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File: [Development] / projects / ogl-sample / main / gfx / samples / redbook_2ed / aaindex.c (download)

Revision 1.2, Wed Apr 5 06:43:46 2000 UTC (17 years, 6 months ago) by ljp
Branch: MAIN
CVS Tags: tested_with_xf86_3_3, HEAD
Changes since 1.1: +1 -1 lines

Change license version to 1.1.

/*
 * License Applicability. Except to the extent portions of this file are
 * made subject to an alternative license as permitted in the SGI Free
 * Software License B, Version 1.1 (the "License"), the contents of this
 * file are subject only to the provisions of the License. You may not use
 * this file except in compliance with the License. You may obtain a copy
 * of the License at Silicon Graphics, Inc., attn: Legal Services, 1600
 * Amphitheatre Parkway, Mountain View, CA 94043-1351, or at:
 * 
 * http://oss.sgi.com/projects/FreeB
 * 
 * Note that, as provided in the License, the Software is distributed on an
 * "AS IS" basis, with ALL EXPRESS AND IMPLIED WARRANTIES AND CONDITIONS
 * DISCLAIMED, INCLUDING, WITHOUT LIMITATION, ANY IMPLIED WARRANTIES AND
 * CONDITIONS OF MERCHANTABILITY, SATISFACTORY QUALITY, FITNESS FOR A
 * PARTICULAR PURPOSE, AND NON-INFRINGEMENT.
 * 
 * Original Code. The Original Code is: OpenGL Sample Implementation,
 * Version 1.2.1, released January 26, 2000, developed by Silicon Graphics,
 * Inc. The Original Code is Copyright (c) 1991-2000 Silicon Graphics, Inc.
 * Copyright in any portions created by third parties is as indicated
 * elsewhere herein. All Rights Reserved.
 * 
 * Additional Notice Provisions: The application programming interfaces
 * established by SGI in conjunction with the Original Code are The
 * OpenGL(R) Graphics System: A Specification (Version 1.2.1), released
 * April 1, 1999; The OpenGL(R) Graphics System Utility Library (Version
 * 1.3), released November 4, 1998; and OpenGL(R) Graphics with the X
 * Window System(R) (Version 1.3), released October 19, 1998. This software
 * was created using the OpenGL(R) version 1.2.1 Sample Implementation
 * published by SGI, but has not been independently verified as being
 * compliant with the OpenGL(R) version 1.2.1 Specification.
 *
 */

/*
 *  aaindex.c
 *  This program draws shows how to draw anti-aliased lines in color
 *  index mode. It draws two diagonal lines to form an X; when 'r' 
 *  is typed in the window, the lines are rotated in opposite 
 *  directions.
 */
#include <GL/glut.h>
#include "stdlib.h"

#define RAMPSIZE 16
#define RAMP1START 32
#define RAMP2START 48

static float rotAngle = 0.;

/*  Initialize antialiasing for color index mode,
 *  including loading a green color ramp starting
 *  at RAMP1START, and a blue color ramp starting
 *  at RAMP2START. The ramps must be a multiple of 16.
 */
void init(void)
{
   int i;

   for (i = 0; i < RAMPSIZE; i++) {
      GLfloat shade;
      shade = (GLfloat) i/(GLfloat) RAMPSIZE;
      glutSetColor(RAMP1START+(GLint)i, 0., shade, 0.);
      glutSetColor(RAMP2START+(GLint)i, 0., 0., shade);
   }

   glEnable (GL_LINE_SMOOTH);
   glHint (GL_LINE_SMOOTH_HINT, GL_DONT_CARE);
   glLineWidth (1.5);

   glClearIndex ((GLfloat) RAMP1START);
}

/*  Draw 2 diagonal lines to form an X
 */
void display(void)
{
   glClear(GL_COLOR_BUFFER_BIT);

   glIndexi(RAMP1START);
   glPushMatrix();
   glRotatef(-rotAngle, 0.0, 0.0, 0.1);
   glBegin (GL_LINES);
      glVertex2f (-0.5, 0.5);
      glVertex2f (0.5, -0.5);
   glEnd ();
   glPopMatrix();

   glIndexi(RAMP2START);
   glPushMatrix();
   glRotatef(rotAngle, 0.0, 0.0, 0.1);
   glBegin (GL_LINES);
      glVertex2f (0.5, 0.5);
      glVertex2f (-0.5, -0.5);
   glEnd ();
   glPopMatrix();

   glFlush();
}

void reshape(int w, int h)
{
   glViewport(0, 0, (GLsizei) w, (GLsizei) h);
   glMatrixMode(GL_PROJECTION);
   glLoadIdentity();
   if (w <= h) 
      gluOrtho2D (-1.0, 1.0, 
         -1.0*(GLfloat)h/(GLfloat)w, 1.0*(GLfloat)h/(GLfloat)w);
   else 
      gluOrtho2D (-1.0*(GLfloat)w/(GLfloat)h, 
         1.0*(GLfloat)w/(GLfloat)h, -1.0, 1.0);
   glMatrixMode(GL_MODELVIEW);
   glLoadIdentity();
}

void keyboard(unsigned char key, int x, int y)
{
   switch (key) {
      case 'r':
      case 'R':
         rotAngle += 20.;
         if (rotAngle >= 360.) rotAngle = 0.;
         glutPostRedisplay();	
         break;
      case 27:  /*  Escape Key */
         exit(0);
         break;
      default:
         break;
    }
}

/*  Main Loop
 *  Open window with initial window size, title bar, 
 *  color index display mode, and handle input events.
 */
int main(int argc, char** argv)
{
   glutInit(&argc, argv);
   glutInitDisplayMode (GLUT_SINGLE | GLUT_INDEX);
   glutInitWindowSize (200, 200);
   glutCreateWindow (argv[0]);
   init();
   glutReshapeFunc (reshape);
   glutKeyboardFunc (keyboard);
   glutDisplayFunc (display);
   glutMainLoop();
   return 0;
}