OpenGL案例2----keyBoard键盘交互和鼠标交互

#include <GL/glut.h>

//keyBoard键盘交互
void init()
{
	glClearColor(1.0, 1.0, 1.0, 0.0); //黑色背景颜色
	glMatrixMode(GL_PROJECTION);  //正投影
	glLoadIdentity();
	gluOrtho2D(-20, 30,-20,30);// 可以显示的范围
}
int xd = 0, yd = 0;
void myDisplay()
{
	glClear(GL_COLOR_BUFFER_BIT);
	glColor3f(0.8, 0.5, 0.6);
	glPointSize(5);
	glBegin(GL_POLYGON);
	glVertex2i(10 + xd, 10 + yd);
	glVertex2i(20 + xd, 10 + yd);
	glVertex2i(20 + xd, 0 + yd);
	glVertex2i(10 + xd, 0 + yd);
	glEnd();
	glFlush();//缓存推送到屏幕
}
void myKeyBoard(unsigned char key, int x, int y)
{
	switch (key)
	{
	case 'w': yd++; break;
	case 's': yd--; break;
	case 'd': xd++; break;
	case 'a': xd--; break;
	}
	glutPostRedisplay(); //重新执行myDisplay方法
}
int main(int argc, char* argv[])
{
	glutInit(&argc, argv);//初始化opengl
	glutInitDisplayMode(GLUT_RGB | GLUT_SINGLE);//
	glutInitWindowPosition(300, 100); //窗口位置
	glutInitWindowSize(600, 500); //窗口大小
	glutCreateWindow("polyonTriangle"); //窗口名称

	init();
	glutDisplayFunc(myDisplay); //绘制函数
	glutKeyboardFunc(myKeyBoard);
	glutMainLoop();
	return 0;
}

结果：

键盘按w:向上；按s:向下 ； 按d:向右 按a:向左

代码2：

#include <GL/glut.h>
GLint w = 600 , h=500;
GLint dx = 0, dy = 0;
//鼠标交互
void init()
{
	glClearColor(1.0, 1.0, 1.0, 0.0); //黑色背景颜色
	glMatrixMode(GL_PROJECTION);  //正投影
	glLoadIdentity();
	gluOrtho2D(0,w,0,h);// 可以显示的范围
}

void myDisplay()
{
	glClear(GL_COLOR_BUFFER_BIT);
	glColor3f(0.87, 0.56, 0.4);
	glPointSize(2);
	glBegin(GL_POLYGON);
	glVertex2i(10 + dx, 10 + dy);
	glVertex2i(10 + dx, 100 + dy);
	glVertex2i(100 + dx, 100 + dy);
	glVertex2i(100 + dx, 10 + dy);
	glEnd();
	glFlush();//缓存推送到屏幕
}

//鼠标点击
void mouseMotion(GLint button,GLint state, GLint x, GLint y)
{
	if (button == GLUT_LEFT_BUTTON && state == GLUT_DOWN) //鼠标左键按下
	{
		dx = x;
		dy = h - y;
		glutPostRedisplay(); //重新绘制
	}
}
int main(int argc, char* argv[])
{
	glutInit(&argc, argv);//初始化opengl
	glutInitDisplayMode(GLUT_RGB | GLUT_SINGLE);//
	glutInitWindowPosition(200, 100); //窗口位置
	glutInitWindowSize(w, h); //窗口大小
	glutCreateWindow("Mouse Motion"); //窗口名称

	init();
	glutDisplayFunc(myDisplay); //绘制函数
	glutMouseFunc(mouseMotion);
	
	glutMainLoop();
	return 0;
}

结果：

矩形随鼠标左键点击而移动