SaI3xScaler.cc

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// 2xSaI is Copyright (c) 1999-2001 by Derek Liauw Kie Fa.
//   http://elektron.its.tudelft.nl/~dalikifa/
// 2xSaI is free under GPL.
//
// Modified for use in openMSX by Maarten ter Huurne.
 
#include "SaI3xScaler.hh"
#include "FrameSource.hh"
#include "ScalerOutput.hh"
#include "vla.hh"
#include "build-info.hh"
#include <cassert>
#include <cstdint>
 
namespace openmsx {
 
template<typename Pixel>
SaI3xScaler<Pixel>::SaI3xScaler(const PixelOperations<Pixel>& pixelOps_)
        : Scaler3<Pixel>(pixelOps_)
        , pixelOps(pixelOps_)
{
}
 
template<typename Pixel>
void SaI3xScaler<Pixel>::scaleBlank1to3(
                FrameSource& src, unsigned srcStartY, unsigned srcEndY,
                ScalerOutput<Pixel>& dst, unsigned dstStartY, unsigned dstEndY)
{
        unsigned dstHeight = dst.getHeight();
        unsigned stopDstY = (dstEndY == dstHeight)
                          ? dstEndY : dstEndY - 3;
        unsigned srcY = srcStartY, dstY = dstStartY;
        for (/* */; dstY < stopDstY; srcY += 1, dstY += 3) {
                auto color = src.getLineColor<Pixel>(srcY);
                for (auto i : xrange(3)) {
                        dst.fillLine(dstY + i, color);
                }
        }
        if (dstY != dstHeight) {
                unsigned nextLineWidth = src.getLineWidth(srcY + 1);
                assert(src.getLineWidth(srcY) == 1);
                assert(nextLineWidth != 1);
                this->dispatchScale(src, srcY, srcEndY, nextLineWidth,
                                    dst, dstY, dstEndY);
        }
}
 
template<typename Pixel>
inline Pixel SaI3xScaler<Pixel>::blend(Pixel p1, Pixel p2) const
{
        return pixelOps.template blend<1, 1>(p1, p2);
}
 
static constexpr unsigned redblueMask = 0xF81F;
static constexpr unsigned greenMask = 0x7E0;
 
// TODO use PixelOperations::lerp()
template<typename Pixel>
[[nodiscard]] static Pixel bilinear(unsigned a, unsigned b, unsigned x);
 
template<> [[nodiscard]] uint16_t bilinear<uint16_t>(unsigned a, unsigned b, unsigned x)
{
        if (a == b) return a;
 
        const unsigned areaB = x >> 11; // reduce 16 bit fraction to 5 bits
        const unsigned areaA = 0x20 - areaB;
 
        a = (a & redblueMask) | ((a & greenMask) << 16);
        b = (b & redblueMask) | ((b & greenMask) << 16);
        const unsigned result = ((areaA * a) + (areaB * b)) >> 5;
        return (result & redblueMask) | ((result >> 16) & greenMask);
}
 
template<> [[nodiscard]] uint32_t bilinear<uint32_t>(unsigned a, unsigned b, unsigned x)
{
        if (a == b) return a;
 
        const unsigned areaB = x >> 8; // reduce 16 bit fraction to 8 bits
        const unsigned areaA = 0x100 - areaB;
 
        const unsigned result0 =
                ((a & 0x00FF00FF) * areaA + (b & 0x00FF00FF) * areaB) >> 8;
        const unsigned result1 =
                ((a & 0xFF00FF00) >> 8) * areaA + ((b & 0xFF00FF00) >> 8) * areaB;
        return (result0 & 0x00FF00FF) | (result1 & 0xFF00FF00);
}
 
// TODO move to PixelOperations
template<typename Pixel> [[nodiscard]] static Pixel bilinear4(
        unsigned a, unsigned b, unsigned c, unsigned d, unsigned x, unsigned y);
 
template<> uint16_t bilinear4<uint16_t>(
        unsigned a, unsigned b, unsigned c, unsigned d, unsigned x, unsigned y)
{
        x >>= 11;
        y >>= 11;
        const unsigned xy = (x * y) >> 5;
 
        const unsigned areaA = 0x20 + xy - x - y;
        const unsigned areaB = x - xy;
        const unsigned areaC = y - xy;
        const unsigned areaD = xy;
 
