图形学第1次作业-2D的Sierpinski镂垫

在基于多边形的Sierpinski镂垫的基础上增加如下功能：

1、按q键退出；

2、右键菜单-随机换一种颜色；

3、在细分三角形之前增加了扰动；

代码如下：

#include <Windows.h>
#include <cstdio>
#include <random>
#include <functional>
#include "glut.h"

typedef GLfloat point2d[2];

point2d v[3] = { { 0.0, 0.0 }, { 250.0, 500.0 }, { 500.0, 0.0 } };

std::uniform_int_distribution<int> uniform_dist(0, 255);
std::normal_distribution<double> normal_dist(2.0, 0.05); //这个正态分布发生器用于扰动细分三角形的中点
std::default_random_engine engine;
auto uniform_rand = std::bind(uniform_dist, engine);
auto normal_rand = std::bind(normal_dist, engine);

void triangle(point2d a, point2d b, point2d c) {
    glBegin(GL_LINE_LOOP);
    glVertex2fv(a);
    glVertex2fv(b);
    glVertex2fv(c);
    glEnd();
}

void divide_triangle(point2d a, point2d b, point2d c, int k) {
    point2d ab, ac, bc;
    if (k > 0)
    {
        for (int j = 0; j < 2; j++)
            ab[j] = (a[j] + b[j]) / normal_rand();
        for (int j = 0; j < 2; j++)
            ac[j] = (a[j] + c[j]) / normal_rand();
        for (int j = 0; j < 2; j++)
            bc[j] = (b[j] + c[j]) / normal_rand();
        divide_triangle(a, ab, ac, k - 1);
        divide_triangle(b, ab, bc, k - 1);
        divide_triangle(c, ac, bc, k - 1);
    }
    else
        triangle(a, b, c);
}

void display(void) {
    glClear(GL_COLOR_BUFFER_BIT);
    divide_triangle(v[0], v[1], v[2], 5);
    glFlush();
}

void my_init(void) {
    glClearColor(1.0, 1.0, 1.0, 1.0);
    glColor3f(1.0, 0.0, 0.0);
    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    gluOrtho2D(0.0, 500.0, 0.0, 500.0);
    glMatrixMode(GL_MODELVIEW);
}

void my_menu(int entry_id) {
    switch (entry_id) {
    case 0:
        glClear(GL_COLOR_BUFFER_BIT);
        glColor3b(uniform_rand(), uniform_rand(), uniform_rand());
        glutPostRedisplay();
        break;
    /*case 1: {
        CHOOSECOLOR color;
        printf("%d\n", ChooseColor(&color));
        glClear(GL_COLOR_BUFFER_BIT);
        glColor3b(GetRValue(color.rgbResult), GetGValue(color.rgbResult), GetBValue(color.rgbResult));
        glutPostRedisplay();
        break;
    }*/
    default:
        break;
    }
}

void keyboard(unsigned char key, int x, int y) {
    if (key = ‘q‘ || key == ‘Q‘)
        exit(0);
}

int main(int argc, char *argv[]) {
    HWND hWnd = GetForegroundWindow();
    ShowWindow(hWnd, SW_HIDE); //hide cmd window

    glutInit(&argc, argv);
    glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB);
    glutInitWindowPosition(100, 100);
    glutInitWindowSize(500, 500);
    glutCreateWindow("2D Sierpinski (Triangle Ver)");
    glutDisplayFunc(display);

    int menu_id = glutCreateMenu(my_menu);
    glutAddMenuEntry("随机颜色重画", 0);
    //glutAddMenuEntry("选择颜色", 1);
    glutAttachMenu(GLUT_RIGHT_BUTTON);
    glutKeyboardFunc(keyboard);
    my_init();
    glutMainLoop();

    return 0;
}

运行截图：