color-lcms: LCMS transform for color mapping

Use 3D LUT for color mapping.
For category CMLCMS_CATEGORY_INPUT_TO_BLEND use transform which has
3 profiles: input, output and light linearizing transfer function.
For category CMLCMS_CATEGORY_INPUT_TO_OUTPUT use input and output profiles +VCGT.
For category CMLCMS_CATEGORY_BLEND_TO_OUTPUT use output inverse EOTF + VCGT.

Co-authored-by: Pekka Paalanen <pekka.paalanen@collabora.com>
Signed-off-by: Vitaly Prosyak <vitaly.prosyak@amd.com>

libweston/color-lcms/color-lcms.c

@@ -99,13 +99,7 @@ cmlcms_get_surface_color_transform(struct weston_color_manager *cm_base,
 				   struct weston_surface_color_transform *surf_xform)
 {
 	struct weston_color_manager_lcms *cm = get_cmlcms(cm_base);
-	struct cmlcms_color_transform_search_param param = {
-		/*
-		 * Assumes both content and output color spaces are sRGB SDR.
-		 * This defines the blending space as optical sRGB SDR.
-		 */
-		.type = CMLCMS_TYPE_EOTF_sRGB,
-	};
+	struct cmlcms_color_transform_search_param param = {};
 	struct cmlcms_color_transform *xform;
 
 	setup_search_param(CMLCMS_CATEGORY_INPUT_TO_BLEND, surface, output,
@@ -116,7 +110,15 @@ cmlcms_get_surface_color_transform(struct weston_color_manager *cm_base,
 		return false;
 
 	surf_xform->transform = &xform->base;
-	surf_xform->identity_pipeline = true;
+	/*
+	 * When we introduce LCMS plug-in we can precisely answer this question
+	 * by examining the color pipeline using precision parameters. For now
+	 * we just compare if it is same pointer or not.
+	 */
+	if (xform->search_key.input_profile == xform->search_key.output_profile)
+		surf_xform->identity_pipeline = true;
+	else
+		surf_xform->identity_pipeline = false;
 
 	return true;
 }
@@ -127,13 +129,7 @@ cmlcms_get_output_color_transform(struct weston_color_manager *cm_base,
 				  struct weston_color_transform **xform_out)
 {
 	struct weston_color_manager_lcms *cm = get_cmlcms(cm_base);
-	struct cmlcms_color_transform_search_param param = {
-		/*
-		 * Assumes blending space is optical sRGB SDR and
-		 * output color space is sRGB SDR.
-		 */
-		.type = CMLCMS_TYPE_EOTF_sRGB_INV,
-	};
+	struct cmlcms_color_transform_search_param param = {};
 	struct cmlcms_color_transform *xform;
 
 	setup_search_param(CMLCMS_CATEGORY_BLEND_TO_OUTPUT, NULL, output,
@@ -152,16 +148,24 @@ cmlcms_get_sRGB_to_output_color_transform(struct weston_color_manager *cm_base,
 					  struct weston_output *output,
 					  struct weston_color_transform **xform_out)
 {
-	/* Assumes output color space is sRGB SDR */
 	struct weston_color_manager_lcms *cm = get_cmlcms(cm_base);
-
 	struct cmlcms_color_transform_search_param param = {};
+	struct cmlcms_color_transform *xform;
 
 	setup_search_param(CMLCMS_CATEGORY_INPUT_TO_OUTPUT, NULL, output,
 			   cm->sRGB_profile, &param);
-
-	/* Identity transform */
-	*xform_out = NULL;
+	/*
+	 * Create a color transformation when output profile is not stock
+	 * sRGB profile.
+	 */
+	if (param.output_profile != cm->sRGB_profile) {
+		xform = cmlcms_color_transform_get(cm, &param);
+		if (!xform)
+			return false;
+		*xform_out = &xform->base;
+	} else {
+		*xform_out = NULL; /* Identity transform */
+	}
 
 	return true;
 }
@@ -172,10 +176,7 @@ cmlcms_get_sRGB_to_blend_color_transform(struct weston_color_manager *cm_base,
 					 struct weston_color_transform **xform_out)
 {
 	struct weston_color_manager_lcms *cm = get_cmlcms(cm_base);
-	struct cmlcms_color_transform_search_param param = {
-		/* Assumes blending space is optical sRGB SDR */
-		.type = CMLCMS_TYPE_EOTF_sRGB,
-	};
+	struct cmlcms_color_transform_search_param param = {};
 	struct cmlcms_color_transform *xform;
 
 	setup_search_param(CMLCMS_CATEGORY_INPUT_TO_BLEND, NULL, output,

libweston/color-lcms/color-lcms.h

@@ -131,19 +131,8 @@ cmlcms_get_color_profile_from_icc(struct weston_color_manager *cm,
 void
 cmlcms_destroy_color_profile(struct weston_color_profile *cprof_base);
 
