五角星自由变换和移动 & 结构体数组初始化 & DIRECTION

// 五角星运动方向
#include <GL/glut.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <math.h>
#include <time.h>
#include <iostream>
using namespace std;
int wWidth, wHeight;
int rtheta, movex = 0, movey = 0;
int len_star = 100;
float scale = 1, dscale = 0.1;
const double PI = acos(-1.0);
typedef struct tagDIRECTION
{
int x_offset;
int y_offset;
} DIRECTION;
// DIRECTION direction_8[] = { { -10, 0}, { -10, 10}, {0, 10}, {10, 10}, {10, 0}, {10, -10}, {0, -10}, { -10, -10} };
DIRECTION direction_8[] = { { -10, 0}, {10, 10}, { -10, -10}, {10, 0}, { -10, 10}, {0, -10}, {0, 10}, {10, -10}};
int idx_dir = 0;
int idx_circle = 3;
int R = 25;
int circle_x = 0, circle_y = 0;
typedef struct
{
int x;
int y;
} Point;
typedef struct
{
float R;
float G;
float B;
} RGB; // glColor3f();
// RGB *rgb = new RGB;
void myDraw(Point point, RGB rgb, float Length, float theta)
{
// glColor3ub(255, 0, 0);
glColor3f(rgb.R, rgb.G, rgb.B);
glBegin(GL_LINE_LOOP);
float Short = Length * sin(0.1 * PI) / sin(0.7 * PI);
float beta = 18 + theta; //五角星NE的长半径和x轴的夹角
float p1[2];
glColor3f(1.0, 0.0, 0.0);
for (int i = 0; i < 5; i++) //从最右边的那个长边顶点开始画
{
p1[0] = Length * cos(i * 2 * 0.2 * PI + beta * 3.1415926 / 180.0) + point.x; //x坐标 18 * 3.1415926 = 56.55
p1[1] = Length * sin(i * 2 * 0.2 * PI + beta * 3.1415926 / 180.0) + point.y; //y坐标
glVertex2fv(p1);
p1[0] = Short * cos((i * 2 + 1) * 0.2 * PI + beta * 3.1415926 / 180.0) + point.x;
p1[1] = Short * sin((i * 2 + 1) * 0.2 * PI + beta * 3.1415926 / 180.0) + point.y;
glVertex2fv(p1);
}
glEnd();

// glPushMatrix();
// glLoadIdentity();
// // 绘制坐标系
// glBegin(GL_LINES);
// glVertex2i(0, -wHeight / 2 + 5);
// glVertex2i(0, wHeight / 2 - 5);
// glVertex2i(wWidth / 2 - 5, 0);
// glVertex2i(-wWidth / 2 + 5, 0);
// glEnd();
// glPopMatrix();
}
void drawCircle()
{
glBegin(GL_POLYGON);
glColor3f(0, 1, 0);
for (float i = 0; i < 360; i += 0.1) {
glVertex2f(R * cos(i * PI / 180), R * sin(i * PI / 180));
}
glEnd();
}
void display()
{
glClearColor(0, 1, 1, 0);
glClear(GL_COLOR_BUFFER_BIT);
Point point = {0, 0};
RGB rgb = {1, 0, 0};
myDraw(point, rgb, len_star, 0);

//题目要求画一个小圆，沿任意方向运动
glPushMatrix();
glLoadIdentity();

circle_x += direction_8[idx_circle].x_offset;
circle_y += direction_8[idx_circle].y_offset;
if (circle_x + R > wWidth / 2 || circle_x - R < (-wWidth / 2) || circle_y + R > wHeight / 2 || circle_y - R < (-wHeight / 2)) {
circle_x -= direction_8[idx_circle].x_offset;
circle_y -= direction_8[idx_circle].y_offset;
int ii = rand() % 8;
idx_circle = ii;
}
cout << circle_x << " " << circle_y << endl;
glTranslatef(circle_x, circle_y, 0);
drawCircle();
glPopMatrix();

glFlush();
glutSwapBuffers();
}
void change() {
// 改变方向
movex += direction_8[idx_dir].x_offset;
movey += direction_8[idx_dir].y_offset;
if ((movex + len_star) > (wWidth / 2) || (movex - len_star) < (-(wWidth / 2)) || (movey + len_star) > (wHeight / 2) || (movey - len_star) < (-(wHeight / 2))) {
movex -= direction_8[idx_dir].x_offset;
movey -= direction_8[idx_dir].y_offset;
idx_dir += 1;
idx_dir %= 8;
// return;
}
// cout << idx_dir << endl;

// 改变旋转方向
rtheta += 10;
rtheta %= 360;

// 改变大小
scale += dscale;
if (scale > 2 || scale < 0.5)
dscale = -dscale;
// cout << movex << " " << movey << endl;
// cout << wWidth << " " << wHeight << endl;
glTranslatef (movex, movey, 0.0);
glRotatef (rtheta, 0.0, 0.0, 1.0);
glScalef(scale, scale, 0);
display();

usleep(100000);
glLoadIdentity();
}
void myReshape(GLsizei w, GLsizei h)
{
wWidth = w; wHeight = h;
glMatrixMode (GL_PROJECTION);
glLoadIdentity (); // cout << w << " " << h << " " << endl;
gluOrtho2D(-w / 2, w / 2, -h / 2, h / 2); // gluOrtho2D(-w / 2, w / 2, -h / 2, h / 2);
glMatrixMode (GL_MODELVIEW);
glLoadIdentity ();
glViewport (0, 0, w, h);
}
int main(int argc, char* argv[]) //main(int argc, char **argv)
{
glutInit(&argc, argv);
glutInitDisplayMode(GLUT_DEPTH | GLUT_DOUBLE | GLUT_RGB);
glutInitWindowPosition(300, 300);
glutInitWindowSize(900, 900);
glutCreateWindow("example");
srand(time(NULL));
glutDisplayFunc(display);
glutReshapeFunc(myReshape);
glutIdleFunc(change);
glutMainLoop();
return 0;
}