--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mupdf-source/source/fitz/color-lcms.c	Mon Sep 15 11:43:07 2025 +0200
@@ -0,0 +1,534 @@
+// Copyright (C) 2004-2024 Artifex Software, Inc.
+//
+// This file is part of MuPDF.
+//
+// MuPDF is free software: you can redistribute it and/or modify it under the
+// terms of the GNU Affero General Public License as published by the Free
+// Software Foundation, either version 3 of the License, or (at your option)
+// any later version.
+//
+// MuPDF is distributed in the hope that it will be useful, but WITHOUT ANY
+// WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+// FOR A PARTICULAR PURPOSE. See the GNU Affero General Public License for more
+// details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with MuPDF. If not, see <https://www.gnu.org/licenses/agpl-3.0.en.html>
+//
+// Alternative licensing terms are available from the licensor.
+// For commercial licensing, see <https://www.artifex.com/> or contact
+// Artifex Software, Inc., 39 Mesa Street, Suite 108A, San Francisco,
+// CA 94129, USA, for further information.
+
+#include "mupdf/fitz.h"
+
+#include "color-imp.h"
+
+#include <string.h>
+
+#if FZ_ENABLE_ICC
+
+#ifndef LCMS_USE_FLOAT
+#define LCMS_USE_FLOAT 0
+#endif
+
+#ifdef HAVE_LCMS2MT
+#define GLOINIT cmsContext glo = ctx->colorspace->icc_instance;
+#define GLO glo,
+#include "lcms2mt.h"
+#include "lcms2mt_plugin.h"
+#else
+#define GLOINIT
+#define GLO
+#include "lcms2.h"
+#endif
+
+static void fz_premultiply_row(fz_context *ctx, int n, int c, int w, unsigned char *s)
+{
+	unsigned char a;
+	int k;
+	int n1 = n-1;
+	for (; w > 0; w--)
+	{
+		a = s[n1];
+		if (a == 0)
+			memset(s, 0, c);
+		else if (a != 255)
+			for (k = 0; k < c; k++)
+				s[k] = fz_mul255(s[k], a);
+		s += n;
+	}
+}
+
+static void fz_premultiply_row_0or1(fz_context *ctx, int n, int c, int w, unsigned char *s)
+{
+	unsigned char a;
+	int n1 = n-1;
+	for (; w > 0; w--)
+	{
+		a = s[n1];
+		if (a == 0)
+			memset(s, 0, c);
+		s += n;
+	}
+}
+
+/* Returns 0 for all the alphas being 0, 1 for them being 0 or 255, 2 otherwise. */
+static int fz_unmultiply_row(fz_context *ctx, int n, int c, int w, unsigned char *s, const unsigned char *in)
+{
+	int a, inva;
+	int k;
+	int n1 = n-1;
+	for (; w > 0; w--)
+	{
+		a = in[n1];
+		if (a != 0)
+			goto nonzero;
+		for (k = 0; k < c; k++)
+			s[k] = 0;
+		for (;k < n1; k++)
+			s[k] = in[k];
+		s[n1] = 0;
+		s += n;
+		in += n;
+	}
+	return 0;
+	for (; w > 0; w--)
+	{
+		a = in[n1];
+nonzero:
+		if (a != 0 && a != 255)
+			goto varying;
+		k = 0;
+		if (a == 0)
+			for (; k < c; k++)
+				s[k] = 0;
+		for (;k < n; k++)
+			s[k] = in[k];
+		s += n;
+		in += n;
+	}
+	return 1;
+	for (; w > 0; w--)
+	{
+		a = in[n1];
+varying:
+		if (a == 0)
+		{
+			for (k = 0; k < c; k++)
+				s[k] = 0;
+			for (;k < n1; k++)
+				s[k] = in[k];
+			s[k] = 0;
+		}
+		else if (a == 255)
+		{
+			memcpy(s, in, n);
+		}
+		else
+		{
+			inva = 255 * 256 / a;
+			for (k = 0; k < c; k++)
+				s[k] = (in[k] * inva) >> 8;
+			for (;k < n1; k++)
+				s[k] = in[k];
+			s[n1] = a;
+		}
+		s += n;
+		in += n;
+	}
+	return 2;
+}
+
+struct fz_icc_link
+{
+	fz_storable storable;
+	void *handle;
+};
+
+#ifdef HAVE_LCMS2MT
+
+static void fz_lcms_log_error(cmsContext id, cmsUInt32Number error_code, const char *error_text)
+{
+	fz_context *ctx = (fz_context *)cmsGetContextUserData(id);
+	fz_warn(ctx, "lcms: %s.", error_text);
+}
+
+static void *fz_lcms_malloc(cmsContext id, unsigned int size)
+{
+	fz_context *ctx = cmsGetContextUserData(id);
+	return Memento_label(fz_malloc_no_throw(ctx, size), "lcms");
+}
+
+static void *fz_lcms_realloc(cmsContext id, void *ptr, unsigned int size)
+{
+	fz_context *ctx = cmsGetContextUserData(id);
+	return Memento_label(fz_realloc_no_throw(ctx, ptr, size), "lcms");
+}
+
+static void fz_lcms_free(cmsContext id, void *ptr)
+{
+	fz_context *ctx = cmsGetContextUserData(id);
+	fz_free(ctx, ptr);
+}
+
+static cmsPluginMemHandler fz_lcms_memhandler =
+{
+	{
+		cmsPluginMagicNumber,
+		LCMS_VERSION,
+		cmsPluginMemHandlerSig,
+		NULL
+	},
+	fz_lcms_malloc,
+	fz_lcms_free,
+	fz_lcms_realloc,
+	NULL,
+	NULL,
+	NULL,
+};
+
+void fz_new_icc_context(fz_context *ctx)
+{
+	cmsContext glo = cmsCreateContext(&fz_lcms_memhandler, ctx);
+	if (!glo)
+		fz_throw(ctx, FZ_ERROR_LIBRARY, "cmsCreateContext failed");
+	ctx->colorspace->icc_instance = glo;
+	cmsSetLogErrorHandler(glo, fz_lcms_log_error);
+}
+
+void fz_drop_icc_context(fz_context *ctx)
+{
+	cmsContext glo = ctx->colorspace->icc_instance;
+	if (glo)
+		cmsDeleteContext(glo);
+	ctx->colorspace->icc_instance = NULL;
+}
+
+#else
+
+static fz_context *glo_ctx = NULL;
+
+static void fz_lcms_log_error(cmsContext id, cmsUInt32Number error_code, const char *error_text)
+{
+	fz_warn(glo_ctx, "lcms: %s.", error_text);
+}
+
+void fz_new_icc_context(fz_context *ctx)
+{
+	if (glo_ctx != NULL)
+		fz_throw(ctx, FZ_ERROR_ARGUMENT, "Stock LCMS2 library cannot be used in multiple contexts!");
+	glo_ctx = ctx;
+	cmsSetLogErrorHandler(fz_lcms_log_error);
+}
+
+void fz_drop_icc_context(fz_context *ctx)
+{
+	glo_ctx = NULL;
+	cmsSetLogErrorHandler(NULL);
+}
+
+#endif
+
+fz_icc_profile *fz_new_icc_profile(fz_context *ctx, unsigned char *data, size_t size)
+{
+	GLOINIT
+	fz_icc_profile *profile;
+	profile = cmsOpenProfileFromMem(GLO data, (cmsUInt32Number)size);
+	if (profile == NULL)
+		fz_throw(ctx, FZ_ERROR_FORMAT, "cmsOpenProfileFromMem failed");
+	return profile;
+}
+
+int fz_icc_profile_is_lab(fz_context *ctx, fz_icc_profile *profile)
