OpenGL / 绘制折线图以及扇形图

一、利用OpenGL绘制形如下图的折线加柱状图，数据和颜色自己设定，要有文字的显示。

二、 利用OpenGL绘制形如下图的饼状图，数据和颜色自己设定，要有文字的显示。

一、直方图、折线图

#include 
#include
using namespace std;

Glubyte label[18]={'J','a','n','F','e','b',
'M','a','r','A','p','r','M','a','y','J','u','n'};

GLint dataValue[6]={195,215,335,210,365,270};

void init (void)
{
	glClearColor(1.0,1.0,1.0,0.0);

	glMatrixMode(GL_PROJECTION);
	glLoadIdentity();
	gluOrtho2D(0.0,600.0,0.0,500.0);
}

void lineGraph_barChart (void)
{
	GLint month,k;
	glClear(GL_COLOR_BUFFER_BIT);   //清除clear display window
	glLineWidth(1.3);
	glColor3f(0.0,0.5,0.2);
	//---------------------------------------------坐标轴
	glBegin(GL_LINES);
		glVertex2i(60,30);      //y轴
		glVertex2i(60,450);

		glVertex2i(60,150);     //100
		glVertex2i(55,150);

		glVertex2i(60,250);     //200
		glVertex2i(55,250);

		glVertex2i(60,350);     //300
		glVertex2i(55,350);

		glVertex2i(30,50);      //x轴
		glVertex2i(530,50);
		
	glEnd();
    //----------------------------------------
	glPointSize(4.5);
	glColor3f(0.0,0.0,0.0);
	glBegin(GL_POINTS);
	
	for(k=0;k<6;k++)
	{
		glVertex2i(120+k*70,dataValue[k]);
	}
	glEnd();
	//---------------------

	glLineWidth(2.0);
	glColor3f(0.0,0.3,0.7);
	glBegin(GL_LINE_STRIP);
	
	for(k=0;k<6;k++)
	{
		glVertex2i(120+k*70,dataValue[k]);
	}
	glEnd();
	//---------------------
	for(k=0;k<6;k++)
	{
		glColor3f(0.0,0.3,0.7);
		glBegin(GL_POLYGON);

		glVertex2i(110+k*70,50);
		glVertex2i(130+k*70,50);
		glVertex2i(130+k*70,dataValue[k]-40);
		glVertex2i(110+k*70,dataValue[k]-40);
	
		glEnd();
	}
	//----------------------------------

	glColor3f(0.0,0.0,0.0);
	GLint xRaster=110;
	for(month=0;month<6;month++)
	{
		glRasterPos2i(xRaster,35);
		for(k=3*month;k<3*month+3;k++)
		{
			glutBitmapCharacter(GLUT_BITMAP_HELVETICA_12,label[k]);
		}
		xRaster+=70;
	}
//--------------
	glColor3f(0.0,0.0,0.0);
	GLint yRaster=145;
	GLubyte A[9]={'1','0','0','2','0','0','3','0','0'};
	for(GLint i=0;i<3;i++)
	{
		glRasterPos2i(30,yRaster);
		for(GLint j=i*3;j<3*i+3;j++)
		glutBitmapCharacter(GLUT_BITMAP_HELVETICA_12,A[j]);
		yRaster+=100;
	}
	//---------------------------------------------
	
	glRasterPos2i(45,35);
	glutBitmapCharacter(GLUT_BITMAP_HELVETICA_12,'O');

	for(k=0;k<6;k++)
	{
		glColor3f(0.0,0.0,0.0);
		glLineWidth(2.0);
		glBegin(GL_LINE_STRIP);
		glVertex2i(110+k*70,50);
		glVertex2i(110+k*70,dataValue[k]-40);		
		glVertex2i(130+k*70,dataValue[k]-40);
		glVertex2i(130+k*70,50);
		glEnd();
	}

	glFlush();
}

void main(int argc,char** argv)
{
	glutInit(&argc,argv);
	glutInitDisplayMode(GLUT_RGB);
	glutInitWindowPosition(100,100);
	glutInitWindowSize(600,500);
	glutCreateWindow("实验一：直方图、折线图");

	init();
	glutDisplayFunc(lineGraph_barChart);
	glutMainLoop();
}

//------------------------------------------------------------------

二、扇形图

#include 
#include
#include

#include
using namespace std;

const GLdouble twoPi = 6.283185;

GLubyte label[24]={'J','a','n','F','e','b','M',
'a','r','A','p','r','M','a','y','J','u','n'};
GLint R[18]={'3','0','%','1','5','%','1',
'0','%','1','0','%','1','5','%','2','0','%'};

GLsizei winWidth = 600 , winHeight = 500;

