rect.cpp

可以进行柱状图

// Rect.cpp: implementation of the CRect class.
//
//////////////////////////////////////////////////////////////////////

#include "stdafx.h"
#include "Rect.h"
#include "gl/glut.h"
#include "stdlib.h"

//////////////////////////////////////////////////////////////////////
// Construction/Destruction
//////////////////////////////////////////////////////////////////////

CRect::CRect()
{
	Data[8]=(10,24,54,65,43,22,70,65);
	dy=0;
	step = 8;


	for(int i = 0;i<8;i++)
	{
		pt[i].x0 = 10+10*i;
		pt[i].y0 = 40+4*(rand()%5);
	}

}

CRect::~CRect()
{

}

void CRect::Draw()
{
	int i = 0;
	DrawAxis();            //调用画坐标轴的函数
	
	glEnable(GL_SMOOTH);
	for(i = 0;i<8;i++)
	{
		glBegin(GL_POLYGON);

		glColor3f(0.2 *i, 0.5 * i, 0.2f); // Blue
		glVertex2f(pt[i].x0, 0.0f);

		glColor3f(0.3 *i, 0.6 * i, 0.9f); // Blue
		glVertex2f(pt[i].x0 + step, 0.0f);

		glColor3f( 0.3f, 0.5 * i, 0.2 *i); // Blue
		glVertex2f(pt[i].x0 + step,pt[i].y0);

		glColor3f( 0.8f, 0.05 * i  , 0.2 *i); // Blue
		glVertex2f(pt[i].x0,pt[i].y0);

		glEnd();
		glFlush();
	}
	glDisable(GL_SMOOTH);
}

void CRect::DrawAxis()
{
	//画线
	glLineWidth(2.0f);		
		glColor3f(0.5f,0.0f,0.5f);
		glBegin(GL_LINES);
			glVertex3f(0,0,0);
			glVertex3f(250/2,0,0);   //画x轴

			glVertex3f(0,0,0);       //画y轴
			glVertex3f(0,200/2,0);
		glEnd();
		glFlush();
    //画箭头
	glColor3f(0.5f,0.0f,0.5f);
		glBegin(GL_TRIANGLES);      //用三角形表示箭头
		
			glVertex3f(250/2,0,0);
			glVertex3f(250/2-5,5,0);
			glVertex3f(250/2-5,-5,0);

			glVertex3f(0,200/2,0);
			glVertex3f(-5,200/2 -5,0);
			glVertex3f(+5,200/2 -5,0);
		glEnd();
		glFlush();

}