/* avivA Starkman
 * May 16, 1996
 * "Electro-Sketch": An Electronic Etch-A-Sketch
 * written for PowerC compiler */


#include <graphics.h>
#include <bios.h>

#define STEP 2				/* line increment amount */
#define MAXX 319			/* screen size for CGA_320 */
#define MAXY 199
#define BGCOLOR 1			/* background color: blue */
#define PALETTE 1			/* palette: cyan/magenta/white */
#define TITLECOLOR 1			/* title color: cyan */
#define BOXCOLOR 2			/* box color: magenta */
#define LINECOLOR 3			/* line color: white */
/* colors used to be [8, 0, 3, 1]: gray, brown, green */

void ShakeScreen(int *x, int *y);

main() {

int locx, locy;				/* current screen position */
char ch;

if (setvmode(CGA_320) != CGA_320) {
    printf ("ERROR: This program requires CGA, EGA, or VGA card\n");
    exit(1);
}
else {
    setcolor(BGCOLOR, PALETTE);
    ShakeScreen(&locx, &locy);

ch = getch();

while ((ch != 'q') && (ch != 'Q'))
{
    switch (ch)
    {
	/* clear screen */
	case 'c':
	case 'C': clrscrn2(0xf0);
		  ShakeScreen(&locx, &locy);
		  break;

	/* move up */
	case 'k':
	case 'K': if (locy >= STEP) {
		    locy -= STEP;
		    line_to(locx, locy);
		  }
		  break;

	/* move down */
	case 'j':
	case 'J': if (locy <= MAXY - STEP) {
		    locy += STEP;
		    line_to(locx, locy);
		  }
		  break;

	/* move left */
	case 'h':
	case 'H': if (locx >= STEP) {
		    locx -= STEP;
		    line_to(locx, locy);
		  }
		  break;

	/* move right */
	case 'l':
	case 'L': if (locx <= MAXX - STEP) {
		    locx += STEP;
		    line_to(locx, locy);
		  }
    } /* end switch */

    /* show current position in title color */
    pen_color(TITLECOLOR);
    setpixel(locx, locy);
    pen_color(LINECOLOR);

    ch = getch();
    } /* end while */

    setvmode(DEFAULTMODE);
    exit(0);
    } /* end else */
} /* end main */

void ShakeScreen(int *x, int *y) {
/* ShakeScreen re-initializes the screen for a new drawing */

    pen_color(TITLECOLOR);		/* print title */
    move_to(100, 0);
    plots("Electro-Sketch");

    move_to (8, 127);			/* print instruction box */
    plots("Left:");
    move_to(8, (127 + 1*11));
    plots("Right:");
    move_to(8, (127 + 2*11));
    plots("Up:");
    move_to(8, (127 + 3*11));
    plots("Down:");
    move_to(8, (127 + 4*11));
    plots("Clear:");
    move_to(8, (127 + 5*11));
    plots("Quit:");

    pen_color(BOXCOLOR);
    move_to(0, 120);
    box(81, 77, 0);
    move_to(64, 127);
    plotch('H');
    move_to(64, (127 + 1*11));
    plotch('L');
    move_to(64, (127 + 2*11));
    plotch('K');
    move_to(64, (127 + 3*11));
    plotch('J');
    move_to(64, (127 + 4*11));
    plotch('C');
    move_to(64, (127 + 5*11));
    plotch('Q');

    move_to(132, 190);			/* print our names */
    plots("By: Doug, Chris & Aviva");

    pen_color(TITLECOLOR);		/* print title */
    move_to(160,100);			/* go to center of screen */
    *x = 160;				/* initialize loc variables */
    *y = 100;
    setpixel(*x, *y);			/* show current position */
    pen_color(LINECOLOR);
}