드래그하면서 점선으로 된 원 그리기

Study/OpenGL

드래그하면서 점선으로 된 원 그리기

코딩하는 야구쟁이 2011. 9. 15. 18:49

#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;
int draw_type;
int redraw;
float delta = 2.0 * PI / 180;
float rX, rY;

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

void init (void) // 초기화설정, 상수값 설정 
{ 
    glClearColor (1.0, 1.0, 1.0, 0.0) ; // 배경색 초기화
    glMatrixMode (GL_PROJECTION); // Set projection parameters. 
    gluOrtho2D (-200, 200, -200, 200); // 관측공간 설정, 2D 좌표계
    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); // 윈도우크기만큼 Viewport 설정
    glMatrixMode(GL_PROJECTION); 
    glLoadIdentity(); 
    gluOrtho2D (-200, 200, -200, 200); 
    glMatrixMode(GL_MODELVIEW); 
    glLoadIdentity(); 
}

void Draw_Rectangle(void) //사각형 그리기  
{
	rX = (right_up.x - left_down.x) / 2;
	rY = (right_up.y - left_down.y) / 2;
	
    if (draw_type == RUBBER) // 드래그할때 점선을 그린다
    { 
        glEnable(GL_LINE_STIPPLE); // 점선기능 활성화
        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(); 
        */
		glBegin(GL_LINE_LOOP);
		for(int i=0;i<360;i++)
			glVertex2f(left_down.x + rX + (rX * cos(delta*i)), left_down.y + rY + (rY*sin(delta*i)));
			glEnd();
    }            
    else if ( draw_type == SOLID) //드랍할때 사각형과 원을 그린다
    { 
        glDisable(GL_LINE_STIPPLE); // 점선기능 비 활성화
        //glRectf(left_down.x, left_down.y, right_up.x, right_up.y);

glColor3f(1.0,1.0,0.0);
		glBegin(GL_POLYGON);
		for(int i=0; i<360;i++)
			glVertex2f(left_down.x + rX + (rX * cos(delta*i)), left_down.y + rY + (rY*sin(delta*i)));
			glEnd();
    }; 
}

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();  
} 
;