--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mupdf-source/thirdparty/lcms2/src/cmswtpnt.c	Mon Sep 15 11:43:07 2025 +0200
@@ -0,0 +1,356 @@
+//---------------------------------------------------------------------------------
+//
+//  Little Color Management System
+//  Copyright (c) 1998-2023 Marti Maria Saguer
+//
+// Permission is hereby granted, free of charge, to any person obtaining
+// a copy of this software and associated documentation files (the "Software"),
+// to deal in the Software without restriction, including without limitation
+// the rights to use, copy, modify, merge, publish, distribute, sublicense,
+// and/or sell copies of the Software, and to permit persons to whom the Software
+// is furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO
+// THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+// LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+// OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+//
+//---------------------------------------------------------------------------------
+//
+
+#include "lcms2_internal.h"
+
+
+// D50 - Widely used
+const cmsCIEXYZ* CMSEXPORT cmsD50_XYZ(cmsContext ContextID)
+{
+    static cmsCIEXYZ D50XYZ = {cmsD50X, cmsD50Y, cmsD50Z};
+    cmsUNUSED_PARAMETER(ContextID);
+
+    return &D50XYZ;
+}
+
+const cmsCIExyY* CMSEXPORT cmsD50_xyY(cmsContext ContextID)
+{
+    static cmsCIExyY D50xyY;
+
+    cmsXYZ2xyY(ContextID, &D50xyY, cmsD50_XYZ(ContextID));
+
+    return &D50xyY;
+}
+
+// Obtains WhitePoint from Temperature
+cmsBool  CMSEXPORT cmsWhitePointFromTemp(cmsContext ContextID, cmsCIExyY* WhitePoint, cmsFloat64Number TempK)
+{
+    cmsFloat64Number x, y;
+    cmsFloat64Number T, T2, T3;
+    // cmsFloat64Number M1, M2;
+    cmsUNUSED_PARAMETER(ContextID);
+
+    _cmsAssert(WhitePoint != NULL);
+
+    T = TempK;
+    T2 = T*T;            // Square
+    T3 = T2*T;           // Cube
+
+    // For correlated color temperature (T) between 4000K and 7000K:
+
+    if (T >= 4000. && T <= 7000.)
+    {
+        x = -4.6070*(1E9/T3) + 2.9678*(1E6/T2) + 0.09911*(1E3/T) + 0.244063;
+    }
+    else
+        // or for correlated color temperature (T) between 7000K and 25000K:
+
+        if (T > 7000.0 && T <= 25000.0)
+        {
+            x = -2.0064*(1E9/T3) + 1.9018*(1E6/T2) + 0.24748*(1E3/T) + 0.237040;
+        }
+        else {
+            cmsSignalError(0, cmsERROR_RANGE, "cmsWhitePointFromTemp: invalid temp");
+            return FALSE;
+        }
+
+    // Obtain y(x)
+    y = -3.000*(x*x) + 2.870*x - 0.275;
+
+    // wave factors (not used, but here for futures extensions)
+
+    // M1 = (-1.3515 - 1.7703*x + 5.9114 *y)/(0.0241 + 0.2562*x - 0.7341*y);
+    // M2 = (0.0300 - 31.4424*x + 30.0717*y)/(0.0241 + 0.2562*x - 0.7341*y);
+
+    WhitePoint -> x = x;
+    WhitePoint -> y = y;
+    WhitePoint -> Y = 1.0;
+
+    return TRUE;
+}
+
+
+
+typedef struct {
+
+    cmsFloat64Number mirek;  // temp (in microreciprocal kelvin)
