SGI Developer Toolbox 6.1/SGI Developer Toolbox 6.1 - Disc 1.iso/toolbox/src/tutorials/custEducation/opengl2/examples/rasterops/windowSnap.c

C/C++ Source or Header | 1996-11-11 | 4.2 KB | 185 lines

/*
 * Copyright 1995, Silicon Graphics, Inc.
 * All Rights Reserved.
 *
 * This is UNPUBLISHED PROPRIETARY SOURCE CODE of Silicon Graphics, Inc.;
 * the contents of this file may not be disclosed to third parties, copied or
 * duplicated in any form, in whole or in part, without the prior written
 * permission of Silicon Graphics, Inc.
 *
 * RESTRICTED RIGHTS LEGEND:
 * Use, duplication or disclosure by the Government is subject to restrictions
 * as set forth in subdivision (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, DOD or NASA FAR Supplement. Unpublished -
 * rights reserved under the Copyright Laws of the United States.
 */

/* windowSnap.c
 *    Type "windowSnap <imageFileName>".  When the leftmouse
 *    button is pressed the scene in the window is captured,
 *    and the pixel data is written into a file.
 */
#include <GL/gl.h>
#include <GL/glu.h>
#include <GL/glut.h>

#include <math.h>
#include <stdio.h>
#include "rgbImageFile.h"    /* should be in ../../include */

/*  Function Prototypes  */

GLvoid  initgfx( GLvoid );
GLvoid  keyboard( GLubyte, GLint, GLint );
GLvoid  mouse( GLint, GLint, GLint, GLint );
GLvoid  drawScene( GLvoid );
GLvoid  reshape( GLsizei, GLsizei );

GLvoid    grabImage( void );

void    printHelp( char * );

/* Global Variables */

static char    *imageFileName;
static GLsizei    winWidth, winHeight;

GLvoid
main ( int argc, char *argv[] )
{
    GLsizei width, height;

    glutInit( &argc,  argv );

    if (argc < 2) {
        fprintf(stderr, "usage:  windowSnap <imageFileName>\n");
        imageFileName = "windowSnap.rgb";
    } else
        imageFileName = argv[1];
    fprintf(stdout, "\n\nImage will be saved in %s\n",
        imageFileName);

    width = glutGet(GLUT_SCREEN_WIDTH);
    height = glutGet(GLUT_SCREEN_HEIGHT);
    winWidth = width / 2;
    winHeight = height / 2;
    glutInitWindowPosition( width/4, height/4 );
    glutInitWindowSize( winWidth, winHeight);
    glutInitDisplayMode( GLUT_RGBA | GLUT_DEPTH );
    glutCreateWindow( argv[0] );

    initgfx();

    glutReshapeFunc( reshape );
    glutMouseFunc( mouse );
    glutDisplayFunc(drawScene);

    printHelp( argv[0] );

    glutMainLoop();
}

GLvoid
printHelp( char *progname )
{
    fprintf(stdout, "\n%s, reads pixels from window and saves \n"
        "them in a file when the Left Mousebutton is released\n\n"
        "Left Mousebutton, up        - snapshot of window\n\n",
        progname);
}

GLvoid
initgfx( void )
{
    GLfloat mat_specular[] = { 0.8, 0.8, 0.8, 1.0 };
    GLfloat mat_shininess[] = { 10.0 };

    GLfloat light_position[] = { 1.0, 1.0, 1.0, 0.0 };

    glMaterialfv(GL_FRONT, GL_SPECULAR, mat_specular);
    glMaterialfv(GL_FRONT, GL_SHININESS, mat_shininess);

    glLightfv(GL_LIGHT0, GL_POSITION, light_position);
    glEnable(GL_LIGHT0);

    glEnable(GL_LIGHTING);

    glClearColor( 0, 0, 0, 1 );

    glEnable( GL_DEPTH_TEST );
}

GLvoid
mouse( GLint button, GLint state, GLint x, GLint y )
{
    switch (button) {
    case GLUT_LEFT_BUTTON:
        if (state == GLUT_DOWN) {
            grabImage();
        }
        break;
    }
}

GLvoid
reshape( GLsizei width, GLsizei height )
{
    GLdouble    aspect;

    glViewport( 0, 0, width, height );

    winWidth = width;
    winHeight = height;

    aspect = (GLdouble) width / (GLdouble) height;

    glMatrixMode( GL_PROJECTION );
    glLoadIdentity();
    gluPerspective( 45.0, aspect, 3.0, 13.0 );
    glMatrixMode( GL_MODELVIEW );
    glLoadIdentity();
    glTranslatef( 0.0, 0.0, -8.0 );
}

GLvoid
grabImage( void )
{
    GLuint    *image;

    /* allocate space for the pixel data we're going to read
     * each pixel consists of four 1-byte components (R, G, B and A) */
    image = (GLuint *) malloc( winWidth * winHeight * 4 );

    glReadPixels( 0, 0, winWidth, winHeight, GL_RGBA, GL_UNSIGNED_BYTE,
            image );

    rgbWriteImageFile( imageFileName, winWidth, winHeight, image );

    exit(0);
}

GLvoid
drawScene( GLvoid )
{
    int i,  slices = 8;

    glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );

    glColorMaterial( GL_FRONT, GL_AMBIENT_AND_DIFFUSE );
    glEnable( GL_COLOR_MATERIAL );
    for ( i = 0; i < slices; i++ )
    {
        glColor3f( i/10.0, i/10.0, 1.0 - i/10.0 );
        glPushMatrix();
            glRotatef( i * 360.0/slices, 0, 0, 1 );
            glTranslatef( 1.5, 0.0, 0.0 );
            glRotatef( i * 360.0/slices, 0, 1, 0 );
            glutSolidTorus( 0.25, 0.75, 8, 16 );
        glPopMatrix();
    }
    glDisable( GL_COLOR_MATERIAL );
    glFlush();
}