openGL 大作业之n星变换-白红宇

openGL 大作业之n星变换

阅读量：4627 次

发布时间：2019-06-09

本文共 3091 字，大约阅读时间需要 10 分钟。

#include "stdafx.h"#include
     
      #define GLUT_DISABLE_ATEXIT_HACK //不写这句话总运行出错，我也不知道为啥。。。#include
      
       #include
       
        int change = 10;static GLfloat spin = 0.0;//static:静态全局变量，只要程序运行，内存中一直存在，文件内可见，文件外不可见void init(void){    glClearColor(0.0, 0.0, 0.0, 0.0);//将清空颜色设置为黑    }int z = -1;void fillOption(GLint selectedOption){     z = -1;    switch (selectedOption) {    case 1:change-=2;   break;     case 2:z=-z;  break;     case 3:z =0;  break;    }    glutPostRedisplay();}void display(void){    glClear(GL_COLOR_BUFFER_BIT);//清除颜色缓存    glPushMatrix();//将当前矩阵压栈（保存现场）    glRotatef(spin, 0.0, 0.0,z);//旋转方向，遵循右手原则    glColor3f(1.0, 1.0, 1.0);    glEnable(GL_LINE_SMOOTH);//让线条更平滑    GLint x = 100;    GLdouble a = 1.256637, c = 1;    while (x--)    {        glShadeModel(GL_SMOOTH);//渐变色        glBegin(GL_LINE_STRIP);                glVertex2f(50 * cos(a + c), 50 * sin(a + c));        glColor3f(1.0, 0.0, 0.0);        glVertex2f(50 * cos(3 * a + c), 50 * sin(3 * a + c));        glColor3f(0.0, 1.0, 0.0);        glVertex2f(50 * cos(5 * a + c), 50 * sin(5 * a + c));        glColor3f(0.0, 0.0, 1.0);        glVertex2f(50 * cos(2 * a + c), 50 * sin(2 * a + c));        glColor3f(0.0, 1.0, 1.0);        glVertex2f(50 * cos(4 * a + c), 50 * sin(4 * a + c));        glColor3f(1.0, 1.0, 1.0);        glVertex2f(50 * cos(a + c), 50 * sin(a + c));        glEnd();        c+=0.0314159365*change;            }    glColor3f(1.0, 0.0, 0.0);    glBegin(GL_LINE_STRIP);        glEnd();    glPopMatrix();    glutSwapBuffers();//双缓存技术的函数，作用为交换两个缓冲区的指针}void spinDisplay(void){    spin = spin + 0.04;    if (spin > 360.0)    {        spin = spin - 360.0;    }    glutPostRedisplay();//glutPostRedisplay 标记当前窗口需要重新绘制。通过glutMainLoop下一次循环时，窗口显示将被回调以重新显示窗口的正常面板}void reshape(int w, int h){    glViewport(0, 0, (GLsizei)w, (GLsizei)h);//函数作用：用一个视景体截取图像    glMatrixMode(GL_PROJECTION);//mode 指定哪一个矩阵堆栈是下一个矩阵操作的目标,参数表示接下来要进行投影相关的操作    glLoadIdentity();//设置当前变化矩阵为单位矩阵；单位矩阵就是对角线上都是1，其余元素皆为0的矩阵。然后复位    glOrtho(-50.0, 50.0, -50.0, 50.0, -1.0, 1.0);    glMatrixMode(GL_MODELVIEW);//进行视景相关的操作    glLoadIdentity();}void mouse(int button, int state, int x, int y){    switch (button)    {    case GLUT_LEFT_BUTTON:        if (state == GLUT_DOWN)            glutIdleFunc(spinDisplay);//glutIdleFunc函数如果启用，这个idle function会被不断调用，直到有窗口事件发生        break;    case GLUT_RIGHT_BUTTON:        if (state == GLUT_DOWN)            glutIdleFunc(NULL);        break;    default:        break;    }}int main(int argc, char** argv){    glutInit(&argc, argv);    glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGB);    glutInitWindowSize(680, 680);    glutInitWindowPosition(400, 0);    glutCreateWindow("big homework");    init();    glutDisplayFunc(display);//每次重绘场景时调用    glutCreateMenu(fillOption);      glutAddMenuEntry("amount", 1);    glutAddMenuEntry("reverse", 2);    glutAddMenuEntry("narrow", 3);    glutAttachMenu(GLUT_RIGHT_BUTTON);    glutReshapeFunc(reshape);//每次窗口改变时调用    glutMouseFunc(mouse);//每次使用鼠标时调用    glutMainLoop();    return 0;}