+    cmsFloat64Number ut;     // u coord of intersection w/ blackbody locus
+    cmsFloat64Number vt;     // v coord of intersection w/ blackbody locus
+    cmsFloat64Number tt;     // slope of ISOTEMPERATURE. line
+
+    } ISOTEMPERATURE;
+
+static const ISOTEMPERATURE isotempdata[] = {
+//  {Mirek, Ut,       Vt,      Tt      }
+    {0,     0.18006,  0.26352,  -0.24341},
+    {10,    0.18066,  0.26589,  -0.25479},
+    {20,    0.18133,  0.26846,  -0.26876},
+    {30,    0.18208,  0.27119,  -0.28539},
+    {40,    0.18293,  0.27407,  -0.30470},
+    {50,    0.18388,  0.27709,  -0.32675},
+    {60,    0.18494,  0.28021,  -0.35156},
+    {70,    0.18611,  0.28342,  -0.37915},
+    {80,    0.18740,  0.28668,  -0.40955},
+    {90,    0.18880,  0.28997,  -0.44278},
+    {100,   0.19032,  0.29326,  -0.47888},
+    {125,   0.19462,  0.30141,  -0.58204},
+    {150,   0.19962,  0.30921,  -0.70471},
+    {175,   0.20525,  0.31647,  -0.84901},
+    {200,   0.21142,  0.32312,  -1.0182 },
+    {225,   0.21807,  0.32909,  -1.2168 },
+    {250,   0.22511,  0.33439,  -1.4512 },
+    {275,   0.23247,  0.33904,  -1.7298 },
+    {300,   0.24010,  0.34308,  -2.0637 },
+    {325,   0.24702,  0.34655,  -2.4681 },
+    {350,   0.25591,  0.34951,  -2.9641 },
+    {375,   0.26400,  0.35200,  -3.5814 },
+    {400,   0.27218,  0.35407,  -4.3633 },
+    {425,   0.28039,  0.35577,  -5.3762 },
+    {450,   0.28863,  0.35714,  -6.7262 },
+    {475,   0.29685,  0.35823,  -8.5955 },
+    {500,   0.30505,  0.35907,  -11.324 },
+    {525,   0.31320,  0.35968,  -15.628 },
+    {550,   0.32129,  0.36011,  -23.325 },
+    {575,   0.32931,  0.36038,  -40.770 },
+    {600,   0.33724,  0.36051,  -116.45  }
+};
+
+#define NISO sizeof(isotempdata)/sizeof(ISOTEMPERATURE)
+
+
+// Robertson's method
+cmsBool  CMSEXPORT cmsTempFromWhitePoint(cmsContext ContextID, cmsFloat64Number* TempK, const cmsCIExyY* WhitePoint)
+{
+    cmsUInt32Number j;
+    cmsFloat64Number us,vs;
+    cmsFloat64Number uj,vj,tj,di,dj,mi,mj;
+    cmsFloat64Number xs, ys;
+    cmsUNUSED_PARAMETER(ContextID);
+
+    _cmsAssert(WhitePoint != NULL);
+    _cmsAssert(TempK != NULL);
+
+    di = mi = 0;
+    xs = WhitePoint -> x;
+    ys = WhitePoint -> y;
+
+    // convert (x,y) to CIE 1960 (u,WhitePoint)
+
+    us = (2*xs) / (-xs + 6*ys + 1.5);
+    vs = (3*ys) / (-xs + 6*ys + 1.5);
+
+
+    for (j=0; j < NISO; j++) {
+
+        uj = isotempdata[j].ut;
+        vj = isotempdata[j].vt;
+        tj = isotempdata[j].tt;
+        mj = isotempdata[j].mirek;
+
+        dj = ((vs - vj) - tj * (us - uj)) / sqrt(1.0 + tj * tj);
+
+        if ((j != 0) && (di/dj < 0.0)) {
+
+            // Found a match
+            *TempK = 1000000.0 / (mi + (di / (di - dj)) * (mj - mi));
+            return TRUE;
+        }
+
+        di = dj;
+        mi = mj;
+    }
+
+    // Not found
+    return FALSE;
+}
+
+
+// Compute chromatic adaptation matrix using Chad as cone matrix
+
+static
+cmsBool ComputeChromaticAdaptation(cmsContext ContextID, cmsMAT3* Conversion,
