gdk: Add public api for cicp

Add a GdkCicpParams object that acts a bit like a builder for
cicp color states.

gdk/gdk.h

@@ -29,6 +29,7 @@
 #include <gdk/gdkapplaunchcontext.h>
 #include <gdk/gdkcairo.h>
 #include <gdk/gdkcairocontext.h>
+#include <gdk/gdkcicpparams.h>
 #include <gdk/gdkclipboard.h>
 #include <gdk/gdkcolorstate.h>
 #include <gdk/gdkconfig.h>

gdk/gdkcicpparams.c

@@ -0,0 +1,469 @@
+/* gdkcicpparams.c
+ *
+ * Copyright 2024 Matthias Clasen
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include "gdkcicpparamsprivate.h"
+#include "gdkcolorstateprivate.h"
+#include "gdkenumtypes.h"
+
+/**
+ * GdkCicpParams:
+ *
+ * The `GdkCicpParams` struct contains the parameters that define
+ * a colorstate according to the ITU-T H.273
+ * [specification](https://www.itu.int/rec/T-REC-H.273/en).
+ *
+ * See the documentation of individual properties for supported values.
+ *
+ * The 'unspecified' value (2) is not treated in any special way, and
+ * must be replaced by a different value before creating a color state.
+ *
+ * `GdkCicpParams` can be used as a builder object to construct a color
+ * state from Cicp data with [method@Gdk.CicpParams.build_color_state].
+ * The function will return an error if the given parameters are not
+ * supported.
+ *
+ * You can obtain a `GdkCicpParams` object from a color state with
+ * [method@Gdk.ColorState.create_cicp_params]. This can be used to
+ * create a variant of a color state, by changing just one of the cicp
+ * parameters, or just to obtain information about the color state.
+ *
+ * Since: 4.16
+ */
+
+/* {{{ GObject boilerplate */
+
+struct _GdkCicpParams
+{
+  GObject parent_instance;
+
+  GdkCicp cicp;
+};
+
+struct _GdkCicpParamsClass
+{
+  GObjectClass parent_class;
+};
+
+G_DEFINE_TYPE (GdkCicpParams, gdk_cicp_params, G_TYPE_OBJECT)
+
+enum
+{
+  PROP_COLOR_PRIMARIES = 1,
+  PROP_TRANSFER_FUNCTION,
+  PROP_MATRIX_COEFFICIENTS,
+  PROP_RANGE,
+
+  N_PROPERTIES,
+};
+
+static GParamSpec *properties[N_PROPERTIES] = { NULL, };
+
+static void
+gdk_cicp_params_init (GdkCicpParams *self)
+{
+  self->cicp.color_primaries = 2;
+  self->cicp.transfer_function = 2;
+  self->cicp.matrix_coefficients = 2;
+  self->cicp.range = GDK_CICP_RANGE_NARROW;
+}
+
+static void
+gdk_cicp_params_get_property (GObject    *object,
+                              guint       property_id,
+                              GValue     *value,
+                              GParamSpec *pspec)
+{
+  GdkCicpParams *self = GDK_CICP_PARAMS (object);
+
+  switch (property_id)
+    {
+    case PROP_COLOR_PRIMARIES:
+      g_value_set_uint (value, self->cicp.color_primaries);
+      break;
+
+    case PROP_TRANSFER_FUNCTION:
+      g_value_set_uint (value, self->cicp.transfer_function);
+      break;
+
+    case PROP_MATRIX_COEFFICIENTS:
+      g_value_set_uint (value, self->cicp.matrix_coefficients);
+      break;
+
+    case PROP_RANGE:
+      g_value_set_enum (value, self->cicp.range);
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+      break;
+    }
+}
+
+static void
+gdk_cicp_params_set_property (GObject      *object,
+                              guint         property_id,
+                              const GValue *value,
+                              GParamSpec   *pspec)
+{
+  GdkCicpParams *self = GDK_CICP_PARAMS (object);
+
+  switch (property_id)
+    {
+    case PROP_COLOR_PRIMARIES:
+      gdk_cicp_params_set_color_primaries (self, g_value_get_uint (value));
+      break;
+
+    case PROP_TRANSFER_FUNCTION:
+      gdk_cicp_params_set_transfer_function (self, g_value_get_uint (value));
+      break;
+
+    case PROP_MATRIX_COEFFICIENTS:
+      gdk_cicp_params_set_matrix_coefficients (self, g_value_get_uint (value));
+      break;
+
+    case PROP_RANGE:
+      gdk_cicp_params_set_range (self, g_value_get_enum (value));
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+      break;
+    }
+}
+
+static void
+gdk_cicp_params_class_init (GdkCicpParamsClass *klass)