+{
+	GLOINIT
+	if (profile == NULL)
+		return 0;
+	return (cmsGetColorSpace(GLO profile) == cmsSigLabData);
+}
+
+void fz_drop_icc_profile(fz_context *ctx, fz_icc_profile *profile)
+{
+	GLOINIT
+	if (profile)
+		cmsCloseProfile(GLO profile);
+}
+
+void fz_icc_profile_name(fz_context *ctx, fz_icc_profile *profile, char *name, size_t size)
+{
+	GLOINIT
+	cmsMLU *descMLU;
+	descMLU = cmsReadTag(GLO profile, cmsSigProfileDescriptionTag);
+	name[0] = 0;
+	cmsMLUgetASCII(GLO descMLU, "en", "US", name, (cmsUInt32Number)size);
+}
+
+int fz_icc_profile_components(fz_context *ctx, fz_icc_profile *profile)
+{
+	GLOINIT
+	return cmsChannelsOf(GLO cmsGetColorSpace(GLO profile));
+}
+
+void fz_drop_icc_link_imp(fz_context *ctx, fz_storable *storable)
+{
+	GLOINIT
+	fz_icc_link *link = (fz_icc_link*)storable;
+	cmsDeleteTransform(GLO link->handle);
+	fz_free(ctx, link);
+}
+
+void fz_drop_icc_link(fz_context *ctx, fz_icc_link *link)
+{
+	fz_drop_storable(ctx, &link->storable);
+}
+
+fz_icc_link *
+fz_new_icc_link(fz_context *ctx,
+	fz_colorspace *src, int src_extras,
+	fz_colorspace *dst, int dst_extras,
+	fz_colorspace *prf,
+	fz_color_params rend,
+	int format,
+	int copy_spots,
+	int premult)
+{
+	GLOINIT
+	cmsHPROFILE src_pro = src->u.icc.profile;
+	cmsHPROFILE dst_pro = dst->u.icc.profile;
+	cmsHPROFILE prf_pro = prf ? prf->u.icc.profile : NULL;
+	int src_bgr = (src->type == FZ_COLORSPACE_BGR);
+	int dst_bgr = (dst->type == FZ_COLORSPACE_BGR);
+	cmsColorSpaceSignature src_cs, dst_cs;
+	cmsUInt32Number src_fmt, dst_fmt;
+	cmsUInt32Number flags;
+	cmsHTRANSFORM transform;
+	fz_icc_link *link;
+
+	flags = cmsFLAGS_LOWRESPRECALC;
+
+	src_cs = cmsGetColorSpace(GLO src_pro);
+	src_fmt = COLORSPACE_SH(_cmsLCMScolorSpace(GLO src_cs));
+	src_fmt |= CHANNELS_SH(cmsChannelsOf(GLO src_cs));
+	src_fmt |= DOSWAP_SH(src_bgr);
+	src_fmt |= SWAPFIRST_SH(src_bgr && (src_extras > 0));
+#if LCMS_USE_FLOAT
+	src_fmt |= BYTES_SH(format ? 4 : 1);
+	src_fmt |= FLOAT_SH(format ? 1 : 0)
+#else
+	src_fmt |= BYTES_SH(format ? 2 : 1);
+#endif
+	src_fmt |= EXTRA_SH(src_extras);
+
+	dst_cs = cmsGetColorSpace(GLO dst_pro);
+	dst_fmt = COLORSPACE_SH(_cmsLCMScolorSpace(GLO dst_cs));
+	dst_fmt |= CHANNELS_SH(cmsChannelsOf(GLO dst_cs));
+	dst_fmt |= DOSWAP_SH(dst_bgr);
+	dst_fmt |= SWAPFIRST_SH(dst_bgr && (dst_extras > 0));
+#if LCMS_USE_FLOAT
+	dst_fmt |= BYTES_SH(format ? 4 : 1);
+	dst_fmt |= FLOAT_SH(format ? 1 : 0);
+#else
+	dst_fmt |= BYTES_SH(format ? 2 : 1);
+#endif
+	dst_fmt |= EXTRA_SH(dst_extras);
+
+	/* flags */
+	if (rend.bp)
+		flags |= cmsFLAGS_BLACKPOINTCOMPENSATION;
+
+	if (copy_spots)
+		flags |= cmsFLAGS_COPY_ALPHA;
+
+#ifdef cmsFLAGS_PREMULT
+	if (premult)
+		flags |= cmsFLAGS_PREMULT;
+#endif
+
+	if (prf_pro == NULL)