+                                const cmsCIEXYZ* SourceWhitePoint,
+                                const cmsCIEXYZ* DestWhitePoint,
+                                const cmsMAT3* Chad)
+
+{
+
+    cmsMAT3 Chad_Inv;
+    cmsVEC3 ConeSourceXYZ, ConeSourceRGB;
+    cmsVEC3 ConeDestXYZ, ConeDestRGB;
+    cmsMAT3 Cone, Tmp;
+
+
+    Tmp = *Chad;
+    if (!_cmsMAT3inverse(ContextID, &Tmp, &Chad_Inv)) return FALSE;
+
+    _cmsVEC3init(ContextID, &ConeSourceXYZ, SourceWhitePoint -> X,
+                             SourceWhitePoint -> Y,
+                             SourceWhitePoint -> Z);
+
+    _cmsVEC3init(ContextID, &ConeDestXYZ,   DestWhitePoint -> X,
+                             DestWhitePoint -> Y,
+                             DestWhitePoint -> Z);
+
+    _cmsMAT3eval(ContextID, &ConeSourceRGB, Chad, &ConeSourceXYZ);
+    _cmsMAT3eval(ContextID, &ConeDestRGB,   Chad, &ConeDestXYZ);
+
+    if ((fabs(ConeSourceRGB.n[0]) < MATRIX_DET_TOLERANCE) ||
+        (fabs(ConeSourceRGB.n[1]) < MATRIX_DET_TOLERANCE) ||
+        (fabs(ConeSourceRGB.n[2]) < MATRIX_DET_TOLERANCE)) return FALSE;
+
+    // Build matrix
+    _cmsVEC3init(ContextID, &Cone.v[0], ConeDestRGB.n[0]/ConeSourceRGB.n[0],    0.0,  0.0);
+    _cmsVEC3init(ContextID, &Cone.v[1], 0.0,   ConeDestRGB.n[1]/ConeSourceRGB.n[1],   0.0);
+    _cmsVEC3init(ContextID, &Cone.v[2], 0.0,   0.0,   ConeDestRGB.n[2]/ConeSourceRGB.n[2]);
+
+    // Normalize
+    _cmsMAT3per(ContextID, &Tmp, &Cone, Chad);
+    _cmsMAT3per(ContextID, Conversion, &Chad_Inv, &Tmp);
+
+    return TRUE;
+}
+
+// Returns the final chrmatic adaptation from illuminant FromIll to Illuminant ToIll
+// The cone matrix can be specified in ConeMatrix. If NULL, Bradford is assumed
+cmsBool  _cmsAdaptationMatrix(cmsContext ContextID, cmsMAT3* r, const cmsMAT3* ConeMatrix, const cmsCIEXYZ* FromIll, const cmsCIEXYZ* ToIll)
+{
+    cmsMAT3 LamRigg   = {{ // Bradford matrix
+        {{  0.8951,  0.2664, -0.1614 }},
+        {{ -0.7502,  1.7135,  0.0367 }},
+        {{  0.0389, -0.0685,  1.0296 }}
+    }};
+
+    if (ConeMatrix == NULL)
+        ConeMatrix = &LamRigg;
+
+    return ComputeChromaticAdaptation(ContextID, r, FromIll, ToIll, ConeMatrix);
+}
+
+// Same as anterior, but assuming D50 destination. White point is given in xyY
+static
+cmsBool _cmsAdaptMatrixToD50(cmsContext ContextID, cmsMAT3* r, const cmsCIExyY* SourceWhitePt)
+{
+    cmsCIEXYZ Dn;
+    cmsMAT3 Bradford;
+    cmsMAT3 Tmp;
+
+    cmsxyY2XYZ(ContextID, &Dn, SourceWhitePt);
+
+    if (!_cmsAdaptationMatrix(ContextID, &Bradford, NULL, &Dn, cmsD50_XYZ(ContextID))) return FALSE;
+
+    Tmp = *r;
+    _cmsMAT3per(ContextID, r, &Bradford, &Tmp);
+
+    return TRUE;
+}
+
+// Build a White point, primary chromas transfer matrix from RGB to CIE XYZ
+// This is just an approximation, I am not handling all the non-linear
+// aspects of the RGB to XYZ process, and assuming that the gamma correction
+// has transitive property in the transformation chain.
