Q2.rar_assignment

// Polygon Drawing with mouse and moving with arrow keys //Use arrow keys on numpad(4 for laft and 6 for right). #include "stdafx.h" #include "math.h" #include <windows.h> #include <gl/Gl.h> #include <gl/glut.h> #include "canvas.h" Canvas cvs(640,480,"Moving Polygon,Mouse and Keyboard control"); int screenHeight=480; int p=0,m=0,chk=0,gva=0; //global variables int gvb=0; void myInit(void) { glClearColor(1.0,1.0,1.0,0.0); glColor3f(0.0f,0.0f,0.0f); glMatrixMode(GL_PROJECTION); glLoadIdentity(); gluOrtho2D(0.0, 640.0, 0.0, 480.0); } void draw(int x,int y) //to draw polygon { glClear(GL_COLOR_BUFFER_BIT); glBegin(GL_LINE_LOOP); glVertex2i(x,screenHeight-y); glVertex2i(x+40,screenHeight-y); glVertex2i(x,screenHeight-(y-40)); glVertex2i(x+40,screenHeight-(y-40)); glEnd(); } void myMouse( int button, int state,int x,int y) { if( button == GLUT_LEFT_BUTTON && state == GLUT_DOWN ) { draw(x,y); //draw polygon where left button clicked gva=x; //passing polygon starting coordinates to global gvb=y; //variables gva and gvb } } void myKeyboard(unsigned char theKey,int x,int y) { GLint a=gva; //passing global values (from mouse func) to keyboard GLint b=gvb; //function variables switch(theKey) { case '+': p=p+20; // add 20 pixels break; case '-': m=m-20; // subtract 20 pixels break; case '4': glClear(GL_COLOR_BUFFER_BIT); a=a-10; //to move on left chk=p+m; if (chk>0){chk=-1*chk;} //to keep direction left ,if p+m becomes greater than zero a=a+chk; draw(a,b); break; case '6': glClear(GL_COLOR_BUFFER_BIT); a=a+10; chk=p+m; if (chk<0){chk=-1*chk;} a=a+chk; draw(a,b); break; } } void myDisplay() { glClear(GL_COLOR_BUFFER_BIT); glutMouseFunc(myMouse); glutKeyboardFunc(myKeyboard); glFlush(); } void main(int argc, char** argv) { glutDisplayFunc(myDisplay); myInit(); glutMainLoop(); }