+{
+  GObjectClass *object_class = G_OBJECT_CLASS (klass);
+
+  object_class->get_property = gdk_cicp_params_get_property;
+  object_class->set_property = gdk_cicp_params_set_property;
+
+  /**
+   * GdkCicpParams:color-primaries:
+   *
+   * Supported values:
+   * 1 - sRGB
+   * 2 - unspecified
+   * 5 - PAL
+   * 6,7 - NTSC
+   * 9 - BT.2020
+   * 10 - CIE XYZ
+   * 12 - Display P3
+   *
+   * Since: 4.16
+   */
+  properties[PROP_COLOR_PRIMARIES] =
+    g_param_spec_uint ("color-primaries", NULL, NULL,
+                       0, 255, 2,
+                       G_PARAM_READWRITE | G_PARAM_EXPLICIT_NOTIFY | G_PARAM_STATIC_STRINGS);
+
+  /**
+   * GdkCicpParams:transfer-function:
+   *
+   * Supported values:
+   * 1,6,14,15 - BT.709
+   * 2 - unspecified
+   * 8 - linear
+   * 13 - sRGB
+   * 16 - PQ
+   * 18 - HLG
+   *
+   * Since: 4.16
+   */
+  properties[PROP_TRANSFER_FUNCTION] =
+    g_param_spec_uint ("transfer-function", NULL, NULL,
+                       0, 255, 2,
+                       G_PARAM_READWRITE | G_PARAM_EXPLICIT_NOTIFY | G_PARAM_STATIC_STRINGS);
+
+  /**
+   * GdkCicpParams:matrix-coefficients:
+   *
+   * Supported values:
+   * 0 - RGB
+   * 2 - unspecified
+   *
+   * Since: 4.16
+   */
+  properties[PROP_MATRIX_COEFFICIENTS] =
+    g_param_spec_uint ("matrix-coefficients", NULL, NULL,
+                       0, 255, 2,
+                       G_PARAM_READWRITE | G_PARAM_EXPLICIT_NOTIFY | G_PARAM_STATIC_STRINGS);
+
+  /**
+   * GdkCicpParams:range:
+   *
+   * The range of the data.
+   *
+   * Since: 4.16
+   */
+  properties[PROP_RANGE] =
+    g_param_spec_enum ("range", NULL, NULL,
+                       GDK_TYPE_CICP_RANGE,
+                       GDK_CICP_RANGE_NARROW,
+                       G_PARAM_READWRITE | G_PARAM_EXPLICIT_NOTIFY | G_PARAM_STATIC_STRINGS);
+
+  g_object_class_install_properties (object_class, N_PROPERTIES, properties);
+}
+
+/* }}} */
+/* {{{ Public API */
+
+/**
+ * gdk_cicp_params_new:
+ *
+ * Creates a new `GdkCicpParams` object.
+ *
+ * The initial values of the properties are the values for "undefined"
+ * and need to be set before a color state object can be built.
+ *
+ * Returns: (transfer full): a new `GdkCicpParams`
+ *
+ * Since: 4.16
+ */
+GdkCicpParams  *
+gdk_cicp_params_new (void)
+{
+  return g_object_new (GDK_TYPE_CICP_PARAMS, NULL);
+}
+
+/**
+ * gdk_cicp_params_get_color_primaries:
+ * @self: a `GdkCicpParams`
+ *
+ * Returns the value of the color-primaries property
+ * of @self.
+ *
+ * Returns: the color-primaries value
+ *
+ * Since: 4.16
+ */
+guint
+gdk_cicp_params_get_color_primaries (GdkCicpParams *self)
+{
+  g_return_val_if_fail (GDK_IS_CICP_PARAMS (self), 0);
+
+  return self->cicp.color_primaries;
+}
+
+/**
+ * gdk_cicp_params_set_color_primaries:
+ * @self: a `GdkCicpParams`
+ * @color_primaries: the new color primaries value
+ *
+ * Sets the color-primaries property of @self.
+ *
+ * Since: 4.16
+ */
+void
+gdk_cicp_params_set_color_primaries (GdkCicpParams *self,
+                                     guint          color_primaries)
+{
+  g_return_if_fail (GDK_IS_CICP_PARAMS (self));
+
+  if (self->cicp.color_primaries == color_primaries)
+    return;
+
+  self->cicp.color_primaries = color_primaries;
+  g_object_notify_by_pspec (G_OBJECT (self), properties[PROP_COLOR_PRIMARIES]);
+}
+
+/**
+ * gdk_cicp_params_get_transfer_function:
+ * @self: a `GdkCicpParams`
+ *
+ * Gets the transfer-function property of @self.
+ *
+ * Returns: the transfer-function value
+ *
+ * Since: 4.16
+ */
+guint
+gdk_cicp_params_get_transfer_function (GdkCicpParams *self)
+{
+  g_return_val_if_fail (GDK_IS_CICP_PARAMS (self), 0);
+
+  return self->cicp.transfer_function;
+}
+
+/**
+ * gdk_cicp_params_set_transfer_function:
+ * @self: a `GdkCicpParams`
+ * @transfer_function: the new transfer-function value
+ *
+ * Sets the transfer-function property of @self.
+ *
+ * Since: 4.16
+ */
+void