+//
+// the algorithm:
+//
+//            - First I build the absolute conversion matrix using
+//              primaries in XYZ. This matrix is next inverted
+//            - Then I eval the source white point across this matrix
+//              obtaining the coefficients of the transformation
+//            - Then, I apply these coefficients to the original matrix
+//
+cmsBool _cmsBuildRGB2XYZtransferMatrix(cmsContext ContextID, cmsMAT3* r, const cmsCIExyY* WhitePt, const cmsCIExyYTRIPLE* Primrs)
+{
+    cmsVEC3 WhitePoint, Coef;
+    cmsMAT3 Result, Primaries;
+    cmsFloat64Number xn, yn;
+    cmsFloat64Number xr, yr;
+    cmsFloat64Number xg, yg;
+    cmsFloat64Number xb, yb;
+
+    xn = WhitePt -> x;
+    yn = WhitePt -> y;
+    xr = Primrs -> Red.x;
+    yr = Primrs -> Red.y;
+    xg = Primrs -> Green.x;
+    yg = Primrs -> Green.y;
+    xb = Primrs -> Blue.x;
+    yb = Primrs -> Blue.y;
+
+    // Build Primaries matrix
+    _cmsVEC3init(ContextID, &Primaries.v[0], xr,        xg,         xb);
+    _cmsVEC3init(ContextID, &Primaries.v[1], yr,        yg,         yb);
+    _cmsVEC3init(ContextID, &Primaries.v[2], (1-xr-yr), (1-xg-yg),  (1-xb-yb));
+
+
+    // Result = Primaries ^ (-1) inverse matrix
+    if (!_cmsMAT3inverse(ContextID, &Primaries, &Result))
+        return FALSE;
+
+
+    _cmsVEC3init(ContextID, &WhitePoint, xn/yn, 1.0, (1.0-xn-yn)/yn);
+
+    // Across inverse primaries ...
+    _cmsMAT3eval(ContextID, &Coef, &Result, &WhitePoint);
+
+    // Give us the Coefs, then I build transformation matrix
+    _cmsVEC3init(ContextID, &r -> v[0], Coef.n[VX]*xr,          Coef.n[VY]*xg,          Coef.n[VZ]*xb);
+    _cmsVEC3init(ContextID, &r -> v[1], Coef.n[VX]*yr,          Coef.n[VY]*yg,          Coef.n[VZ]*yb);
+    _cmsVEC3init(ContextID, &r -> v[2], Coef.n[VX]*(1.0-xr-yr), Coef.n[VY]*(1.0-xg-yg), Coef.n[VZ]*(1.0-xb-yb));
+
+
+    return _cmsAdaptMatrixToD50(ContextID, r, WhitePt);
+
+}
+
+
+// Adapts a color to a given illuminant. Original color is expected to have
+// a SourceWhitePt white point.
+cmsBool CMSEXPORT cmsAdaptToIlluminant(cmsContext ContextID, cmsCIEXYZ* Result,
+                                       const cmsCIEXYZ* SourceWhitePt,
+                                       const cmsCIEXYZ* Illuminant,
+                                       const cmsCIEXYZ* Value)
+{
+    cmsMAT3 Bradford;
+    cmsVEC3 In, Out;
+
+    _cmsAssert(Result != NULL);
+    _cmsAssert(SourceWhitePt != NULL);
+    _cmsAssert(Illuminant != NULL);
+    _cmsAssert(Value != NULL);
+
+    if (!_cmsAdaptationMatrix(ContextID, &Bradford, NULL, SourceWhitePt, Illuminant)) return FALSE;
+
+    _cmsVEC3init(ContextID, &In, Value -> X, Value -> Y, Value -> Z);
+    _cmsMAT3eval(ContextID, &Out, &Bradford, &In);
+
+    Result -> X = Out.n[0];
+    Result -> Y = Out.n[1];
+    Result -> Z = Out.n[2];
+
+    return TRUE;
+}
+
+