teapots.cpp

QT4 gui programming的随书光盘

/*
 * The OpenGL code in this example is based on the "teapots" example in
 * "OpenGL Programming Guide" by Jackie Neider, Tom Davis, and Mason
 * Woo, Addison-Wesley, 1993. It can be obtained from ftp.sgi.com and
 * contains the following copyright notice:
 *
 * (c) Copyright 1993, Silicon Graphics, Inc.
 * ALL RIGHTS RESERVED
 * Permission to use, copy, modify, and distribute this software for
 * any purpose and without fee is hereby granted, provided that the
 * above copyright notice appear in all copies and that both the
 * copyright notice and this permission notice appear in supporting
 * documentation, and that the name of Silicon Graphics, Inc. not be
 * used in advertising or publicity pertaining to distribution of the
 * software without specific, written prior permission.
 *
 * THE MATERIAL EMBODIED ON THIS SOFTWARE IS PROVIDED TO YOU "AS-IS"
 * AND WITHOUT WARRANTY OF ANY KIND, EXPRESS, IMPLIED OR OTHERWISE,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTY OF MERCHANTABILITY OR
 * FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL SILICON
 * GRAPHICS, INC. BE LIABLE TO YOU OR ANYONE ELSE FOR ANY DIRECT,
 * SPECIAL, INCIDENTAL, INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY
 * KIND, OR ANY DAMAGES WHATSOEVER, INCLUDING WITHOUT LIMITATION,
 * LOSS OF PROFIT, LOSS OF USE, SAVINGS OR REVENUE, OR THE CLAIMS OF
 * THIRD PARTIES, WHETHER OR NOT SILICON GRAPHICS, INC. HAS BEEN
 * ADVISED OF THE POSSIBILITY OF SUCH LOSS, HOWEVER CAUSED AND ON
 * ANY THEORY OF LIABILITY, ARISING OUT OF OR IN CONNECTION WITH THE
 * POSSESSION, USE OR PERFORMANCE OF THIS SOFTWARE.
 *
 * US Government Users Restricted Rights
 * Use, duplication, or disclosure by the Government is subject to
 * restrictions set forth in FAR 52.227.19(c)(2) or subparagraph
 * (c)(1)(ii) of the Rights in Technical Data and Computer Software
 * clause at DFARS 252.227-7013 and/or in similar or successor
 * clauses in the FAR or the DOD or NASA FAR Supplement.
 * Unpublished-- rights reserved under the copyright laws of the
 * United States. Contractor/manufacturer is Silicon Graphics,
 * Inc., 2011 N. Shoreline Blvd., Mountain View, CA 94039-7311.
 *
 * OpenGL(TM) is a trademark of Silicon Graphics, Inc.
 */

#include <QtGui>
#include <QtOpenGL>

#include "teapots.h"

Teapots::Teapots(QWidget *parent)
    : QGLWidget(parent)
{
    rubberBandIsShown = false;

    makeCurrent();
    fbObject = new QGLFramebufferObject(1024, 1024,
                                        QGLFramebufferObject::Depth);
    createGLTeapotObject();
}

Teapots::~Teapots()
{
    makeCurrent();
    delete fbObject;
    glDeleteLists(glTeapotObject, 1);
}

void Teapots::initializeGL()
{
    static const GLfloat ambient[] = { 0.0, 0.0, 0.0, 1.0 };
    static const GLfloat diffuse[] = { 1.0, 1.0, 1.0, 1.0 };
    static const GLfloat position[] = { 0.0, 3.0, 3.0, 0.0 };
    static const GLfloat lmodelAmbient[] = { 0.2, 0.2, 0.2, 1.0 };
    static const GLfloat localView[] = { 0.0 };

    glLightfv(GL_LIGHT0, GL_AMBIENT, ambient);
    glLightfv(GL_LIGHT0, GL_DIFFUSE, diffuse);
    glLightfv(GL_LIGHT0, GL_POSITION, position);
    glLightModelfv(GL_LIGHT_MODEL_AMBIENT, lmodelAmbient);
    glLightModelfv(GL_LIGHT_MODEL_LOCAL_VIEWER, localView);

    glFrontFace(GL_CW);
    glEnable(GL_LIGHTING);
    glEnable(GL_LIGHT0);
    glEnable(GL_AUTO_NORMAL);
    glEnable(GL_NORMALIZE);
    glEnable(GL_DEPTH_TEST);
    glDepthFunc(GL_LESS);
}

