diff --git a/client/xBRZ/Changelog.txt b/client/xBRZ/Changelog.txt
new file mode 100644
index 000000000..4526b86b7
--- /dev/null
+++ b/client/xBRZ/Changelog.txt
@@ -0,0 +1,66 @@
+xBRZ 1.8 [2019-11-28]
+---------------------
+Consider ARGB outside area as transparent
+Fixed ARGB scaling issue on image borders
+
+
+xBRZ 1.7 [2019-07-04]
+---------------------
+Fixed asymmetric color distance
+New parameter: "Center direction bias"
+
+
+xBRZ 1.6 [2018-02-27]
+---------------------
+Added bilinear scaling
+Option to skip color buffer creation
+Updated license info
+
+
+xBRZ 1.5 [2017-08-07]
+---------------------
+Added RGB conversion routines
+
+
+xBRZ 1.4 [2015-07-25]
+---------------------
+Added 6xBRZ scaler
+Create color distance buffer lazily
+
+
+xBRZ 1.3 [2015-04-03]
+---------------------
+Improved ARGB performance by 15%
+Fixed alpha channel gradient bug
+
+
+xBRZ 1.2 [2014-11-21]
+---------------------
+Further improved performance by over 30%
+
+
+xBRZ 1.1 [2014-11-02]
+---------------------
+Support images with alpha channel
+Improved color analysis
+
+
+xBRZ 1.0 [2013-02-11]
+---------------------
+Fixed xBRZ scaler compiler issues for GCC
+
+
+xBRZ 0.2 [2012-12-11]
+---------------------
+Added 5xBRZ scaler
+Optimized xBRZ scaler performance by factor 3
+Further improved image quality of xBRZ scaler
+
+
+xBRZ 0.1 [2012-09-26]
+---------------------
+Initial release:
+- scale while preserving small image features
+- support multithreading
+- support 64-bit architectures
+- support processing image slices
diff --git a/client/xBRZ/License.txt b/client/xBRZ/License.txt
new file mode 100644
index 000000000..ea09e3734
--- /dev/null
+++ b/client/xBRZ/License.txt
@@ -0,0 +1,621 @@
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+GNU General Public License, you may choose any version ever published
+by the Free Software Foundation.
+
+ If the Program specifies that a proxy can decide which future
+versions of the GNU General Public License can be used, that proxy's
+public statement of acceptance of a version permanently authorizes you
+to choose that version for the Program.
+
+ Later license versions may give you additional or different
+permissions. However, no additional obligations are imposed on any
+author or copyright holder as a result of your choosing to follow a
+later version.
+
+ 15. Disclaimer of Warranty.
+
+ THERE IS NO WARRANTY FOR THE PROGRAM, TO THE EXTENT PERMITTED BY
+APPLICABLE LAW. EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT
+HOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY
+OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO,
+THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+PURPOSE. THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE PROGRAM
+IS WITH YOU. SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF
+ALL NECESSARY SERVICING, REPAIR OR CORRECTION.
+
+ 16. Limitation of Liability.
+
+ IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING
+WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MODIFIES AND/OR CONVEYS
+THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES, INCLUDING ANY
+GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE
+USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED TO LOSS OF
+DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD
+PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER PROGRAMS),
+EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF
+SUCH DAMAGES.
+
+ 17. Interpretation of Sections 15 and 16.
+
+ If the disclaimer of warranty and limitation of liability provided
+above cannot be given local legal effect according to their terms,
+reviewing courts shall apply local law that most closely approximates
+an absolute waiver of all civil liability in connection with the
+Program, unless a warranty or assumption of liability accompanies a
+copy of the Program in return for a fee.
+
+ END OF TERMS AND CONDITIONS
diff --git a/client/xBRZ/xbrz.cpp b/client/xBRZ/xbrz.cpp
new file mode 100644
index 000000000..a48ff83eb
--- /dev/null
+++ b/client/xBRZ/xbrz.cpp
@@ -0,0 +1,1356 @@
+// ****************************************************************************
+// * This file is part of the xBRZ project. It is distributed under *
+// * GNU General Public License: https://www.gnu.org/licenses/gpl-3.0 *
+// * Copyright (C) Zenju (zenju AT gmx DOT de) - All Rights Reserved *
+// * *
+// * Additionally and as a special exception, the author gives permission *
+// * to link the code of this program with the following libraries *
+// * (or with modified versions that use the same licenses), and distribute *
+// * linked combinations including the two: MAME, FreeFileSync, Snes9x, ePSXe *
+// * You must obey the GNU General Public License in all respects for all of *
+// * the code used other than MAME, FreeFileSync, Snes9x, ePSXe. *
+// * If you modify this file, you may extend this exception to your version *
+// * of the file, but you are not obligated to do so. If you do not wish to *
+// * do so, delete this exception statement from your version. *
+// ****************************************************************************
+
+#include "xbrz.h"
+#include
+#include
+#include
+#include //std::sqrt
+#include "xbrz_tools.h"
+
+using namespace xbrz;
+
+
+namespace
+{
+template inline
+uint32_t gradientRGB(uint32_t pixFront, uint32_t pixBack) //blend front color with opacity M / N over opaque background: https://en.wikipedia.org/wiki/Alpha_compositing#Alpha_blending
+{
+ static_assert(0 < M && M < N && N <= 1000);
+
+ auto calcColor = [](unsigned char colFront, unsigned char colBack) -> unsigned char { return (colFront * M + colBack * (N - M)) / N; };
+
+ return makePixel(calcColor(getRed (pixFront), getRed (pixBack)),
+ calcColor(getGreen(pixFront), getGreen(pixBack)),
+ calcColor(getBlue (pixFront), getBlue (pixBack)));
+}
+
+
+template inline
+uint32_t gradientARGB(uint32_t pixFront, uint32_t pixBack) //find intermediate color between two colors with alpha channels (=> NO alpha blending!!!)
+{
+ static_assert(0 < M && M < N && N <= 1000);
+
+ const unsigned int weightFront = getAlpha(pixFront) * M;
+ const unsigned int weightBack = getAlpha(pixBack) * (N - M);
+ const unsigned int weightSum = weightFront + weightBack;
+ if (weightSum == 0)
+ return 0;
+
+ auto calcColor = [=](unsigned char colFront, unsigned char colBack)
+ {
+ return static_cast((colFront * weightFront + colBack * weightBack) / weightSum);
+ };
+
+ return makePixel(static_cast(weightSum / N),
+ calcColor(getRed (pixFront), getRed (pixBack)),
+ calcColor(getGreen(pixFront), getGreen(pixBack)),
+ calcColor(getBlue (pixFront), getBlue (pixBack)));
+}
+
+
+//inline
+//double fastSqrt(double n)
+//{
+// __asm //speeds up xBRZ by about 9% compared to std::sqrt which internally uses the same assembler instructions but adds some "fluff"
+// {
+// fld n
+// fsqrt
+// }
+//}
+//
+
+
+#ifdef _MSC_VER
+ #define FORCE_INLINE __forceinline
+#elif defined __GNUC__
+ #define FORCE_INLINE __attribute__((always_inline)) inline
+#else
+ #define FORCE_INLINE inline
+#endif
+
+
+enum RotationDegree //clock-wise
+{
+ ROT_0,
+ ROT_90,
+ ROT_180,
+ ROT_270
+};
+
+//calculate input matrix coordinates after rotation at compile time
+template
+struct MatrixRotation;
+
+template
+struct MatrixRotation
+{
+ static const size_t I_old = I;
+ static const size_t J_old = J;
+};
+
+template //(i, j) = (row, col) indices, N = size of (square) matrix
+struct MatrixRotation
+{
+ static const size_t I_old = N - 1 - MatrixRotation(rotDeg - 1), I, J, N>::J_old; //old coordinates before rotation!
+ static const size_t J_old = MatrixRotation(rotDeg - 1), I, J, N>::I_old; //
+};
+
+
+template
+class OutputMatrix
+{
+public:
+ OutputMatrix(uint32_t* out, int outWidth) : //access matrix area, top-left at position "out" for image with given width
+ out_(out),
+ outWidth_(outWidth) {}
+
+ template
+ uint32_t& ref() const
+ {
+ static const size_t I_old = MatrixRotation::I_old;
+ static const size_t J_old = MatrixRotation::J_old;
+ return *(out_ + J_old + I_old * outWidth_);
+ }
+
+private:
+ uint32_t* out_;
+ const int outWidth_;
+};
+
+
+template inline
+T square(T value) { return value * value; }
+
+
+#if 0
+inline
+double distRGB(uint32_t pix1, uint32_t pix2)
+{
+ const double r_diff = static_cast(getRed (pix1)) - getRed (pix2);
+ const double g_diff = static_cast(getGreen(pix1)) - getGreen(pix2);
+ const double b_diff = static_cast(getBlue (pix1)) - getBlue (pix2);
+
+ //euklidean RGB distance
+ return std::sqrt(square(r_diff) + square(g_diff) + square(b_diff));
+}
+#endif
+
+
+inline
+double distYCbCr(uint32_t pix1, uint32_t pix2, double lumaWeight)
+{
+ //https://en.wikipedia.org/wiki/YCbCr#ITU-R_BT.601_conversion
+ //YCbCr conversion is a matrix multiplication => take advantage of linearity by subtracting first!
+ const int r_diff = static_cast(getRed (pix1)) - getRed (pix2); //we may delay division by 255 to after matrix multiplication
+ const int g_diff = static_cast(getGreen(pix1)) - getGreen(pix2); //
+ const int b_diff = static_cast(getBlue (pix1)) - getBlue (pix2); //substraction for int is noticeable faster than for double!
+
+ //const double k_b = 0.0722; //ITU-R BT.709 conversion
+ //const double k_r = 0.2126; //
+ const double k_b = 0.0593; //ITU-R BT.2020 conversion
+ const double k_r = 0.2627; //
+ const double k_g = 1 - k_b - k_r;
+
+ const double scale_b = 0.5 / (1 - k_b);
+ const double scale_r = 0.5 / (1 - k_r);
+
+ const double y = k_r * r_diff + k_g * g_diff + k_b * b_diff; //[!], analog YCbCr!
