perl-opengl基本图形操作-缩放，二维旋转，二维平移

#!/usr/bin/perl -w
use strict;
use warnings;
use OpenGL qw/ :all /;
use OpenGL::Config;   

glutInit();
glutInitDisplayMode(GLUT_RGB|GLUT_SINGLE);
glutInitWindowPosition(100,100);
glutInitWindowSize(400,400);
glutCreateWindow("平移");
glClearColor(0,0,0,255);
glClear(GL_COLOR_BUFFER_BIT);  
glMatrixMode(GL_PROJECTION);
gluOrtho2D(-100,100,-100,100);
glutDisplayFunc(\&mydis);
glutMainLoop();
return 0;

sub mydis()
{
  glColor3f(0,255,0);
  glBegin(GL_LINES);
  glVertex2f(-100,0);
  glVertex2f(100,0); 
  glEnd();
  glBegin(GL_LINES);
  glVertex2f(0,-100);
  glVertex2f(0,100); 
  glEnd(); 
  glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
  # 画矩形
  glColor3f(0.5,0.5,0);  
  glRecti(-50,-50,50,50);
  glFlush();
  #向x方向移动5个单位,y方向移动10个单位
  glColor3f(0.2,0.2,0.9);  
  glRecti(-50+5,-50+10,50+5,50+10);
  glFlush();  
  #直线的二维旋转,以(5,10)为基准点旋转
  glColor3f(0.1,0.8,0.5);
  my ($x1,$y1,$x2,$y2)=(15,15,15,50);
  for (my $theta=10;$theta<360;$theta+=10)
  {
    glBegin(GL_LINES);    
	glVertex2f(5+($x1-5)*cos($theta)-($y1-10)*sin($theta),10+($x1-5)*sin($theta)+($y1-10)*cos($theta));
    glVertex2f(5+($x2-5)*cos($theta)-($y2-10)*sin($theta),10+($x2-5)*sin($theta)+($y2-10)*cos($theta));  
 	glEnd(); 
    glFlush();  	
  } 
  #缩放
  #缩小成原来大小的0.8
  glColor3f(0.6,0.1,0.1);  
  glRecti((-50+5)*0.8,(-50+10)*0.8,(50+5)*0.8,(50+10)*0.8);
  glFlush();  
  #放大成原来大小的1.5
  glColor3f(0.1,0.9,0.1);  
  glRecti((-50+5)*1.5,(-50+10)*1.5,(50+5)*1.5,(50+10)*1.5);
  glFlush();   
}