OpenGL——折线图柱状图饼图绘制

折线图绘制代码：

1#include<iostream>
2
3//旧版本 固定管线
4#include<Windows.h>
5#include <GL/glut.h>
6//新版本 可编程管线
7/*#define GLEW_STATIC
8#include <GL/glew.h>
9#include<GLFW\glfw3.h>
10*/
11
12using namespace std;
13
14GLsizei winWidth = 610, winHeight = 500;
15GLint xRaster = 25, yRaster = 150;
16
17GLubyte label[36] = { 'J','a','n', 'F','e','b', 'M','a','r', 'A','p','r',
18                        'M','a','y', 'J','u','n', 'J','u','l', 'A','u','g',
19                        'S','e','p', 'O','c','t', 'N','o','v', 'D','e','c' };
20
21GLint dataValue[12] = { 420,342,324,310,262,185,190,196,217,240,312,438 };
22
23void init()
24{
25    //窗口背景为白色
26    glClearColor(1, 1, 1, 1);
27    glMatrixMode(GL_PROJECTION);
28    gluOrtho2D(0.0, 610.0, 0.0, 500.0);
29}
30
31void lineGraph()
32{
33    GLint month, k;
34    GLint x = 30;
35
36    glClear(GL_COLOR_BUFFER_BIT);
37    //蓝色
38    glColor3f(0.0, 0.0, 1.0);
39    glBegin(GL_LINE_STRIP);   //画出折线段
40    for (k = 0; k < 12; k++) {
41        glVertex2i(x + k * 50, dataValue[k]);
42    }
43    glEnd();
44    
45    //红色
46    glColor3f(1.0, 0.0, 0.0);     //标注各点
47    for (k = 0; k < 12; k++) {
48        glRasterPos2i(xRaster + k * 50, dataValue[k] - 4);
49        glutBitmapCharacter(GLUT_BITMAP_9_BY_15, '*');
50    }
51    
52    //黑色
53    glColor3f(0.0, 0.0, 0.0);      //横坐标说明
54    xRaster = 20;          
55    for (month = 0; month < 12; month++) {
56        glRasterPos2i(xRaster, yRaster);
57        for (k = 3 * month;k < 3 * month + 3;k++) {
58            glutBitmapCharacter(GLUT_BITMAP_HELVETICA_12, label[k]);
59            xRaster += 17;
60        }
61    }
62    glFlush();
63}
64
65void winReshapeFcn(GLint newWidth, GLint newHeight)
66{
67    glMatrixMode(GL_PROJECTION);
68    glLoadIdentity();
69    gluOrtho2D(0, GLdouble(newWidth), 0, GLdouble(newHeight));
70    glClear(GL_COLOR_BUFFER_BIT);
71}
72
73int main(int argc, char* argv[])
74{
75    
76    //对GLUT进行初始化，并处理所有的命令行参数
77    glutInit(&argc, argv);
78    //指定使用RGBA模式还是颜色索引模式，还可指定使用单缓冲还是双缓冲窗口
79    glutInitDisplayMode(GLUT_RGB | GLUT_SINGLE);
80    //指定了窗口左上角在屏幕上的位置
81    glutInitWindowPosition(100, 100);
82    //制定了窗口大小（以像素为单位）
83    glutInitWindowSize(winWidth, winHeight);
84    //创建支持opengl渲染的窗口，在调用glutMainLoop函数前，窗口没有显示
85    glutCreateWindow("折线图");
86    init();
87    //显示回调函数
88    //每当GLUT确定一个窗口的内容需要重新显示时，通过glutDisplayFunc()注册的那个回调函数就会被执行
89    glutDisplayFunc(lineGraph);
90    glutReshapeFunc(winReshapeFcn);
91    //启动程序，所有窗口这时显示
92    glutMainLoop();
93
94    system("pause");
95    return 0;
96
97
98}

运行结果：

柱状图代码：

1void barChart()
2{
3    GLint month, k;
4
5    glClear(GL_COLOR_BUFFER_BIT);
6
7    //红色
8    glColor3f(1.0, 0.0, 0.0);     
9    for (k = 0; k < 12; k++) {
10        glRecti(20 + k * 50, 165, 40 + k * 50, dataValue[k]);
11    }
12
13    //黑色
14    glColor3f(0.0, 0.0, 0.0);      //横坐标说明
15    xRaster = 20;
16    for (month = 0; month < 12; month++) {
17        glRasterPos2i(xRaster, yRaster);
18        for (k = 3 * month;k < 3 * month + 3;k++) {
19            glutBitmapCharacter(GLUT_BITMAP_HELVETICA_12, label[k]);
20            xRaster += 17;
21        }
22    }
23    glFlush();
24}