+ const double c_b = scale_b * (b_diff - y);
+ const double c_r = scale_r * (r_diff - y);
+
+ //we skip division by 255 to have similar range like other distance functions
+ return std::sqrt(square(lumaWeight * y) + square(c_b) + square(c_r));
+}
+
+
+inline
+double distYCbCrBuffered(uint32_t pix1, uint32_t pix2)
+{
+ //30% perf boost compared to plain distYCbCr()!
+ //consumes 64 MB memory; using double is only 2% faster, but takes 128 MB
+ static const std::vector diffToDist = []
+ {
+ std::vector tmp;
+
+ for (uint32_t i = 0; i < 256 * 256 * 256; ++i) //startup time: 114 ms on Intel Core i5 (four cores)
+ {
+ const int r_diff = static_cast(getByte<2>(i)) * 2;
+ const int g_diff = static_cast(getByte<1>(i)) * 2;
+ const int b_diff = static_cast(getByte<0>(i)) * 2;
+
+ const double k_b = 0.0593; //ITU-R BT.2020 conversion
+ const double k_r = 0.2627; //
+ const double k_g = 1 - k_b - k_r;
+
+ const double scale_b = 0.5 / (1 - k_b);
+ const double scale_r = 0.5 / (1 - k_r);
+
+ const double y = k_r * r_diff + k_g * g_diff + k_b * b_diff; //[!], analog YCbCr!
+ const double c_b = scale_b * (b_diff - y);
+ const double c_r = scale_r * (r_diff - y);
+
+ tmp.push_back(static_cast(std::sqrt(square(y) + square(c_b) + square(c_r))));
+ }
+ return tmp;
+ }();
+
+ //if (pix1 == pix2) -> 8% perf degradation!
+ // return 0;
+ //if (pix1 < pix2)
+ // std::swap(pix1, pix2); -> 30% perf degradation!!!
+
+ const int r_diff = static_cast(getRed (pix1)) - getRed (pix2);
+ const int g_diff = static_cast(getGreen(pix1)) - getGreen(pix2);
+ const int b_diff = static_cast(getBlue (pix1)) - getBlue (pix2);
+
+ const size_t index = (static_cast(r_diff / 2) << 16) | //slightly reduce precision (division by 2) to squeeze value into single byte
+ (static_cast(g_diff / 2) << 8) |
+ (static_cast(b_diff / 2));
+
+#if 0 //attention: the following calculation creates an asymmetric color distance!!! (e.g. r_diff=46 will be unpacked as 45, but r_diff=-46 unpacks to -47
+ const size_t index = (((r_diff + 0xFF) / 2) << 16) | //slightly reduce precision (division by 2) to squeeze value into single byte
+ (((g_diff + 0xFF) / 2) << 8) |
+ (( b_diff + 0xFF) / 2);
+#endif
+ return diffToDist[index];
+}
+
+
+#if defined _MSC_VER && !defined NDEBUG
+ const int debugPixelX = -1;
+ const int debugPixelY = 58;
+
+ thread_local bool breakIntoDebugger = false;
+#endif
+
+
+enum BlendType
+{
+ BLEND_NONE = 0,
+ BLEND_NORMAL, //a normal indication to blend
+ BLEND_DOMINANT, //a strong indication to blend
+ //attention: BlendType must fit into the value range of 2 bit!!!
+};
+
+struct BlendResult
+{
+ BlendType
+ /**/blend_f, blend_g,
+ /**/blend_j, blend_k;
+};
+
+
+struct Kernel_3x3
+{
+ uint32_t
+ a, b, c,
+ d, e, f,
+ g, h, i;
+};
+
+struct Kernel_4x4 //kernel for preprocessing step
+{
+ uint32_t
+ a, b, c, //
+ e, f, g, // support reinterpret_cast from Kernel_4x4 => Kernel_3x3
+ i, j, k, //
+ m, n, o,
+ d, h, l, p;
+};
+
+/* input kernel area naming convention:
+-----------------
+| A | B | C | D |
+|---|---|---|---|
+| E | F | G | H | evaluate the four corners between F, G, J, K
+|---|---|---|---| input pixel is at position F
+| I | J | K | L |
+|---|---|---|---|
+| M | N | O | P |
+-----------------
+*/
+template
+FORCE_INLINE //detect blend direction
+BlendResult preProcessCorners(const Kernel_4x4& ker, const xbrz::ScalerCfg& cfg) //result: F, G, J, K corners of "GradientType"
+{
+#if defined _MSC_VER && !defined NDEBUG
+ if (breakIntoDebugger)
+ __debugbreak(); //__asm int 3;
+#endif
+
+ BlendResult result = {};
+
+ if ((ker.f == ker.g &&
+ ker.j == ker.k) ||
+ (ker.f == ker.j &&
+ ker.g == ker.k))
+ return result;
+
+ auto dist = [&](uint32_t pix1, uint32_t pix2) { return ColorDistance::dist(pix1, pix2, cfg.luminanceWeight); };
+
+ double jg = dist(ker.i, ker.f) + dist(ker.f, ker.c) + dist(ker.n, ker.k) + dist(ker.k, ker.h) + cfg.centerDirectionBias * dist(ker.j, ker.g);
+ double fk = dist(ker.e, ker.j) + dist(ker.j, ker.o) + dist(ker.b, ker.g) + dist(ker.g, ker.l) + cfg.centerDirectionBias * dist(ker.f, ker.k);
+
+ if (jg < fk) //test sample: 70% of values max(jg, fk) / min(jg, fk) are between 1.1 and 3.7 with median being 1.8
+ {
+ const bool dominantGradient = cfg.dominantDirectionThreshold * jg < fk;
+ if (ker.f != ker.g && ker.f != ker.j)
+ result.blend_f = dominantGradient ? BLEND_DOMINANT : BLEND_NORMAL;
+
+ if (ker.k != ker.j && ker.k != ker.g)
+ result.blend_k = dominantGradient ? BLEND_DOMINANT : BLEND_NORMAL;
+ }
+ else if (fk < jg)
+ {
+ const bool dominantGradient = cfg.dominantDirectionThreshold * fk < jg;
+ if (ker.j != ker.f && ker.j != ker.k)
+ result.blend_j = dominantGradient ? BLEND_DOMINANT : BLEND_NORMAL;
+
+ if (ker.g != ker.f && ker.g != ker.k)
+ result.blend_g = dominantGradient ? BLEND_DOMINANT : BLEND_NORMAL;
+ }
+ return result;
+}
+
+#define DEF_GETTER(x) template uint32_t inline get_##x(const Kernel_3x3& ker) { return ker.x; }
+//we cannot and NEED NOT write "ker.##x" since ## concatenates preprocessor tokens but "." is not a token
+DEF_GETTER(a) DEF_GETTER(b) DEF_GETTER(c)
+DEF_GETTER(d) DEF_GETTER(e) DEF_GETTER(f)
+DEF_GETTER(g) DEF_GETTER(h) DEF_GETTER(i)
+#undef DEF_GETTER
+
+#define DEF_GETTER(x, y) template <> inline uint32_t get_##x(const Kernel_3x3& ker) { return ker.y; }
+DEF_GETTER(a, g) DEF_GETTER(b, d) DEF_GETTER(c, a)
+DEF_GETTER(d, h) DEF_GETTER(e, e) DEF_GETTER(f, b)
+DEF_GETTER(g, i) DEF_GETTER(h, f) DEF_GETTER(i, c)
+#undef DEF_GETTER
+
+#define DEF_GETTER(x, y) template <> inline uint32_t get_##x(const Kernel_3x3& ker) { return ker.y; }
+DEF_GETTER(a, i) DEF_GETTER(b, h) DEF_GETTER(c, g)
+DEF_GETTER(d, f) DEF_GETTER(e, e) DEF_GETTER(f, d)
+DEF_GETTER(g, c) DEF_GETTER(h, b) DEF_GETTER(i, a)
+#undef DEF_GETTER
+
+#define DEF_GETTER(x, y) template <> inline uint32_t get_##x(const Kernel_3x3& ker) { return ker.y; }
+DEF_GETTER(a, c) DEF_GETTER(b, f) DEF_GETTER(c, i)
+DEF_GETTER(d, b) DEF_GETTER(e, e) DEF_GETTER(f, h)
+DEF_GETTER(g, a) DEF_GETTER(h, d) DEF_GETTER(i, g)
+#undef DEF_GETTER
+
+
+//compress four blend types into a single byte
+//inline BlendType getTopL (unsigned char b) { return static_cast(0x3 & b); }
+inline BlendType getTopR (unsigned char b) { return static_cast(0x3 & (b >> 2)); }
+inline BlendType getBottomR(unsigned char b) { return static_cast(0x3 & (b >> 4)); }
+inline BlendType getBottomL(unsigned char b) { return static_cast(0x3 & (b >> 6)); }
+
+inline void clearAddTopL(unsigned char& b, BlendType bt) { b = static_cast(bt); }
+inline void addTopR (unsigned char& b, BlendType bt) { b |= (bt << 2); } //buffer is assumed to be initialized before preprocessing!
+inline void addBottomR (unsigned char& b, BlendType bt) { b |= (bt << 4); } //e.g. via clearAddTopL()
+inline void addBottomL (unsigned char& b, BlendType bt) { b |= (bt << 6); } //
+
+inline bool blendingNeeded(unsigned char b)
+{
+ static_assert(BLEND_NONE == 0);
+ return b != 0;
+}
+
+template inline
+unsigned char rotateBlendInfo(unsigned char b) { return b; }
+template <> inline unsigned char rotateBlendInfo(unsigned char b) { return ((b << 2) | (b >> 6)) & 0xff; }
+template <> inline unsigned char rotateBlendInfo(unsigned char b) { return ((b << 4) | (b >> 4)) & 0xff; }
+template <> inline unsigned char rotateBlendInfo(unsigned char b) { return ((b << 6) | (b >> 2)) & 0xff; }
+
+
+/* input kernel area naming convention:
+-------------
+| A | B | C |
+|---|---|---|
+| D | E | F | input pixel is at position E
+|---|---|---|
+| G | H | I |
+-------------
+*/
+template
+FORCE_INLINE //perf: quite worth it!
