Case Study 2-6-6.txt

#include<Windows.h>
#include<gl/GL.h>
#include<gl/glut.h>


class GLintPoint {
public:
	GLint x, y;
};


#define NUM 20
static GLintPoint List[NUM][NUM];
static int polylineNum = 0;            // last index used so far
static int lineNum = 0;            // last index used so far

int mouseMode;

bool empty = true;
int buffer1 = -1;
int buffer2 = -1;
int inputx;
int inputy;

void myInit(void)
{
	glClearColor(1.0, 1.0, 1.0, 0.0);
	glColor3f(R, G, B);
	glPointSize(4.0);
	glClear(GL_COLOR_BUFFER_BIT);
	glMatrixMode(GL_PROJECTION);
	glLoadIdentity();
	gluOrtho2D(0.0, 640, 0.0, 480);
}

void drawDot(GLint x, GLint y)
{
	glBegin(GL_POINTS);
	glPointSize(10);
	glVertex2i(x, y);
	glEnd();
	glFlush();
}

void myMouse(int button, int state, int x, int y)
{

	// test for mouse button as well as for a full array 
	if (button == GLUT_LEFT_BUTTON && state == GLUT_DOWN && lineNum < NUM - 1)
	{
		inputx = x;
		inputy = 480 - y;

		switch (mouseMode)
		{
		case 1:
			List[polylineNum][lineNum].x = inputx;			// add new point to list 
			List[polylineNum][lineNum].y = inputy;		// window height is 480 
			lineNum++;
			break;
		case 2:
			for (int ia = 0; ia < 20; ia++) 
			{
				for (size_t i = 0; i < 20; i++)
				{
					if ((abs(List[ia][i].x - inputx) < 5) && (abs(List[ia][i].y - inputy) < 5)) 
					{
						for (size_t ib = i; ib < 20; ib++)
						{
							List[ia][ib].x = List[ia][ib + 1].x;
							List[ia][ib].y = List[ia][ib + 1].y;

						}
					}
				}
			}
			break;
		case 3:
			if (empty)
			{
				for (int ia = 0; ia < 20; ia++)
				{
					for (size_t i = 0; i < 20; i++)
					{
						if ((abs(List[ia][i].x - inputx) < 5) && (abs(List[ia][i].y - inputy) < 5))
						{
							buffer1 = ia;
							buffer2 = i;
							empty = false;
							
						}
					}
				}
			}
			else
			{
				List[buffer1][buffer2].x = inputx;
				List[buffer1][buffer2].y = inputy;
				buffer1 = -1;
				buffer2 = -1;
				empty = true;
			}
			break;

		default:
			break;
		}


		glClear(GL_COLOR_BUFFER_BIT);				// clear the screen 
		glColor3f(1.0, 0.0, 0.0);
		for (int ia = 0; ia < 20; ia++) 
		{

			glBegin(GL_LINE_STRIP);
			glLineWidth(4);
			for (size_t i = 0; i < 20; i++)
			{
				if (List[ia + 1][i].x == 0 && List[ia + 1][i].y == 0) break; // stop if polygon end
				glVertex2i(List[ia + 1][i].x, List[ia + 1][i].y);
			}
			glEnd();
			glFlush();
		}

	}
}

void myKeyboard(unsigned char theKey, int mouseX, int mouseY) {

	GLint x = mouseX; //grab the mouse position
	mouseY = 480 - mouseY;
	GLint y = mouseY; // flip it as usual
	switch (theKey) 
	{
	case 'b':   // create a new polyline
		polylineNum++;
		lineNum = 0;
		mouseMode = 1;
		break;
	case 'd':
		mouseMode = 2;
		break;
	case 'm':
		mouseMode = 3;
		break;
	case 'r':
		for (int ia = 0; ia < 20; ia++) 
		{
			for (size_t i = 0; i < 20; i++)
			{
				List[ia][i].x = 0;
				List[ia][i].y = 0;
			}
		}
		break;
	case 'q':
		exit(-1);   //terminate the program
		break;

	default:
		break;      // do nothing
	}
}

void main(int argc, char** argv)
{

	glutInit(&argc, argv);
	glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB);
	glutInitWindowSize(640, 480);
	glutInitWindowPosition(50, 50);
	glutCreateWindow("Case Study 2.6.6");

	glutKeyboardFunc(myKeyboard);
	glutMouseFunc(myMouse);
	//glutDisplayFunc(house);
	myInit();
	glutMainLoop();

}