        a = (a & redblueMask) | ((a & greenMask) << 16);
        b = (b & redblueMask) | ((b & greenMask) << 16);
        c = (c & redblueMask) | ((c & greenMask) << 16);
        d = (d & redblueMask) | ((d & greenMask) << 16);
        unsigned result = (
                (areaA * a) + (areaB * b) + (areaC * c) + (areaD * d)
                ) >> 5;
        return (result & redblueMask) | ((result >> 16) & greenMask);
}
 
template<> [[nodiscard]] uint32_t bilinear4<uint32_t>(
        unsigned a, unsigned b, unsigned c, unsigned d, unsigned x, unsigned y)
{
        x >>= 8;
        y >>= 8;
        const unsigned xy = (x * y) >> 8;
 
        const unsigned areaA = (1 << 8) + xy - x - y;
        const unsigned areaB = x - xy;
        const unsigned areaC = y - xy;
        const unsigned areaD = xy;
 
        const unsigned result0 =
                ((a & 0x00FF00FF) * areaA + (b & 0x00FF00FF) * areaB +
                 (c & 0x00FF00FF) * areaC + (d & 0x00FF00FF) * areaD) >> 8;
        const unsigned result1 =
                ((a & 0xFF00FF00) >> 8) * areaA + ((b & 0xFF00FF00) >> 8) * areaB +
                ((c & 0xFF00FF00) >> 8) * areaC + ((d & 0xFF00FF00) >> 8) * areaD;
        return (result0 & 0x00FF00FF) | (result1 & 0xFF00FF00);
}
 
template<typename Pixel>
class Blender
{
public:
        template<unsigned x>
        [[nodiscard]] inline static Pixel blend(unsigned a, unsigned b);
 
        template<unsigned x, unsigned y>
        [[nodiscard]] inline static Pixel blend(unsigned a, unsigned b, unsigned c, unsigned d);
};
 
template<unsigned X, unsigned OLD, unsigned NEW>
struct Round {
        static_assert(OLD > NEW);
        static constexpr unsigned result =
                (X >> (OLD - NEW)) + ((X >> (OLD - NEW - 1)) & 1);
};
 
template<typename Pixel>
template<unsigned x>
inline Pixel Blender<Pixel>::blend(unsigned a, unsigned b)
{
        if (a == b) return a;
 
        const unsigned bits = (sizeof(Pixel) == 2) ? 5 : 8;
        const unsigned areaB = Round<x, 16, bits>::result;
        const unsigned areaA = (1 << bits) - areaB;
 
        if constexpr (sizeof(Pixel) == 2) {
                a = (a & redblueMask) | ((a & greenMask) << 16);
                b = (b & redblueMask) | ((b & greenMask) << 16);
                const unsigned result = ((areaA * a) + (areaB * b)) >> bits;
                return (result & redblueMask) | ((result >> 16) & greenMask);
        } else {
                const unsigned result0 =
                        ((a & 0x00FF00FF) * areaA +
                         (b & 0x00FF00FF) * areaB) >> bits;
                const unsigned result1 =
                        ((a & 0xFF00FF00) >> bits) * areaA +
                        ((b & 0xFF00FF00) >> bits) * areaB;
                return (result0 & 0x00FF00FF) | (result1 & 0xFF00FF00);
        }
}
 
template<typename Pixel>
template<unsigned wx, unsigned wy>
inline Pixel Blender<Pixel>::blend(
        unsigned a, unsigned b, unsigned c, unsigned d)
{
        const unsigned bits = (sizeof(Pixel) == 2) ? 5 : 8;
        const unsigned xy = (wx * wy) >> 16;
        const unsigned areaB = Round<wx - xy, 16, bits>::result;
        const unsigned areaC = Round<wy - xy, 16, bits>::result;
        const unsigned areaD = Round<xy,      16, bits>::result;
        const unsigned areaA = (1 << bits) - areaB - areaC - areaD;
 