+void blendPixel(const Kernel_3x3& ker,
+ uint32_t* target, int trgWidth,
+ unsigned char blendInfo, //result of preprocessing all four corners of pixel "e"
+ const xbrz::ScalerCfg& cfg)
+{
+ //#define a get_a(ker)
+#define b get_b(ker)
+#define c get_c(ker)
+#define d get_d(ker)
+#define e get_e(ker)
+#define f get_f(ker)
+#define g get_g(ker)
+#define h get_h(ker)
+#define i get_i(ker)
+
+#if defined _MSC_VER && !defined NDEBUG
+ if (breakIntoDebugger)
+ __debugbreak(); //__asm int 3;
+#endif
+
+ const unsigned char blend = rotateBlendInfo(blendInfo);
+
+ if (getBottomR(blend) >= BLEND_NORMAL)
+ {
+ auto eq = [&](uint32_t pix1, uint32_t pix2) { return ColorDistance::dist(pix1, pix2, cfg.luminanceWeight) < cfg.equalColorTolerance; };
+ auto dist = [&](uint32_t pix1, uint32_t pix2) { return ColorDistance::dist(pix1, pix2, cfg.luminanceWeight); };
+
+ const bool doLineBlend = [&]() -> bool
+ {
+ if (getBottomR(blend) >= BLEND_DOMINANT)
+ return true;
+
+ //make sure there is no second blending in an adjacent rotation for this pixel: handles insular pixels, mario eyes
+ if (getTopR(blend) != BLEND_NONE && !eq(e, g)) //but support double-blending for 90° corners
+ return false;
+ if (getBottomL(blend) != BLEND_NONE && !eq(e, c))
+ return false;
+
+ //no full blending for L-shapes; blend corner only (handles "mario mushroom eyes")
+ if (!eq(e, i) && eq(g, h) && eq(h, i) && eq(i, f) && eq(f, c))
+ return false;
+
+ return true;
+ }();
+
+ const uint32_t px = dist(e, f) <= dist(e, h) ? f : h; //choose most similar color
+
+ OutputMatrix out(target, trgWidth);
+
+ if (doLineBlend)
+ {
+ const double fg = dist(f, g); //test sample: 70% of values max(fg, hc) / min(fg, hc) are between 1.1 and 3.7 with median being 1.9
+ const double hc = dist(h, c); //
+
+ const bool haveShallowLine = cfg.steepDirectionThreshold * fg <= hc && e != g && d != g;
+ const bool haveSteepLine = cfg.steepDirectionThreshold * hc <= fg && e != c && b != c;
+
+ if (haveShallowLine)
+ {
+ if (haveSteepLine)
+ Scaler::blendLineSteepAndShallow(px, out);
+ else
+ Scaler::blendLineShallow(px, out);
+ }
+ else
+ {
+ if (haveSteepLine)
+ Scaler::blendLineSteep(px, out);
+ else
+ Scaler::blendLineDiagonal(px, out);
+ }
+ }
+ else
+ Scaler::blendCorner(px, out);
+ }
+
+ //#undef a
+#undef b
+#undef c
+#undef d
+#undef e
+#undef f
+#undef g
+#undef h
+#undef i
+}
+
+
+class OobReaderTransparent
+{
+public:
+ OobReaderTransparent(const uint32_t* src, int srcWidth, int srcHeight, int y) :
+ s_m1(0 <= y - 1 && y - 1 < srcHeight ? src + srcWidth * (y - 1) : nullptr),
+ s_0 (0 <= y && y < srcHeight ? src + srcWidth * y : nullptr),
+ s_p1(0 <= y + 1 && y + 1 < srcHeight ? src + srcWidth * (y + 1) : nullptr),
+ s_p2(0 <= y + 2 && y + 2 < srcHeight ? src + srcWidth * (y + 2) : nullptr),
+ srcWidth_(srcWidth) {}
+
+ void readDhlp(Kernel_4x4& ker, int x) const //(x, y) is at kernel position F
+ {
+ [[likely]] if (const int x_p2 = x + 2; 0 <= x_p2 && x_p2 < srcWidth_)
+ {
+ ker.d = s_m1 ? s_m1[x_p2] : 0;
+ ker.h = s_0 ? s_0 [x_p2] : 0;
+ ker.l = s_p1 ? s_p1[x_p2] : 0;
+ ker.p = s_p2 ? s_p2[x_p2] : 0;
+ }
+ else
+ {
+ ker.d = 0;
+ ker.h = 0;
+ ker.l = 0;
+ ker.p = 0;
+ }
+ }
+
+private:
+ const uint32_t* const s_m1;
+ const uint32_t* const s_0;
+ const uint32_t* const s_p1;
+ const uint32_t* const s_p2;
+ const int srcWidth_;
+};
+
+
+class OobReaderDuplicate
+{
+public:
+ OobReaderDuplicate(const uint32_t* src, int srcWidth, int srcHeight, int y) :
+ s_m1(src + srcWidth * std::clamp(y - 1, 0, srcHeight - 1)),
+ s_0 (src + srcWidth * std::clamp(y, 0, srcHeight - 1)),
+ s_p1(src + srcWidth * std::clamp(y + 1, 0, srcHeight - 1)),
+ s_p2(src + srcWidth * std::clamp(y + 2, 0, srcHeight - 1)),
+ srcWidth_(srcWidth) {}
+
+ void readDhlp(Kernel_4x4& ker, int x) const //(x, y) is at kernel position F
+ {
+ const int x_p2 = std::clamp(x + 2, 0, srcWidth_ - 1);
+ ker.d = s_m1[x_p2];
+ ker.h = s_0 [x_p2];
+ ker.l = s_p1[x_p2];
+ ker.p = s_p2[x_p2];
+ }
+
+private:
+ const uint32_t* const s_m1;
+ const uint32_t* const s_0;
+ const uint32_t* const s_p1;
+ const uint32_t* const s_p2;
+ const int srcWidth_;
+};
+
+
+template //scaler policy: see "Scaler2x" reference implementation
+void scaleImage(const uint32_t* src, uint32_t* trg, int srcWidth, int srcHeight, const xbrz::ScalerCfg& cfg, int yFirst, int yLast)
+{
+ yFirst = std::max(yFirst, 0);
+ yLast = std::min(yLast, srcHeight);
+ if (yFirst >= yLast || srcWidth <= 0)
+ return;
+
+ const int trgWidth = srcWidth * Scaler::scale;
+
+ //(ab)use space of "sizeof(uint32_t) * srcWidth * Scaler::scale" at the end of the image as temporary
+ //buffer for "on the fly preprocessing" without risk of accidental overwriting before accessing
+ unsigned char* const preProcBuf = reinterpret_cast(trg + yLast * Scaler::scale * trgWidth) - srcWidth;
+
+ //initialize preprocessing buffer for first row of current stripe: detect upper left and right corner blending
+ //this cannot be optimized for adjacent processing stripes; we must not allow for a memory race condition!
