void KisColorSelectorRing::paintCache()
{
QImage cache(m_cachedSize, m_cachedSize, QImage::Format_ARGB32_Premultiplied);
Eigen::Vector2i center(cache.width()/2., cache.height()/2.);
for(int x=0; x<cache.width(); x++) {
for(int y=0; y<cache.height(); y++) {
Eigen::Vector2i currentPoint((float)x, (float)y);
Eigen::Vector2i relativeVector = currentPoint-center;
qreal currentRadius = relativeVector.squaredNorm();
currentRadius=sqrt(currentRadius);
if(currentRadius < outerRadius()+1
&& currentRadius > innerRadius()-1)
{
float angle = std::atan2((float)relativeVector.y(), (float)relativeVector.x())+((float)M_PI);
angle/=2*((float)M_PI);
angle*=359.f;
if(currentRadius < outerRadius()
&& currentRadius > innerRadius()) {
cache.setPixel(x, y, m_cachedColors.at(angle));
}
else {
// draw antialiased border
qreal coef=1.;
if(currentRadius > outerRadius()) {
// outer border
coef-=currentRadius;
coef+=outerRadius();
}
else {
// inner border
coef+=currentRadius;
coef-=innerRadius();
}
coef=qBound(qreal(0.), coef, qreal(1.));
int red=qRed(m_cachedColors.at(angle));
int green=qGreen(m_cachedColors.at(angle));
int blue=qBlue(m_cachedColors.at(angle));
// the format is premultiplied, so we have to take care of that
QRgb color = qRgba(red*coef, green*coef, blue*coef, 255*coef);
cache.setPixel(x, y, color);
}
}
else {
cache.setPixel(x, y, qRgba(0,0,0,0));
}
}
}
m_pixelCache = cache;
}