        if constexpr (sizeof(Pixel) == 2) {
                a = (a & redblueMask) | ((a & greenMask) << 16);
                b = (b & redblueMask) | ((b & greenMask) << 16);
                c = (c & redblueMask) | ((c & greenMask) << 16);
                d = (d & redblueMask) | ((d & greenMask) << 16);
                unsigned result = (
                        (areaA * a) + (areaB * b) + (areaC * c) + (areaD * d)
                        ) >> bits;
                return (result & redblueMask) | ((result >> 16) & greenMask);
        } else {
                const unsigned result0 =
                        ((a & 0x00FF00FF) * areaA +
                         (b & 0x00FF00FF) * areaB +
                         (c & 0x00FF00FF) * areaC +
                         (d & 0x00FF00FF) * areaD) >> bits;
                const unsigned result1 =
                        ((a & 0xFF00FF00) >> bits) * areaA +
                        ((b & 0xFF00FF00) >> bits) * areaB +
                        ((c & 0xFF00FF00) >> bits) * areaC +
                        ((d & 0xFF00FF00) >> bits) * areaD;
                return (result0 & 0x00FF00FF) | (result1 & 0xFF00FF00);
        }
}
 
template<unsigned i>
class PixelStripRepeater
{
public:
        template<typename Pixel>
        inline static void fill(Pixel*& dp, unsigned sa) {
                *dp++ = sa;
                PixelStripRepeater<i - 1>::template fill<Pixel>(dp, sa);
        }
 
        template<unsigned NX, unsigned y, typename Pixel>
        inline static void blendBackslash(
                Pixel*& dp,
                unsigned sa, unsigned sb, unsigned sc, unsigned sd,
                unsigned se, unsigned sg, unsigned sj, unsigned sl)
        {
                // Fractional parts of the fixed point X coordinates.
                const unsigned x1 = ((NX - i) << 16) / NX;
                const unsigned y1 = y;
                const unsigned f1 = (x1 >> 1) + (0x10000 >> 2);
                const unsigned f2 = (y1 >> 1) + (0x10000 >> 2);
                if (y1 <= f1 && sa == sj && sa != se) {
                        *dp++ = Blender<Pixel>::template blend<f1 - y1>(sa, sb);
                } else if (y1 >= f1 && sa == sg && sa != sl) {
                        *dp++ = Blender<Pixel>::template blend<y1 - f1>(sa, sc);
                } else if (x1 >= f2 && sa == se && sa != sj) {
                        *dp++ = Blender<Pixel>::template blend<x1 - f2>(sa, sb);
                } else if (x1 <= f2 && sa == sl && sa != sg) {
                        *dp++ = Blender<Pixel>::template blend<f2 - x1>(sa, sc);
                } else if (y1 >= x1) {
                        *dp++ = Blender<Pixel>::template blend<y1 - x1>(sa, sc);
                } else if (y1 <= x1) {
                        *dp++ = Blender<Pixel>::template blend<x1 - y1>(sa, sb);
                }
                PixelStripRepeater<i - 1>::template blendBackslash<NX, y, Pixel>(
                        dp, sa, sb, sc, sd, se, sg, sj, sl);
        }
 
        template<unsigned NX, unsigned y, typename Pixel>
        inline static void blendSlash(
                Pixel*& dp,
                unsigned sa, unsigned sb, unsigned sc, unsigned sd,
                unsigned sf, unsigned sh, unsigned si, unsigned sk)
        {
                // Fractional parts of the fixed point X coordinates.
                const unsigned x1 = ((NX - i) << 16) / NX;
                const unsigned x2 = 0x10000 - x1;
                const unsigned y1 = y;
                const unsigned y2 = 0x10000 - y1;
                const unsigned f1 = (x1 >> 1) + (0x10000 >> 2);
                const unsigned f2 = (y1 >> 1) + (0x10000 >> 2);
                if (y2 >= f1 && sb == sh && sb != sf) {
                        *dp++ = Blender<Pixel>::template blend<y2 - f1>(sb, sa);
                } else if (y2 <= f1 && sb == si && sb != sk) {
                        *dp++ = Blender<Pixel>::template blend<f1 - y2>(sb, sd);
                } else if (x2 >= f2 && sb == sf && sb != sh) {
                        *dp++ = Blender<Pixel>::template blend<x2 - f2>(sb, sa);
                } else if (x2 <= f2 && sb == sk && sb != si) {
                        *dp++ = Blender<Pixel>::template blend<f2 - x2>(sb, sd);
                } else if (y2 >= x1) {
                        *dp++ = Blender<Pixel>::template blend<y2 - x1>(sb, sa);
                } else if (y2 <= x1) {
                        *dp++ = Blender<Pixel>::template blend<x1 - y2>(sb, sd);
                }
                PixelStripRepeater<i - 1>::template blendSlash<NX, y, Pixel>(
                        dp, sa, sb, sc, sd, sf, sh, si, sk);
        }
 
