SMOOTH.C

/* 
 * (c) Copyright 1993, Silicon Graphics, Inc. 
 *               1993-1995 Microsoft Corporation 
 * 
 * ALL RIGHTS RESERVED 
 * 
 * Please refer to OpenGL/readme.txt for additional information 
 * 
 */ 
 
/* 
 * smooth.c 
 * This program demonstrates smooth shading. 
 * A smooth shaded polygon is drawn in a 2-D projection. 
 */ 
#include "glos.h" 
 
#include <GL/gl.h> 
#include <GL/glu.h> 
#include <GL/glaux.h> 
 
void myinit(void); 
void triangle(void); 
void CALLBACK display(void); 
void CALLBACK myReshape(GLsizei w, GLsizei h); 
 
/*  GL_SMOOTH is actually the default shading model.  */ 
void myinit (void) 
{ 
    glShadeModel (GL_SMOOTH); 
} 
 
void triangle(void) 
{ 
    glBegin (GL_TRIANGLES); 
    glColor3f (1.0, 0.0, 0.0); 
    glVertex2f (5.0, 5.0); 
    glColor3f (0.0, 1.0, 0.0); 
    glVertex2f (25.0, 5.0); 
    glColor3f (0.0, 0.0, 1.0); 
    glVertex2f (5.0, 25.0); 
    glEnd (); 
} 
 
void CALLBACK display(void) 
{ 
    glClear (GL_COLOR_BUFFER_BIT); 
    triangle (); 
    glFlush (); 
} 
 
void CALLBACK myReshape(GLsizei w, GLsizei h) 
{ 
    if (!h) return; 
    glViewport(0, 0, w, h); 
    glMatrixMode(GL_PROJECTION); 
    glLoadIdentity(); 
    if (w <= h)  
    gluOrtho2D (0.0, 30.0, 0.0, 30.0 * (GLfloat) h/(GLfloat) w); 
    else  
    gluOrtho2D (0.0, 30.0 * (GLfloat) w/(GLfloat) h, 0.0, 30.0); 
    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 ("Smooth Shading"); 
    myinit(); 
    auxReshapeFunc (myReshape); 
    auxMainLoop(display); 
    return(0); 
}