+ {
+ const OobReader oobReader(src, srcWidth, srcHeight, yFirst - 1);
+
+ //initialize at position x = -1
+ Kernel_4x4 ker4 = {};
+ oobReader.readDhlp(ker4, -4); //hack: read a, e, i, m at x = -1
+ ker4.a = ker4.d;
+ ker4.e = ker4.h;
+ ker4.i = ker4.l;
+ ker4.m = ker4.p;
+
+ oobReader.readDhlp(ker4, -3);
+ ker4.b = ker4.d;
+ ker4.f = ker4.h;
+ ker4.j = ker4.l;
+ ker4.n = ker4.p;
+
+ oobReader.readDhlp(ker4, -2);
+ ker4.c = ker4.d;
+ ker4.g = ker4.h;
+ ker4.k = ker4.l;
+ ker4.o = ker4.p;
+
+ oobReader.readDhlp(ker4, -1);
+
+ {
+ const BlendResult res = preProcessCorners(ker4, cfg);
+ clearAddTopL(preProcBuf[0], res.blend_k); //set 1st known corner for (0, yFirst)
+ }
+
+ for (int x = 0; x < srcWidth; ++x)
+ {
+ ker4.a = ker4.b; //shift previous kernel to the left
+ ker4.e = ker4.f; // -----------------
+ ker4.i = ker4.j; // | A | B | C | D |
+ ker4.m = ker4.n; // |---|---|---|---|
+ /**/ // | E | F | G | H | (x, yFirst - 1) is at position F
+ ker4.b = ker4.c; // |---|---|---|---|
+ ker4.f = ker4.g; // | I | J | K | L |
+ ker4.j = ker4.k; // |---|---|---|---|
+ ker4.n = ker4.o; // | M | N | O | P |
+ /**/ // -----------------
+ ker4.c = ker4.d;
+ ker4.g = ker4.h;
+ ker4.k = ker4.l;
+ ker4.o = ker4.p;
+
+ oobReader.readDhlp(ker4, x);
+
+ /* preprocessing blend result:
+ ---------
+ | F | G | evaluate corner between F, G, J, K
+ |---+---| current input pixel is at position F
+ | J | K |
+ --------- */
+ const BlendResult res = preProcessCorners(ker4, cfg);
+ addTopR(preProcBuf[x], res.blend_j); //set 2nd known corner for (x, yFirst)
+
+ if (x + 1 < srcWidth)
+ clearAddTopL(preProcBuf[x + 1], res.blend_k); //set 1st known corner for (x + 1, yFirst)
+ }
+ }
+ //------------------------------------------------------------------------------------
+
+ for (int y = yFirst; y < yLast; ++y)
+ {
+ uint32_t* out = trg + Scaler::scale * y * trgWidth; //consider MT "striped" access
+
+ const OobReader oobReader(src, srcWidth, srcHeight, y);
+
+ //initialize at position x = -1
+ Kernel_4x4 ker4 = {};
+ oobReader.readDhlp(ker4, -4); //hack: read a, e, i, m at x = -1
+ ker4.a = ker4.d;
+ ker4.e = ker4.h;
+ ker4.i = ker4.l;
+ ker4.m = ker4.p;
+
+ oobReader.readDhlp(ker4, -3);
+ ker4.b = ker4.d;
+ ker4.f = ker4.h;
+ ker4.j = ker4.l;
+ ker4.n = ker4.p;
+
+ oobReader.readDhlp(ker4, -2);
+ ker4.c = ker4.d;
+ ker4.g = ker4.h;
+ ker4.k = ker4.l;
+ ker4.o = ker4.p;
+
+ oobReader.readDhlp(ker4, -1);
+
+ unsigned char blend_xy1 = 0; //corner blending for current (x, y + 1) position
+ {
+ const BlendResult res = preProcessCorners(ker4, cfg);
+ clearAddTopL(blend_xy1, res.blend_k); //set 1st known corner for (0, y + 1) and buffer for use on next column
+
+ addBottomL(preProcBuf[0], res.blend_g); //set 3rd known corner for (0, y)
+ }
+
+ for (int x = 0; x < srcWidth; ++x, out += Scaler::scale)
+ {
+#if defined _MSC_VER && !defined NDEBUG
+ breakIntoDebugger = debugPixelX == x && debugPixelY == y;
+#endif
+ ker4.a = ker4.b; //shift previous kernel to the left
+ ker4.e = ker4.f; // -----------------
+ ker4.i = ker4.j; // | A | B | C | D |
+ ker4.m = ker4.n; // |---|---|---|---|
+ /**/ // | E | F | G | H | (x, y) is at position F
+ ker4.b = ker4.c; // |---|---|---|---|
+ ker4.f = ker4.g; // | I | J | K | L |
+ ker4.j = ker4.k; // |---|---|---|---|
+ ker4.n = ker4.o; // | M | N | O | P |
+ /**/ // -----------------
+ ker4.c = ker4.d;
+ ker4.g = ker4.h;
+ ker4.k = ker4.l;
+ ker4.o = ker4.p;
+
+ oobReader.readDhlp(ker4, x);
+
+ //evaluate the four corners on bottom-right of current pixel
+ unsigned char blend_xy = preProcBuf[x]; //for current (x, y) position
+ {
+ /* preprocessing blend result:
+ ---------
+ | F | G | evaluate corner between F, G, J, K
+ |---+---| current input pixel is at position F
+ | J | K |
+ --------- */
+ const BlendResult res = preProcessCorners(ker4, cfg);
+ addBottomR(blend_xy, res.blend_f); //all four corners of (x, y) have been determined at this point due to processing sequence!
+
+ addTopR(blend_xy1, res.blend_j); //set 2nd known corner for (x, y + 1)
+ preProcBuf[x] = blend_xy1; //store on current buffer position for use on next row
+
+ [[likely]] if (x + 1 < srcWidth)
+ {
+ //blend_xy1 -> blend_x1y1
+ clearAddTopL(blend_xy1, res.blend_k); //set 1st known corner for (x + 1, y + 1) and buffer for use on next column
+
+ addBottomL(preProcBuf[x + 1], res.blend_g); //set 3rd known corner for (x + 1, y)
+ }
+ }
+
+ //fill block of size scale * scale with the given color
+ fillBlock(out, trgWidth * sizeof(uint32_t), ker4.f, Scaler::scale, Scaler::scale);
+ //place *after* preprocessing step, to not overwrite the results while processing the last pixel!
+
+ //blend all four corners of current pixel
+ if (blendingNeeded(blend_xy))
+ {
+ const auto& ker3 = reinterpret_cast(ker4); //"The Things We Do for Perf"
+ blendPixel(ker3, out, trgWidth, blend_xy, cfg);
+ blendPixel(ker3, out, trgWidth, blend_xy, cfg);
+ blendPixel(ker3, out, trgWidth, blend_xy, cfg);
+ blendPixel(ker3, out, trgWidth, blend_xy, cfg);
+ }
+ }
+ }
+}
+
+//------------------------------------------------------------------------------------
+
+template
+struct Scaler2x : public ColorGradient
+{
+ static const int scale = 2;
+
+ template //bring template function into scope for GCC
+ static void alphaGrad(uint32_t& pixBack, uint32_t pixFront) { ColorGradient::template alphaGrad(pixBack, pixFront); }
+
+
+ template
+ static void blendLineShallow(uint32_t col, OutputMatrix& out)
+ {
+ alphaGrad<1, 4>(out.template ref(), col);
+ alphaGrad<3, 4>(out.template ref(), col);
+ }
+
+ template
+ static void blendLineSteep(uint32_t col, OutputMatrix& out)
+ {
+ alphaGrad<1, 4>(out.template ref<0, scale - 1>(), col);
+ alphaGrad<3, 4>(out.template ref<1, scale - 1>(), col);
+ }
+
+ template
+ static void blendLineSteepAndShallow(uint32_t col, OutputMatrix& out)
+ {
+ alphaGrad<1, 4>(out.template ref<1, 0>(), col);
+ alphaGrad<1, 4>(out.template ref<0, 1>(), col);
+ alphaGrad<5, 6>(out.template ref<1, 1>(), col); //[!] fixes 7/8 used in xBR
+ }
+
+ template
+ static void blendLineDiagonal(uint32_t col, OutputMatrix& out)
+ {
+ alphaGrad<1, 2>(out.template ref<1, 1>(), col);
+ }
+
+ template
+ static void blendCorner(uint32_t col, OutputMatrix& out)
+ {
+ //model a round corner
+ alphaGrad<21, 100>(out.template ref<1, 1>(), col); //exact: 1 - pi/4 = 0.2146018366
+ }
+};
+
+
+template
+struct Scaler3x : public ColorGradient
+{
+ static const int scale = 3;
+
+ template //bring template function into scope for GCC
+ static void alphaGrad(uint32_t& pixBack, uint32_t pixFront) { ColorGradient::template alphaGrad(pixBack, pixFront); }
+
+
+ template
+ static void blendLineShallow(uint32_t col, OutputMatrix& out)
+ {
+ alphaGrad<1, 4>(out.template ref(), col);
+ alphaGrad<1, 4>(out.template ref(), col);
+
+ alphaGrad<3, 4>(out.template ref(), col);
+ out.template ref() = col;
+ }
+
+ template
+ static void blendLineSteep(uint32_t col, OutputMatrix& out)
+ {
+ alphaGrad<1, 4>(out.template ref<0, scale - 1>(), col);
+ alphaGrad<1, 4>(out.template ref<2, scale - 2>(), col);
+
+ alphaGrad<3, 4>(out.template ref<1, scale - 1>(), col);
+ out.template ref<2, scale - 1>() = col;
+ }
+
+ template
+ static void blendLineSteepAndShallow(uint32_t col, OutputMatrix& out)
+ {
+ alphaGrad<1, 4>(out.template ref<2, 0>(), col);
+ alphaGrad<1, 4>(out.template ref<0, 2>(), col);
+ alphaGrad<3, 4>(out.template ref<2, 1>(), col);
+ alphaGrad<3, 4>(out.template ref<1, 2>(), col);
+ out.template ref<2, 2>() = col;
+ }
+
+ template
+ static void blendLineDiagonal(uint32_t col, OutputMatrix& out)
+ {
+ alphaGrad<1, 8>(out.template ref<1, 2>(), col); //conflict with other rotations for this odd scale
+ alphaGrad<1, 8>(out.template ref<2, 1>(), col);
+ alphaGrad<7, 8>(out.template ref<2, 2>(), col); //
+ }
+
+ template
+ static void blendCorner(uint32_t col, OutputMatrix& out)
