Problem 2. Modify the interactive program paint.cpp.

• Arrange the five small boxes against the left border of the screen, starting from the top-left corner.
• Keep the current draw_mode if a new one is not picked.

Provide three options in the pixel menu: double the size, triple the size, and halve the size

#include #include // definitions #define NULL 0 #define LINE 1 #define RECTANGLE 2 #define TRIANGLE 3 #define POINTS 4 #define TEXT 5

// function prototypes void mouse(int, int, int, int); void key(unsigned char, int, int); void display(); void drawSquare(int, int); void myReshape(GLsizei, GLsizei); void myinit(); void screen_box(int, int, int); void right_menu(int); void middle_menu(int); void color_menu(int); void pixel_menu(int); void fill_menu(int); int pick(int, int);

/* globals */ GLsizei wh = 500, ww = 500; /* initial window size */ GLfloat size = 3.0; /* half side length of square */ int draw_mode = 0; /* drawing mode */ int rx, ry; /*raster position*/ GLfloat r = 1.0, g = 1.0, b = 1.0; /* drawing color */ int fill = 0; /* fill flag */

void drawSquare(int x, int y)//to represent a point { y=wh-y; glColor3ub( (char) rand()%256, (char) rand()%256, (char) rand()%256); glBegin(GL_POLYGON); glVertex2f(x+size, y+size); glVertex2f(x-size, y+size); glVertex2f(x-size, y-size); glVertex2f(x+size, y-size); glEnd(); }

/* reshaping routine called whenever window is resized or moved */

void myReshape(GLsizei w, GLsizei h) {

/* adjust clipping box */

glMatrixMode(GL_PROJECTION); glLoadIdentity(); glOrtho(0.0, (GLdouble)w, 0.0, (GLdouble)h, -1.0, 1.0); glMatrixMode(GL_MODELVIEW); glLoadIdentity();

/* adjust viewport and clear */

glViewport(0,0,w,h); glClearColor (0.8, 0.8, 0.8, 1.0); glClear(GL_COLOR_BUFFER_BIT); display(); glFlush();

/* set global size for use by drawing routine */

ww = w; wh = h; }

void myinit() { glViewport(0,0,ww,wh);

/* Pick 2D clipping window to match size of X window. This choice avoids having to scale object coordinates each time window is resized. */

glMatrixMode(GL_PROJECTION); glLoadIdentity(); glOrtho(0.0, (GLdouble) ww , 0.0, (GLdouble) wh , -1.0, 1.0);

/* set clear color to black and clear window */

glClearColor (0.8, 0.8, 0.8, 1.0); glClear(GL_COLOR_BUFFER_BIT); glFlush(); }

void mouse(int btn, int state, int x, int y) { static int count; int where; static int xp[2],yp[2];

if(btn==GLUT_LEFT_BUTTON && state==GLUT_DOWN) { glPushAttrib(GL_ALL_ATTRIB_BITS); where = pick(x,y); glColor3f(r, g, b);

if(where != 0) { count = 0; draw_mode = where; } else switch(draw_mode) { case(LINE): if(count==0) { count++; xp[0] = x; yp[0] = y; } else { glBegin(GL_LINES); glVertex2i(x,wh-y); glVertex2i(xp[0],wh-yp[0]); glEnd(); draw_mode=0; count=0; } break;

case(RECTANGLE): if(count == 0) { count++; xp[0] = x; yp[0] = y; } else { if(fill) glBegin(GL_POLYGON); else glBegin(GL_LINE_LOOP); glVertex2i(x,wh-y); glVertex2i(x,wh-yp[0]); glVertex2i(xp[0],wh-yp[0]); glVertex2i(xp[0],wh-y); glEnd(); draw_mode=0; count=0; } break;

case (TRIANGLE): switch(count) { case(0): count++; xp[0] = x; yp[0] = y; break; case(1): count++; xp[1] = x; yp[1] = y; break; case(2): if(fill) glBegin(GL_POLYGON); else glBegin(GL_LINE_LOOP); glVertex2i(xp[0],wh-yp[0]); glVertex2i(xp[1],wh-yp[1]); glVertex2i(x,wh-y); glEnd(); draw_mode=0; count=0; } break;

case(POINTS): { drawSquare(x,y); count++; } break;

case(TEXT): { rx=x; ry=wh-y; //glRasterPos2i(rx,ry); count=0; } break; }

glPopAttrib(); glFlush(); } }

int pick(int x, int y) { y = wh - y; if(y < wh-ww/10) return 0; else if(x < ww/10) return LINE; else if(x < ww/5) return RECTANGLE; else if(x < 3*ww/10) return TRIANGLE; else if(x < 2*ww/5) return POINTS; else if(x < ww/2) return TEXT; else return 0; }

