/************************************************************************/
/* Display black and white sprite and move it using arrow keys          */
/************************************************************************/

demo_cursor()
        {
        #define MAX_X           (640 - 16)
        #define MAX_Y           (350 - 16)

        #define KEY_ESC         0x011B
        #define KEY_UP          0x4800
        #define KEY_DOWN        0x5000
        #define KEY_LEFT        0x4B00
        #define KEY_RIGHT       0x4D00
        #define KEY_ENTER       0x1C0D

        static  char    and_mask[] = {
                0x00,0x00, 0x00,0x00, 0x00,0x00, 0x1F,0xF8,
                0x1F,0xF8, 0x1F,0xF8, 0x1F,0xF8, 0x1F,0xF8,
                0x1F,0xF8, 0x1F,0xF8, 0x1F,0xF8, 0x1F,0xF8,
                0x1F,0xF8, 0x00,0x00, 0x00,0x00, 0x00,0x00};
        static  char    xor_mask[] = {
                0xFF,0xFF, 0x80,0x01, 0xBF,0xFD, 0xA0,0x05,
                0xA0,0x05, 0xA0,0x05, 0xA0,0x05, 0xA0,0x05,
                0xA0,0x05, 0xA0,0x05, 0xA0,0x05, 0xA0,0x05,
                0xA0,0x05, 0xBF,0xFD, 0x80,0x01, 0xFF,0xFF};
        int     key, x, y, i;

        /* Draw a background pattern  and a solid white box             */

        clear_screen();
        for (i = 0; i < 640; i += 20) line(320,100,i,  0,i/20);
        for (i = 0; i < 640; i += 20) line(320,100,i,199,i/20);
        for (i = 0; i < 200; i += 10) line(320,100,0,  i,i/10);
        for (i = 0; i < 200; i += 10) line(320,100,639,i,i/10);
        solid_box(320,100,150,150,15);

        /* Set cursor shape and color, and display the first cursor     */

        set_cursor(and_mask, xor_mask, 0, 15);
        x = 320;                        /* initial position of cursor   */
        y = 100;
        move_cursor(x,y);               /* show cursor at initial pos   */

        /* Loop while keys are pressed                                          */

        do
                {
                switch (key = get_key())/* Move cursor according to key */
                        {
                        case KEY_ESC:
                        case KEY_ENTER:
                                remove_cursor();
                                break;
                        case KEY_UP:
                                y = (y -1) > 0 ? --y : 0;
                                move_cursor(x, y);
                                break;
                        case KEY_DOWN:
                                y = (y + 1) < MAX_Y ? ++y : MAX_Y;
                                move_cursor(x, y);
                                break;
                        case KEY_RIGHT:
                                x = (x + 1) < MAX_X ? ++x : MAX_X;
                                move_cursor(x, y);
                                break;
                        case KEY_LEFT:
                                x = (x - 1) > 0 ? --x : 0;
                                move_cursor(x, y);
                                break;
                        default:
                                break;
                        }
                } while (key != KEY_ENTER);
        }