1 files changed, 260 insertions, 0 deletions
diff --git a/gdk/gdkcolor.c b/gdk/gdkcolor.c
new file mode 100644
index 0000000000..8eeef26f4b
--- /dev/null
+++ b/gdk/gdkcolor.c
@@ -0,0 +1,260 @@
+/* GDK - The GIMP Drawing Kit
+ *
+ * Copyright (C) 2021 Benjamin Otte
+ *
+ * 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 "gdkcolor.h"
+
+#include "gdkcolorspaceprivate.h"
+#include "gdkrgba.h"
+
+/**
+ * GdkColor:
+ *
+ * GdkColor is a high level description of a color for use in a color managed context.
+ *
+ * FIXME: Add stuff about colors in the real world and looking at `GdkColorSpace` for
+ * how this is important.
+ *
+ * If you only want to use RGB colors, consider using `GdkRGBA` instead.
+ */
+
+#define GDK_IS_COLOR(self) ((self) != NULL)
+
+struct _GdkColor
+{
+  GdkColorSpace *color_space;
+  float components[]; /* alpha is last component, so that RGBA is in exactly that order */
+};
+
+G_DEFINE_BOXED_TYPE (GdkColor, gdk_color,
+                     gdk_color_copy, gdk_color_free)
+
+static GdkColor *
+gdk_color_alloc (GdkColorSpace *space)
+{
+  gsize n_components = gdk_color_space_get_n_components (space);
+  GdkColor *self;
+
+  self = g_malloc (sizeof (GdkColor) + n_components * sizeof (float));
+
+  self->color_space = g_object_ref (space);
+
+  return self;
+}
+
+/**
+ * gdk_color_new:
+ * @space: the color space of the color
+ * @alpha: the alpha value for this color
+ * @components: (array length=n_components) (nullable): an array of
+ *   component values for this color
+ * @n_components: number of components
+ *
+ * Creates a new GdkColor representing the color for the given component
+ * values in the given color space.
+ *
+ * The alpha value is independent of the component values (also known as
+ * "unassociated" or "component values are not premultiplied").
+ *
+ * If the number of components passed is larger than the color space's
+ * components, extra values will be discarded. If it is smaller, the
+ * remaining components will be initialized as 0.
+ *
+ * Returns: a new GdkColor.
+ **/
+GdkColor *
+gdk_color_new (GdkColorSpace *space,
+               float          alpha,
+               float         *components,
+               gsize          n_components)
+{
+  gsize n_color_components;
+  GdkColor *self;
+
+  g_return_val_if_fail (GDK_IS_COLOR_SPACE (space), NULL);
+  g_return_val_if_fail (components != NULL || n_components == 0, NULL);
+
+  self = gdk_color_alloc (space);
+  n_color_components = gdk_color_space_get_n_components (space);
+  if (n_components)
+    memcpy (self->components, components, MIN (n_components, n_color_components));
+  if (n_components < n_color_components)
+    memset (&self->components[n_components], 0, sizeof (float) * (n_color_components - n_components));
+  self->components[n_color_components] = alpha;
+
+  return self;
+}
+
+G_STATIC_ASSERT (sizeof (GdkRGBA) == 4 * sizeof (float));
+
+/**
+ * gdk_color_new_from_rgba:
+ * @rgba: a GdkRGBA
+ *
+ * Creates a new GdkColor from the given GdkRGBA.
+ *
+ * Returns: a new GdkColor
+ **/
+GdkColor *
+gdk_color_new_from_rgba (const GdkRGBA *rgba)
+{
+  GdkColor *self;
+
+  g_return_val_if_fail (rgba != NULL, NULL);
+
+  self = gdk_color_alloc (gdk_color_space_get_srgb ());
+  memcpy (self->components, rgba, sizeof (GdkRGBA));
+
+  return self;
+}
+
+/**
+ * gdk_color_copy:
+ * @self: a `GdkColor`
+ *
+ * Copies the color.
+ *
+ * Returns: a copy of the color.
+ **/
+GdkColor *
+gdk_color_copy (const GdkColor *self)
+{
+  GdkColor *copy;
+
+  copy = gdk_color_alloc (self->color_space);
+  memcpy (copy->components,
+          self->components,
+          sizeof (float) * (gdk_color_space_get_n_components (self->color_space) + 1));
+  
+  return copy;
+}
+
+/**
+ * gdk_color_free:
+ * @self: a #GdkColor
+ *
+ * Frees a `GdkColor`.
+ **/
+void
+gdk_color_free (GdkColor *self)
+{
+  g_object_unref (self->color_space);
+  g_free (self);
+}
+
+/**
+ * gdk_color_get_color_space:
+ * @self: a `GdkColor`
+ *
+ * Returns the color space that this color is defined in.
+ *
+ * Returns: the color space this color is defined in
+ **/
+GdkColorSpace *
+gdk_color_get_color_space (const GdkColor *self)
+{
+  g_return_val_if_fail (GDK_IS_COLOR (self), gdk_color_space_get_srgb ());
+
+  return self->color_space;
+}
+
+/**
+ * gdk_color_get_alpha:
+ * @self: a `GdkColor`
+ *
+ * Gets the alpha value of this color. Alpha values range from 0.0
+ * (fully translucent) to 1.0 (fully opaque).
+ *
+ * Returns: The alpha value
+ **/
+float
+gdk_color_get_alpha (const GdkColor *self)
+{
+  g_return_val_if_fail (GDK_IS_COLOR (self), 1.f);
+
+  return self->components[gdk_color_space_get_n_components (self->color_space)];
+}
+
+/**
+ * gdk_color_get_components:
+ * @self: a `GdkColor`
+ *
+ * Returns the array of component values for this color.
+ *
+ * For an RGB color, this will be an array of 3 values with intensities of
+ * the red, green and blue components, respectively, in a range from 0 to 1.
+ *
+ * Other color spaces that are not RGB colors can have a different amount of
+ * components with different meanings and different ranges.
+ *
+ * Returns: the component values
+ **/
+const float *
+gdk_color_get_components (const GdkColor *self)
+{
+  g_return_val_if_fail (GDK_IS_COLOR (self), NULL);
+
+  return self->components;
+}
+
+/**
+ * gdk_color_get_n_components:
+ * @self: a `GdkColor`
+ *
+ * Gets the number of components of this color. This will be the number of
+ * components returned by gdk_color_get_components().
+ *
+ * Returns: the number of components
+ **/
+gsize
+gdk_color_get_n_components (const GdkColor *self)
+{
+  g_return_val_if_fail (GDK_IS_COLOR (self), 3);
+
+  return gdk_color_space_get_n_components (self->color_space);
+}
+
+/**
+ * gdk_color_convert:
+ * @self: a `GdkColor`
+ * @space: the color space to convert to
+ *
+ * Converts a color into a different colorspace, potentially
+ * tone-mapping it if it is out of gamut.
+ *
+ * Returns: a new color in the new colorspace.
+ **/
+GdkColor *
+gdk_color_convert (const GdkColor *self,
+                   GdkColorSpace  *space)
+{
+  GdkColor *result;
+  gsize n_components;
+
+  g_return_val_if_fail (GDK_IS_COLOR (self), NULL);
+  g_return_val_if_fail (GDK_IS_COLOR_SPACE (space), NULL);
+
+  result = gdk_color_alloc (space);
+  n_components = gdk_color_space_get_n_components (self->color_space);
+  result->components[n_components] = self->components[n_components];
+  GDK_COLOR_SPACE_GET_CLASS (space)->convert_color (space, result->components, self);
+
+  return result;
+}
+