/* size of touchpad area, it will be evenly divided for the buttons */
#define TOUCHPAD_WIDTH  3010
#define TOUCHPAD_HEIGHT 1975

#define DEADZONE_XMUL 50 /* x deadzone multiplier */
#define DEADZONE_YMUL 40 /* y deadzone multiplier */

/* we emulate a 3x3 grid, this gives the button mapping
 * WARNING: the y-axis is reversed ! */
int button_mapping[3][3] =
{
    {BUTTON_BOTTOMLEFT, BUTTON_DOWN, BUTTON_BOTTOMRIGHT},
    {BUTTON_LEFT, BUTTON_SELECT, BUTTON_RIGHT},
    {BUTTON_TOPLEFT, BUTTON_UP, BUTTON_TOPRIGHT},
};

int x_deadzone, y_deadzone;

/* Ignore deadzone function */
static int find_button_no_deadzone(int x, int y)
{
    /* compute grid coordinate */
    int gx = x * 3 / TOUCHPAD_WIDTH;
    int gy = y * 3 / TOUCHPAD_HEIGHT;
    if(gx < 0 || gx >= 3 || gy < 0 || gy >= 3)
        return 0; /* something went wrong, these coordinates are useless */
    return button_mapping[gx][gy];
}

/* Ignore deadzone function */
static int find_button(int x, int y)
{
    /* compute grid coordinate */
    int gx = x * 3 / TOUCHPAD_WIDTH;
    int gy = y * 3 / TOUCHPAD_HEIGHT;
    /* find button ignoring deadzones */
    int btn = find_button_no_deadzone(x, y);
    if(btn == 0)
        return 0;
    /* to see if we are in a deadzone, we try to shift the coordinate
     * and see if we get the same button, however we do not want the
     * deadzone to apply on the borders, only between buttons ! */
    /* right deadzone: only if not in the last column */
    if(gx != 2 && find_button_no_deadzone(x + x_deadzone, y) != btn)
        return 0;
    /* left deadzone: only if not in the first column */
    if(gx != 0 && find_button_no_deadzone(x - x_deadzone, y) != btn)
        return 0;
    /* top deadzone: only if not in the first row */
    if(gy != 2 && find_button_no_deadzone(x, y + y_deadzone) != btn)
        return 0;
    /* bottom deadzone: only if not in the last row */
    if(gy != 0 && find_button_no_deadzone(x, y - y_deadzone) != btn)
        return 0;
    return btn;
}

void touchpad_set_deadzone(int deadzone)
{
    x_deadzone = deadzone * DEADZONE_XMUL;
    y_deadzone = deadzone * DEADZONE_YMUL;
}