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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), parent)

    53 {

    54     setWindowTitle(tr("OpenGL pbuffers 2"));

    55 

    56     pbuffer = new QGLPixelBuffer(1024, 1024, format(), this);

    57 

    58     rot_x = rot_y = rot_z = 0.0f;

    59     scale = 0.1f;

    60     anim = new QTimeLine(750, this);

    61     anim->setUpdateInterval(20);

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

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

    64 

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

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

    67 

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

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

    70 

    71     makeCurrent(); // need a current context to create the display list

    72     tile_list = glGenLists(1);

    73     glNewList(tile_list, GL_COMPILE);

    74     glBegin(GL_QUADS);

    75     {

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

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

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

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

    80 

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

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

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

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

    85 

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

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

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

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

    90 

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

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

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

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

    95 

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

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

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

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

   100 

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

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

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

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

   105 }

   106     glEnd();

   107     glEndList();

   108 

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

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

   111     startTimer(30); // wave timer

   112 

   113     pbuffer->makeCurrent();

   114     dynamicTexture = pbuffer->generateDynamicTexture();

   115 

   116     // bind the dynamic texture to the pbuffer - this is a no-op under X11

   117     hasDynamicTextureUpdate = pbuffer->bindToDynamicTexture(dynamicTexture);

   118 }

   119 

   120 GLWidget::~GLWidget()

   121 {

   122     delete[] wave;

   123     glDeleteLists(tile_list, 1);

   124     pbuffer->releaseFromDynamicTexture();

   125     glDeleteTextures(1, &dynamicTexture);

   126     delete pbuffer;

   127 }

   128 

   129 void GLWidget::paintEvent(QPaintEvent *)

   130 {

   131     draw();

   132 }

   133 

   134 void GLWidget::draw()

   135 {

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

   137 

   138     // save the GL state set for QPainter

   139     p.beginNativePainting();

   140     saveGLState();

   141 

   142     // render the 'bubbles.svg' file into our pbuffer

   143     QPainter pbuffer_painter(pbuffer);

   144     svg_renderer->render(&pbuffer_painter);

   145     pbuffer_painter.end();

   146     glFlush();

   147 

   148     // rendering directly to a texture is not supported on X11 and

   149     // some Windows implementations, unfortunately

   150     if (!hasDynamicTextureUpdate)

   151         pbuffer->updateDynamicTexture(dynamicTexture);

   152 

   153     makeCurrent();

   154     // draw into the GL widget

   155     glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

   156     glMatrixMode(GL_PROJECTION);

   157     glLoadIdentity();

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

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

   160     glMatrixMode(GL_MODELVIEW);

   161     glLoadIdentity();

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

   163 

   164     glBindTexture(GL_TEXTURE_2D, dynamicTexture);

   165     glEnable(GL_TEXTURE_2D);

   166     glEnable(GL_MULTISAMPLE);

   167     glEnable(GL_CULL_FACE);

   168     glEnable(GL_BLEND);

   169     glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);

   170 

   171     // draw background

   172     glPushMatrix();

   173     glScalef(1.7f, 1.7f, 1.7f);

   174     glColor4f(1.0f, 1.0f, 1.0f, 1.0f);

   175     glCallList(tile_list);

   176     glPopMatrix();

   177 

   178     const int w = logo.width();

   179     const int h = logo.height();

   180 

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

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

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

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

   185 

   186     glDepthFunc(GL_LESS);

   187     glEnable(GL_DEPTH_TEST);

   188 

   189     // draw the Qt icon

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

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

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

   193         uint *end = p + w;

   194         int  x = 0;

   195         while (p < end) {

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

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

   198             if (qAlpha(*p) > 128)

   199                 glCallList(tile_list);

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

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

   202             ++x;

   203             ++p;

   204         }

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

   206     }

   207 

   208     // restore the GL state that QPainter expects

   209     restoreGLState();

   210     p.endNativePainting();

   211 

   212     // draw the overlayed text using QPainter

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

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

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

   216     p.setPen(Qt::black);

   217     p.setBrush(Qt::NoBrush);

   218     const QString str1(tr("A simple OpenGL pbuffer example."));

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

   220     QFontMetrics fm(p.font());

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

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

   223 }

   224 

   225 void GLWidget::mousePressEvent(QMouseEvent *e)

   226 {

   227     anchor = e->pos();

   228 }

   229 

   230 void GLWidget::mouseMoveEvent(QMouseEvent *e)

   231 {

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

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

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

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

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

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

   238     }

   239 

   240     anchor = e->pos();

   241     draw();

   242 }

   243 

   244 void GLWidget::wheelEvent(QWheelEvent *e)

   245 {

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

   247     draw();

   248 }

   249 

   250 void GLWidget::mouseDoubleClickEvent(QMouseEvent *)

   251 {

   252     anim->start();

   253 }

   254 

   255 void GLWidget::animate(qreal val)

   256 {

   257     rot_y = val * 180;

   258     draw();

   259 }

   260 

   261 void GLWidget::animFinished()

   262 {

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

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

   265     else

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

   267 }

   268 

   269 void GLWidget::saveGLState()

   270 {

   271     glPushAttrib(GL_ALL_ATTRIB_BITS);

   272     glMatrixMode(GL_PROJECTION);

   273     glPushMatrix();

   274     glMatrixMode(GL_MODELVIEW);

   275     glPushMatrix();

   276 }

   277 

   278 void GLWidget::restoreGLState()

   279 {

   280     glMatrixMode(GL_PROJECTION);

   281     glPopMatrix();

   282     glMatrixMode(GL_MODELVIEW);

   283     glPopMatrix();

   284     glPopAttrib();

   285 }

   286 

   287 #define PI 3.14159

   288 

   289 void GLWidget::timerEvent(QTimerEvent *)

   290 {

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

   292         return;

   293 

   294     static bool scale_in = true;

   295 

   296     if (scale_in && scale > 35.0f)

   297         scale_in = false;

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

   299         scale_in = true;

   300 

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

   302     rot_z += 0.3f;

   303     rot_x += 0.1f;

   304 

   305     int dx, dy; // disturbance point

   306     float s, v, W, t;

   307     int i, j;

   308     static float wt[128][128];

   309     const int width = logo.width();

   310     const int AMP = 5;

   311 

   312     dx = dy = width >> 1;

   313 

   314     W = .3f;

   315     v = -4; // wave speed

   316 

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

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

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

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

   321             t = s / v;

   322             if (s != 0)

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

   324             else

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

   326         }

   327     }

   328 }