-/*
- * Perhaps a placeholder, until we get actual color spaces involved and
- * see how this would work better.
- */
-enum cmlcms_color_transform_type {
-	CMLCMS_TYPE_EOTF_sRGB = 0,
-	CMLCMS_TYPE_EOTF_sRGB_INV,
-	CMLCMS_TYPE__END,
-};
 
 struct cmlcms_color_transform_search_param {
-	enum cmlcms_color_transform_type type;
-
 	enum cmlcms_category category;
 	struct cmlcms_color_profile *input_profile;
 	struct cmlcms_color_profile *output_profile;
@@ -158,9 +147,6 @@ struct cmlcms_color_transform {
 
 	struct cmlcms_color_transform_search_param search_key;
 
-	/* for EOTF types It would be deprecated */
-	cmsToneCurve *curve;
-
 	/**
 	 * 3D LUT color mapping part of the transformation, if needed.
 	 * For category CMLCMS_CATEGORY_INPUT_TO_OUTPUT it includes pre-curve and

libweston/color-lcms/color-transform.c

@@ -33,12 +33,6 @@
 #include "color-lcms.h"
 #include "shared/helpers.h"
 
-/* Arguments to cmsBuildParametricToneCurve() */
-struct tone_curve_def {
-	cmsInt32Number cmstype;
-	cmsFloat64Number params[5];
-};
-
 /**
  * The method is used in linearization of an arbitrary color profile
  * when EOTF is retrieved we want to know a generic way to decide the number
@@ -50,42 +44,87 @@ cmlcms_reasonable_1D_points(void)
 	return 1024;
 }
 
-/*
- * LCMS uses the required number of 'params' based on 'cmstype', the parametric
- * tone curve number. LCMS honors negative 'cmstype' as inverse function.
- * These are LCMS built-in parametric tone curves.
- */
-static const struct tone_curve_def predefined_eotf_curves[] = {
-	[CMLCMS_TYPE_EOTF_sRGB] = {
-		.cmstype = 4,
-		.params = { 2.4, 1. / 1.055, 0.055 / 1.055, 1. / 12.92, 0.04045 },
-	},
-	[CMLCMS_TYPE_EOTF_sRGB_INV] = {
-		.cmstype = -4,
-		.params = { 2.4, 1. / 1.055, 0.055 / 1.055, 1. / 12.92, 0.04045 },
-	},
-};
+static unsigned int
+cmlcms_reasonable_3D_points(void)
+{
+	return 33;
+}
 
 static void
-cmlcms_fill_in_tone_curve(struct weston_color_transform *xform_base,
-			  float *values, unsigned len)
+fill_in_curves(cmsToneCurve *curves[3], float *values, unsigned len)
 {
-	struct cmlcms_color_transform *xform = get_xform(xform_base);
 	float *R_lut = values;
 	float *G_lut = R_lut + len;
 	float *B_lut = G_lut + len;
 	unsigned i;
-	cmsFloat32Number x, y;
-
-	assert(xform->curve != NULL);
-	assert(len > 1);
+	cmsFloat32Number x;
 
