www.pudn.com > openglbk.rar > aargb.c

/* 
 * Copyright (c) 1993-1999, 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 * Unpublished-- rights reserved under the copyright laws of the 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(R) is a registered trademark of Silicon Graphics, Inc. 
 */ 
 
/* 
 *  aargb.c 
 *  This program draws shows how to draw anti-aliased lines. It draws 
 *  two diagonal lines to form an X; when 'r' is typed in the window,  
 *  the lines are rotated in opposite directions. 
 */ 
#include  
#include  
#include  
 
static float rotAngle = 0.; 
 
/*  Initialize antialiasing for RGBA mode, including alpha 
 *  blending, hint, and line width.  Print out implementation 
 *  specific info on line width granularity and width. 
 */ 
void init(void) 
{ 
   GLfloat values[2]; 
   glGetFloatv (GL_LINE_WIDTH_GRANULARITY, values); 
   printf ("GL_LINE_WIDTH_GRANULARITY value is %3.1f\n", values[0]); 
 
   glGetFloatv (GL_LINE_WIDTH_RANGE, values); 
   printf ("GL_LINE_WIDTH_RANGE values are %3.1f %3.1f\n", 
      values[0], values[1]); 
 
   glEnable (GL_LINE_SMOOTH); 
   glEnable (GL_BLEND); 
   glBlendFunc (GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA); 
   glHint (GL_LINE_SMOOTH_HINT, GL_DONT_CARE); 
   glLineWidth (1.5); 
 
   glClearColor(0.0, 0.0, 0.0, 0.0); 
} 
 
/* Draw 2 diagonal lines to form an X 
 */ 
void display(void) 
{ 
   glClear(GL_COLOR_BUFFER_BIT); 
 
   glColor3f (0.0, 1.0, 0.0); 
   glPushMatrix(); 
   glRotatef(-rotAngle, 0.0, 0.0, 0.1); 
   glBegin (GL_LINES); 
      glVertex2f (-0.5, 0.5); 
      glVertex2f (0.5, -0.5); 
   glEnd (); 
   glPopMatrix(); 
 
   glColor3f (0.0, 0.0, 1.0); 
   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, w, 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,  
 *  RGBA display mode, and handle input events. 
 */ 
int main(int argc, char** argv) 
{ 
   glutInit(&argc, argv); 
   glutInitDisplayMode (GLUT_SINGLE | GLUT_RGB); 
   glutInitWindowSize (200, 200); 
   glutCreateWindow (argv[0]); 
   init(); 
   glutReshapeFunc (reshape); 
   glutKeyboardFunc (keyboard); 
   glutDisplayFunc (display); 
   glutMainLoop(); 
   return 0; 
}