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();
}