GLfloat dataValue[6]={30.0,15.0,10.0,10.0,15.0,20.0};

class scrPt
{
public:
	GLint x,y;
};

void init (void)
{
	glClearColor(1.0,1.0,1.0,0.0);

	glMatrixMode(GL_PROJECTION);
	glLoadIdentity();
	gluOrtho2D(0.0,600.0,0.0,500.0);
}

void pieChart (void)
{
	GLint k,n = 6;
	scrPt circCtr;
	scrPt piePt[6];
	GLdouble A[6];
	GLint r = winWidth/4;
	GLdouble sliceAngle, previousSliceangle = 0.36;
	GLfloat dataSum = 0.0;


	circCtr.x = winWidth/2;
	circCtr.y = winHeight/2;

	
	GLdouble i;
	
//--------------------------------------------------
	for(k=0;k<n;k++)
	{
		dataSum+=dataValue[k];
	}

GLdouble B[7];

	for (k=0;k<n;k++)
	{
		B[k]=sliceAngle = twoPi*dataValue[k]/dataSum + previousSliceangle;
		piePt[k].x = circCtr.x - r * cos(sliceAngle);
		piePt[k].y = circCtr.y + r * sin(sliceAngle);
		A[k] = twoPi*dataValue[k]/dataSum;
	//	B[k] = sliceAngle;
		B[6] = B[0];
		previousSliceangle = sliceAngle;
	}
	
	//----------------------------------------------------------------扇形
	glColor3f(0.482,0.227,0.69);
	glBegin(GL_TRIANGLE_FAN);
	glVertex2f(circCtr.x,circCtr.y);

	for(i=0;i<1000000;i++)
	{	
		GLdouble t=i*B[0]/1000000;
		glVertex2i(circCtr.x - r * cos(t),circCtr.y + r * sin(t));
	}
	glEnd();


for(k=1;k<6;k++)
{
	GLfloat a,b,c;
	if(k==1)
	{
		a=0.917;
		b=0.0;
		c=0.0;
	}
	if(k==2)
	{
		a=0.067;
		b=0.627;
		c=0.850;
	}
	if(k==3)
	{
		a=0.592;
		b=0.592;
		c=0.592;
	}
	if(k==4)
	{
		a=0.4;
		b=0.929;
		c=0.2549;
	}
	if(k==5)
	{
		a=0.968;
		b=0.968;
		c=0.215;
	}

	glColor3f(a,b,c);
	glBegin(GL_TRIANGLE_FAN);
	glVertex2f(circCtr.x,circCtr.y);

	for(i=0;i<1000000;i++)
	{	
		GLdouble t=B[k-1]+i*A[k]/1000000;
		glVertex2i(circCtr.x - r * cos(t),circCtr.y + r * sin(t));
	}
	glEnd();

}

//-------------------------------------------------园
	glColor3f(0.0,0.0,0.0);
	glLineWidth(3.0);
	glBegin(GL_LINE_LOOP);
	for(i=0;i<1000000;i++)
	{
		GLdouble t=i*twoPi/1000000;
	
		glVertex2f(circCtr.x+r * cos(t),circCtr.y+r * sin(t));
	}
	glEnd();

//----------------------------------
for(k=0;k<n;k++)
	{
		glLineWidth(2.0);
		glBegin(GL_LINES);
		glVertex2i(circCtr.x,circCtr.y);
		glVertex2i(piePt[k].x,piePt[k].y);
		glEnd();
	}	
//---------------------------------------------



//----输出字符
scrPt piePt1[6];
	
	piePt1[0].x = circCtr.x + (2*r/3)*cos((B[5]+B[0])/2);
	piePt1[0].y = circCtr.y - (2*r/3)*sin((B[5]+B[0])/2);
	
	for(k=1;k<6;k++)
	{
		piePt1[k].x = circCtr.x - (2*r/3)*cos((B[k-1]+B[k])/2);
		piePt1[k].y = circCtr.y + (2*r/3)*sin((B[k-1]+B[k])/2);
	}



	glColor3f(0.0,0.0,0.0);

	for(GLint t=0;t<6;t++)
	{
		glRasterPos2i(piePt1[t].x,piePt1[t].y);
		for(GLint j=t*3;j<3*t+3;j++)
		glutBitmapCharacter(GLUT_BITMAP_HELVETICA_12,label[j]);
	
		glRasterPos2i(piePt1[t].x,piePt1[t].y-20);
		for(j=t*3;j<3*t+3;j++)
		glutBitmapCharacter(GLUT_BITMAP_HELVETICA_12,R[j]);
	}
}

void displayFcn(void)
{
	glClear(GL_COLOR_BUFFER_BIT);
	glColor3f(0.0,0.0,0.0);
	pieChart();
	glFlush();
}

void main(int argc,char** argv)
{
	glutInit(&argc,argv);
	glutInitDisplayMode(GLUT_RGB);
	glutInitWindowPosition(100,100);
	glutInitWindowSize(winWidth,winHeight);
	glutCreateWindow("实验一：扇形图");
	
	init();
	glutDisplayFunc(displayFcn);
	glutMainLoop();
}

//-------------------------------------------------------