OpenGL program

Development Platform:
C/C++

main.cpp：Code Content
							#include <iostream>
#include <math.h>
#include <stdlib.h>
#include <GLglut.h>
using namespace std;
int Width=800;
int Height=600;
const float Pi=3.1415;
int Mystate=0; 
int oldx=0;
int oldy=0;
float rate=1;
float x1=1,x2=1,x3=1,x4=1;
int color1=0,color2=0,color3=1;
void MyInit()
{
	glClear(GL_COLOR_BUFFER_BIT);
	glMatrixMode(GL_PROJECTION);
	glLoadIdentity();
}
void graph1()
{
	/***************** area graph1 ****************************/
	//draw the blue line
	glLineWidth(1);
	glColor3f(0.0,0.0,1.0);
	glBegin(GL_LINES);
	glVertex2f(-1.0,1.0);
	glVertex2f(1.0,-1.0);
	glEnd();
	//draw the red broken line
	glLineWidth(1);
	glColor3f(1.0,0.0,0.0);
	glEnable(GL_LINE_STIPPLE);
	glLineStipple(1, 0x00FF);
	glBegin(GL_LINES);
	glVertex2f(-1.0,-1.0);
	glVertex2f(1.0,1.0);
	glEnd();
	//draw the yellow strip line
	glColor3f(1.0,1.0,0.0);
	glLineStipple(1, 0x67E6);
	glBegin(GL_LINE_STRIP);
	glVertex2f(-1.0,-1.0);
	glVertex2f(-0.8,-0.7);	
	glVertex2f(0.7,0.8);
	glVertex2f(1.0,1.0);
	glEnd();
}
void graph2()
{
	/************ area graph2 ************************/
	glDisable(GL_LINE_STIPPLE);
	glColor3f(0.0,1.0,0.0);
	glBegin(GL_TRIANGLES);
	glVertex2f(-0.8,-0.8);
	glVertex2f(0.5,0.5);
	glVertex2f(-0.2,0.3);
	glEnd();
}
void graph3()
{
	/*********** area graph3 **********************/
	glShadeModel(GL_SMOOTH); 
	glBegin(GL_QUADS);
	glColor3f(0.9,0.0,0.0);
	glVertex2f(-1.0,0);
	glColor3f(0.0,0.8,0.0);
	glVertex2f(1.0,0.5);
	glColor3f(0.9,0.9,0.9);
	glVertex2f(0.6,-0.7);
	glColor3f(0.0,0.0,0.8);
	glVertex2f(-1.0,-0.5);
	glEnd();
}
void graph4()
{
	/********** area graph4 ***********************/
	int blocknum=300;
	glColor3f(1,0,0);
	glBegin(GL_POLYGON);
	for(int i=0;i<blocknum;i++)
	{
		GLfloat Loc[2];
		Loc[0]=0.4*cos(2*Pi*i/blocknum);
		Loc[1]=0.5*sin(2*Pi*i/blocknum);
		glVertex2fv(Loc);
	}
	glEnd();
}
void MyDisplay()	//绘制要显示的场景
{
	if (Mystate==0)
	{
		glClear(GL_COLOR_BUFFER_BIT);
		glViewport( 0, Height/2, Width/2, Height/2 );
		glScalef(x1,x1,x1);
		graph1();
		glViewport( Width/2, Height/2, Width/2, Height/2 );
		glScalef(x2/x1,x2/x1,x2/x1);
		graph2();
		glViewport( 0, 0, Width/2, Height/2 );
		glScalef(x3/x2,x3/x2,x3/x2);
		graph3();
		glViewport( Width/2,0, Width/2, Height/2 );
		glScalef(x4/x3,x4/x3,x4/x3);
		graph4();
		glViewport(0,0,Width,Height);
		glFlush();
	}
	else if (Mystate==1)
	{
		glViewport(0,0,Width,Height);
		glClear(GL_COLOR_BUFFER_BIT);
		glScalef(x1,x1,x1);
		graph1();
		glFlush();
	}
	else if (Mystate==2)
	{
		glViewport(0,0,Width,Height);
		glClear(GL_COLOR_BUFFER_BIT);
		glScalef(x2,x2,x2);
		graph2();
		glFlush();
	}
	else if (Mystate==3)
	{
		glViewport(0,0,Width,Height);
		glClear(GL_COLOR_BUFFER_BIT);
		glScalef(x3,x3,x3);
		graph3();
		glFlush();
	}
	else 
	{
		glViewport(0,0,Width,Height);
		glClear(GL_COLOR_BUFFER_BIT);
		glScalef(x4,x4,x4);
		graph4();
		glFlush();
	}
}
void MyReshape(GLint cx,GLint cy)	//窗口大小发生变化时的操作,cx为窗口宽,cy为窗口高
{
	// 防止除数即高度为0 
	// (你可以设置窗口宽度为0). 
	if(cy == 0) 
		cy = 1; 
	Width=cx;
	Height=cy;
}
void MyMouse(GLint button,GLint state,GLint cx,GLint cy)	//鼠标点击操作
{
	//button为鼠标键,有左键GLUT_LEFT_BUTTON,右键GLUT_RIGHT_BUTTON,滚轮向上GLUT_WHEEL_UP,滚轮向下GLUT_WHEEL_DOWN
	//state为鼠标按键状态,有按下GLUT_DOWN,弹起GLUT_UP
	//cx,cy为鼠标当前坐标
	//对于滚轮的操作,需要较新的GLUT版本才能支持,可以使用主页上的glut2004
