Multiply32.cc

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#include "Multiply32.hh"
#include "PixelOperations.hh"
#include "enumerate.hh"
#include "narrow.hh"
 
namespace openmsx {
 
Multiply32<uint16_t>::Multiply32(const PixelOperations<uint16_t>& pixelOps)
        : Rshift1(narrow<int>(((2 + pixelOps.getRloss()) - pixelOps.getRshift()) & 31))
        , Gshift1(narrow<int>(((2 + pixelOps.getGloss()) - pixelOps.getGshift()) & 31))
        , Bshift1(narrow<int>(((2 + pixelOps.getBloss()) - pixelOps.getBshift()) & 31))
 
        , Rshift2(narrow<int>((2 * (2 + pixelOps.getRloss()) - pixelOps.getRshift() - 10) & 31))
        , Gshift2(narrow<int>((2 * (2 + pixelOps.getGloss()) - pixelOps.getGshift() - 10) & 31))
        , Bshift2(narrow<int>((2 * (2 + pixelOps.getBloss()) - pixelOps.getBshift() - 10) & 31))
 
        , Rshift3((Rshift1 +  0) & 31)
        , Gshift3((Gshift1 + 10) & 31)
        , Bshift3((Bshift1 + 20) & 31)
 
        , Rmask1(narrow_cast<uint16_t>(pixelOps.getRmask()))
        , Gmask1(narrow_cast<uint16_t>(pixelOps.getGmask()))
        , Bmask1(narrow_cast<uint16_t>(pixelOps.getBmask()))
 
        , Rmask2(narrow_cast<uint16_t>(
                ((1 << (2 + pixelOps.getRloss())) - 1) <<
                        (10 + pixelOps.getRshift() - 2 * (2 + pixelOps.getRloss()))))
        , Gmask2(narrow_cast<uint16_t>(
                ((1 << (2 + pixelOps.getGloss())) - 1) <<
                        (10 + pixelOps.getGshift() - 2 * (2 + pixelOps.getGloss()))))
        , Bmask2(narrow_cast<uint16_t>(
                ((1 << (2 + pixelOps.getBloss())) - 1) <<
                        (10 + pixelOps.getBshift() - 2 * (2 + pixelOps.getBloss()))))
{
}
 
void Multiply32<uint16_t>::setFactor32(unsigned f)
{
        if (factor == f) return;
        factor = f;
 
        for (auto [p, t] : enumerate(tab)) {
                uint32_t r = std::rotl(uint16_t(p & Rmask1), Rshift1) |
                             std::rotl(uint16_t(p & Rmask2), Rshift2);
                uint32_t g = std::rotl(uint16_t(p & Gmask1), Gshift1) |
                             std::rotl(uint16_t(p & Gmask2), Gshift2);
                uint32_t b = std::rotl(uint16_t(p & Bmask1), Bshift1) |
                             std::rotl(uint16_t(p & Bmask2), Bshift2);
                t = (((r * factor) >> 8) <<  0) |
                    (((g * factor) >> 8) << 10) |
                    (((b * factor) >> 8) << 20);
        }
}
 
} // namespace openmsx