+gdk_cicp_params_set_transfer_function (GdkCicpParams *self,
+                                       guint          transfer_function)
+{
+  g_return_if_fail (GDK_IS_CICP_PARAMS (self));
+
+  if (self->cicp.transfer_function == transfer_function)
+    return;
+
+  self->cicp.transfer_function = transfer_function;
+  g_object_notify_by_pspec (G_OBJECT (self), properties[PROP_TRANSFER_FUNCTION]);
+}
+
+/**
+ * gdk_cicp_params_get_matrix_coefficients:
+ * @self: a `GdkCicpParams`
+ *
+ * Gets the matrix-coefficients property of @self.
+ *
+ * Returns: the matrix-coefficients value
+ *
+ * Since: 4.16
+ */
+guint
+gdk_cicp_params_get_matrix_coefficients (GdkCicpParams *self)
+{
+  g_return_val_if_fail (GDK_IS_CICP_PARAMS (self), 0);
+
+  return self->cicp.matrix_coefficients;
+}
+
+/**
+ * gdk_cicp_params_set_matrix_coefficients:
+ * @self a `GdkCicpParams`
+ * @matrix_coefficients: the new matrix-coefficients value
+ *
+ * Sets the matrix-coefficients property of @self.
+ *
+ * Since: 4.16
+ */
+void
+gdk_cicp_params_set_matrix_coefficients (GdkCicpParams *self,
+                                         guint          matrix_coefficients)
+{
+  g_return_if_fail (GDK_IS_CICP_PARAMS (self));
+
+  if (self->cicp.matrix_coefficients == matrix_coefficients)
+    return;
+
+  self->cicp.matrix_coefficients = matrix_coefficients;
+  g_object_notify_by_pspec (G_OBJECT (self), properties[PROP_MATRIX_COEFFICIENTS]);
+}
+
+/**
+ * gdk_cicp_params_get_range:
+ * @self: a `GdkCicpParams`
+ *
+ * Gets the range property of @self.
+ *
+ * Returns: the range value
+ *
+ * Since: 4.16
+ */
+GdkCicpRange
+gdk_cicp_params_get_range (GdkCicpParams *self)
+{
+  g_return_val_if_fail (GDK_IS_CICP_PARAMS (self), GDK_CICP_RANGE_NARROW);
+
+  return self->cicp.range;
+}
+
+/**
+ * gdk_cicp_params_set_range:
+ * @self: a `GdkCipParams`
+ * @range: the range value
+ *
+ * Sets the range property of @self
+ *
+ * Since: 4.16
+ */
+void
+gdk_cicp_params_set_range (GdkCicpParams *self,
+                           GdkCicpRange   range)
+{
+  g_return_if_fail (GDK_IS_CICP_PARAMS (self));
+
+  if (self->cicp.range == range)
+    return;
+
+  self->cicp.range = range;
+  g_object_notify_by_pspec (G_OBJECT (self), properties[PROP_RANGE]);
+}
+
+/**
+ * gdk_cicp_params_build_color_state:
+ * @self: a `GdkCicpParams`
+ * @error: return location for errors
+ *
+ * Creates a new `GdkColorState` object for the cicp parameters in @self.
+ *
+ * Note that this may fail if the cicp parameters in @self are not
+ * supported by GTK. In that case, `NULL` is returned, and @error is set
+ * with an error message that can be presented to the user.
+ *
+ * Returns: (transfer full) (nullable): A newly allocated `GdkColorState`
+ *
+ * Since: 4.16
+ */
+GdkColorState *
+gdk_cicp_params_build_color_state (GdkCicpParams  *self,
+                                   GError        **error)
+{
+  return gdk_color_state_new_for_cicp (gdk_cicp_params_get_cicp (self), error);
+}
+
+/* }}} */
+/* {{{ Private API */
+
+/*< private >
+ * gdk_cicp_params_new_for_cicp:
+ * @cicp: a GdkCicp struct
+ *
+ * Create a `GdkCicpParams` from the values in @cicp.
+ *
+ * Returns: (transfer full): a new `GdkCicpParams` object
+ */
+GdkCicpParams *
+gdk_cicp_params_new_for_cicp (const GdkCicp *cicp)
+{
+  return g_object_new (GDK_TYPE_CICP_PARAMS,
+                       "color-primaries", cicp->color_primaries,
+                       "transfer-function", cicp->transfer_function,
+                       "matrix-coefficients", cicp->matrix_coefficients,
+                       "range", cicp->range,
+                       NULL);
+}
+
+/*< private >
+ * gdk_cicp_params_get_cicp:
+ * @self: a `GdkCicpParams` object
+ *
+ * Gets the `GdkCicp` struct of @self.
+ *
+ * Returns: (transfer none): a `GdkCicp` struct containing
+ *     the values of @self
+ */
+const GdkCicp *
+gdk_cicp_params_get_cicp (GdkCicpParams *self)
+{
+  return &self->cicp;
+}
+
+/* }}} */
+
+/* vim:set foldmethod=marker expandtab: */