void screen_box(int x, int y, int s )//a square with size s and (x,y) as the left bottom vertex { glBegin(GL_QUADS); glVertex2i(x, y); glVertex2i(x+s, y); glVertex2i(x+s, y+s); glVertex2i(x, y+s); glEnd(); }

void right_menu(int id) { if(id == 1) exit(0); else display();//redraw the window }

void middle_menu(int id) {

}

void color_menu(int id) { if(id == 1) {r = 1.0; g = 0.0; b = 0.0;} else if(id == 2) {r = 0.0; g = 1.0; b = 0.0;} else if(id == 3) {r = 0.0; g = 0.0; b = 1.0;} else if(id == 4) {r = 0.0; g = 1.0; b = 1.0;} else if(id == 5) {r = 1.0; g = 0.0; b = 1.0;} else if(id == 6) {r = 1.0; g = 1.0; b = 0.0;} else if(id == 7) {r = 1.0; g = 1.0; b = 1.0;} else if(id == 8) {r = 0.0; g = 0.0; b = 0.0;} }

void pixel_menu(int id) { if (id == 1) size = 2 * size; else if (size > 1) size = size/2; }

void fill_menu(int id) { if (id == 1) fill = 1; else fill = 0; }

void key(unsigned char k, int xx, int yy) { if(draw_mode!=TEXT) return;

glColor3f(0.0,0.0,0.0);//color is black glRasterPos2i(rx,ry); glutBitmapCharacter(GLUT_BITMAP_9_BY_15, k); //glutStrokeCharacter(GLUT_STROKE_ROMAN,k); rx+=glutBitmapWidth(GLUT_BITMAP_9_BY_15,k);

glFlush(); // to display immediately }

void display() { glClearColor (0.8, 0.8, 0.8, 1.0); glClear(GL_COLOR_BUFFER_BIT);

glColor3f(1.0, 1.0, 1.0); screen_box(0,wh-ww/10,ww/10);//the first square, in white

glColor3f(1.0, 0.0, 0.0); screen_box(ww/10,wh-ww/10,ww/10);//the second one, in red

glColor3f(0.0, 1.0, 0.0); screen_box(ww/5,wh-ww/10,ww/10);//the third one, in green

glColor3f(0.0, 0.0, 1.0); screen_box(3*ww/10,wh-ww/10,ww/10);//the fourth one, in blue

glColor3f(1.0, 1.0, 0.0); screen_box(2*ww/5,wh-ww/10,ww/10);//the fifth one, in yellow

glColor3f(0.0, 0.0, 0.0);//set the drawing color to black glBegin(GL_LINES); glVertex2i(wh/40,wh-ww/20); glVertex2i(wh/40+ww/20,wh-ww/20); glEnd();

glBegin(GL_TRIANGLES); glVertex2i(ww/5+ww/40,wh-ww/10+ww/40); glVertex2i(ww/5+ww/20,wh-ww/40); glVertex2i(ww/5+3*ww/40,wh-ww/10+ww/40); glEnd();

glPointSize(3.0); glBegin(GL_POINTS); glVertex2i(3*ww/10+ww/20, wh-ww/20); glEnd();

glRasterPos2i(2*ww/5,wh-ww/20); glutBitmapCharacter(GLUT_BITMAP_9_BY_15, 'A'); glutBitmapCharacter(GLUT_BITMAP_9_BY_15, 'B'); glutBitmapCharacter(GLUT_BITMAP_9_BY_15, 'C'); glFlush(); }

int main(int argc, char** argv) { int c_menu, p_menu, f_menu;

glutInit(&argc,argv); glutInitDisplayMode (GLUT_SINGLE | GLUT_RGB); glutCreateWindow("paint2"); glutDisplayFunc(display);

c_menu = glutCreateMenu(color_menu); glutAddMenuEntry("Red",1); glutAddMenuEntry("Green",2); glutAddMenuEntry("Blue",3); glutAddMenuEntry("Cyan",4); glutAddMenuEntry("Magenta",5); glutAddMenuEntry("Yellow",6); glutAddMenuEntry("White",7); glutAddMenuEntry("Black",8);

p_menu = glutCreateMenu(pixel_menu); glutAddMenuEntry("increase pixel size", 1); glutAddMenuEntry("decrease pixel size", 2);

f_menu = glutCreateMenu(fill_menu); glutAddMenuEntry("fill on", 1); glutAddMenuEntry("fill off", 2);

glutCreateMenu(right_menu); glutAddMenuEntry("quit",1); glutAddMenuEntry("clear",2); glutAttachMenu(GLUT_RIGHT_BUTTON);

glutCreateMenu(middle_menu); glutAddSubMenu("Colors", c_menu); glutAddSubMenu("Pixel Size", p_menu); glutAddSubMenu("Fill", f_menu); glutAttachMenu(GLUT_MIDDLE_BUTTON);

myinit (); glutReshapeFunc (myReshape); glutKeyboardFunc(key); glutMouseFunc (mouse); glutMainLoop();

}