 	for (i = 0; i < len; i++) {
 		x = (double)i / (len - 1);
-		y = cmsEvalToneCurveFloat(xform->curve, x);
-		R_lut[i] = y;
-		G_lut[i] = y;
-		B_lut[i] = y;
+		R_lut[i] = cmsEvalToneCurveFloat(curves[0], x);
+		G_lut[i] = cmsEvalToneCurveFloat(curves[1], x);
+		B_lut[i] = cmsEvalToneCurveFloat(curves[2], x);
+	}
+}
+
+static void
+cmlcms_fill_in_pre_curve(struct weston_color_transform *xform_base,
+			 float *values, unsigned len)
+{
+	struct cmlcms_color_transform *xform = get_xform(xform_base);
+
+	assert(xform->search_key.category == CMLCMS_CATEGORY_BLEND_TO_OUTPUT);
+
+	assert(len > 1);
+
+	fill_in_curves(xform->search_key.output_profile->output_inv_eotf_vcgt,
+		       values, len);
+}
+
+/**
+ * Clamp value to [0.0, 1.0], except pass NaN through.
+ *
+ * This function is not intended for hiding NaN.
+ */
+static float
+ensure_unorm(float v)
+{
+	if (v <= 0.0f)
+		return 0.0f;
+	if (v > 1.0f)
+		return 1.0f;
+	return v;
+}
+
+static void
+cmlcms_fill_in_3dlut(struct weston_color_transform *xform_base,
+		     float *lut, unsigned int len)
+{
+	struct cmlcms_color_transform *xform = get_xform(xform_base);
+	float rgb_in[3];
+	float rgb_out[3];
+	unsigned int index;
+	unsigned int value_b, value_r, value_g;
+	float divider = len - 1;
+
+	assert(xform->search_key.category == CMLCMS_CATEGORY_INPUT_TO_BLEND ||
+	       xform->search_key.category == CMLCMS_CATEGORY_INPUT_TO_OUTPUT);
+
+	for (value_b = 0; value_b < len; value_b++) {
+		for (value_g = 0; value_g < len; value_g++) {
+			for (value_r = 0; value_r < len; value_r++) {
+				rgb_in[0] = (float)value_r / divider;
+				rgb_in[1] = (float)value_g / divider;
+				rgb_in[2] = (float)value_b / divider;
+
+				cmsDoTransform(xform->cmap_3dlut, rgb_in, rgb_out, 1);
+
+				index = 3 * (value_r + len * (value_g + len * value_b));
+				lut[index    ] = ensure_unorm(rgb_out[0]);
+				lut[index + 1] = ensure_unorm(rgb_out[1]);
+				lut[index + 2] = ensure_unorm(rgb_out[2]);
+			}
+		}
 	}
 }
 
@@ -93,57 +132,129 @@ void
 cmlcms_color_transform_destroy(struct cmlcms_color_transform *xform)
 {
 	wl_list_remove(&xform->link);
-	if (xform->curve)
-		cmsFreeToneCurve(xform->curve);
+
+	if (xform->cmap_3dlut)
+		cmsDeleteTransform(xform->cmap_3dlut);
+
+	unref_cprof(xform->search_key.input_profile);
+	unref_cprof(xform->search_key.output_profile);
 	free(xform);
 }
 
+static bool
+xform_set_cmap_3dlut(struct cmlcms_color_transform *xform,
+		     cmsHPROFILE input_profile,
+		     cmsHPROFILE output_profile,
+		     cmsToneCurve *curves[3],
+		     cmsUInt32Number intent)
+{
+	struct weston_color_manager_lcms *cm = get_cmlcms(xform->base.cm);
+	cmsHPROFILE arr_prof[3] = { input_profile, output_profile, NULL };
+	int num_profiles = 2;
+
+	if (curves[0]) {
+		arr_prof[2] = cmsCreateLinearizationDeviceLinkTHR(cm->lcms_ctx,
+								  cmsSigRgbData,
+								  curves);
+		if (!arr_prof[2])
+			return false;
+
+		num_profiles = 3;
+	}
+
+	xform->cmap_3dlut = cmsCreateMultiprofileTransformTHR(cm->lcms_ctx,
+							      arr_prof,
+							      num_profiles,
+							      TYPE_RGB_FLT,
+							      TYPE_RGB_FLT,
+							      intent,
+							      0);
+	if (!xform->cmap_3dlut) {
+		cmsCloseProfile(arr_prof[2]);
+		weston_log("color-lcms error: fail cmsCreateMultiprofileTransformTHR.\n");
+		return false;
+	}
+	xform->base.mapping.type = WESTON_COLOR_MAPPING_TYPE_3D_LUT;
+	xform->base.mapping.u.lut3d.fill_in = cmlcms_fill_in_3dlut;
+	xform->base.mapping.u.lut3d.optimal_len =
+				cmlcms_reasonable_3D_points();
+	cmsCloseProfile(arr_prof[2]);
+
+	return true;
+}
+
 static struct cmlcms_color_transform *
 cmlcms_color_transform_create(struct weston_color_manager_lcms *cm,
-			const struct cmlcms_color_transform_search_param *param)
+			      const struct cmlcms_color_transform_search_param *search_param)
 {
+	struct cmlcms_color_profile *input_profile = search_param->input_profile;
+	struct cmlcms_color_profile *output_profile = search_param->output_profile;
 	struct cmlcms_color_transform *xform;
-	const struct tone_curve_def *tonedef;
-
-	if (param->type < 0 || param->type >= CMLCMS_TYPE__END) {
-		weston_log("color-lcms error: bad color transform type in %s.\n",
-			   __func__);
-		return NULL;
-	}
-	tonedef = &predefined_eotf_curves[param->type];
+	bool ok = false;
 
