static QRgb getSubpixel(const QImage &img, double x, double y)
{
int fx = fixedfraction(x);
int fy = fixedfraction(y);
int px = (int)x;
int py = (int)y;
QRgb p1;
QRgb p2;
QRgb p3;
QRgb p4;
int right = 1;
int below = 1;
if (py >= img.height() - 1 ) {
// We are partially outside the image, do our best here.
below = 0;
}
if (px >= img.width() - 1) {
// We are partially outside the image, do our best here.
right = 0;
}
p1 = weighpixel(img.pixel(px, py), (FIXEDPOINT_MULTIPLIER-fx)*(FIXEDPOINT_MULTIPLIER-fy));
p2 = weighpixel(img.pixel(px+right, py), fx*(FIXEDPOINT_MULTIPLIER-fy));
p3 = weighpixel(img.pixel(px, py+below), (FIXEDPOINT_MULTIPLIER-fx)*fy);
p4 = weighpixel(img.pixel(px+right, py+below), fx*fy);
return qRgb((qRed(p1) + qRed(p2) + qRed(p3) + qRed(p4)),
(qGreen(p1) + qGreen(p2) + qGreen(p3) + qGreen(p4)),
(qBlue(p1) + qBlue(p2) + qBlue(p3) + qBlue(p4)));
}
/*
* Gets a pixel at a floating-point coordinate, thus causing it to take into
* accountance neighbour pixels if one of the coordinates have a fractional part
*
* The function will calculate the pixel value by calculating all areas the
* pixel occupies in each neighbouring pixel.
*/
static QRgb getPixel(const QImage &img, double x, double y)
{
int fx = fixedfraction(x);
int fy = fixedfraction(y);
int px = (int) x;
int py = (int) y;
int right = 1;
if (px >= img.width() - 1) {
right = 0;
}
int below = 1;
if (py >= img.height() - 1) {
below = 0;
}
QRgb p1 = weighpixel(img.pixel(px, py), (FIXEDPOINT_MULTIPLIER - fx) * (FIXEDPOINT_MULTIPLIER - fy));
QRgb p2 = weighpixel(img.pixel(px + right, py), fx * (FIXEDPOINT_MULTIPLIER - fy));
QRgb p3 = weighpixel(img.pixel(px, py + below), (FIXEDPOINT_MULTIPLIER - fx) * fy);
QRgb p4 = weighpixel(img.pixel(px + right, py + below), fx * fy);
return qRgb((qRed(p1) + qRed(p2) + qRed(p3) + qRed(p4)),
(qGreen(p1) + qGreen(p2) + qGreen(p3) + qGreen(p4)),
(qBlue(p1) + qBlue(p2) + qBlue(p3) + qBlue(p4)));
}
