Devo12 with improved touch screen

struct touch SPITouch_GetCoords()
{
    #define TOUCH_READS 3
    struct touch res, data[TOUCH_READS];
    u32 center_x = 0, center_y = 0;
    CS_LO();
    // read TOUCH_READS times from the touchpad and store the values
    for (int i=0; i<TOUCH_READS; i++) {
        #if _TOUCH_COORDS_REVERSE
            /* X and Y are swapped on Devo8 */
            /* and X is reversed */
            data[i].x = 255 - read_channel(READ_Y);
            data[i].y = read_channel(READ_X);
        #else
            data[i].x = 255 - read_channel(READ_X);
            data[i].y = read_channel(READ_Y);
        #endif
        // TODO: is it necessary to read all values? Must they also be calculated (or: are they used somewhere? AFAIK only in tx_configure.c for display testing)?
        data[i].z1 = read_channel(READ_Z1);
        data[i].z2 = read_channel(READ_Z2);
        // add values to calculate center of measuring points
        center_x += data[i].x;
        center_y += data[i].y;
    }
    CS_HI();
    #if TOUCH_READS > 1
        // divide by number of measurements to correct the range
        center_x /= TOUCH_READS;
        center_y /= TOUCH_READS;
        // search for the data point with the greatest distance to the calculated center
        u32 dist = 0, max_dist = 0;
        int index_max_dist = 0;
        for (int i=0; i<TOUCH_READS; i++) {
            dist = ((center_x - data[i].x) * (center_x - data[i].x) + (center_y - data[i].y) * (center_y - data[i].y));
            // rather dist^2, but 'dist > 0' and 'a > b ==> a^2 > b^2' this will suffice to search the outlier
            if (dist > max_dist) {
                max_dist = dist;
                index_max_dist = i;
            }
        }
        // reset this data point
        data[index_max_dist].x = 0;
        data[index_max_dist].y = 0;
        // recalculate the center
        center_x = 0;
        center_y = 0;
        for (int i=0; i<TOUCH_READS; i++) {
            center_x += data[i].x;
            center_y += data[i].y;
        }
        // divide by number of measurements -1 (!, one data point discarded) to correct the range and store
        res.x = center_x / (TOUCH_READS - 1);
        res.y = center_y / (TOUCH_READS - 1);
    #else
        res.x = data[0].x;
        res_y = data[0].y;
    #endif
    res.x = res.x * Transmitter.touch.xscale / 0x10000 + Transmitter.touch.xoffset;
    if(res.x & 0x8000)
        res.x = 0;
    res.y = res.y * Transmitter.touch.yscale / 0x10000 + Transmitter.touch.yoffset;
    if(res.y & 0x8000)
        res.y = 0;
    return res;
}