CPT-205 lab04 task

讲道理，半节课没上，在搞这个小游戏，直接上代码：

玩法：

• 就是个简单的吃金币的游戏，成功吃到以后人（会跳的小方块）会随机变一个颜色
• 金币每次到最左边（没吃到）以后会返回最右边，同时移动速度会随机变化
• w键跳跃，s键让金币停止移动，m键让金币恢复运动，q退出游戏
• 无聊的小游戏，别玩太久。
• 原理代码注释里写挺多的，不再赘述了。
• UI设计的比较丑，大家可以自己改一下代码里的颜色（doge
• 

#define FREEGLUT_STATIC
#include 
#include 
#include 
#include 
#include 
#include 
typedef struct { GLfloat x, y; } point; // define a 2D point
point p0 = { 400,200 }; // set initial co-ordinate values of the point  金币
point p1 = { 0,50 }; // set initial co-ordinate values of the point  小人
GLfloat finishx = 300; // declare position of vertical axis

//Task 2
GLfloat jump = 0; //跳跃步长
GLfloat step = 10; //移动步长
GLint count = 0;
int time_interval = 16; // declare refresh interval in ms
void when_in_mainloop()
{ // idle callback function
	glutPostRedisplay(); // force OpenGL to redraw the current window
}

bool checkHug() {
	if ((p0.x >= 0 && p0.x <= 20 )&& (p1.y + 20 >= 200)) {
		return 1;
	}
	else return 0;
}

void OnTimer(int value)
{	
	p0.x -= step; //移动步长
	if (p0.x >= 600)
		p0.x = 0;
	else if (p0.x <= 0) {
		p0.x = 599;
		step = rand()%10+5;//5以上的2位数
	}//反向则从另一侧刷新
		

	bool check = 0;
		check = checkHug();
		if (check == 1) {
			p0.x = 400; 
			count++;
		}

	glutTimerFunc(time_interval, OnTimer, 1);
}

bool flag = 0;

void JumpOnTimer(int value) {
	
	if (flag==0 && p1.y <= 200) {
		p1.y += jump;
		if (p1.y == 200) {
			flag = 1;
		}
	}
	if (flag == 1 && p1.y>=50) {
		p1.y -= jump;
		if (p1.y ==50) {
			flag = 0;
			jump = 0;
		}
	}
	glutTimerFunc(time_interval, JumpOnTimer, 2);
}

//Task 3
void keyboard_input(unsigned char key, int x, int y) // keyboard interactions
{
	if (key == 'q' || key == 'Q')
		exit(0);
	else if (key == 'w' || key == 'W') // change direction of movement
	{
		jump = 10;
	}
	else if (key == 's' || key == 'S') // stop movement
		step = 0;
	else if (key == 'r' || key == 'R') // reset step (resume movement)
		p0.x=400;
	else if (key == 'm' || key == 'M') // reset step (resume movement)
		step = 2;
}

//Task 4

void display(void)
{
	glMatrixMode(GL_PROJECTION);
	glLoadIdentity();
	gluOrtho2D(0, 600, 0, 400);
	glClearColor(0, 0, 1, 1);
	glClear(GL_COLOR_BUFFER_BIT);
	glColor3f(1, 1, 1);
	glBegin(GL_LINES);
	glVertex2f(finishx, 50);
	glVertex2f(finishx, 350);
	glEnd();

	glColor3f(0, 1, 0);
	glBegin(GL_POLYGON);
	glVertex2f(0, 0);
	glVertex2f(0, 50);
	glVertex2f(600, 50);
	glVertex2f(600, 0);
	glEnd();
	glPolygonMode(GL_BACK, GL_FILL);           // 设置反面为填充方式
	// guy
	for (int i = 0; i < count; i++)
	{
		glColor3f(i & 0x04, i & 0x02, i & 0x01);
	}
	//glColor3f(1, 0, 0);
	glBegin(GL_POLYGON);
	glVertex2f(p1.x, p1.y);
	glVertex2f(p1.x, p1.y + 20);
	glVertex2f(p1.x + 20, p1.y + 20);
	glVertex2f(p1.x + 20, p1.y);
	glEnd();

	glPolygonMode(GL_FRONT, GL_LINE);            // 设置正面(顺时针)为边缘绘制方式

	glColor3f(0, 0, 0); 
	glBegin(GL_POLYGON);
	glVertex2f(p1.x, p1.y);
	glVertex2f(p1.x + 20, p1.y);
	glVertex2f(p1.x + 20, p1.y + 20);
	glVertex2f(p1.x, p1.y + 20); //换为反向顺序
	glEnd();

	glPolygonMode(GL_BACK, GL_FILL);           // 设置正面为填充方式
// gold
	glColor3f(1, 1, 0);
	glBegin(GL_POLYGON);
	glVertex2f(p0.x, p0.y);
	glVertex2f(p0.x, p0.y + 10);
	glVertex2f(p0.x + 10, p0.y + 10);
	glVertex2f(p0.x + 10, p0.y);
	glEnd();

	glPolygonMode(GL_FRONT, GL_LINE);            // 设置反面为边缘绘制方式
	glColor3f(0, 0, 0); //黑色边框
	glBegin(GL_POLYGON);
	glVertex2f(p0.x, p0.y);
	glVertex2f(p0.x + 10, p0.y);
	glVertex2f(p0.x + 10, p0.y + 10);
	glVertex2f(p0.x, p0.y + 10);
	glEnd();

	glutSwapBuffers();
}
int main(int argc, char** argv)
{
	glutInit(&argc, argv);
	glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGB);
	glutInitWindowPosition(100, 100);
	glutInitWindowSize(600, 400);
	glutCreateWindow("My Interactive Window");
	glutDisplayFunc(display);
		//Task 2
		//Task 3
	glutIdleFunc(when_in_mainloop);
	/* glutIdleFunc sets the global idle callback to be func so a GLUT program can perform background
	processing tasks or continuous animation when window system events are not being received.
	If enabled, the idle callback is continuously called when events are not being received. The callback
	routine has no parameters. The current window and current menu will not be changed before the idle
	callback. Programs with multiple windows and/or menus should explicitly set the current window and/or
	current menu and not rely on its current setting. The amount of computation and rendering done in an idle
	callback should be minimized to avoid affecting the program's interactive response. In general, not more
	than a single frame of rendering should be done in an idle callback.
	Assigning NULL to glutIdleFunc disables the generation of the idle callback. */
	glutTimerFunc(time_interval, OnTimer, 1);
	glutTimerFunc(time_interval, JumpOnTimer, 2);
	glutKeyboardFunc(keyboard_input); // keyboard callback function

		glutMainLoop();
}