Move colour management to its own compilation unit

Also make it apparent that CMM profiles are pointer types.

This isn't all that pretty, but it's a necessary first step.

1 files changed, 366 insertions, 0 deletions

diff --git a/fiv-io-profile.c b/fiv-io-profile.c
new file mode 100644
index 0000000..84b310e
--- /dev/null
+++ b/fiv-io-profile.c
@@ -0,0 +1,366 @@
+//
+// fiv-profile.c: colour management
+//
+// Copyright (c) 2024, Přemysl Eric Janouch <p@janouch.name>
+//
+// Permission to use, copy, modify, and/or distribute this software for any
+// purpose with or without fee is hereby granted.
+//
+// THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+// WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+// MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
+// SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+// WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
+// OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
+// CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+//
+
+#include "config.h"
+
+#include <glib.h>
+#include <stdbool.h>
+
+#include "fiv-io.h"
+
+// Colour management must be handled before RGB conversions.
+#ifdef HAVE_LCMS2
+#include <lcms2.h>
+#endif  // HAVE_LCMS2
+#ifdef HAVE_LCMS2_FAST_FLOAT
+#include <lcms2_fast_float.h>
+#endif  // HAVE_LCMS2_FAST_FLOAT
+
+void
+fiv_io_profile_init(void)
+{
+	// TODO(p): Use Little CMS with contexts instead.
+#ifdef HAVE_LCMS2_FAST_FLOAT
+	cmsPluginTHR(NULL, cmsFastFloatExtensions());
+#endif  // HAVE_LCMS2_FAST_FLOAT
+}
+
+FivIoProfile *
+fiv_io_profile_new(const void *data, size_t len)
+{
+#ifdef HAVE_LCMS2
+	return cmsOpenProfileFromMemTHR(NULL, data, len);
+#else
+	(void) data;
+	(void) len;
+	return NULL;
+#endif
+}
+
+FivIoProfile *
+fiv_io_profile_new_sRGB(void)
+{
+#ifdef HAVE_LCMS2
+	return cmsCreate_sRGBProfileTHR(NULL);
+#else
+	return NULL;
+#endif
+}
+
+FivIoProfile *
+fiv_io_profile_new_parametric(
+	double gamma, double whitepoint[2], double primaries[6])
+{
+#ifdef HAVE_LCMS2
+	// TODO(p): Make sure to use the library in a thread-safe manner.
+	cmsContext context = NULL;
+
+	const cmsCIExyY cmsWP = {whitepoint[0], whitepoint[1], 1.0};
+	const cmsCIExyYTRIPLE cmsP = {
+		{primaries[0], primaries[1], 1.0},
+		{primaries[2], primaries[3], 1.0},
+		{primaries[4], primaries[5], 1.0},
+	};
+
+	cmsToneCurve *curve = cmsBuildGamma(context, gamma);
+	if (!curve)
+		return NULL;
+
+	cmsHPROFILE profile = cmsCreateRGBProfileTHR(
+		context, &cmsWP, &cmsP, (cmsToneCurve *[3]){curve, curve, curve});
+	cmsFreeToneCurve(curve);
+	return profile;
+#else
+	(void) gamma;
+	(void) whitepoint;
+	(void) primaries;
+	return NULL;
+#endif
+}
+
+FivIoProfile *
+fiv_io_profile_new_sRGB_gamma(double gamma)
+{
+	return fiv_io_profile_new_parametric(gamma,
+		(double[2]){0.3127, 0.3290},
+		(double[6]){0.6400, 0.3300, 0.3000, 0.6000, 0.1500, 0.0600});
+}
+
+FivIoProfile *
+fiv_io_profile_new_from_bytes(GBytes *bytes)
+{
+	gsize len = 0;
+	gconstpointer p = g_bytes_get_data(bytes, &len);
+	return fiv_io_profile_new(p, len);
+}
+
+GBytes *
+fiv_io_profile_to_bytes(FivIoProfile *profile)
+{
+#ifdef HAVE_LCMS2
+	cmsUInt32Number len = 0;
+	(void) cmsSaveProfileToMem(profile, NULL, &len);
+	gchar *data = g_malloc0(len);
+	if (!cmsSaveProfileToMem(profile, data, &len)) {
+		g_free(data);
+		return NULL;
+	}
+	return g_bytes_new_take(data, len);
+#else
+	(void) profile;
+	return NULL;
+#endif
+}
+
+void
+fiv_io_profile_free(FivIoProfile *self)
+{
+#ifdef HAVE_LCMS2
+	cmsCloseProfile(self);
+#else
+	(void) self;
+#endif
+}
+
+// --- Image loading -----------------------------------------------------------
+
+// TODO(p): In general, try to use CAIRO_FORMAT_RGB30 or CAIRO_FORMAT_RGBA128F.
