用opengl做的折线图和直方图

#include <GL/glut.h>

//初始化窗口大小
GLsizei winWidth =600,winHeight=600; 
GLint xRaster=25,yRaster=150;
GLubyte label[36]={'J','a','n',    'F','e','b',   'M','a','r', 
'A','p','r',     'M','a','y',   'J','u','n',
'J','u','l',      'A','u','g',    'S','e','p',
'O','c','t',      'N','o','v',     'D','e','c'};
GLint dataValue[12]={420,342,324,310,262,185,190,196,217,240,312,438};
void init(void)
{
    glClearColor(1.0,1.0,1.0,1.0);
    glMatrixMode(GL_PROJECTION);
    gluOrtho2D(0.0,600.0,0.0,500.0);
}

void lineGraph(void)
{
    GLint month,k;
    GLint x=30;
    glClear(GL_COLOR_BUFFER_BIT);
    glColor3f(1.0,0.0,0.0);
    for (k=0;k<12;k++)
    {
        glRecti(20+k*50,165,40+k*50,dataValue[k]);
    }


    glColor3f(0.0,0.0,1.0);
    glBegin(GL_LINE_STRIP);
    for (k=0;k<12;k++)
    {
        glVertex2i(x+k*50,dataValue[k]);
    }
    glEnd();

    glColor3f(1.0,0.0,0.0);
    for (k=0;k<12;k++)
    {
        glRasterPos2i(xRaster+k*50,dataValue[k]-4);
        glutBitmapCharacter(GLUT_BITMAP_9_BY_15,'*');
    }

    glColor3f(0.0,0.0,0.0);
    xRaster=20;
    for (month=0;month<12;month++)
    {
        glRasterPos2i(xRaster,yRaster);
        for (k=3*month;k<3*month+3;k++)
        {
            glutBitmapCharacter(GLUT_BITMAP_HELVETICA_12,label[k]);
        }
        xRaster+=50;
    }
    glFlush();
}


void winReshapeFcn(int newWidth,int newHeight)
{
    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    gluOrtho2D(0.0,(GLdouble)newWidth,0.0,(GLdouble)newHeight);
    glClear(GL_COLOR_BUFFER_BIT);
}

void main( int  argc,char** argv)
{
    glutInit(&argc,argv);
    glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB);
    glutInitWindowPosition(100,100);
    glutInitWindowSize(winWidth,winHeight);
    glutCreateWindow("Line Chart Data Plot");

    init();
    glutDisplayFunc(lineGraph);
    glutReshapeFunc(winReshapeFcn);

    glutMainLoop();