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This is a sample OpenGL program.
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I got this error when the console window (black screen) shows:
freeglut Error: Function <glutDisplayFunc> called without first calling ‘glutInit’ -
VC++ 2008, WinXP OS, Win32 consolde app project, all libraries installed.
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I run OpenGL on VC++2008, i copied glut.h, freeglut.h, …
Is that right? What should i set up more?
#include <windows.h>
#include <gl/glut.h>
void display()
{
// clear all pixels
glClear(GL_COLOR_BUFFER_BIT);
// draw white polygon (rectangle) with corners at (0.25, 0.25, 0.0) and
// (0.75, 0.75, 0.0)
glColor3f(1.0, 1.0, 1.0);
glBegin(GL_POLYGON);
glVertex3f(0.25, 0.25, 0.0);
glVertex3f(0.75, 0.25, 0.0);
glVertex3f(0.75, 0.75, 0.0);
glVertex3f(0.25, 0.75, 0.0);
glEnd();
// start pocessing buffered OpenGL routines
glFlush();
}
void init()
{
// select clearing (background) color
glClearColor(0.0, 0.0, 0.0, 0.0);
// init viewing values
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
glOrtho(0.0, 1.0, 0.0, 1.0, -1.0, 1.0);
}
int main(int argc, char **argv)
{
glutInit(&argc, argv);
glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB);
glutInitWindowSize(250, 250);
glutInitWindowPosition(100, 100);
glutCreateWindow("Hello");
init();
glutDisplayFunc(display);
glutMainLoop();
return 0;
}