Multiply32.cc

Go to the documentation of this file.

#include "Multiply32.hh"
#include "PixelOperations.hh"
#include "enumerate.hh"
#include <cstring>
 
namespace openmsx {
 
// class Multiply32<uint32_t>
 
Multiply32<uint32_t>::Multiply32(const PixelOperations<uint32_t>& /*pixelOps*/)
{
        // nothing
}
 
 
// class Multiply32<uint16_t>
 
Multiply32<uint16_t>::Multiply32(const PixelOperations<uint16_t>& pixelOps)
{
        Rmask1 = pixelOps.getRmask();
        Gmask1 = pixelOps.getGmask();
        Bmask1 = pixelOps.getBmask();
 
        Rshift1 = ((2 + pixelOps.getRloss()) - pixelOps.getRshift()) & 31;
        Gshift1 = ((2 + pixelOps.getGloss()) - pixelOps.getGshift()) & 31;
        Bshift1 = ((2 + pixelOps.getBloss()) - pixelOps.getBshift()) & 31;
 
        Rmask2 = ((1 << (2 + pixelOps.getRloss())) - 1) <<
                        (10 + pixelOps.getRshift() - 2 * (2 + pixelOps.getRloss()));
        Gmask2 = ((1 << (2 + pixelOps.getGloss())) - 1) <<
                        (10 + pixelOps.getGshift() - 2 * (2 + pixelOps.getGloss()));
        Bmask2 = ((1 << (2 + pixelOps.getBloss())) - 1) <<
                        (10 + pixelOps.getBshift() - 2 * (2 + pixelOps.getBloss()));
 
        Rshift2 = (2 * (2 + pixelOps.getRloss()) - pixelOps.getRshift() - 10) & 31;
        Gshift2 = (2 * (2 + pixelOps.getGloss()) - pixelOps.getGshift() - 10) & 31;
        Bshift2 = (2 * (2 + pixelOps.getBloss()) - pixelOps.getBshift() - 10) & 31;
 
        Rshift3 = (Rshift1 +  0) & 31;
        Gshift3 = (Gshift1 + 10) & 31;
        Bshift3 = (Bshift1 + 20) & 31;
 
        factor = 0;
        memset(tab, 0, sizeof(tab));
}
 
void Multiply32<uint16_t>::setFactor32(unsigned f)
{
        if (factor == f) return;
        factor = f;
 
        for (auto [p, t] : enumerate(tab)) {
                uint32_t r = std::rotl((p & Rmask1), Rshift1) |
                             std::rotl((p & Rmask2), Rshift2);
                uint32_t g = std::rotl((p & Gmask1), Gshift1) |
                             std::rotl((p & Gmask2), Gshift2);
                uint32_t b = std::rotl((p & Bmask1), Bshift1) |
                             std::rotl((p & Bmask2), Bshift2);
                t = (((r * factor) >> 8) <<  0) |
                    (((g * factor) >> 8) << 10) |
                    (((b * factor) >> 8) << 20);
        }
}
 
} // namespace openmsx