        template<unsigned NX, unsigned y, typename Pixel>
        inline static void blend4(
                Pixel*& dp, unsigned sa, unsigned sb, unsigned sc, unsigned sd)
        {
                const unsigned x = ((NX - i) << 16) / NX;
                *dp++ = Blender<Pixel>::template blend<x, y>(sa, sb, sc, sd);
                PixelStripRepeater<i - 1>::template blend4<NX, y, Pixel>(dp, sa, sb, sc, sd);
        }
};
template<>
class PixelStripRepeater<0>
{
public:
        template<typename Pixel>
        inline static void fill(Pixel*& /*dp*/, unsigned /*sa*/) { }
 
        template<unsigned NX, unsigned y, typename Pixel>
        inline static void blendBackslash(
                Pixel*& /*dp*/, unsigned /*sa*/, unsigned /*sb*/,
                unsigned /*sc*/, unsigned /*sd*/, unsigned /*se*/,
                unsigned /*sg*/, unsigned /*sj*/, unsigned /*sl*/) { }
 
        template<unsigned NX, unsigned y, typename Pixel>
        inline static void blendSlash(
                Pixel*& /*dp*/, unsigned /*sa*/, unsigned /*sb*/,
                unsigned /*sc*/, unsigned /*sd*/, unsigned /*sf*/,
                unsigned /*sh*/, unsigned /*si*/, unsigned /*sk*/) { }
 
        template<unsigned NX, unsigned y, typename Pixel>
        inline static void blend4(Pixel*& /*dp*/, unsigned /*sa*/,
                unsigned /*sb*/, unsigned /*sc*/, unsigned /*sd*/) { }
};
 
template<unsigned i>
class LineRepeater
{
public:
        template<unsigned NX, unsigned NY, typename Pixel>
        inline static void scaleFixedLine(
                const Pixel* __restrict src0, const Pixel* __restrict src1,
                const Pixel* __restrict src2, const Pixel* __restrict src3,
                unsigned srcWidth, ScalerOutput<Pixel>& dst, unsigned& dstY)
        {
                auto* dstLine = dst.acquireLine(dstY);
                auto* dp = dstLine;
                // Calculate fixed point coordinate.
                static constexpr unsigned y1 = ((NY - i) << 16) / NY;
 
                unsigned pos1 = 0;
                unsigned pos2 = 0;
                unsigned pos3 = 1;
                Pixel sb = src1[0];
                Pixel sd = src2[0];
                repeat(srcWidth, [&] {
                        const unsigned pos0 = pos1;
                        pos1 = pos2;
                        pos2 = pos3;
                        pos3 = std::min(pos1 + 3, srcWidth) - 1;
                        // Get source pixels.
                        const Pixel sa = sb; // current pixel
                        sb = src1[pos2]; // next pixel
                        const Pixel sc = sd;
                        sd = src2[pos2];
 
                        // Compute and write color of destination pixel.
                        if (sa == sb && sc == sd && sa == sc) {
                                // All the same color; fill.
                                PixelStripRepeater<NX>::template fill<Pixel>(dp, sa);
                        } else if (sa == sd && sb != sc) {
                                // Pattern in the form of a backslash.
                                PixelStripRepeater<NX>::template blendBackslash<NX, y1, Pixel>(
                                        dp, sa, sb, sc, sd, src0[pos1], src1[pos0], src2[pos3], src3[pos2]);
                        } else if (sb == sc && sa != sd) {
                                // Pattern in the form of a slash.
                                PixelStripRepeater<NX>::template blendSlash<NX, y1, Pixel>(
                                        dp, sa, sb, sc, sd, src0[pos2], src2[pos0], src1[pos3], src3[pos1]);
                        } else {
                                // No pattern; use bilinear interpolatation.
                                PixelStripRepeater<NX>::template blend4<NX, y1, Pixel>(
                                        dp, sa, sb, sc, sd);
                        }
                });
                dst.releaseLine(dstY, dstLine);
                ++dstY;
 