+#ifndef HAVE_LCMS2
+#define FIV_IO_PROFILE_ARGB32 0
+#define FIV_IO_PROFILE_4X16LE 0
+#else
+#define FIV_IO_PROFILE_ARGB32 \
+	(G_BYTE_ORDER == G_LITTLE_ENDIAN ? TYPE_BGRA_8 : TYPE_ARGB_8)
+#define FIV_IO_PROFILE_4X16LE \
+	(G_BYTE_ORDER == G_LITTLE_ENDIAN ? TYPE_BGRA_16 : TYPE_BGRA_16_SE)
+#endif
+
+// CAIRO_STRIDE_ALIGNMENT is 4 bytes, so there will be no padding with
+// ARGB/BGRA/XRGB/BGRX.
+static void
+trivial_cmyk_to_host_byte_order_argb(unsigned char *p, int len)
+{
+	// This CMYK handling has been seen in gdk-pixbuf/JPEG, GIMP/JPEG, skcms.
+	// It will typically produce horribly oversaturated results.
+	// Assume that all YCCK/CMYK JPEG files use inverted CMYK, as Photoshop
+	// does, see https://bugzilla.gnome.org/show_bug.cgi?id=618096
+	while (len--) {
+		int c = p[0], m = p[1], y = p[2], k = p[3];
+#if G_BYTE_ORDER == G_LITTLE_ENDIAN
+		p[0] = k * y / 255;
+		p[1] = k * m / 255;
+		p[2] = k * c / 255;
+		p[3] = 255;
+#else
+		p[3] = k * y / 255;
+		p[2] = k * m / 255;
+		p[1] = k * c / 255;
+		p[0] = 255;
+#endif
+		p += 4;
+	}
+}
+
+void
+fiv_io_profile_cmyk(
+	FivIoImage *image, FivIoProfile *source, FivIoProfile *target)
+{
+#ifndef HAVE_LCMS2
+	(void) source;
+	(void) target;
+#else
+	cmsHTRANSFORM transform = NULL;
+	if (source && target) {
+		transform = cmsCreateTransformTHR(NULL, source, TYPE_CMYK_8_REV, target,
+			FIV_IO_PROFILE_ARGB32, INTENT_PERCEPTUAL, 0);
+	}
+	if (transform) {
+		cmsDoTransform(
+			transform, image->data, image->data, image->width * image->height);
+		cmsDeleteTransform(transform);
+		return;
+	}
+#endif
+	trivial_cmyk_to_host_byte_order_argb(
+		image->data, image->width * image->height);
+}
+
+static bool
+fiv_io_profile_rgb_direct(unsigned char *data, int w, int h,
+	FivIoProfile *source, FivIoProfile *target,
+	uint32_t source_format, uint32_t target_format)
+{
+#ifndef HAVE_LCMS2
+	(void) data;
+	(void) w;
+	(void) h;
+	(void) source;
+	(void) source_format;
+	(void) target;
+	(void) target_format;
+	return false;
+#else
+	// TODO(p): We should make this optional.
+	cmsHPROFILE src_fallback = NULL;
+	if (target && !source)
+		source = src_fallback = cmsCreate_sRGBProfileTHR(NULL);
+
+	cmsHTRANSFORM transform = NULL;
+	if (source && target) {
+		transform = cmsCreateTransformTHR(NULL,
+			source, source_format, target, target_format, INTENT_PERCEPTUAL, 0);
+	}
+	if (transform) {
+		cmsDoTransform(transform, data, data, w * h);
+		cmsDeleteTransform(transform);
+	}
+	if (src_fallback)
+		cmsCloseProfile(src_fallback);
+	return transform != NULL;
+#endif
+}
+
+static void
+fiv_io_profile_xrgb32(
+	FivIoImage *image, FivIoProfile *source, FivIoProfile *target)
+{
+	fiv_io_profile_rgb_direct(image->data, image->width, image->height,
+		source, target, FIV_IO_PROFILE_ARGB32, FIV_IO_PROFILE_ARGB32);
+}
+
+void
+fiv_io_profile_4x16le_direct(unsigned char *data,
+	int w, int h, FivIoProfile *source, FivIoProfile *target)
+{
+	fiv_io_profile_rgb_direct(data, w, h, source, target,
+		FIV_IO_PROFILE_4X16LE, FIV_IO_PROFILE_4X16LE);
+}
+
+// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+
+void
+fiv_io_profile_page(FivIoImage *page, FivIoProfile *target,
+	void (*frame_cb) (FivIoImage *, FivIoProfile *, FivIoProfile *))
+{
+	FivIoProfile *source = NULL;
+	if (page->icc)
+		source = fiv_io_profile_new_from_bytes(page->icc);
+
+	// TODO(p): All animations need to be composited in a linear colour space.
