드래그하면서 점선으로 된 사각형 그리기

Study/OpenGL

드래그하면서 점선으로 된 사각형 그리기

코딩하는 야구쟁이 2011. 9. 15. 11:33

#include <windows.h>
#include <iostream.h>
#include <math.h>
#include <gl/gl.h>
#include <gl/glut.h> // (or others, depending on the system in use)

#define		PI				3.1415926
#define		Window_Width	400
#define		Window_Height	400
#define		DOT				0
#define		RUBBER			1
#define		SOLID			2

int			position_x = 0;
int			position_y = 0;
int			width, 	height; 
int			point[1000][2];
int			num = 0;

struct Point
{
	float	x;
	float	y;
};
Point	left_down, right_up;
Point	start_point, end_point;

int		draw_type;
int		redraw;

void init (void) // 초기화설정, 상수값 설정
{
	glClearColor (1.0, 1.0, 1.0, 0.0) ; // Set display-window color to white.
	glMatrixMode (GL_PROJECTION); // Set projection parameters.
	gluOrtho2D (-200, 200, -200, 200); // 관측공간 설정
	width = Window_Width;
	height = Window_Height;
	draw_type = DOT; // 점선이냐 실선이냐 
	redraw = 0;
}

void MyReshape(int w, int h)
{
	glViewport(position_x, position_y, w, h);
	glMatrixMode(GL_PROJECTION);
	glLoadIdentity();
	gluOrtho2D (-200, 200, -200, 200);
	glMatrixMode(GL_MODELVIEW);
	glLoadIdentity();
}

void Draw_Rectangle(void) //사각형 그리기 
{
	
	if (draw_type == RUBBER)
	{
		glEnable(GL_LINE_STIPPLE); 
		glLineStipple(1, 0x0101); // 점선의 모양 결정
		// 0x0101 은 16진수 숫자로써 점선의 패턴을 만들어내는 코드 이다
		glBegin(GL_LINE_LOOP);
		glVertex2f(left_down.x, left_down.y);
		glVertex2f(right_up.x, left_down.y);
		glVertex2f(right_up.x, right_up.y);
		glVertex2f(left_down.x, right_up.y);
		glEnd();
	}			
	else if ( draw_type == SOLID)
	{
		glDisable(GL_LINE_STIPPLE);
		glRectf(left_down.x, left_down.y, right_up.x, right_up.y);
	};
}

void RenderScene (void) // 전체적인 그림 그리기
 {
	glClear (GL_COLOR_BUFFER_BIT); 
	
	glDisable(GL_LINE_STIPPLE);
	glBegin (GL_LINES);
	glColor3f(1.0, 0.0, 0.0);
	glVertex2f (-200, 0); 
	glVertex2f ( 200, 0);
	
	glColor3f(0.0, 0.0, 1.0);
	glVertex2f (0, -200); 
	glVertex2f (0, 200);
	glEnd();
	
	Draw_Rectangle();
	
	
	glFlush (); 
	glutSwapBuffers();
}

void Check_Position(void) // 마우스좌표
{
	if ( start_point.x <= end_point.x )
	{ 
		if ( start_point.y <= end_point.y ) 
		{
			left_down.x = 	start_point.x;
			left_down.y = 	start_point.y;
			right_up.x = 	end_point.x;
			right_up.y = 	end_point.y;
		}
		else {
			left_down.x = 	start_point.x;
			left_down.y = 	end_point.y;
			right_up.x = 	end_point.x;
			right_up.y = 	start_point.y;
		}
	}
	else {
		if ( start_point.y <= end_point.y )
		{
			left_down.x = 	end_point.x;
			left_down.y = 	start_point.y;
			right_up.x = 	start_point.x;
			right_up.y = 	end_point.y;
		}
		else
		{
			left_down.x = 	end_point.x;
			left_down.y = 	end_point.y;
			right_up.x = 	start_point.x;
			right_up.y = 	start_point.y;
		}
	}
}

void mouse( int button, int state, int x, int y) // 마우스 왼쪽버튼과 오른쪽 실행시
 {
	if ( draw_type == DOT && button == GLUT_LEFT_BUTTON && state == GLUT_DOWN )
	{
		start_point.x = x - Window_Width/2;
		start_point.y = Window_Height/2 - y;
		draw_type = RUBBER; // 사각형 그리기 시작
		if ( redraw == 1 ) 
		{
			end_point.x = start_point.x;
			end_point.y = start_point.y;
			redraw = 0;
			Check_Position();
		}
	}
	if ( draw_type == RUBBER && button == GLUT_LEFT_BUTTON && state == GLUT_UP )
	{
		draw_type = SOLID; // 왼쪽버튼을 눌리다가 때어버리면 왼쪽버튼은 쓸모가 없는 이벤트가 되어 버린다 
		end_point.x = x - Window_Width/2;
		end_point.y = Window_Height/2 - y;
	}
	if ( draw_type == SOLID && button == GLUT_RIGHT_BUTTON && state == GLUT_DOWN )
	{
		draw_type = DOT; // 오른쪽 버튼 눌리면 제일처음 상태로 돌아간다 (사각형이 지워진다)
		redraw = 1;
	}
	glutPostRedisplay();
	RenderScene();
}

void MyKey (unsigned char key, int x, int y) // 창을 키웠을시에 6번을 누르게 되면 좌표가 작아 지게 됨
 {
	switch( key )
	{
    case '6' :	position_x = 0;
		position_y = 0;
		width = Window_Width;
		height = Window_Height;
		break;
	}
	glViewport(position_x, position_y, width, height);
	glutPostRedisplay();
}

void MyMotion(int x, int y) // 마우스의 움직임을 찾는다, 왼쪽버튼을 눌렀을때 진행되는 함수 
 {
	if ( draw_type == RUBBER )
	{
		end_point.x = x - Window_Width/2;
		end_point.y = Window_Height/2 - y;
	}
	Check_Position();
	glutPostRedisplay();
}

void main (int argc, char** argv) 
{
	glutInit (&argc, argv); 
	glutInitDisplayMode (GLUT_DOUBLE | GLUT_RGB); 
	glutInitWindowPosition(100, 100);
	glutInitWindowSize(Window_Width, Window_Height);
	glutCreateWindow ("Motion_Event"); 
	init(); 
	glutDisplayFunc (RenderScene); 
	glutMotionFunc(MyMotion);
	glutReshapeFunc(MyReshape);
	glutKeyboardFunc(MyKey);
	glutMouseFunc(mouse);
	glutMainLoop(); 
}
;