                LineRepeater<i - 1>::template scaleFixedLine<NX, NY, Pixel>(
                        src0, src1, src2, src3, srcWidth, dst, dstY);
        }
};
template<>
class LineRepeater<0>
{
public:
        template<unsigned NX, unsigned NY, typename Pixel>
        inline static void scaleFixedLine(
                const Pixel* /*src0*/, const Pixel* /*src1*/, const Pixel* /*src2*/,
                const Pixel* /*src3*/, unsigned /*srcWidth*/,
                ScalerOutput<Pixel>& /*dst*/, unsigned& /*dstY*/)
        { }
};
 
template<typename Pixel>
template<unsigned NX, unsigned NY>
void SaI3xScaler<Pixel>::scaleFixed(FrameSource& src,
        unsigned srcStartY, unsigned /*srcEndY*/, unsigned srcWidth,
        ScalerOutput<Pixel>& dst, unsigned dstStartY, unsigned dstEndY)
{
        assert(dst.getWidth() == srcWidth * NX);
        assert(dst.getHeight() == src.getHeight() * NY);
 
        VLA_SSE_ALIGNED(Pixel, buf0_, srcWidth); auto* buf0 = buf0_;
        VLA_SSE_ALIGNED(Pixel, buf1_, srcWidth); auto* buf1 = buf1_;
        VLA_SSE_ALIGNED(Pixel, buf2_, srcWidth); auto* buf2 = buf2_;
        VLA_SSE_ALIGNED(Pixel, buf3_, srcWidth); auto* buf3 = buf3_;
 
        int srcY = srcStartY;
        auto* src0 = src.getLinePtr(srcY - 1, srcWidth, buf0);
        auto* src1 = src.getLinePtr(srcY + 0, srcWidth, buf1);
        auto* src2 = src.getLinePtr(srcY + 1, srcWidth, buf2);
 
        for (auto dstY : xrange(dstStartY, dstEndY)) {
                auto* src3 = src.getLinePtr(srcY + 2, srcWidth, buf3);
                LineRepeater<NY>::template scaleFixedLine<NX, NY, Pixel>(
                        src0, src1, src2, src3, srcWidth, dst, dstY);
                src0 = src1;
                src1 = src2;
                src2 = src3;
                std::swap(buf0, buf1);
                std::swap(buf1, buf2);
                std::swap(buf2, buf3);
        }
}
 
template<typename Pixel>
void SaI3xScaler<Pixel>::scaleAny(FrameSource& src,
        unsigned srcStartY, unsigned /*srcEndY*/, unsigned srcWidth,
        ScalerOutput<Pixel>& dst, unsigned dstStartY, unsigned dstEndY) __restrict
{
        // Calculate fixed point end coordinates and deltas.
        const unsigned wFinish = (srcWidth - 1) << 16;
        const unsigned dw = wFinish / (dst.getWidth() - 1);
        const unsigned hFinish = (src.getHeight() - 1) << 16;
        const unsigned dh = hFinish / (dst.getHeight() - 1);
 
        VLA_SSE_ALIGNED(Pixel, buf0, srcWidth);
        VLA_SSE_ALIGNED(Pixel, buf1, srcWidth);
        VLA_SSE_ALIGNED(Pixel, buf2, srcWidth);
        VLA_SSE_ALIGNED(Pixel, buf3, srcWidth);
 
        unsigned h = 0;
        for (auto dstY : xrange(dstStartY, dstEndY)) {
                // Get source line pointers.
                int line = srcStartY + (h >> 16);
                // TODO possible optimization: reuse srcN from previous step
                auto* src0 = src.getLinePtr(line - 1, srcWidth, buf0);
                auto* src1 = src.getLinePtr(line + 0, srcWidth, buf1);
                auto* src2 = src.getLinePtr(line + 1, srcWidth, buf2);
                auto* src3 = src.getLinePtr(line + 2, srcWidth, buf3);
 
                // Get destination line pointer.
                auto* dstLine = dst.acquireLine(dstY);
                auto* dp = dstLine;
 
                // Fractional parts of the fixed point Y coordinates.
                const unsigned y1 = h & 0xffff;
                const unsigned y2 = 0x10000 - y1;
                // Next line.
                h += dh;
 
                unsigned pos1 = 0;
                unsigned pos2 = 0;
                unsigned pos3 = 1;
                Pixel B = src1[0];
                Pixel D = src2[0];
                for (unsigned w = 0; w < wFinish; ) {
                        const unsigned pos0 = pos1;
                        pos1 = pos2;
                        pos2 = pos3;
                        pos3 = std::min(pos1 + 3, srcWidth) - 1;
                        // Get source pixels.
                        const Pixel A = B; // current pixel
                        B = src1[pos2]; // next pixel
                        const Pixel C = D;
                        D = src2[pos2];
 
