#include <QtGui>#include <QtOpenGL>#include "tetrahedron.h"Tetrahedron::Tetrahedron(QWidget *parent)    : QGLWidget(parent){    setFormat(QGLFormat(QGL::DoubleBuffer | QGL::DepthBuffer));    rotationX = -21.0;    rotationY = -57.0;    rotationZ = 0.0;    faceColors[0] = Qt::red;    faceColors[1] = Qt::green;    faceColors[2] = Qt::blue;    faceColors[3] = Qt::yellow;}void Tetrahedron::initializeGL(){    qglClearColor(Qt::black);    glShadeModel(GL_FLAT);    glEnable(GL_DEPTH_TEST);    glEnable(GL_CULL_FACE);}void Tetrahedron::resizeGL(int width, int height){    glViewport(0, 0, width, height);    glMatrixMode(GL_PROJECTION);    glLoadIdentity();    GLfloat x = GLfloat(width) / height;    glFrustum(-x, x, -1.0, 1.0, 4.0, 15.0);    glMatrixMode(GL_MODELVIEW);}void Tetrahedron::paintGL(){    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);    draw();}void Tetrahedron::mousePressEvent(QMouseEvent *event){    lastPos = event->pos();}void Tetrahedron::mouseMoveEvent(QMouseEvent *event){    GLfloat dx = GLfloat(event->x() - lastPos.x()) / width();    GLfloat dy = GLfloat(event->y() - lastPos.y()) / height();    if (event->buttons() & Qt::LeftButton) {        rotationX += 180 * dy;        rotationY += 180 * dx;        updateGL();    } else if (event->buttons() & Qt::RightButton) {        rotationX += 180 * dy;        rotationZ += 180 * dx;        updateGL();    }    lastPos = event->pos();}void Tetrahedron::mouseDoubleClickEvent(QMouseEvent *event){    int face = faceAtPosition(event->pos());    if (face != -1) {        QColor color = QColorDialog::getColor(faceColors[face], this);        if (color.isValid()) {            faceColors[face] = color;            updateGL();        }    }}void Tetrahedron::draw(){    static const GLfloat P1[3] = { 0.0, -1.0, +2.0 };    static const GLfloat P2[3] = { +1.73205081, -1.0, -1.0 };    static const GLfloat P3[3] = { -1.73205081, -1.0, -1.0 };    static const GLfloat P4[3] = { 0.0, +2.0, 0.0 };    static const GLfloat * const coords[4][3] = {        { P1, P2, P3 }, { P1, P3, P4 }, { P1, P4, P2 }, { P2, P4, P3 }    };    glMatrixMode(GL_MODELVIEW);    glLoadIdentity();    glTranslatef(0.0, 0.0, -10.0);    glRotatef(rotationX, 1.0, 0.0, 0.0);    glRotatef(rotationY, 0.0, 1.0, 0.0);    glRotatef(rotationZ, 0.0, 0.0, 1.0);    for (int i = 0; i < 4; ++i) {        glLoadName(i);        glBegin(GL_TRIANGLES);        qglColor(faceColors[i]);        for (int j = 0; j < 3; ++j) {            glVertex3f(coords[i][j][0], coords[i][j][1],                       coords[i][j][2]);        }        glEnd();    }}int Tetrahedron::faceAtPosition(const QPoint &pos){    const int MaxSize = 512;    GLuint buffer[MaxSize];    GLint viewport[4];    glGetIntegerv(GL_VIEWPORT, viewport);    glSelectBuffer(MaxSize, buffer);    glRenderMode(GL_SELECT);    glInitNames();    glPushName(0);    glMatrixMode(GL_PROJECTION);    glPushMatrix();    glLoadIdentity();    gluPickMatrix(GLdouble(pos.x()), GLdouble(viewport[3] - pos.y()),                  5.0, 5.0, viewport);    GLfloat x = GLfloat(width()) / height();    glFrustum(-x, x, -1.0, 1.0, 4.0, 15.0);    draw();    glMatrixMode(GL_PROJECTION);    glPopMatrix();    if (!glRenderMode(GL_RENDER))        return -1;    return buffer[3];}