#include <stdlib.h>
#include <string.h>
#include <GL/glut.h>

#define display display_list

static GLint v0[] = {0, 5};
static GLint v1[] = {-5, -5, 0};
static GLint v2[] = {4, 8, 0};
static GLint v3[] = {5, -6, 0};

void 
display_list(void)
{
        GLuint lid;
        glClear(GL_COLOR_BUFFER_BIT);
        glColor3f (0.0, 0.0, 1.0);

        lid = glGenLists(1);
        glNewList(lid, GL_COMPILE);
        glBegin (GL_TRIANGLE_STRIP);
        glVertex2iv(v0);
        glVertex3iv(v1);
        glVertex3iv(v2);
        glVertex3iv(v3);
        glEnd ();
        glEndList();
        glCallList(lid);
        glDeleteLists(lid, 1);

        glFlush();
}

static void
key(unsigned char k, int x, int y)
{
        switch (k) {
        case 27:
                exit(0);
                break;
        default:
                return;
        }
        glutPostRedisplay();
}


static void 
reshape(int width, int height)
{
        float ar = (float)width / (float)height + 10.0;
        glViewport(0, 0, width, height);
        glMatrixMode(GL_PROJECTION);
        glLoadIdentity();
        gluOrtho2D (-ar, ar, -ar, ar);
        glMatrixMode(GL_MODELVIEW);
        glLoadIdentity();
}

int 
main(int argc, char** argv)
{
        glutInit(&argc, argv);
        glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB);
        glutInitWindowSize(250, 250);
        glutInitWindowPosition(100, 100);
        glutCreateWindow("Vertex");
        glutReshapeFunc(reshape);
        glutDisplayFunc(display);
        glutKeyboardFunc(key);
        glutMainLoop();
        return 0;
}