+ {
+ //model a round corner
+ alphaGrad<45, 100>(out.template ref<2, 2>(), col); //exact: 0.4545939598
+ //alphaGrad<7, 256>(out.template ref<2, 1>(), col); //0.02826017254 -> negligible + avoid conflicts with other rotations for this odd scale
+ //alphaGrad<7, 256>(out.template ref<1, 2>(), col); //0.02826017254
+ }
+};
+
+
+template
+struct Scaler4x : public ColorGradient
+{
+ static const int scale = 4;
+
+ template //bring template function into scope for GCC
+ static void alphaGrad(uint32_t& pixBack, uint32_t pixFront) { ColorGradient::template alphaGrad(pixBack, pixFront); }
+
+
+ template
+ static void blendLineShallow(uint32_t col, OutputMatrix& out)
+ {
+ alphaGrad<1, 4>(out.template ref(), col);
+ alphaGrad<1, 4>(out.template ref(), col);
+
+ alphaGrad<3, 4>(out.template ref(), col);
+ alphaGrad<3, 4>(out.template ref(), col);
+
+ out.template ref() = col;
+ out.template ref() = col;
+ }
+
+ template
+ static void blendLineSteep(uint32_t col, OutputMatrix& out)
+ {
+ alphaGrad<1, 4>(out.template ref<0, scale - 1>(), col);
+ alphaGrad<1, 4>(out.template ref<2, scale - 2>(), col);
+
+ alphaGrad<3, 4>(out.template ref<1, scale - 1>(), col);
+ alphaGrad<3, 4>(out.template ref<3, scale - 2>(), col);
+
+ out.template ref<2, scale - 1>() = col;
+ out.template ref<3, scale - 1>() = col;
+ }
+
+ template
+ static void blendLineSteepAndShallow(uint32_t col, OutputMatrix& out)
+ {
+ alphaGrad<3, 4>(out.template ref<3, 1>(), col);
+ alphaGrad<3, 4>(out.template ref<1, 3>(), col);
+ alphaGrad<1, 4>(out.template ref<3, 0>(), col);
+ alphaGrad<1, 4>(out.template ref<0, 3>(), col);
+
+ alphaGrad<1, 3>(out.template ref<2, 2>(), col); //[!] fixes 1/4 used in xBR
+
+ out.template ref<3, 3>() = col;
+ out.template ref<3, 2>() = col;
+ out.template ref<2, 3>() = col;
+ }
+
+ template
+ static void blendLineDiagonal(uint32_t col, OutputMatrix& out)
+ {
+ alphaGrad<1, 2>(out.template ref(), col);
+ alphaGrad<1, 2>(out.template ref(), col);
+ out.template ref() = col;
+ }
+
+ template
+ static void blendCorner(uint32_t col, OutputMatrix& out)
+ {
+ //model a round corner
+ alphaGrad<68, 100>(out.template ref<3, 3>(), col); //exact: 0.6848532563
+ alphaGrad< 9, 100>(out.template ref<3, 2>(), col); //0.08677704501
+ alphaGrad< 9, 100>(out.template ref<2, 3>(), col); //0.08677704501
+ }
+};
+
+
+template
+struct Scaler5x : public ColorGradient
+{
+ static const int scale = 5;
+
+ template //bring template function into scope for GCC
+ static void alphaGrad(uint32_t& pixBack, uint32_t pixFront) { ColorGradient::template alphaGrad(pixBack, pixFront); }
+
+
+ template
+ static void blendLineShallow(uint32_t col, OutputMatrix& out)
+ {
+ alphaGrad<1, 4>(out.template ref(), col);
+ alphaGrad<1, 4>(out.template ref(), col);
+ alphaGrad<1, 4>(out.template ref(), col);
+
+ alphaGrad<3, 4>(out.template ref(), col);
+ alphaGrad<3, 4>(out.template ref(), col);
+
+ out.template ref() = col;
+ out.template ref() = col;
+ out.template ref() = col;
+ out.template ref() = col;
+ }
+
+ template
+ static void blendLineSteep(uint32_t col, OutputMatrix& out)
+ {
+ alphaGrad<1, 4>(out.template ref<0, scale - 1>(), col);
+ alphaGrad<1, 4>(out.template ref<2, scale - 2>(), col);
+ alphaGrad<1, 4>(out.template ref<4, scale - 3>(), col);
+
+ alphaGrad<3, 4>(out.template ref<1, scale - 1>(), col);
+ alphaGrad<3, 4>(out.template ref<3, scale - 2>(), col);
+
+ out.template ref<2, scale - 1>() = col;
+ out.template ref<3, scale - 1>() = col;
+ out.template ref<4, scale - 1>() = col;
+ out.template ref<4, scale - 2>() = col;
+ }
+
+ template
+ static void blendLineSteepAndShallow(uint32_t col, OutputMatrix& out)
+ {
+ alphaGrad<1, 4>(out.template ref<0, scale - 1>(), col);
+ alphaGrad<1, 4>(out.template ref<2, scale - 2>(), col);
+ alphaGrad<3, 4>(out.template ref<1, scale - 1>(), col);
+
+ alphaGrad<1, 4>(out.template ref(), col);
+ alphaGrad<1, 4>(out.template ref(), col);
+ alphaGrad<3, 4>(out.template ref(), col);
+
+ alphaGrad<2, 3>(out.template ref<3, 3>(), col);
+
+ out.template ref<2, scale - 1>() = col;
+ out.template ref<3, scale - 1>() = col;
+ out.template ref<4, scale - 1>() = col;
+
+ out.template ref() = col;
+ out.template ref() = col;
+ }
+
+ template
+ static void blendLineDiagonal(uint32_t col, OutputMatrix& out)
+ {
+ alphaGrad<1, 8>(out.template ref(), col); //conflict with other rotations for this odd scale
+ alphaGrad<1, 8>(out.template ref(), col);
+ alphaGrad<1, 8>(out.template ref(), col); //
+
+ alphaGrad<7, 8>(out.template ref<4, 3>(), col);
+ alphaGrad<7, 8>(out.template ref<3, 4>(), col);
+
+ out.template ref<4, 4>() = col;
+ }
+
+ template
+ static void blendCorner(uint32_t col, OutputMatrix& out)
+ {
+ //model a round corner
+ alphaGrad<86, 100>(out.template ref<4, 4>(), col); //exact: 0.8631434088
+ alphaGrad<23, 100>(out.template ref<4, 3>(), col); //0.2306749731
+ alphaGrad<23, 100>(out.template ref<3, 4>(), col); //0.2306749731
+ //alphaGrad<1, 64>(out.template ref<4, 2>(), col); //0.01676812367 -> negligible + avoid conflicts with other rotations for this odd scale
+ //alphaGrad<1, 64>(out.template ref<2, 4>(), col); //0.01676812367
+ }
+};
+
+
+template
+struct Scaler6x : public ColorGradient
+{
+ static const int scale = 6;
+
+ template //bring template function into scope for GCC
+ static void alphaGrad(uint32_t& pixBack, uint32_t pixFront) { ColorGradient::template alphaGrad(pixBack, pixFront); }
+
+
+ template
+ static void blendLineShallow(uint32_t col, OutputMatrix& out)
+ {
+ alphaGrad<1, 4>(out.template ref(), col);
+ alphaGrad<1, 4>(out.template ref(), col);
+ alphaGrad<1, 4>(out.template ref(), col);
+
+ alphaGrad<3, 4>(out.template ref(), col);
+ alphaGrad<3, 4>(out.template ref(), col);
+ alphaGrad<3, 4>(out.template ref(), col);
+
+ out.template ref() = col;
+ out.template ref() = col;
+ out.template ref() = col;
+ out.template ref() = col;
+
+ out.template ref() = col;
+ out.template ref() = col;
+ }
+
+ template
+ static void blendLineSteep(uint32_t col, OutputMatrix& out)
+ {
+ alphaGrad<1, 4>(out.template ref<0, scale - 1>(), col);
+ alphaGrad<1, 4>(out.template ref<2, scale - 2>(), col);
+ alphaGrad<1, 4>(out.template ref<4, scale - 3>(), col);
+
+ alphaGrad<3, 4>(out.template ref<1, scale - 1>(), col);
+ alphaGrad<3, 4>(out.template ref<3, scale - 2>(), col);
+ alphaGrad<3, 4>(out.template ref<5, scale - 3>(), col);
+
+ out.template ref<2, scale - 1>() = col;
+ out.template ref<3, scale - 1>() = col;
+ out.template ref<4, scale - 1>() = col;
+ out.template ref<5, scale - 1>() = col;
+
+ out.template ref<4, scale - 2>() = col;
+ out.template ref<5, scale - 2>() = col;
+ }
+
+ template
+ static void blendLineSteepAndShallow(uint32_t col, OutputMatrix& out)
+ {
+ alphaGrad<1, 4>(out.template ref<0, scale - 1>(), col);
+ alphaGrad<1, 4>(out.template ref<2, scale - 2>(), col);
+ alphaGrad<3, 4>(out.template ref<1, scale - 1>(), col);
+ alphaGrad<3, 4>(out.template ref<3, scale - 2>(), col);
+
+ alphaGrad<1, 4>(out.template ref(), col);
+ alphaGrad<1, 4>(out.template ref(), col);
+ alphaGrad<3, 4>(out.template ref(), col);
+ alphaGrad<3, 4>(out.template ref(), col);
+
+ out.template ref<2, scale - 1>() = col;
+ out.template ref<3, scale - 1>() = col;
+ out.template ref<4, scale - 1>() = col;
+ out.template ref<5, scale - 1>() = col;
+
+ out.template ref<4, scale - 2>() = col;
+ out.template ref<5, scale - 2>() = col;
+
+ out.template ref() = col;
+ out.template ref() = col;
+ }
+
+ template
+ static void blendLineDiagonal(uint32_t col, OutputMatrix& out)
+ {
+ alphaGrad<1, 2>(out.template ref(), col);
+ alphaGrad<1, 2>(out.template ref(), col);
+ alphaGrad<1, 2>(out.template ref(), col);
+
+ out.template ref() = col;
+ out.template ref() = col;
+ out.template ref() = col;
+ }
+
+ template
+ static void blendCorner(uint32_t col, OutputMatrix& out)
+ {
