   137 

   138 void GLWidget::draw()

   139 {

   140     QPainter p(this); // used for text overlay

   141 

   142     // save the GL state set for QPainter

   143     saveGLState();

   144 

   145     // render the 'bubbles.svg' file into our framebuffer object

   146     QPainter fbo_painter(render_fbo);

   147     svg_renderer->render(&fbo_painter);

   148     fbo_painter.end();

   149 

   150     if (render_fbo != texture_fbo) {

   151         QRect rect(0, 0, render_fbo->width(), render_fbo->height());

   152         QGLFramebufferObject::blitFramebuffer(texture_fbo, rect,

   153                                               render_fbo, rect);

   154     }

   155 

   156     // draw into the GL widget

   157     glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

   158     glMatrixMode(GL_PROJECTION);

   159     glLoadIdentity();

   160     glFrustum(-1, 1, -1, 1, 10, 100);

   161     glTranslatef(0.0f, 0.0f, -15.0f);

   162     glMatrixMode(GL_MODELVIEW);

   163     glLoadIdentity();

   164     glViewport(0, 0, width(), height());

   165     glEnable(GL_BLEND);

   166     glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);

   167 

   168     glBindTexture(GL_TEXTURE_2D, texture_fbo->texture());

   169     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);

   170     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);

   171     glEnable(GL_TEXTURE_2D);

   172     glEnable(GL_MULTISAMPLE);

   173     glEnable(GL_CULL_FACE);

   174 

   175     // draw background

   176     glPushMatrix();

   177     glScalef(1.7f, 1.7f, 1.7f);

   178     glColor4f(1.0f, 1.0f, 1.0f, 1.0f);

   179     glCallList(tile_list);

   180     glPopMatrix();

   181 

   182     const int w = logo.width();

   183     const int h = logo.height();

   184 

   185     glRotatef(rot_x, 1.0f, 0.0f, 0.0f);

   186     glRotatef(rot_y, 0.0f, 1.0f, 0.0f);

   187     glRotatef(rot_z, 0.0f, 0.0f, 1.0f);

   188     glScalef(scale/w, scale/w, scale/w);

   189 

   190     glDepthFunc(GL_LESS);

   191     glEnable(GL_DEPTH_TEST);

   192     // draw the Qt icon

   193     glTranslatef(-w+1, -h+1, 0.0f);

   194     for (int y=h-1; y>=0; --y) {

   195         uint *p = (uint*) logo.scanLine(y);

   196         uint *end = p + w;

   197         int  x = 0;

   198         while (p < end) {

   199             glColor4ub(qRed(*p), qGreen(*p), qBlue(*p), uchar(qAlpha(*p)*.9));

   200             glTranslatef(0.0f, 0.0f, wave[y*w+x]);

   201             if (qAlpha(*p) > 128)

   202                 glCallList(tile_list);

   203             glTranslatef(0.0f, 0.0f, -wave[y*w+x]);

   204             glTranslatef(2.0f, 0.0f, 0.0f);

   205             ++x;

   206             ++p;

   207         }

   208         glTranslatef(-w*2.0f, 2.0f, 0.0f);

   209     }

   210 

   211     // restore the GL state that QPainter expects

   212     restoreGLState();

   213 

   214     // draw the overlayed text using QPainter

   215     p.setPen(QColor(197, 197, 197, 157));

   216     p.setBrush(QColor(197, 197, 197, 127));

   217     p.drawRect(QRect(0, 0, width(), 50));

   218     p.setPen(Qt::black);

   219     p.setBrush(Qt::NoBrush);

   220     const QString str1(tr("A simple OpenGL framebuffer object example."));

   221     const QString str2(tr("Use the mouse wheel to zoom, press buttons and move mouse to rotate, double-click to flip."));

   222     QFontMetrics fm(p.font());

   223     p.drawText(width()/2 - fm.width(str1)/2, 20, str1);

   224     p.drawText(width()/2 - fm.width(str2)/2, 20 + fm.lineSpacing(), str2);

   225 }

   226 

   227 void GLWidget::mousePressEvent(QMouseEvent *e)

   228 {

   229     anchor = e->pos();

   230 }

   231 

   232 void GLWidget::mouseMoveEvent(QMouseEvent *e)

   233 {

   234     QPoint diff = e->pos() - anchor;

   235     if (e->buttons() & Qt::LeftButton) {

   236         rot_x += diff.y()/5.0f;

   237         rot_y += diff.x()/5.0f;

   238     } else if (e->buttons() & Qt::RightButton) {

   239         rot_z += diff.x()/5.0f;

   240     }

   241 

   242     anchor = e->pos();

   243     draw();

   244 }

   245 

   246 void GLWidget::wheelEvent(QWheelEvent *e)

   247 {

   248     e->delta() > 0 ? scale += scale*0.1f : scale -= scale*0.1f;

   249     draw();

   250 }

   251 

   252 void GLWidget::mouseDoubleClickEvent(QMouseEvent *)

   253 {

   254     anim->start();

   255 }

   256 

   257 void GLWidget::animate(qreal val)

   258 {

   259     rot_y = val * 180;

   260     draw();

   261 }

   262 

   263 void GLWidget::animFinished()

   264 {

   265     if (anim->direction() == QTimeLine::Forward)

   266         anim->setDirection(QTimeLine::Backward);

   267     else

   268         anim->setDirection(QTimeLine::Forward);

   269 }

   270 

   271 void GLWidget::saveGLState()

   272 {

   273     glPushAttrib(GL_ALL_ATTRIB_BITS);

   274     glMatrixMode(GL_PROJECTION);

   275     glPushMatrix();

   276     glMatrixMode(GL_MODELVIEW);

   277     glPushMatrix();

   278 }

   279 

   280 void GLWidget::restoreGLState()

   281 {

   282     glMatrixMode(GL_PROJECTION);

   283     glPopMatrix();

   284     glMatrixMode(GL_MODELVIEW);

   285     glPopMatrix();

   286     glPopAttrib();

   287 }

   288 

   289 #define PI 3.14159

   290 

   291 void GLWidget::timerEvent(QTimerEvent *)

   292 {

   293     if (QApplication::mouseButtons() != 0)

   294         return;

   295 

   296     static bool scale_in = true;

   297 

   298     if (scale_in && scale > 35.0f)

   299         scale_in = false;

   300     else if (!scale_in && scale < .5f)

   301         scale_in = true;

   302 

   303     scale = scale_in ? scale + scale*0.01f : scale-scale*0.01f;

   304     rot_z += 0.3f;

   305     rot_x += 0.1f;

   306 

   307     int dx, dy; // disturbance point

   308     float s, v, W, t;

   309     int i, j;

   310     static float wt[128][128];

   311     const int width = logo.width();

   312     const int AMP = 5;

   313 

   314     dx = dy = width >> 1;

   315 

   316     W = .3f;

   317     v = -4; // wave speed

   318 

   319     for (i = 0; i < width; ++i) {

   320 	for ( j = 0; j < width; ++j) {

   321 	    s = sqrt((double) ((j - dx) * (j - dx) + (i - dy) * (i - dy)));

   322 	    wt[i][j] += 0.1f;

   323 	    t = s / v;

   324             if (s != 0)

   325                 wave[i*width + j] = AMP * sin(2 * PI * W * (wt[i][j] + t)) / (0.2*(s + 2));

   326             else

   327                 wave[i*width + j] = AMP * sin(2 * PI * W * (wt[i][j] + t));

   328 	}

   329     }

   330 }