gdk/gdkcicpparams.h

@@ -0,0 +1,76 @@
+/* gdkcicpparams.h
+ *
+ * Copyright 2024 Red Hat, Inc.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+
+#if !defined (__GDK_H_INSIDE__) && !defined (GTK_COMPILATION)
+#error "Only <gdk/gdk.h> can be included directly."
+#endif
+
+#include <gdk/gdktypes.h>
+
+G_BEGIN_DECLS
+
+
+#define GDK_TYPE_CICP_PARAMS (gdk_cicp_params_get_type ())
+GDK_AVAILABLE_IN_4_16
+GDK_DECLARE_INTERNAL_TYPE (GdkCicpParams, gdk_cicp_params, GDK, CICP_PARAMS, GObject)
+
+GDK_AVAILABLE_IN_4_16
+GdkCicpParams  *gdk_cicp_params_new                     (void);
+
+GDK_AVAILABLE_IN_4_16
+guint           gdk_cicp_params_get_color_primaries     (GdkCicpParams    *self);
+
+GDK_AVAILABLE_IN_4_16
+void            gdk_cicp_params_set_color_primaries     (GdkCicpParams    *self,
+                                                         guint             color_primaries);
+
+GDK_AVAILABLE_IN_4_16
+guint           gdk_cicp_params_get_transfer_function   (GdkCicpParams    *self);
+
+GDK_AVAILABLE_IN_4_16
+void            gdk_cicp_params_set_transfer_function   (GdkCicpParams    *self,
+                                                         guint             transfer_function);
+
+GDK_AVAILABLE_IN_4_16
+guint           gdk_cicp_params_get_matrix_coefficients (GdkCicpParams    *self);
+
+GDK_AVAILABLE_IN_4_16
+void            gdk_cicp_params_set_matrix_coefficients (GdkCicpParams    *self,
+                                                         guint             matrix_coefficients);
+
+typedef enum
+{
+  GDK_CICP_RANGE_NARROW,
+  GDK_CICP_RANGE_FULL,
+} GdkCicpRange;
+
+GDK_AVAILABLE_IN_4_16
+GdkCicpRange    gdk_cicp_params_get_range               (GdkCicpParams    *self);
+
+GDK_AVAILABLE_IN_4_16
+void            gdk_cicp_params_set_range               (GdkCicpParams    *self,
+                                                         GdkCicpRange      range);
+
+GDK_AVAILABLE_IN_4_16
+GdkColorState * gdk_cicp_params_build_color_state       (GdkCicpParams    *self,
+                                                         GError          **error);
+
+
+G_END_DECLS

gdk/gdkcicpparamsprivate.h

@@ -1,12 +1,8 @@
 #pragma once
 
-typedef struct _GdkCicp GdkCicp;
+#include "gdkcicpparams.h"
 