运行结果：

饼图代码：

1#include<iostream>
2#include <math.h>
3//旧版本 固定管线
4#include<Windows.h>
5#include <GL/glut.h>
6//新版本 可编程管线
7/*#define GLEW_STATIC
8#include <GL/glew.h>
9#include<GLFW\glfw3.h>
10*/
11
12using namespace std;
13
14const GLdouble twoPi = 6.283185;
15
16class scrPt {
17public:
18    scrPt() {
19        x = y = 0;
20    }
21    GLint x, y;
22    void setCoords(GLint xCoordValue, GLint yCorrdValue) {
23        x = xCoordValue;
24        y = yCorrdValue;
25    }
26    GLint getx() const {
27        return x;
28    }
29    GLint gety() const {
30        return y;
31    }
32    void incrementx() {
33        x++;
34    }
35    void incrementy() {
36        y--;
37    }
38    
39};
40
41GLsizei winWidth = 400, winHeight = 300;
42
43
44void init()
45{
46    //窗口背景为白色
47    glClearColor(1, 1, 1, 1);
48    glMatrixMode(GL_PROJECTION);
49    gluOrtho2D(0.0, 200.0, 0.0, 150.0);
50}
51
52void setPixel(GLint xCoord, GLint yCoord) 
53{
54    glBegin(GL_POINTS);
55    glVertex2i(xCoord, yCoord);
56    glEnd();
57}
58
59
60void circlePlotPoints(GLint xc, GLint yc, scrPt circPt)
61{
62    setPixel(xc + circPt.getx(), yc + circPt.gety());
63    setPixel(xc - circPt.getx(), yc + circPt.gety());
64    setPixel(xc + circPt.getx(), yc - circPt.gety());
65    setPixel(xc - circPt.getx(), yc - circPt.gety());
66    setPixel(xc + circPt.gety(), yc + circPt.getx());
67    setPixel(xc - circPt.gety(), yc + circPt.getx());
68    setPixel(xc + circPt.gety(), yc - circPt.getx());
69    setPixel(xc - circPt.gety(), yc - circPt.getx());
70}
71
72//中心画圆算法
73void circleMidpoint(GLint xc, GLint yc, GLint radius) 
74{
75    scrPt circPt;
76    GLint p = 1 - radius;//中点参数初值
77    circPt.setCoords(0, radius);
78    circlePlotPoints(xc, yc, circPt);
79    while (circPt.getx() < circPt.gety()) {
80        circPt.incrementx();
81        if (p < 0)
82            p += 2 * circPt.getx() + 1;
83        else {
84            circPt.incrementy();
85            p += 2 * (circPt.getx() - circPt.gety()) + 1;
86        }
87        circlePlotPoints(xc, yc, circPt);
88    }
89}
90
91
92
93void pieChart()
94{
95    scrPt circCtr, piePt;
96    GLint radius = winWidth / 4;
97    GLdouble sliceAngle, previousSliceAngle = 0.0;
98
99    GLint k, nSlices = 12;
100
101    GLfloat dataValues[12] = { 10.0,7.0,13.0,5.0,13.0,14.0,
102                            3.0,16.0,5.0,3.0,17.0,8.0 };
103    GLfloat dataSum = 0.0;
104
105    circCtr.x = winWidth / 2;
106    circCtr.y = winHeight / 2;
107    circleMidpoint(circCtr.x,circCtr.y, radius);
108
109    for (k = 0;k < nSlices;k++) {
110        dataSum += dataValues[k];
111    }
112
113    for (k = 0; k < 12; k++) {
114        sliceAngle = twoPi * dataValues[k] / dataSum + previousSliceAngle;
115        piePt.x = circCtr.x + radius * cos(sliceAngle);
116        piePt.y = circCtr.y + radius * sin(sliceAngle);
117        glBegin(GL_LINES);
118        glVertex2i(circCtr.x, circCtr.y);
119        glVertex2i(piePt.x, piePt.y);
120        glEnd();
121        previousSliceAngle = sliceAngle;
122    }
123    
124}
125
126void displayFcn()
127{    
128    glClear(GL_COLOR_BUFFER_BIT);
129    glColor3f(0.0, 0.0, 1.0);
130    pieChart();
131    glFlush();
132}
133
134void winReshapeFcn(GLint newWidth, GLint newHeight)
135{
136    glMatrixMode(GL_PROJECTION);
137    glLoadIdentity();
138    gluOrtho2D(0.0, GLdouble(newWidth), 0.0, GLdouble(newHeight));
139    glClear(GL_COLOR_BUFFER_BIT);
140
141    winWidth = newWidth;
142    winHeight = newHeight;
143}
144
145int main(int argc, char* argv[])
146{
147    
148    //对GLUT进行初始化，并处理所有的命令行参数
149    glutInit(&argc, argv);
150    //指定使用RGBA模式还是颜色索引模式，还可指定使用单缓冲还是双缓冲窗口
151    glutInitDisplayMode(GLUT_RGB | GLUT_SINGLE);
152    //指定了窗口左上角在屏幕上的位置
153    glutInitWindowPosition(100, 100);
154    //制定了窗口大小（以像素为单位）
155    glutInitWindowSize(winWidth, winHeight);
156    //创建支持opengl渲染的窗口，在调用glutMainLoop函数前，窗口没有显示
157    glutCreateWindow("Pie");
158    init();
159    //显示回调函数
160    //每当GLUT确定一个窗口的内容需要重新显示时，通过glutDisplayFunc()注册的那个回调函数就会被执行
161    glutDisplayFunc(displayFcn);
162    glutReshapeFunc(winReshapeFcn);
163    //启动程序，所有窗口这时显示
164    glutMainLoop();
165
166    system("pause");
167    return 0;
168
169
170}

运行结果：