+	{
+		transform = cmsCreateTransform(GLO src_pro, src_fmt, dst_pro, dst_fmt, rend.ri, flags);
+		if (!transform)
+			fz_throw(ctx, FZ_ERROR_LIBRARY, "cmsCreateTransform(%s,%s) failed", src->name, dst->name);
+	}
+
+	/* LCMS proof creation links don't work properly with the Ghent test files. Handle this in a brutish manner. */
+	else if (src_pro == prf_pro)
+	{
+		transform = cmsCreateTransform(GLO src_pro, src_fmt, dst_pro, dst_fmt, INTENT_RELATIVE_COLORIMETRIC, flags);
+		if (!transform)
+			fz_throw(ctx, FZ_ERROR_LIBRARY, "cmsCreateTransform(src=proof,dst) failed");
+	}
+	else if (prf_pro == dst_pro)
+	{
+		transform = cmsCreateTransform(GLO src_pro, src_fmt, prf_pro, dst_fmt, rend.ri, flags);
+		if (!transform)
+			fz_throw(ctx, FZ_ERROR_LIBRARY, "cmsCreateTransform(src,proof=dst) failed");
+	}
+	else
+	{
+		cmsHPROFILE src_to_prf_pro;
+		cmsHTRANSFORM src_to_prf_link;
+		cmsColorSpaceSignature prf_cs;
+		cmsUInt32Number prf_fmt;
+		cmsHPROFILE hProfiles[3];
+
+		prf_cs = cmsGetColorSpace(GLO prf_pro);
+		prf_fmt = COLORSPACE_SH(_cmsLCMScolorSpace(GLO prf_cs));
+		prf_fmt |= CHANNELS_SH(cmsChannelsOf(GLO prf_cs));
+#if LCMS_USE_FLOAT
+		prf_fmt |= BYTES_SH(format ? 4 : 1);
+		prf_fmt |= FLOAT_SH(format ? 1 : 0);
+#else
+		prf_fmt |= BYTES_SH(format ? 2 : 1);
+#endif
+
+		src_to_prf_link = cmsCreateTransform(GLO src_pro, src_fmt, prf_pro, prf_fmt, rend.ri, flags);
+		if (!src_to_prf_link)
+			fz_throw(ctx, FZ_ERROR_LIBRARY, "cmsCreateTransform(src,proof) failed");
+		src_to_prf_pro = cmsTransform2DeviceLink(GLO src_to_prf_link, 3.4, flags);
+		cmsDeleteTransform(GLO src_to_prf_link);
+		if (!src_to_prf_pro)
+			fz_throw(ctx, FZ_ERROR_LIBRARY, "cmsTransform2DeviceLink(src,proof) failed");
+
+		hProfiles[0] = src_to_prf_pro;
+		hProfiles[1] = prf_pro;
+		hProfiles[2] = dst_pro;
+		transform = cmsCreateMultiprofileTransform(GLO hProfiles, 3, src_fmt, dst_fmt, INTENT_RELATIVE_COLORIMETRIC, flags);
+		cmsCloseProfile(GLO src_to_prf_pro);
+		if (!transform)
+			fz_throw(ctx, FZ_ERROR_LIBRARY, "cmsCreateMultiprofileTransform(src,proof,dst) failed");
+	}
+
+	fz_try(ctx)
+	{
+		link = fz_malloc_struct(ctx, fz_icc_link);
+		FZ_INIT_STORABLE(link, 1, fz_drop_icc_link_imp);
+		link->handle = transform;
+	}
+	fz_catch(ctx)
+	{
+		cmsDeleteTransform(GLO transform);
+		fz_rethrow(ctx);
+	}
+	return link;
+}
+
+void
+fz_icc_transform_color(fz_context *ctx, fz_color_converter *cc, const float *src, float *dst)
+{
+	GLOINIT
+#if LCMS_USE_FLOAT
+	cmsDoTransform(GLO cc->link->handle, src, dst, 1);
+#else
+	uint16_t s16[FZ_MAX_COLORS];
+	uint16_t d16[FZ_MAX_COLORS];
+	int dn = cc->dst_n;
+	int i;
+	if (cc->ss->type == FZ_COLORSPACE_LAB)
+	{
+		s16[0] = src[0] * 655.35f;
+		s16[1] = (src[1] + 128) * 257;
