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     2 **

     3 ** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).

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     7 ** This file is part of the examples of the Qt Toolkit.

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    16 ** GNU Lesser General Public License Usage

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    40 ****************************************************************************/

    41 

    42 #include "glwidget.h"

    43 #include <math.h>

    44 

    45 #include "cube.h"

    46 

    47 #include <QGLPixelBuffer>

    48 

    49 #ifndef GL_MULTISAMPLE

    50 #define GL_MULTISAMPLE  0x809D

    51 #endif

    52 

    53 static GLfloat colorArray[][4] = {

    54     {0.243f, 0.423f, 0.125f, 1.0f},

    55     {0.176f, 0.31f, 0.09f, 1.0f},

    56     {0.4f, 0.69f, 0.212f, 1.0f},

    57     {0.317f, 0.553f, 0.161f, 1.0f}

    58 };

    59 

    60 GLWidget::GLWidget(QWidget *parent)

    61     : QGLWidget(QGLFormat(QGL::SampleBuffers), parent)

    62     , geom(0)

    63     , cube(0)

    64 {

    65     // create the pbuffer

    66     pbuffer = new QGLPixelBuffer(QSize(512, 512), format(), this);

    67     setWindowTitle(tr("OpenGL pbuffers"));

    68     initializeGeometry();

    69 }

    70 

    71 GLWidget::~GLWidget()

    72 {

    73     pbuffer->releaseFromDynamicTexture();

    74     glDeleteTextures(1, &dynamicTexture);

    75     delete pbuffer;

    76 

    77     qDeleteAll(cubes);

    78     qDeleteAll(tiles);

    79     delete cube;

    80 }

    81 

    82 void GLWidget::initializeGL()

    83 {

    84     initCommon();

    85     glShadeModel(GL_SMOOTH);

    86     glEnable(GL_LIGHTING);

    87     glEnable(GL_LIGHT0);

    88     static GLfloat lightPosition[4] = { 0.5, 5.0, 7.0, 1.0 };

    89     glLightfv(GL_LIGHT0, GL_POSITION, lightPosition);

    90     initPbuffer();

    91     cube->startAnimation();

    92     connect(cube, SIGNAL(changed()), this, SLOT(update()));

    93     for (int i = 0; i < 3; ++i)

    94     {

    95         cubes[i]->startAnimation();

    96         connect(cubes[i], SIGNAL(changed()), this, SLOT(update()));

    97     }

    98 }

    99 

   100 void GLWidget::paintGL()

   101 {

   102     pbuffer->makeCurrent();

   103     drawPbuffer();

   104     // On direct render platforms, drawing onto the pbuffer context above

   105     // automatically updates the dynamic texture.  For cases where rendering

   106     // directly to a texture is not supported, explicitly copy.

   107     if (!hasDynamicTextureUpdate)

   108         pbuffer->updateDynamicTexture(dynamicTexture);

   109     makeCurrent();

   110 

   111     // Use the pbuffer as a texture to render the scene

   112     glBindTexture(GL_TEXTURE_2D, dynamicTexture);

   113 

   114     // set up to render the scene

   115     glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

   116     glLoadIdentity();

   117     glTranslatef(0.0f, 0.0f, -10.0f);

   118 

   119     // draw the background

   120     glPushMatrix();

   121     glScalef(aspect, 1.0f, 1.0f);

   122     for (int i = 0; i < tiles.count(); ++i)

   123         tiles[i]->draw();

   124     glPopMatrix();

   125 

   126     // draw the bouncing cubes

   127     for (int i = 0; i < cubes.count(); ++i)

   128         cubes[i]->draw();

   129 }

   130 

   131 void GLWidget::initializeGeometry()

   132 {

   133     geom = new Geometry();

   134     CubeBuilder cBuilder(geom, 0.5);

   135     cBuilder.setColor(QColor(255, 255, 255, 212));

   136     // build the 3 bouncing, spinning cubes

   137     for (int i = 0; i < 3; ++i)

   138         cubes.append(cBuilder.newCube(QVector3D((float)(i-1), -1.5f, 5 - i)));

   139 

   140     // build the spinning cube which goes in the dynamic texture

   141     cube = cBuilder.newCube();

   142     cube->removeBounce();

   143 

   144     // build the background tiles

   145     TileBuilder tBuilder(geom);

   146     tBuilder.setColor(QColor(Qt::white));

   147     for (int c = -2; c <= +2; ++c)

   148         for (int r = -2; r <= +2; ++r)

   149             tiles.append(tBuilder.newTile(QVector3D(c, r, 0)));

   150 

   151     // graded backdrop for the pbuffer scene

   152     TileBuilder bBuilder(geom, 0.0f, 2.0f);

   153     bBuilder.setColor(QColor(102, 176, 54, 210));

   154     backdrop = bBuilder.newTile(QVector3D(0.0f, 0.0f, -1.5f));

   155     backdrop->setColors(colorArray);

   156 }

   157 

   158 void GLWidget::initCommon()

   159 {

   160     qglClearColor(QColor(Qt::darkGray));

   161 

   162     glEnable(GL_DEPTH_TEST);

   163     glEnable(GL_CULL_FACE);

   164     glEnable(GL_MULTISAMPLE);

   165 

   166     glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);

   167     glEnable(GL_BLEND);

   168 

   169     glEnable(GL_TEXTURE_2D);

   170 

   171     geom->loadArrays();

   172 }

   173 

   174 void GLWidget::perspectiveProjection()

   175 {

   176     glMatrixMode(GL_PROJECTION);

   177     glLoadIdentity();

   178     glFrustum(-aspect, +aspect, -1.0, +1.0, 4.0, 15.0);

   179     glMatrixMode(GL_MODELVIEW);

   180 }

   181 

   182 void GLWidget::orthographicProjection()

   183 {

   184     glMatrixMode(GL_PROJECTION);

   185     glLoadIdentity();

   186     glOrtho(-1.0, +1.0, -1.0, +1.0, -90.0, +90.0);

   187     glMatrixMode(GL_MODELVIEW);

   188 }

   189 

   190 void GLWidget::resizeGL(int width, int height)

   191 {

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

   193     aspect = (qreal)width / (qreal)(height ? height : 1);

   194     perspectiveProjection();

   195 }

   196 

   197 void GLWidget::drawPbuffer()

   198 {

   199     orthographicProjection();

   200 

   201     glClearColor(0.0f, 0.0f, 0.0f, 1.0f);

   202     glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

   203 

   204     glDisable(GL_TEXTURE_2D);

   205     backdrop->draw();

   206     glEnable(GL_TEXTURE_2D);

   207 

   208     glBindTexture(GL_TEXTURE_2D, cubeTexture);

   209     glDisable(GL_CULL_FACE);

   210     cube->draw();

   211     glEnable(GL_CULL_FACE);

   212 

   213     glFlush();

   214 }

   215 

   216 void GLWidget::initPbuffer()

   217 {

   218     pbuffer->makeCurrent();

   219 

   220     cubeTexture = bindTexture(QImage(":res/cubelogo.png"));

   221 

   222     initCommon();

   223 

   224     // generate a texture that has the same size/format as the pbuffer

   225     dynamicTexture = pbuffer->generateDynamicTexture();

   226 

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

   228     hasDynamicTextureUpdate = pbuffer->bindToDynamicTexture(dynamicTexture);

   229     makeCurrent();

   230 }

   231 

   232 void GLWidget::setAnimationPaused(bool enable)

   233 {

   234     cube->setAnimationPaused(enable);

   235     for (int i = 0; i < 3; ++i)

   236         cubes[i]->setAnimationPaused(enable);

   237 }