+ //model a round corner
+ alphaGrad<97, 100>(out.template ref<5, 5>(), col); //exact: 0.9711013910
+ alphaGrad<42, 100>(out.template ref<4, 5>(), col); //0.4236372243
+ alphaGrad<42, 100>(out.template ref<5, 4>(), col); //0.4236372243
+ alphaGrad< 6, 100>(out.template ref<5, 3>(), col); //0.05652034508
+ alphaGrad< 6, 100>(out.template ref<3, 5>(), col); //0.05652034508
+ }
+};
+
+//------------------------------------------------------------------------------------
+
+struct ColorDistanceRGB
+{
+ static double dist(uint32_t pix1, uint32_t pix2, double luminanceWeight)
+ {
+ return distYCbCrBuffered(pix1, pix2);
+
+ //if (pix1 == pix2) //about 4% perf boost
+ // return 0;
+ //return distYCbCr(pix1, pix2, luminanceWeight);
+ }
+};
+
+struct ColorDistanceARGB
+{
+ static double dist(uint32_t pix1, uint32_t pix2, double luminanceWeight)
+ {
+ const double a1 = getAlpha(pix1) / 255.0 ;
+ const double a2 = getAlpha(pix2) / 255.0 ;
+ /*
+ Requirements for a color distance handling alpha channel: with a1, a2 in [0, 1]
+
+ 1. if a1 = a2, distance should be: a1 * distYCbCr()
+ 2. if a1 = 0, distance should be: a2 * distYCbCr(black, white) = a2 * 255
+ 3. if a1 = 1, ??? maybe: 255 * (1 - a2) + a2 * distYCbCr()
+ */
+
+ //return std::min(a1, a2) * distYCbCrBuffered(pix1, pix2) + 255 * abs(a1 - a2);
+ //=> following code is 15% faster:
+ const double d = distYCbCrBuffered(pix1, pix2);
+ if (a1 < a2)
+ return a1 * d + 255 * (a2 - a1);
+ else
+ return a2 * d + 255 * (a1 - a2);
+
+ //alternative? return std::sqrt(a1 * a2 * square(distYCbCrBuffered(pix1, pix2)) + square(255 * (a1 - a2)));
+ }
+};
+
+
+struct ColorDistanceUnbufferedARGB
+{
+ static double dist(uint32_t pix1, uint32_t pix2, double luminanceWeight)
+ {
+ const double a1 = getAlpha(pix1) / 255.0 ;
+ const double a2 = getAlpha(pix2) / 255.0 ;
+
+ const double d = distYCbCr(pix1, pix2, luminanceWeight);
+ if (a1 < a2)
+ return a1 * d + 255 * (a2 - a1);
+ else
+ return a2 * d + 255 * (a1 - a2);
+ }
+};
+
+
+struct ColorGradientRGB
+{
+ template
+ static void alphaGrad(uint32_t& pixBack, uint32_t pixFront)
+ {
+ pixBack = gradientRGB(pixFront, pixBack);
+ }
+};
+
+struct ColorGradientARGB
+{
+ template
+ static void alphaGrad(uint32_t& pixBack, uint32_t pixFront)
+ {
+ pixBack = gradientARGB(pixFront, pixBack);
+ }
+};
+}
+
+
+void xbrz::scale(size_t factor, const uint32_t* src, uint32_t* trg, int srcWidth, int srcHeight, ColorFormat colFmt, const xbrz::ScalerCfg& cfg, int yFirst, int yLast)
+{
+ if (factor == 1)
+ {
+ std::copy(src + yFirst * srcWidth, src + yLast * srcWidth, trg);
+ return;
+ }
+
+ static_assert(SCALE_FACTOR_MAX == 6);
+ switch (colFmt)
+ {
+ case ColorFormat::RGB:
+ switch (factor)
+ {
+ case 2:
+ return scaleImage, ColorDistanceRGB, OobReaderDuplicate>(src, trg, srcWidth, srcHeight, cfg, yFirst, yLast);
+ case 3:
+ return scaleImage, ColorDistanceRGB, OobReaderDuplicate>(src, trg, srcWidth, srcHeight, cfg, yFirst, yLast);
+ case 4:
+ return scaleImage, ColorDistanceRGB, OobReaderDuplicate>(src, trg, srcWidth, srcHeight, cfg, yFirst, yLast);
+ case 5:
+ return scaleImage, ColorDistanceRGB, OobReaderDuplicate>(src, trg, srcWidth, srcHeight, cfg, yFirst, yLast);
+ case 6:
+ return scaleImage, ColorDistanceRGB, OobReaderDuplicate>(src, trg, srcWidth, srcHeight, cfg, yFirst, yLast);
+ }
+ break;
+
+ case ColorFormat::ARGB:
+ switch (factor)
+ {
+ case 2:
+ return scaleImage, ColorDistanceARGB, OobReaderTransparent>(src, trg, srcWidth, srcHeight, cfg, yFirst, yLast);
+ case 3:
+ return scaleImage, ColorDistanceARGB, OobReaderTransparent>(src, trg, srcWidth, srcHeight, cfg, yFirst, yLast);
+ case 4:
+ return scaleImage, ColorDistanceARGB, OobReaderTransparent>(src, trg, srcWidth, srcHeight, cfg, yFirst, yLast);
+ case 5:
+ return scaleImage, ColorDistanceARGB, OobReaderTransparent>(src, trg, srcWidth, srcHeight, cfg, yFirst, yLast);
+ case 6:
+ return scaleImage, ColorDistanceARGB, OobReaderTransparent>(src, trg, srcWidth, srcHeight, cfg, yFirst, yLast);
+ }
+ break;
+
+ case ColorFormat::ARGB_UNBUFFERED:
+ switch (factor)
+ {
+ case 2:
+ return scaleImage, ColorDistanceUnbufferedARGB, OobReaderTransparent>(src, trg, srcWidth, srcHeight, cfg, yFirst, yLast);
+ case 3:
+ return scaleImage, ColorDistanceUnbufferedARGB, OobReaderTransparent>(src, trg, srcWidth, srcHeight, cfg, yFirst, yLast);
+ case 4:
+ return scaleImage, ColorDistanceUnbufferedARGB, OobReaderTransparent>(src, trg, srcWidth, srcHeight, cfg, yFirst, yLast);
+ case 5:
+ return scaleImage, ColorDistanceUnbufferedARGB, OobReaderTransparent>(src, trg, srcWidth, srcHeight, cfg, yFirst, yLast);
+ case 6:
+ return scaleImage, ColorDistanceUnbufferedARGB, OobReaderTransparent>(src, trg, srcWidth, srcHeight, cfg, yFirst, yLast);
+ }
+ break;
+ }
+ assert(false);
+}
+
+
+bool xbrz::equalColorTest(uint32_t col1, uint32_t col2, ColorFormat colFmt, double luminanceWeight, double equalColorTolerance)
+{
+ switch (colFmt)
+ {
+ case ColorFormat::RGB:
+ return ColorDistanceRGB::dist(col1, col2, luminanceWeight) < equalColorTolerance;
+ case ColorFormat::ARGB:
+ return ColorDistanceARGB::dist(col1, col2, luminanceWeight) < equalColorTolerance;
+ case ColorFormat::ARGB_UNBUFFERED:
+ return ColorDistanceUnbufferedARGB::dist(col1, col2, luminanceWeight) < equalColorTolerance;
+ }
+ assert(false);
+ return false;
+}
+
+
+void xbrz::bilinearScale(const uint32_t* src, int srcWidth, int srcHeight,
+ /**/ uint32_t* trg, int trgWidth, int trgHeight)
+{
+ bilinearScale(src, srcWidth, srcHeight, srcWidth * sizeof(uint32_t),
+ trg, trgWidth, trgHeight, trgWidth * sizeof(uint32_t),
+ 0, trgHeight, [](uint32_t pix) { return pix; });
+}
+
+
+void xbrz::nearestNeighborScale(const uint32_t* src, int srcWidth, int srcHeight,
+ /**/ uint32_t* trg, int trgWidth, int trgHeight)
+{
+ nearestNeighborScale(src, srcWidth, srcHeight, srcWidth * sizeof(uint32_t),
+ trg, trgWidth, trgHeight, trgWidth * sizeof(uint32_t),
+ 0, trgHeight, [](uint32_t pix) { return pix; });
+}
+
+
+#if 0
+//#include
+void bilinearScaleCpu(const uint32_t* src, int srcWidth, int srcHeight,
+ /**/ uint32_t* trg, int trgWidth, int trgHeight)
+{
+ const int TASK_GRANULARITY = 16;
+
+ concurrency::task_group tg;
+
+ for (int i = 0; i < trgHeight; i += TASK_GRANULARITY)
+ tg.run([=]
+ {
+ const int iLast = std::min(i + TASK_GRANULARITY, trgHeight);
+ xbrz::bilinearScale(src, srcWidth, srcHeight, srcWidth * sizeof(uint32_t),
+ trg, trgWidth, trgHeight, trgWidth * sizeof(uint32_t),
+ i, iLast, [](uint32_t pix) { return pix; });
+ });
+ tg.wait();
+}
+
+
+//Perf: AMP vs CPU: merely ~10% shorter runtime (scaling 1280x800 -> 1920x1080)
+//#include
+void bilinearScaleAmp(const uint32_t* src, int srcWidth, int srcHeight, //throw concurrency::runtime_exception
+ /**/ uint32_t* trg, int trgWidth, int trgHeight)
+{
+ //C++ AMP reference: https://msdn.microsoft.com/en-us/library/hh289390.aspx
+ //introduction to C++ AMP: https://msdn.microsoft.com/en-us/magazine/hh882446.aspx
+ using namespace concurrency;
+ //TODO: pitch
+
+ if (srcHeight <= 0 || srcWidth <= 0) return;
+
+ const float scaleX = static_cast(trgWidth ) / srcWidth;
+ const float scaleY = static_cast(trgHeight) / srcHeight;
+
+ array_view srcView(srcHeight, srcWidth, src);
+ array_view< uint32_t, 2> trgView(trgHeight, trgWidth, trg);
+ trgView.discard_data();
+
+ parallel_for_each(trgView.extent, [=](index<2> idx) restrict(amp) //throw ?
+ {
+ const int y = idx[0];
+ const int x = idx[1];
+ //Perf notes:
+ // -> float-based calculation is (almost) 2x as fas as double!
+ // -> no noticeable improvement via tiling: https://msdn.microsoft.com/en-us/magazine/hh882447.aspx
+ // -> no noticeable improvement with restrict(amp,cpu)
+ // -> iterating over y-axis only is significantly slower!
+ // -> pre-calculating x,y-dependent variables in a buffer + array_view<> is ~ 20 % slower!