void Teapots::resizeGL(int width, int height)
{
    fbObject->bind();

    glDisable(GL_TEXTURE_2D);
    glEnable(GL_LIGHTING);
    glEnable(GL_DEPTH_TEST);

    glViewport(0, 0, width, height);
    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    if (width <= height) {
        glOrtho(0.0, 20.0, 0.0, 20.0 * GLfloat(height) / GLfloat(width),
                -10.0, 10.0);
    } else {
        glOrtho(0.0, 20.0 * GLfloat(width) / GLfloat(height), 0.0, 20.0,
                -10.0, 10.0);
    }
    glMatrixMode(GL_MODELVIEW);
    drawTeapots();

    fbObject->release();
}

void Teapots::paintGL()
{
    glDisable(GL_LIGHTING);
    glViewport(0, 0, width(), height());
    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    glMatrixMode(GL_MODELVIEW);
    glLoadIdentity();
    glDisable(GL_DEPTH_TEST);

    glClear(GL_COLOR_BUFFER_BIT);
    glEnable(GL_TEXTURE_2D);
    glBindTexture(GL_TEXTURE_2D, fbObject->texture());
    glColor3f(1.0, 1.0, 1.0);
    GLfloat s = width() / GLfloat(fbObject->size().width());
    GLfloat t = height() / GLfloat(fbObject->size().height());

    glBegin(GL_QUADS);
    glTexCoord2f(0.0, 0.0);
    glVertex2f(-1.0, -1.0);
    glTexCoord2f(s, 0.0);
    glVertex2f(1.0, -1.0);
    glTexCoord2f(s, t);
    glVertex2f(1.0, 1.0);
    glTexCoord2f(0.0, t);
    glVertex2f(-1.0, 1.0);
    glEnd();

    if (rubberBandIsShown) {
        glMatrixMode(GL_PROJECTION);
        glOrtho(0, width(), height(), 0, 0, 100);
        glMatrixMode(GL_MODELVIEW);

        glDisable(GL_TEXTURE_2D);
        glEnable(GL_BLEND);
        glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
        glLineWidth(4.0);
        glColor4f(1.0, 1.0, 1.0, 0.2);
        glRecti(rubberBandCorner1.x(), rubberBandCorner1.y(),
                rubberBandCorner2.x(), rubberBandCorner2.y());
        glColor4f(1.0, 1.0, 0.0, 0.5);
        glLineStipple(3, 0xAAAA);
        glEnable(GL_LINE_STIPPLE);

        glBegin(GL_LINE_LOOP);
        glVertex2i(rubberBandCorner1.x(), rubberBandCorner1.y());
        glVertex2i(rubberBandCorner2.x(), rubberBandCorner1.y());
        glVertex2i(rubberBandCorner2.x(), rubberBandCorner2.y());
        glVertex2i(rubberBandCorner1.x(), rubberBandCorner2.y());
        glEnd();

        glLineWidth(1.0);
        glDisable(GL_LINE_STIPPLE);
        glDisable(GL_BLEND);
    }
}

void Teapots::mousePressEvent(QMouseEvent *event)
{
    rubberBandCorner1 = event->pos();
    rubberBandCorner2 = event->pos();
    rubberBandIsShown = true;
}

void Teapots::mouseMoveEvent(QMouseEvent *event)
{
    if (rubberBandIsShown) {
        rubberBandCorner2 = event->pos();
        updateGL();
    }
}

void Teapots::mouseReleaseEvent(QMouseEvent * /* event */)
{
    if (rubberBandIsShown) {
        rubberBandIsShown = false;
        updateGL();
    }
}

void Teapots::createGLTeapotObject()
{
    static const int patch[][16] = {
        { 102, 103, 104, 105, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14,
          15 },
        { 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26,
          27 },
        { 24, 25, 26, 27, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39,
          40 },
        { 96, 96, 96, 96, 97, 98, 99, 100, 101, 101, 101, 101, 0, 1, 2,
          3 },
        { 0, 1, 2, 3, 106, 107, 108, 109, 110, 111, 112, 113, 114, 115,
          116, 117 },
        { 118, 118, 118, 118, 124, 122, 119, 121, 123, 126, 125, 120,
          40, 39, 38, 37 },
        { 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55,
          56 },
        { 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 28, 65, 66,
          67 },