Why doesn’t this code display a mult-colored triangle as in lesson03.c in Nehe’s tutorials.
#include <GL/gl.h>
#include <GL/glut.h>
void init(void){
glClearColor(0.0,0.0,0.0,0.0);
glShadeModel(GL_FLAT);
}
void display(void){
glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);
glBegin(GL_POLYGON);
glColor3f(1.0,0.0,0.0);
glVertex3f(0.25,0.1,0.0);
glColor3f(0.0,1.0,0.0);
glVertex3f(0.75,0.1,0.0);
glColor3f(0.0,0.0,1.0);
glVertex3f(0.5,0.9,0.0);
glEnd();
glFlush();
}
int main(int argc,char **argv){
glutInit(&argc,argv);
glutInitDisplayMode(GLUT_SINGLE|GLUT_RGBA|GLUT_ALPHA|GLUT_DEPTH);
glutInitWindowSize(800,600);
glutInitWindowPosition(100,100);
glutCreateWindow("The thrill is gone");
init();
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
glOrtho(0.0,1.0,0.0,1.0,-1.0,1.0);
glutDisplayFunc(display);
glutMainLoop();
return 0;
}