 	xform = zalloc(sizeof *xform);
 	if (!xform)
 		return NULL;
 
-	xform->curve = cmsBuildParametricToneCurve(cm->lcms_ctx,
-						   tonedef->cmstype,
-						   tonedef->params);
-	if (xform->curve == NULL) {
-		weston_log("color-lcms error: failed to build parametric tone curve.\n");
-		free(xform);
-		return NULL;
+	weston_color_transform_init(&xform->base, &cm->base);
+	wl_list_init(&xform->link);
+	xform->search_key = *search_param;
+	xform->search_key.input_profile = ref_cprof(input_profile);
+	xform->search_key.output_profile = ref_cprof(output_profile);
+
+	/* Ensure the linearization etc. have been extracted. */
+	if (!output_profile->output_eotf[0]) {
+		if (!retrieve_eotf_and_output_inv_eotf(cm->lcms_ctx,
+						       output_profile->profile,
+						       output_profile->output_eotf,
+						       output_profile->output_inv_eotf_vcgt,
+						       output_profile->vcgt,
+						       cmlcms_reasonable_1D_points()))
+			goto error;
 	}
 
-	weston_color_transform_init(&xform->base, &cm->base);
-	xform->search_key = *param;
+	switch (search_param->category) {
+	case CMLCMS_CATEGORY_INPUT_TO_BLEND:
+		/* Use EOTF to linearize the result. */
+		ok = xform_set_cmap_3dlut(xform, input_profile->profile,
+					  output_profile->profile,
+					  output_profile->output_eotf,
+					  search_param->intent_output);
+		break;
 
-	xform->base.pre_curve.type = WESTON_COLOR_CURVE_TYPE_LUT_3x1D;
-	xform->base.pre_curve.u.lut_3x1d.fill_in = cmlcms_fill_in_tone_curve;
-	xform->base.pre_curve.u.lut_3x1d.optimal_len = 256;
+	case CMLCMS_CATEGORY_INPUT_TO_OUTPUT:
+		/* Apply also VCGT if it exists. */
+		ok = xform_set_cmap_3dlut(xform, input_profile->profile,
+					  output_profile->profile,
+					  output_profile->vcgt,
+					  search_param->intent_output);
+		break;
+
+	case CMLCMS_CATEGORY_BLEND_TO_OUTPUT:
+		xform->base.pre_curve.type = WESTON_COLOR_CURVE_TYPE_LUT_3x1D;
+		xform->base.pre_curve.u.lut_3x1d.fill_in = cmlcms_fill_in_pre_curve;
+		xform->base.pre_curve.u.lut_3x1d.optimal_len =
+				cmlcms_reasonable_1D_points();
+		ok = true;
+		break;
+	}
+
+	if (!ok)
+		goto error;
 
 	wl_list_insert(&cm->color_transform_list, &xform->link);
-
 	return xform;
+
+error:
+	cmlcms_color_transform_destroy(xform);
+	weston_log("CM cmlcms_color_transform_create failed\n");
+	return NULL;
 }
 
 static bool
 transform_matches_params(const struct cmlcms_color_transform *xform,
 			 const struct cmlcms_color_transform_search_param *param)
 {
-	if (xform->search_key.type != param->type)
-		return false;
-
 	if (xform->search_key.category != param->category)
 		return false;