PLANE.C

/* 
 * (c) Copyright 1993, Silicon Graphics, Inc. 
 *               1993-1995 Microsoft Corporation 
 * 
 * ALL RIGHTS RESERVED 
 * 
 * Please refer to OpenGL/readme.txt for additional information 
 * 
 */ 
 
/* 
 *  plane.c 
 *  This program demonstrates the use of local versus  
 *  infinite lighting on a flat plane. 
 */ 
#include "glos.h" 
 
#include <GL/gl.h> 
#include <GL/glu.h> 
#include <GL/glaux.h> 
 
void myinit(void); 
void drawPlane(void); 
void CALLBACK display(void); 
void CALLBACK myReshape(GLsizei w, GLsizei h); 
 
/*  Initialize material property, light source, and lighting model. 
 */ 
void myinit(void) 
{ 
    GLfloat mat_ambient[] = { 0.0, 0.0, 0.0, 1.0 }; 
/*   mat_specular and mat_shininess are NOT default values  */ 
    GLfloat mat_diffuse[] = { 0.4, 0.4, 0.4, 1.0 }; 
    GLfloat mat_specular[] = { 1.0, 1.0, 1.0, 1.0 }; 
    GLfloat mat_shininess[] = { 15.0 }; 
 
    GLfloat light_ambient[] = { 0.0, 0.0, 0.0, 1.0 }; 
    GLfloat light_diffuse[] = { 1.0, 1.0, 1.0, 1.0 }; 
    GLfloat light_specular[] = { 1.0, 1.0, 1.0, 1.0 }; 
    GLfloat lmodel_ambient[] = { 0.2, 0.2, 0.2, 1.0 }; 
 
    glMaterialfv(GL_FRONT, GL_AMBIENT, mat_ambient); 
    glMaterialfv(GL_FRONT, GL_DIFFUSE, mat_diffuse); 
    glMaterialfv(GL_FRONT, GL_SPECULAR, mat_specular); 
    glMaterialfv(GL_FRONT, GL_SHININESS, mat_shininess); 
    glLightfv(GL_LIGHT0, GL_AMBIENT, light_ambient); 
    glLightfv(GL_LIGHT0, GL_DIFFUSE, light_diffuse); 
    glLightfv(GL_LIGHT0, GL_SPECULAR, light_specular); 
    glLightModelfv(GL_LIGHT_MODEL_AMBIENT, lmodel_ambient); 
 
    glEnable(GL_LIGHTING); 
    glEnable(GL_LIGHT0); 
    glDepthFunc(GL_LESS); 
    glEnable(GL_DEPTH_TEST); 
} 
 
void drawPlane(void) 
{ 
    glBegin (GL_QUADS); 
    glNormal3f (0.0, 0.0, 1.0); 
    glVertex3f (-1.0, -1.0, 0.0); 
    glVertex3f (0.0, -1.0, 0.0); 
    glVertex3f (0.0, 0.0, 0.0); 
    glVertex3f (-1.0, 0.0, 0.0); 
 
    glNormal3f (0.0, 0.0, 1.0); 
    glVertex3f (0.0, -1.0, 0.0); 
    glVertex3f (1.0, -1.0, 0.0); 
    glVertex3f (1.0, 0.0, 0.0); 
    glVertex3f (0.0, 0.0, 0.0); 
 
    glNormal3f (0.0, 0.0, 1.0); 
    glVertex3f (0.0, 0.0, 0.0); 
    glVertex3f (1.0, 0.0, 0.0); 
    glVertex3f (1.0, 1.0, 0.0); 
    glVertex3f (0.0, 1.0, 0.0); 
 
    glNormal3f (0.0, 0.0, 1.0); 
    glVertex3f (0.0, 0.0, 0.0); 
    glVertex3f (0.0, 1.0, 0.0); 
    glVertex3f (-1.0, 1.0, 0.0); 
    glVertex3f (-1.0, 0.0, 0.0); 
    glEnd(); 
} 
 
void CALLBACK display (void) 
{ 
    GLfloat infinite_light[] = { 1.0, 1.0, 1.0, 0.0 }; 
    GLfloat local_light[] = { 1.0, 1.0, 1.0, 1.0 }; 
 
    glClear (GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); 
 
    glPushMatrix (); 
    glTranslatef (-1.5, 0.0, 0.0); 
    glLightfv (GL_LIGHT0, GL_POSITION, infinite_light); 
    drawPlane (); 
    glPopMatrix (); 
 
    glPushMatrix (); 
    glTranslatef (1.5, 0.0, 0.0); 
    glLightfv (GL_LIGHT0, GL_POSITION, local_light); 
    drawPlane (); 
    glPopMatrix (); 
    glFlush (); 
} 
 
void CALLBACK myReshape (GLsizei w, GLsizei h) 
{ 
    if (!h) return; 
    glViewport (0, 0, w, h); 
    glMatrixMode (GL_PROJECTION); 
    glLoadIdentity (); 
    if (w <= h)  
    glOrtho (-1.5, 1.5, -1.5*(GLdouble)h/(GLdouble)w,  
        1.5*(GLdouble)h/(GLdouble)w, -10.0, 10.0); 
    else  
    glOrtho (-1.5*(GLdouble)w/(GLdouble)h,  
        1.5*(GLdouble)w/(GLdouble)h, -1.5, 1.5, -10.0, 10.0); 
    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 | AUX_DEPTH16); 
    auxInitPosition (0, 0, 500, 200); 
    auxInitWindow ("Local vs Infinite Lighting"); 
    myinit(); 
    auxReshapeFunc (myReshape); 
    auxMainLoop(display); 
    return(0); 
}