+ const int y1 = srcHeight * y / trgHeight;
+ int y2 = y1 + 1;
+ if (y2 == srcHeight) --y2;
+
+ const float yy1 = y / scaleY - y1;
+ const float y2y = 1 - yy1;
+ //-------------------------------------
+ const int x1 = srcWidth * x / trgWidth;
+ int x2 = x1 + 1;
+ if (x2 == srcWidth) --x2;
+
+ const float xx1 = x / scaleX - x1;
+ const float x2x = 1 - xx1;
+ //-------------------------------------
+ const float x2xy2y = x2x * y2y;
+ const float xx1y2y = xx1 * y2y;
+ const float x2xyy1 = x2x * yy1;
+ const float xx1yy1 = xx1 * yy1;
+
+ auto interpolate = [=](int offset)
+ {
+ /*
+ https://en.wikipedia.org/wiki/Bilinear_interpolation
+ (c11(x2 - x) + c21(x - x1)) * (y2 - y ) +
+ (c12(x2 - x) + c22(x - x1)) * (y - y1)
+ */
+ const auto c11 = (srcView(y1, x1) >> (8 * offset)) & 0xff;
+ const auto c21 = (srcView(y1, x2) >> (8 * offset)) & 0xff;
+ const auto c12 = (srcView(y2, x1) >> (8 * offset)) & 0xff;
+ const auto c22 = (srcView(y2, x2) >> (8 * offset)) & 0xff;
+
+ return c11 * x2xy2y + c21 * xx1y2y +
+ c12 * x2xyy1 + c22 * xx1yy1;
+ };
+
+ const float bi = interpolate(0);
+ const float gi = interpolate(1);
+ const float ri = interpolate(2);
+ const float ai = interpolate(3);
+
+ const auto b = static_cast(bi + 0.5f);
+ const auto g = static_cast(gi + 0.5f);
+ const auto r = static_cast(ri + 0.5f);
+ const auto a = static_cast(ai + 0.5f);
+
+ trgView(y, x) = (a << 24) | (r << 16) | (g << 8) | b;
+ });
+ trgView.synchronize(); //throw ?
+}
+#endif
\ No newline at end of file
diff --git a/client/xBRZ/xbrz.h b/client/xBRZ/xbrz.h
new file mode 100644
index 000000000..d8f5d0fcb
--- /dev/null
+++ b/client/xBRZ/xbrz.h
@@ -0,0 +1,79 @@
+// ****************************************************************************
+// * This file is part of the xBRZ project. It is distributed under *
+// * GNU General Public License: https://www.gnu.org/licenses/gpl-3.0 *
+// * Copyright (C) Zenju (zenju AT gmx DOT de) - All Rights Reserved *
+// * *
+// * Additionally and as a special exception, the author gives permission *
+// * to link the code of this program with the following libraries *
+// * (or with modified versions that use the same licenses), and distribute *
+// * linked combinations including the two: MAME, FreeFileSync, Snes9x, ePSXe *
+// * You must obey the GNU General Public License in all respects for all of *
+// * the code used other than MAME, FreeFileSync, Snes9x, ePSXe. *
+// * If you modify this file, you may extend this exception to your version *
+// * of the file, but you are not obligated to do so. If you do not wish to *
+// * do so, delete this exception statement from your version. *
+// ****************************************************************************
+
+#ifndef XBRZ_HEADER_3847894708239054
+#define XBRZ_HEADER_3847894708239054
+
+#include //size_t
+#include //uint32_t
+#include
+#include "xbrz_config.h"
+
+
+namespace xbrz
+{
+/*
+-------------------------------------------------------------------------
+| xBRZ: "Scale by rules" - high quality image upscaling filter by Zenju |
+-------------------------------------------------------------------------
+using a modified approach of xBR:
+http://board.byuu.org/viewtopic.php?f=10&t=2248
+- new rule set preserving small image features
+- highly optimized for performance
+- support alpha channel
+- support multithreading
+- support 64-bit architectures
+- support processing image slices
+- support scaling up to 6xBRZ
+*/
+
+enum class ColorFormat //from high bits -> low bits, 8 bit per channel
+{
+ RGB, //8 bit for each red, green, blue, upper 8 bits unused
+ ARGB, //including alpha channel, BGRA byte order on little-endian machines
+ ARGB_UNBUFFERED, //like ARGB, but without the one-time buffer creation overhead (ca. 100 - 300 ms) at the expense of a slightly slower scaling time
+};
+
+const int SCALE_FACTOR_MAX = 6;
+
+/*
+-> map source (srcWidth * srcHeight) to target (scale * width x scale * height) image, optionally processing a half-open slice of rows [yFirst, yLast) only
+-> if your emulator changes only a few image slices during each cycle (e.g. DOSBox) then there's no need to run xBRZ on the complete image:
+ Just make sure you enlarge the source image slice by 2 rows on top and 2 on bottom (this is the additional range the xBRZ algorithm is using during analysis)
+ CAVEAT: If there are multiple changed slices, make sure they do not overlap after adding these additional rows in order to avoid a memory race condition
+ in the target image data if you are using multiple threads for processing each enlarged slice!
+
+THREAD-SAFETY: - parts of the same image may be scaled by multiple threads as long as the [yFirst, yLast) ranges do not overlap!
+ - there is a minor inefficiency for the first row of a slice, so avoid processing single rows only; suggestion: process at least 8-16 rows
+*/
+void scale(size_t factor, //valid range: 2 - SCALE_FACTOR_MAX
+ const uint32_t* src, uint32_t* trg, int srcWidth, int srcHeight,
+ ColorFormat colFmt,
+ const ScalerCfg& cfg = ScalerCfg(),
+ int yFirst = 0, int yLast = std::numeric_limits::max()); //slice of source image
+
+void bilinearScale(const uint32_t* src, int srcWidth, int srcHeight,
+ /**/ uint32_t* trg, int trgWidth, int trgHeight);
+
+void nearestNeighborScale(const uint32_t* src, int srcWidth, int srcHeight,
+ /**/ uint32_t* trg, int trgWidth, int trgHeight);
+
+
+//parameter tuning
+bool equalColorTest(uint32_t col1, uint32_t col2, ColorFormat colFmt, double luminanceWeight, double equalColorTolerance);
+}
+
+#endif
diff --git a/client/xBRZ/xbrz_config.h b/client/xBRZ/xbrz_config.h
new file mode 100644
index 000000000..a5b1739e2
--- /dev/null
+++ b/client/xBRZ/xbrz_config.h
@@ -0,0 +1,35 @@
+// ****************************************************************************
+// * This file is part of the xBRZ project. It is distributed under *
+// * GNU General Public License: https://www.gnu.org/licenses/gpl-3.0 *
+// * Copyright (C) Zenju (zenju AT gmx DOT de) - All Rights Reserved *
+// * *
+// * Additionally and as a special exception, the author gives permission *
+// * to link the code of this program with the following libraries *
+// * (or with modified versions that use the same licenses), and distribute *
+// * linked combinations including the two: MAME, FreeFileSync, Snes9x, ePSXe *
+// * You must obey the GNU General Public License in all respects for all of *
+// * the code used other than MAME, FreeFileSync, Snes9x, ePSXe. *
+// * If you modify this file, you may extend this exception to your version *
+// * of the file, but you are not obligated to do so. If you do not wish to *
+// * do so, delete this exception statement from your version. *
+// ****************************************************************************
+
+#ifndef XBRZ_CONFIG_HEADER_284578425345
+#define XBRZ_CONFIG_HEADER_284578425345
+
+//do NOT include any headers here! used by xBRZ_dll!!!
+
+namespace xbrz
+{
+struct ScalerCfg
+{
+ double luminanceWeight = 1;
+ double equalColorTolerance = 30;
+ double centerDirectionBias = 4;
+ double dominantDirectionThreshold = 3.6;
+ double steepDirectionThreshold = 2.2;
+ double newTestAttribute = 0; //unused; test new parameters
+};
+}
+
+#endif
diff --git a/client/xBRZ/xbrz_tools.h b/client/xBRZ/xbrz_tools.h
new file mode 100644
index 000000000..5f9a10072
--- /dev/null
+++ b/client/xBRZ/xbrz_tools.h
@@ -0,0 +1,266 @@
+// ****************************************************************************
+// * This file is part of the xBRZ project. It is distributed under *
+// * GNU General Public License: https://www.gnu.org/licenses/gpl-3.0 *
+// * Copyright (C) Zenju (zenju AT gmx DOT de) - All Rights Reserved *
+// * *
+// * Additionally and as a special exception, the author gives permission *
+// * to link the code of this program with the following libraries *
+// * (or with modified versions that use the same licenses), and distribute *
+// * linked combinations including the two: MAME, FreeFileSync, Snes9x, ePSXe *
+// * You must obey the GNU General Public License in all respects for all of *
+// * the code used other than MAME, FreeFileSync, Snes9x, ePSXe. *
+// * If you modify this file, you may extend this exception to your version *
+// * of the file, but you are not obligated to do so. If you do not wish to *
+// * do so, delete this exception statement from your version. *
+// ****************************************************************************
+
+#ifndef XBRZ_TOOLS_H_825480175091875
+#define XBRZ_TOOLS_H_825480175091875
+
+#include
+#include
+#include
+
+
+namespace xbrz
+{
+template inline
+unsigned char getByte(uint32_t val) { return static_cast((val >> (8 * N)) & 0xff); }
+
+inline unsigned char getAlpha(uint32_t pix) { return getByte<3>(pix); }
+inline unsigned char getRed (uint32_t pix) { return getByte<2>(pix); }
+inline unsigned char getGreen(uint32_t pix) { return getByte<1>(pix); }
+inline unsigned char getBlue (uint32_t pix) { return getByte<0>(pix); }
+
+inline uint32_t makePixel(unsigned char a, unsigned char r, unsigned char g, unsigned char b) { return (a << 24) | (r << 16) | (g << 8) | b; }
+inline uint32_t makePixel( unsigned char r, unsigned char g, unsigned char b) { return (r << 16) | (g << 8) | b; }
+
+inline uint32_t rgb555to888(uint16_t pix) { return ((pix & 0x7C00) << 9) | ((pix & 0x03E0) << 6) | ((pix & 0x001F) << 3); }
+inline uint32_t rgb565to888(uint16_t pix) { return ((pix & 0xF800) << 8) | ((pix & 0x07E0) << 5) | ((pix & 0x001F) << 3); }
+
+inline uint16_t rgb888to555(uint32_t pix) { return static_cast(((pix & 0xF80000) >> 9) | ((pix & 0x00F800) >> 6) | ((pix & 0x0000F8) >> 3)); }
+inline uint16_t rgb888to565(uint32_t pix) { return static_cast(((pix & 0xF80000) >> 8) | ((pix & 0x00FC00) >> 5) | ((pix & 0x0000F8) >> 3)); }
+
+
+template inline
+Pix* byteAdvance(Pix* ptr, int bytes)
+{
+ using PixNonConst = typename std::remove_cv::type;
+ using PixByte = typename std::conditional::value, char, const char>::type;
+
+ static_assert(std::is_integral::value, "Pix* is expected to be cast-able to char*");
+
+ return reinterpret_cast(reinterpret_cast(ptr) + bytes);
+}
+
+
+//fill block with the given color
+template inline
+void fillBlock(Pix* trg, int pitch /*[bytes]*/, Pix col, int blockWidth, int blockHeight)
+{
+ //for (int y = 0; y < blockHeight; ++y, trg = byteAdvance(trg, pitch))
+ // std::fill(trg, trg + blockWidth, col);
+
+ for (int y = 0; y < blockHeight; ++y, trg = byteAdvance(trg, pitch))
+ for (int x = 0; x < blockWidth; ++x)
+ trg[x] = col;
+}
+
+
+//nearest-neighbor (going over target image - slow for upscaling, since source is read multiple times missing out on cache! Fast for similar image sizes!)
