RawFrame.cc

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#include "RawFrame.hh"
 
namespace openmsx {
 
[[nodiscard]] static unsigned calcMaxWidth(unsigned maxWidth)
{
        unsigned bytes = maxWidth * sizeof(RawFrame::Pixel);
        bytes = (bytes + 63) & ~63; // round up to cache-line size
        return bytes / sizeof(RawFrame::Pixel);
}
 
RawFrame::RawFrame(unsigned maxWidth_, unsigned height_)
        : lineWidths(height_)
        , maxWidth(calcMaxWidth(maxWidth_))
{
        setHeight(height_);
 
        // Allocate memory, make sure each line starts at a 64 byte boundary:
        // - SSE instructions need 16 byte aligned data
        // - cache line size on many CPUs is 64 bytes
        data.resize(size_t(maxWidth) * height_);
 
        // Start with a black frame.
        init(FieldType::NONINTERLACED);
        for (auto line : xrange(height_)) {
                setBlank(line, Pixel(0));
        }
}
 
unsigned RawFrame::getLineWidth(unsigned line) const
{
        assert(line < getHeight());
        return lineWidths[line];
}
 
std::span<const RawFrame::Pixel> RawFrame::getUnscaledLine(
        unsigned line, std::span<Pixel> /*helpBuf*/) const
{
        return getLineDirect(line).subspan(0, lineWidths[line]);
}
 
bool RawFrame::hasContiguousStorage() const
{
        return true;
}
 
} // namespace openmsx