利用 VC++OpenGL 作为开发平台设计程序，以能够在屏幕上生成任意一个像素点，利用像素点绘制基本图形菱形

#include <GL/glut.h>
#include<Windows.h>
void init (void) 
{ 
  glClearColor (1.0, 1.0, 1.0, 0.0);
  glMatrixMode (GL_PROJECTION);// 投影
  gluOrtho2D (-5.0, 5.0, -5.0, 5.0); //设置显示的范围是X:-5.0~5.0, Y:-5.0~5.0
  glMatrixMode (GL_MODELVIEW);//模型视图
}

void drawDiamond(void) //绘制中心在原点的菱形
{
glBegin (GL_POLYGON); //顶点指定需要按逆时针方向
glVertex2f (0.0f,-2.5f);//下点
glVertex2f (1.0f,0.0f);//右点
glVertex2f (0.0f, 2.5f);//上点
glVertex2f (-1.0f,0.0f);//左点
glEnd ( ); 
}

void myDisplay(void)
{
 glClear (GL_COLOR_BUFFER_BIT); //清空

 glLoadIdentity(); //将当前矩阵设为单位矩阵
 glRotatef(45,0.0,0.0,1.0);//顺时针旋转45度
 glTranslatef(0.0,2.5,0.0);
 glColor3f(0.0,1.0,0.0);
 drawDiamond();

 glLoadIdentity(); //将当前矩阵设为单位矩阵
 glRotatef(135,0.0,0.0,1.0);//顺时针旋转135度
 glTranslatef(0.0,2.5,0.0);
 glColor3f(0.0,1.0,0.0);
 drawDiamond();

 glLoadIdentity(); //将当前矩阵设为单位矩阵
 glRotatef(-45,0.0,0.0,1.0);//逆时针旋转45度
 glTranslatef(0.0,2.5,0.0);
 glColor3f(0.0,1.0,0.0);
 drawDiamond();

 glLoadIdentity(); //将当前矩阵设为单位矩阵
 glRotatef(-135,0.0,0.0,1.0);//逆时针旋转135度
 glTranslatef(0.0,2.5,0.0);
 glColor3f(0.0,1.0,0.0);
 drawDiamond();
 
 glLoadIdentity(); //将当前矩阵设为单位矩阵
 glColor3f(1.0,0.0,0.0);
 glTranslatef(0.0,2.5,0.0);
 drawDiamond();

 glLoadIdentity(); //将当前矩阵设为单位矩阵
 glColor3f(1.0,0.0,0.0);
 glRotatef(90,0.0,0.0,1.0);
 glTranslatef(0.0,2.5,0.0);
 drawDiamond();

 glLoadIdentity(); //将当前矩阵设为单位矩阵
 glColor3f(1.0,0.0,0.0);
 glRotatef(-90,0.0,0.0,1.0);
 glTranslatef(0.0,2.5,0.0);
 drawDiamond();

 glLoadIdentity(); //将当前矩阵设为单位矩阵
 glColor3f(1.0,0.0,0.0);
 glTranslatef(0.0,-2.5,0.0);
 drawDiamond();
 glFlush();
}

int main (int argc, char *argv[])
 {
 glutInit (&argc, argv);
 glutInitDisplayMode (GLUT_SINGLE | GLUT_RGB);
 glutInitWindowPosition (0, 0);
 glutInitWindowSize (600, 600);
 glutCreateWindow ("Hello Opengl!");
 init();
 glutDisplayFunc (&myDisplay);
 glutMainLoop ( );
 return 0;
 }