+template
+void nearestNeighborScale(const PixSrc* src, int srcWidth, int srcHeight, int srcPitch /*[bytes]*/,
+ /**/ PixTrg* trg, int trgWidth, int trgHeight, int trgPitch /*[bytes]*/,
+ int yFirst, int yLast, PixConverter pixCvrt /*convert PixSrc to PixTrg*/)
+{
+ static_assert(std::is_integral::value, "PixSrc* is expected to be cast-able to char*");
+ static_assert(std::is_integral::value, "PixTrg* is expected to be cast-able to char*");
+
+ static_assert(std::is_same::value, "PixConverter returning wrong pixel format");
+
+ if (srcPitch < srcWidth * static_cast(sizeof(PixSrc)) ||
+ trgPitch < trgWidth * static_cast(sizeof(PixTrg)))
+ {
+ assert(false);
+ return;
+ }
+
+ yFirst = std::max(yFirst, 0);
+ yLast = std::min(yLast, trgHeight);
+ if (yFirst >= yLast || srcHeight <= 0 || srcWidth <= 0) return;
+
+ for (int y = yFirst; y < yLast; ++y)
+ {
+ const int ySrc = srcHeight * y / trgHeight;
+ const PixSrc* const srcLine = byteAdvance(src, ySrc * srcPitch);
+ PixTrg* const trgLine = byteAdvance(trg, y * trgPitch);
+
+ for (int x = 0; x < trgWidth; ++x)
+ {
+ const int xSrc = srcWidth * x / trgWidth;
+ trgLine[x] = pixCvrt(srcLine[xSrc]);
+ }
+ }
+}
+
+
+//nearest-neighbor (going over source image - fast for upscaling, since source is read only once
+template
+void nearestNeighborScaleOverSource(const PixSrc* src, int srcWidth, int srcHeight, int srcPitch /*[bytes]*/,
+ /**/ PixTrg* trg, int trgWidth, int trgHeight, int trgPitch /*[bytes]*/,
+ int yFirst, int yLast, PixConverter pixCvrt /*convert PixSrc to PixTrg*/)
+{
+ static_assert(std::is_integral::value, "PixSrc* is expected to be cast-able to char*");
+ static_assert(std::is_integral::value, "PixTrg* is expected to be cast-able to char*");
+
+ static_assert(std::is_same::value, "PixConverter returning wrong pixel format");
+
+ if (srcPitch < srcWidth * static_cast(sizeof(PixSrc)) ||
+ trgPitch < trgWidth * static_cast(sizeof(PixTrg)))
+ {
+ assert(false);
+ return;
+ }
+
+ yFirst = std::max(yFirst, 0);
+ yLast = std::min(yLast, srcHeight);
+ if (yFirst >= yLast || trgWidth <= 0 || trgHeight <= 0) return;
+
+ for (int y = yFirst; y < yLast; ++y)
+ {
+ //mathematically: ySrc = floor(srcHeight * yTrg / trgHeight)
+ // => search for integers in: [ySrc, ySrc + 1) * trgHeight / srcHeight
+
+ //keep within for loop to support MT input slices!
+ const int yTrgFirst = ( y * trgHeight + srcHeight - 1) / srcHeight; //=ceil(y * trgHeight / srcHeight)
+ const int yTrgLast = ((y + 1) * trgHeight + srcHeight - 1) / srcHeight; //=ceil(((y + 1) * trgHeight) / srcHeight)
+ const int blockHeight = yTrgLast - yTrgFirst;
+
+ if (blockHeight > 0)
+ {
+ const PixSrc* srcLine = byteAdvance(src, y * srcPitch);
+ /**/ PixTrg* trgLine = byteAdvance(trg, yTrgFirst * trgPitch);
+ int xTrgFirst = 0;
+
+ for (int x = 0; x < srcWidth; ++x)
+ {
+ const int xTrgLast = ((x + 1) * trgWidth + srcWidth - 1) / srcWidth;
+ const int blockWidth = xTrgLast - xTrgFirst;
+ if (blockWidth > 0)
+ {
+ xTrgFirst = xTrgLast;
+
+ const auto trgPix = pixCvrt(srcLine[x]);
+ fillBlock(trgLine, trgPitch, trgPix, blockWidth, blockHeight);
+ trgLine += blockWidth;
+ }
+ }
+ }
+ }
+}
+
+
+template
+void bilinearScale(const uint32_t* src, int srcWidth, int srcHeight, int srcPitch,
+ /**/ PixTrg* trg, int trgWidth, int trgHeight, int trgPitch,
+ int yFirst, int yLast, PixConverter pixCvrt /*convert uint32_t to PixTrg*/)
+{
+ static_assert(std::is_integral::value, "PixTrg* is expected to be cast-able to char*");
+ static_assert(std::is_same::value, "PixConverter returning wrong pixel format");
+
+ if (srcPitch < srcWidth * static_cast(sizeof(uint32_t)) ||
+ trgPitch < trgWidth * static_cast(sizeof(PixTrg)))
+ {
+ assert(false);
+ return;
+ }
+
+ yFirst = std::max(yFirst, 0);
+ yLast = std::min(yLast, trgHeight);
+ if (yFirst >= yLast || srcHeight <= 0 || srcWidth <= 0) return;
+
+ const double scaleX = static_cast(trgWidth ) / srcWidth;
+ const double scaleY = static_cast(trgHeight) / srcHeight;
+
+ //perf notes:
+ // -> double-based calculation is (slightly) faster than float
+ // -> pre-calculation gives significant boost; std::vector<> memory allocation is negligible!
+ struct CoeffsX
+ {
+ int x1 = 0;
+ int x2 = 0;
+ double xx1 = 0;
+ double x2x = 0;
+ };
+ std::vector buf(trgWidth);
+ for (int x = 0; x < trgWidth; ++x)
+ {
+ const int x1 = srcWidth * x / trgWidth;
+ int x2 = x1 + 1;
+ if (x2 == srcWidth) --x2;
+
+ const double xx1 = x / scaleX - x1;
+ const double x2x = 1 - xx1;
+
+ buf[x] = { x1, x2, xx1, x2x };
+ }
+
+ for (int y = yFirst; y < yLast; ++y)
+ {
+ const int y1 = srcHeight * y / trgHeight;
+ int y2 = y1 + 1;
+ if (y2 == srcHeight) --y2;
+
+ const double yy1 = y / scaleY - y1;
+ const double y2y = 1 - yy1;
+
+ const uint32_t* const srcLine = byteAdvance(src, y1 * srcPitch);
+ const uint32_t* const srcLineNext = byteAdvance(src, y2 * srcPitch);
+ PixTrg* const trgLine = byteAdvance(trg, y * trgPitch);
+
+ for (int x = 0; x < trgWidth; ++x)
+ {
+ //perf: do NOT "simplify" the variable layout without measurement!
+ const int x1 = buf[x].x1;
+ const int x2 = buf[x].x2;
+ const double xx1 = buf[x].xx1;
+ const double x2x = buf[x].x2x;
+
+ const double x2xy2y = x2x * y2y;
+ const double xx1y2y = xx1 * y2y;
+ const double x2xyy1 = x2x * yy1;
+ const double xx1yy1 = xx1 * yy1;
+
+ auto interpolate = [=](int offset)
+ {
+ /* https://en.wikipedia.org/wiki/Bilinear_interpolation
+ (c11(x2 - x) + c21(x - x1)) * (y2 - y ) +
+ (c12(x2 - x) + c22(x - x1)) * (y - y1) */
+ const auto c11 = (srcLine [x1] >> (8 * offset)) & 0xff;
+ const auto c21 = (srcLine [x2] >> (8 * offset)) & 0xff;
+ const auto c12 = (srcLineNext[x1] >> (8 * offset)) & 0xff;
+ const auto c22 = (srcLineNext[x2] >> (8 * offset)) & 0xff;
+
+ return c11 * x2xy2y + c21 * xx1y2y +
+ c12 * x2xyy1 + c22 * xx1yy1;
+ };
+
+ const double bi = interpolate(0);
+ const double gi = interpolate(1);
+ const double ri = interpolate(2);
+ const double ai = interpolate(3);
+
+ const auto b = static_cast(bi + 0.5);
+ const auto g = static_cast(gi + 0.5);
+ const auto r = static_cast(ri + 0.5);
+ const auto a = static_cast(ai + 0.5);
+
+ const uint32_t trgPix = (a << 24) | (r << 16) | (g << 8) | b;
+
+ trgLine[x] = pixCvrt(trgPix);
+ }
+ }
+}
+}
+
+#endif //XBRZ_TOOLS_H_825480175091875