	//对滚轮的判定,使用state == GLUT_UP && button == GLUT_WHEEL_UP来判断
	if (button==GLUT_RIGHT_BUTTON&&state==GLUT_DOWN)
	{
		glLoadIdentity(); 
		rate=1;
		if (Mystate==0)
		{
			if (cx<=Width/2&&cy<=Height/2)
			{
				Mystate=1;
				glClear(GL_COLOR_BUFFER_BIT);
				glScalef(x1,x1,x1);
				graph1();
				glFlush();
			}
			else if (cx>Width/2&&cy<=Height/2)
			{
				Mystate=2;
				glClear(GL_COLOR_BUFFER_BIT);
				glScalef(x2,x2,x2);
				graph2();
				glFlush();
			}
			else if (cx<=Width/2&&cy>Height/2)
			{
				Mystate=3;
				glClear(GL_COLOR_BUFFER_BIT);
				glScalef(x3,x3,x3);
				graph3();
				glFlush();
			}
			else 
			{
				Mystate=4;
				glClear(GL_COLOR_BUFFER_BIT);
				glScalef(x4,x4,x4);
				graph4();
				glFlush();
			}
		}
		else
		{
			Mystate=0;
			glClear(GL_COLOR_BUFFER_BIT);
			MyDisplay();
		}
	}
	else if (button==GLUT_WHEEL_UP&&state==GLUT_UP&&Mystate>=1)
	{
		if (Mystate==1)
		{
			rate*=1.1;
			glScalef(1.1,1.1,1.1);
			x1*=1.1;
			glClear(GL_COLOR_BUFFER_BIT);	
			graph1();
			glFlush();
		}
		else if (Mystate==2)
		{
			rate*=1.1;
			glScalef(1.1,1.1,1.1);
			x2*=1.1;
			glClear(GL_COLOR_BUFFER_BIT);
			graph2();
			glFlush();
		}
		else if (Mystate==3)
		{
			rate*=1.1;
			glScalef(1.1,1.1,1.1);
			x3*=1.1;
			glClear(GL_COLOR_BUFFER_BIT);
			graph3();
			glFlush();
		}
		else 
		{
			rate*=1.1;
			x4*=1.1;
			glScalef(1.1,1.1,1.1);
			glClear(GL_COLOR_BUFFER_BIT);
			graph4();
			glFlush();
		}
	}
	else if (button==GLUT_WHEEL_DOWN&&state==GLUT_UP&&Mystate>=1)
	{
		if (Mystate==1)
		{
			glScalef(0.9,0.9,0.1);
			rate*=0.9;
			x1*=0.9;
			glClear(GL_COLOR_BUFFER_BIT);
			graph1();
			glFlush();
		}
		else if (Mystate==2)
		{
			glScalef(0.9,0.9,0.1);
			rate*=0.9;
			x2*=0.9;
			glClear(GL_COLOR_BUFFER_BIT);
			graph2();
			glFlush();
		}
		else if (Mystate==3)
		{
			glScalef(0.9,0.9,0.1);
			rate*=0.9;
			x3*=0.9;
			glClear(GL_COLOR_BUFFER_BIT);
			graph3();
			glFlush();
		}
		else 
		{
			glScalef(0.9,0.9,0.1);
			rate*=0.9;
			x4*=0.9;
			glClear(GL_COLOR_BUFFER_BIT);
			graph4();
			glFlush();
		}
	}
	else if (button==GLUT_LEFT_BUTTON&&state==GLUT_DOWN)
	{
		oldx=cx;
		oldy=cy;
	}
}
void MyMotion(GLint cx,GLint cy)	//处理鼠标移动时的操作,cx,cy为鼠标当前位置
{
	cout << cx <<" "<<cy<<endl;
	if (Mystate>=1)
	{
		if (Mystate==1)
		{
			glTranslatef(2.0*(cx-oldx)/Width/rate,2.0*(oldy-cy)/Height/rate,0);
			oldx=cx;
			oldy=cy;
			glClear(GL_COLOR_BUFFER_BIT);
			graph1();
			glFlush();
		}
		else if (Mystate==2)
		{
			glTranslatef(2.0*(cx-oldx)/Width/rate,2.0*(oldy-cy)/Height/rate,0);
			oldx=cx;
			oldy=cy;
			glClear(GL_COLOR_BUFFER_BIT);
			graph2();
			glFlush();
		}
		else if (Mystate==3)
		{
			glTranslatef(2.0*(cx-oldx)/Width/rate,2.0*(oldy-cy)/Height/rate,0);
			oldx=cx;
			oldy=cy;
			glClear(GL_COLOR_BUFFER_BIT);
			graph3();
			glFlush();
		}
		else 
		{
			glTranslatef(2.0*(cx-oldx)/Width/rate,2.0*(oldy-cy)/Height/rate,0);
			oldx=cx;
			oldy=cy;
			glClear(GL_COLOR_BUFFER_BIT);
			graph4();
			glFlush();
		}
	}
}
int main(int argc,char **argv)
{
	glutInit(&argc,argv);
	glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB);
	glutInitWindowSize(Width,Height);
	glutCreateWindow("rjy_Exp1");
	MyInit();	//自定义OpenGL初始化函数
	glutDisplayFunc(MyDisplay);	//显示
	glutReshapeFunc(MyReshape);	//窗口改变
	glutMouseFunc(MyMouse);		//鼠标点击
	glutMotionFunc(MyMotion);	//鼠标移动
	glutMainLoop();
	return 0;
}

						