C++ Programming Code Examples

/* setviewport() will create a new viewport by accepting left, top, right and bottom coordinates. The 5th argument for this function would be non zero, if you want to clip the drawing beyond this viewport. clearviewport() erases the viewport and moves the CP (current position) to home (0,0), relative to the viewport. */ /* erase the viewport and moves the current position to home (0,0) by clearviewport() function copde example. */ #include <graphics.h> #include <stdlib.h> #include <stdio.h> #include <conio.h> #define CLIP_ON 1 /* activates clipping in viewport */ int main(void) { /* request autodetection */ int gdriver = DETECT, gmode, errorcode, ht; /* initialize graphics and local variables */ initgraph(&gdriver, &gmode, ""); /* read result of initialization */ errorcode = graphresult(); if (errorcode != grOk) { /* an error occurred */ printf("Graphics error: %s\n", grapherrormsg(errorcode)); printf("Press any key to halt:"); getch(); exit(1); /* terminate with an error code */ } setcolor(getmaxcolor()); ht = textheight("W"); /* message in default full-screen viewport */ outtextxy(0, 0, "* <-- (0, 0) in default viewport"); /* create a smaller viewport */ setviewport(50, 50, getmaxx()-50, getmaxy()-50, CLIP_ON); /* display some messages */ outtextxy(0, 0, "* <-- (0, 0) in smaller viewport"); outtextxy(0, 2*ht, "Press any key to clear viewport:"); getch(); /* wait for a key */ clearviewport(); /* clear the viewport */ /* output another message */ outtextxy(0, 0, "Press any key to quit:"); /* clean up */ getch(); closegraph(); return 0; }