-typedef enum
-{
-  GDK_CICP_RANGE_NARROW,
-  GDK_CICP_RANGE_FULL,
-} GdkCicpRange;
+typedef struct _GdkCicp GdkCicp;
 
 struct _GdkCicp
 {
@@ -82,3 +78,7 @@ gdk_cicp_equivalent (const GdkCicp *p1,
 
   return gdk_cicp_equal (&n1, &n2);
 }
+
+const GdkCicp * gdk_cicp_params_get_cicp (GdkCicpParams *params);
+
+GdkCicpParams * gdk_cicp_params_new_for_cicp (const GdkCicp  *cicp);

gdk/gdkcolorstate.c

@@ -192,6 +192,31 @@ gboolean
   return _gdk_color_state_equal (self, other);
 }
 
+/**
+ * gdk_color_state_create_cicp_params:
+ * @self: a `GdkColorState`
+ *
+ * Create a [class@Gdk.CicpParams] representing the colorstate.
+ *
+ * It is not guaranteed that every `GdkColorState` can be
+ * represented with Cicp parameters. If that is the case,
+ * this function returns `NULL`.
+ *
+ * Returns: (transfer full) (nullable): A new [class@Gdk.CicpParams]
+ *
+ * Since: 4.16
+ */
+GdkCicpParams *
+gdk_color_state_create_cicp_params (GdkColorState *self)
+{
+  const GdkCicp *cicp = gdk_color_state_get_cicp (self);
+
+  if (cicp)
+    return gdk_cicp_params_new_for_cicp (cicp);
+
+  return NULL;
+}
+
 /* }}} */
 /* {{{ Conversion functions */
 

gdk/gdkcolorstate.h

@@ -53,6 +53,10 @@ GDK_AVAILABLE_IN_4_16
 gboolean        gdk_color_state_equal                   (GdkColorState  *self,
                                                          GdkColorState  *other);
 
+GDK_AVAILABLE_IN_4_16
+GdkCicpParams  *gdk_color_state_create_cicp_params      (GdkColorState  *self);
+
+
 G_DEFINE_AUTOPTR_CLEANUP_FUNC(GdkColorState, gdk_color_state_unref);
 
 G_END_DECLS

gdk/gdkcolorstateprivate.h

@@ -2,12 +2,11 @@
 
 #include "gdkcolorstate.h"
 
+#include "gdkcicpparamsprivate.h"
 #include "gdkdebugprivate.h"
 #include "gdkmemoryformatprivate.h"
 #include "gdkrgba.h"
 
-#include "gdkcicpparamsprivate.h"
-
 typedef enum
 {
   GDK_COLOR_STATE_ID_SRGB,

gdk/gdktypes.h

@@ -74,6 +74,7 @@ typedef cairo_rectangle_int_t         GdkRectangle;
 
 /* Forward declarations of commonly used types */
 typedef struct _GdkRGBA               GdkRGBA;
+typedef struct _GdkCicpParams         GdkCicpParams;
 typedef struct _GdkColorState         GdkColorState;
 typedef struct _GdkContentFormats     GdkContentFormats;
 typedef struct _GdkContentProvider    GdkContentProvider;

gdk/meson.build

@@ -5,6 +5,7 @@ gdk_public_sources = files([
   'gdkapplaunchcontext.c',
   'gdkcairo.c',
   'gdkcairocontext.c',
+  'gdkcicpparams.c',
   'gdkclipboard.c',
   'gdkcolorstate.c',
   'gdkcontentdeserializer.c',
@@ -77,6 +78,7 @@ gdk_public_headers = files([
   'gdkapplaunchcontext.h',
   'gdkcairo.h',
   'gdkcairocontext.h',
+  'gdkcicpparams.h',
   'gdkclipboard.h',
   'gdkcolorstate.h',
   'gdkcontentdeserializer.h',