                        // Compute and write color of destination pixel.
                        if (A == B && C == D && A == C) { // 0
                                do {
                                        *dp++ = A;
                                        w += dw;
                                } while ((w >> 16) == pos1);
                        } else if (A == D && B != C) { // 1
                                do {
                                        // Fractional parts of the fixed point X coordinates.
                                        const unsigned x1 = w & 0xffff;
                                        const unsigned f1 = (x1 >> 1) + (0x10000 >> 2);
                                        const unsigned f2 = (y1 >> 1) + (0x10000 >> 2);
                                        Pixel product1;
                                        if (y1 <= f1 && A == src2[pos3] && A != src0[pos1]) { // close to B
                                                product1 = bilinear<Pixel>(A, B, f1 - y1);
                                        } else if (y1 >= f1 && A == src1[pos0] && A != src3[pos2]) { // close to C
                                                product1 = bilinear<Pixel>(A, C, y1 - f1);
                                        } else if (x1 >= f2 && A == src0[pos1] && A != src2[pos3]) { // close to B
                                                product1 = bilinear<Pixel>(A, B, x1 - f2);
                                        } else if (x1 <= f2 && A == src3[pos2] && A != src1[pos0]) { // close to C
                                                product1 = bilinear<Pixel>(A, C, f2 - x1);
                                        } else if (y1 >= x1) { // close to C
                                                product1 = bilinear<Pixel>(A, C, y1 - x1);
                                        } else {
                                                assert(y1 < x1); // close to B
                                                product1 = bilinear<Pixel>(A, B, x1 - y1);
                                        }
                                        *dp++ = product1;
                                        w += dw;
                                } while ((w >> 16) == pos1);
                        } else if (B == C && A != D) { // 2
                                do {
                                        // Fractional parts of the fixed point X coordinates.
                                        const unsigned x1 = w & 0xffff;
                                        const unsigned x2 = 0x10000 - x1;
                                        const unsigned f1 = (x1 >> 1) + (0x10000 >> 2);
                                        const unsigned f2 = (y1 >> 1) + (0x10000 >> 2);
                                        Pixel product1;
                                        if (y2 >= f1 && B == src2[pos0] && B != src0[pos2]) { // close to A
                                                product1 = bilinear<Pixel>(B, A, y2 - f1);
                                        } else if (y2 <= f1 && B == src1[pos3] && B != src3[pos1]) { // close to D
                                                product1 = bilinear<Pixel>(B, D, f1 - y2);
                                        } else if (x2 >= f2 && B == src0[pos2] && B != src2[pos0]) { // close to A
                                                product1 = bilinear<Pixel>(B, A, x2 - f2);
                                        } else if (x2 <= f2 && B == src3[pos1] && B != src1[pos3]) { // close to D
                                                product1 = bilinear<Pixel>(B, D, f2 - x2);
                                        } else if (y2 >= x1) { // close to A
                                                product1 = bilinear<Pixel>(B, A, y2 - x1);
                                        } else {
                                                assert(y2 < x1); // close to D
                                                product1 = bilinear<Pixel>(B, D, x1 - y2);
                                        }
                                        *dp++ = product1;
                                        w += dw;
                                } while ((w >> 16) == pos1);
                        } else { // 3
                                do {
                                        // Fractional parts of the fixed point X coordinates.
                                        const unsigned x1 = w & 0xffff;
                                        *dp++ = bilinear4<Pixel>(A, B, C, D, x1, y1);
                                        w += dw;
                                } while ((w >> 16) == pos1);
                        }
                }
                dst.releaseLine(dstY, dstLine);
        }
}
 
template<typename Pixel>
void SaI3xScaler<Pixel>::scale1x1to3x3(FrameSource& src,
        unsigned srcStartY, unsigned srcEndY, unsigned srcWidth,
        ScalerOutput<Pixel>& dst, unsigned dstStartY, unsigned dstEndY)
{
        scaleFixed<3, 3>(src, srcStartY, srcEndY, srcWidth, dst, dstStartY, dstEndY);
}
 
 
// Force template instantiation.
#if HAVE_16BPP
template class SaI3xScaler<uint16_t>;
#endif
#if HAVE_32BPP
template class SaI3xScaler<uint32_t>;
#endif
 
} // namespace openmsx