CLIP.C

/* 
 * (c) Copyright 1993, Silicon Graphics, Inc. 
 *               1993-1995 Microsoft Corporation 
 * 
 * ALL RIGHTS RESERVED 
 * 
 * Please refer to OpenGL/readme.txt for additional information 
 * 
 */ 
 
/* 
 *  clip.c 
 *  This program demonstrates arbitrary clipping planes. 
 */ 
#include "glos.h" 
 
#include <GL/gl.h> 
#include <GL/glu.h> 
#include <GL/glaux.h> 
 
void myinit(void); 
void CALLBACK myReshape(GLsizei w, GLsizei h); 
void CALLBACK display(void); 
 
void CALLBACK display(void) 
{ 
    GLdouble eqn[4] = {0.0, 1.0, 0.0, 0.0}; 
    GLdouble eqn2[4] = {1.0, 0.0, 0.0, 0.0}; 
 
    glClear(GL_COLOR_BUFFER_BIT); 
 
    glColor3f (1.0, 1.0, 1.0); 
    glPushMatrix(); 
    glTranslatef (0.0, 0.0, -5.0); 
 
/*    clip lower half -- y < 0      */ 
    glClipPlane (GL_CLIP_PLANE0, eqn); 
    glEnable (GL_CLIP_PLANE0); 
/*    clip left half -- x < 0       */ 
    glClipPlane (GL_CLIP_PLANE1, eqn2); 
    glEnable (GL_CLIP_PLANE1); 
 
    glRotatef (90.0, 1.0, 0.0, 0.0); 
    auxWireSphere(1.0); 
    glPopMatrix(); 
    glFlush(); 
} 
 
void myinit (void) { 
    glShadeModel (GL_FLAT); 
} 
 
void CALLBACK myReshape(GLsizei w, GLsizei h) 
{ 
    if (!h) return; 
    glViewport(0, 0, w, h); 
    glMatrixMode(GL_PROJECTION); 
    glLoadIdentity(); 
    gluPerspective(60.0, (GLfloat) w/(GLfloat) h, 1.0, 20.0); 
    glMatrixMode(GL_MODELVIEW); 
} 
 
/*  Main Loop 
 *  Open window with initial window size, title bar,  
 *  RGBA display mode, and handle input events. 
 */ 
int main(int argc, char** argv) 
{ 
    auxInitDisplayMode (AUX_SINGLE | AUX_RGB); 
    auxInitPosition (0, 0, 500, 500); 
    auxInitWindow ("Arbitrary Clipping Planes"); 
    myinit (); 
    auxReshapeFunc (myReshape); 
    auxMainLoop(display); 
    return(0); 
}