+	for (FivIoImage *frame = page; frame != NULL; frame = frame->frame_next)
+		frame_cb(frame, source, target);
+
+	if (source)
+		fiv_io_profile_free(source);
+}
+
+// From libwebp, verified to exactly match [x * a / 255].
+#define PREMULTIPLY8(a, x) (((uint32_t) (x) * (uint32_t) (a) * 32897U) >> 23)
+
+void
+fiv_io_premultiply_argb32(FivIoImage *image)
+{
+	if (image->format != CAIRO_FORMAT_ARGB32)
+		return;
+
+	for (uint32_t y = 0; y < image->height; y++) {
+		uint32_t *dstp = (uint32_t *) (image->data + image->stride * y);
+		for (uint32_t x = 0; x < image->width; x++) {
+			uint32_t argb = dstp[x], a = argb >> 24;
+			dstp[x] = a << 24 |
+				PREMULTIPLY8(a, 0xFF & (argb >> 16)) << 16 |
+				PREMULTIPLY8(a, 0xFF & (argb >>  8)) <<  8 |
+				PREMULTIPLY8(a, 0xFF &  argb);
+		}
+	}
+}
+
+#if defined HAVE_LCMS2 && LCMS_VERSION >= 2130
+
+#define FIV_IO_PROFILE_ARGB32_PREMUL \
+	(G_BYTE_ORDER == G_LITTLE_ENDIAN ? TYPE_BGRA_8_PREMUL : TYPE_ARGB_8_PREMUL)
+
+static void
+fiv_io_profile_argb32(FivIoImage *image,
+	FivIoProfile *source, FivIoProfile *target)
+{
+	g_return_if_fail(image->format == CAIRO_FORMAT_ARGB32);
+
+	fiv_io_profile_rgb_direct(image->data, image->width, image->height,
+		source, target,
+		FIV_IO_PROFILE_ARGB32_PREMUL, FIV_IO_PROFILE_ARGB32_PREMUL);
+}
+
+void
+fiv_io_profile_argb32_premultiply(
+	FivIoImage *image, FivIoProfile *source, FivIoProfile *target)
+{
+	if (image->format != CAIRO_FORMAT_ARGB32) {
+		fiv_io_profile_xrgb32(image, source, target);
+	} else if (!fiv_io_profile_rgb_direct(image->data,
+			image->width, image->height, source, target,
+			FIV_IO_PROFILE_ARGB32, FIV_IO_PROFILE_ARGB32_PREMUL)) {
+		g_debug("failed to create a premultiplying transform");
+		fiv_io_premultiply_argb32(image);
+	}
+}
+
+#else  // ! HAVE_LCMS2 || LCMS_VERSION < 2130
+
+// TODO(p): Unpremultiply, transform, repremultiply. Or require lcms2>=2.13.
+#define fiv_io_profile_argb32(surface, source, target)
+
+static void
+fiv_io_profile_argb32_premultiply(
+	FivIoImage *image, FivIoProfile *source, FivIoProfile *target)
+{
+	fiv_io_profile_xrgb32(image, source, target);
+	fiv_io_premultiply_argb32(image);
+}
+
+#endif  // ! HAVE_LCMS2 || LCMS_VERSION < 2130
+
+// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+
+void
+fiv_io_profile_any(
+	FivIoImage *image, FivIoProfile *source, FivIoProfile *target)
+{
+	// TODO(p): Ensure we do colour management early enough, so that
+	// no avoidable increase of quantization error occurs beforehands,
+	// and also for correct alpha compositing.
+	switch (image->format) {
+	break; case CAIRO_FORMAT_RGB24:
+		fiv_io_profile_xrgb32(image, source, target);
+	break; case CAIRO_FORMAT_ARGB32:
+		fiv_io_profile_argb32(image, source, target);
+	break; default:
+		g_debug("CM attempted on an unsupported surface format");
+	}
+}
+
+// TODO(p): Offer better integration, upgrade the bit depth if appropriate.
+FivIoImage *
+fiv_io_profile_finalize(FivIoImage *image, FivIoProfile *target)
+{
+	if (!target)
+		return image;
+
+	for (FivIoImage *page = image; page != NULL; page = page->page_next)
+		fiv_io_profile_page(page, target, fiv_io_profile_any);
+	return image;
+}