+		s16[2] = (src[2] + 128) * 257;
+	}
+	else
+	{
+		int sn = cc->ss->n;
+		for (i = 0; i < sn; ++i)
+			s16[i] = src[i] * 65535;
+	}
+	cmsDoTransform(GLO cc->link->handle, s16, d16, 1);
+	for (i = 0; i < dn; ++i)
+		dst[i] = d16[i] / 65535.0f;
+#endif
+}
+
+void
+fz_icc_transform_pixmap(fz_context *ctx, fz_icc_link *link, const fz_pixmap *src, fz_pixmap *dst, int copy_spots)
+{
+	GLOINIT
+	int cmm_num_src, cmm_num_dst, cmm_extras;
+	unsigned char *inputpos, *outputpos, *buffer;
+	int ss = src->stride;
+	int ds = dst->stride;
+	int sw = src->w;
+	int dw = dst->w;
+	int sn = src->n;
+	int dn = dst->n;
+	int sa = src->alpha;
+	int da = dst->alpha;
+	int ssp = src->s;
+	int dsp = dst->s;
+	int sc = sn - ssp - sa;
+	int dc = dn - dsp - da;
+	int h = src->h;
+	cmsUInt32Number src_format, dst_format;
+
+	/* check the channels. */
+	src_format = cmsGetTransformInputFormat(GLO link->handle);
+	dst_format = cmsGetTransformOutputFormat(GLO link->handle);
+	cmm_num_src = T_CHANNELS(src_format);
+	cmm_num_dst = T_CHANNELS(dst_format);
+	cmm_extras = T_EXTRA(src_format);
+	if (cmm_num_src != sc || cmm_num_dst != dc || cmm_extras != ssp+sa || sa != da || (copy_spots && ssp != dsp))
+		fz_throw(ctx, FZ_ERROR_ARGUMENT, "bad setup in ICC pixmap transform: src: %d vs %d+%d+%d, dst: %d vs %d+%d+%d", cmm_num_src, sc, ssp, sa, cmm_num_dst, dc, dsp, da);
+
+	inputpos = src->samples;
+	outputpos = dst->samples;
+
+#ifdef cmsFLAGS_PREMULT
+	/* LCMS2MT can only handle premultiplied data if the number of 'extra'
+	 * channels is the same. If not, do it by steam. */
+	if (sa && cmm_extras != (int)T_EXTRA(dst_format))
+#else
+	/* Vanilla LCMS2 cannot handle premultiplied data. If present, do it by steam. */
+	if (sa)
+#endif
+	{
+		buffer = fz_malloc(ctx, ss);
+		for (; h > 0; h--)
+		{
+			int mult = fz_unmultiply_row(ctx, sn, sc, sw, buffer, inputpos);
+			if (mult == 0)
+			{
+				/* Solid transparent row. No point in doing the transform
+				 * because it will premultiplied back to 0. */
+				memset(outputpos, 0, ds);
+			}
+			else
+			{
+				cmsDoTransform(GLO link->handle, buffer, outputpos, sw);
+				if (!copy_spots)
+				{
+					/* Copy the alpha by steam */
+					unsigned char *d = outputpos + dn - 1;
+					const unsigned char *s = inputpos + sn -1;
+					int w = sw;
+
+					while (w--)
+					{
+						*d = *s;
+						d += dn;
+						s += sn;
+					}
+				}
+				if (mult == 1)
+					fz_premultiply_row_0or1(ctx, dn, dc, dw, outputpos);
+				else if (mult == 2)
+					fz_premultiply_row(ctx, dn, dc, dw, outputpos);
+			}
+			inputpos += ss;
+			outputpos += ds;
+		}
+		fz_free(ctx, buffer);
+	}
+	else
+		for (; h > 0; h--)
+		{
+			cmsDoTransform(GLO link->handle, inputpos, outputpos, sw);
+			inputpos += ss;
+			outputpos += ds;
+		}
+}
+
+#endif