[gtk/wip/otte/colorspace: 50/50] colorspace: Add gdk_color_space_get_named ()

[Benjamin Otte <otte src gnome org>]

commit abbd7f0c92e35ebf2001c15e75519ad524a079c8
Author: Benjamin Otte <otte redhat com>
Date:   Mon Oct 25 22:55:34 2021 +0200

    colorspace: Add gdk_color_space_get_named ()
    
    And add a bunch of common color spaces

 gdk/gdkcolorspace.c | 83 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 gdk/gdkcolorspace.h |  2 ++
 gdk/gdkenums.h      | 44 ++++++++++++++++++++++++++++
 3 files changed, 129 insertions(+)
---
diff --git a/gdk/gdkcolorspace.c b/gdk/gdkcolorspace.c
index 4f8d9a74af..08065b9fd8 100644
--- a/gdk/gdkcolorspace.c
+++ b/gdk/gdkcolorspace.c
@@ -159,6 +159,89 @@ gdk_color_space_get_srgb (void)
   return srgb_profile;
 }
 
+GdkColorSpace *
+gdk_color_space_get_named (GdkNamedColorSpace name)
+{
+  static GdkColorSpace *space_array[GDK_NAMED_COLOR_SPACE_N_SPACES];
+  static GdkColorSpace **color_spaces;
+
+  g_return_val_if_fail (name < GDK_NAMED_COLOR_SPACE_N_SPACES, gdk_color_space_get_srgb ());
+
+  if (g_once_init_enter (&color_spaces))
+    {
+      static const cmsCIExyY D65 = { 0.3127, 0.3290, 1.0 };
+      static const cmsFloat64Number srgb_tonecurve[5] = { 2.4, 1. / 1.055, 0.055 / 1.055, 1. / 12.92, 
0.04045 };
+      static const cmsFloat64Number rec709_tonecurve[5] = { 1.0 / 0.45, 1.0 / 1.099, 0.099 / 1.099, 1.0 / 
4.5, 0.081 };
+      cmsToneCurve *curve;
+      cmsHPROFILE lcms_profile;
+
+      space_array[GDK_NAMED_COLOR_SPACE_SRGB] = g_object_ref (gdk_color_space_get_srgb ());
+
+      curve = cmsBuildGamma (NULL, 1.0);
+      lcms_profile = cmsCreateRGBProfile (&D65,
+                                          &(cmsCIExyYTRIPLE) {
+                                            { 0.640, 0.330, 1.0 },
+                                            { 0.300, 0.600, 1.0 },
+                                            { 0.150, 0.060, 1.0 }
+                                          },
+                                          (cmsToneCurve*[3]) { curve, curve, curve });
+      cmsFreeToneCurve (curve);
+      space_array[GDK_NAMED_COLOR_SPACE_SRGB_LINEAR] = gdk_lcms_color_space_new_from_lcms_profile 
(lcms_profile);
+
+      space_array[GDK_NAMED_COLOR_SPACE_XYZ_D50] = gdk_lcms_color_space_new_from_lcms_profile 
(cmsCreateXYZProfile ());
+      /* XXX: This needs a D65 whitepoint here */
+      space_array[GDK_NAMED_COLOR_SPACE_XYZ_D65] = gdk_lcms_color_space_new_from_lcms_profile 
(cmsCreateXYZProfile ());
+
+      curve = cmsBuildParametricToneCurve (NULL, 4, srgb_tonecurve);
+      lcms_profile = cmsCreateRGBProfile (&D65,
+                                          &(cmsCIExyYTRIPLE) {
+                                            { 0.680, 0.320, 1.0 },
+                                            { 0.265, 0.690, 1.0 },
+                                            { 0.150, 0.060, 1.0 }
+                                          },
+                                          (cmsToneCurve*[3]) { curve, curve, curve });
+      cmsFreeToneCurve (curve);
+      space_array[GDK_NAMED_COLOR_SPACE_DISPLAY_P3] = gdk_lcms_color_space_new_from_lcms_profile 
(lcms_profile);
+
+      curve = cmsBuildGamma(NULL, 2.19921875);
+      lcms_profile = cmsCreateRGBProfile (&D65,
+                                          &(cmsCIExyYTRIPLE) {
+                                            { 0.640, 0.330, 1.0 },
+                                            { 0.210, 0.710, 1.0 },
+                                            { 0.150, 0.060, 1.0 }
+                                          },
+                                          (cmsToneCurve*[3]) { curve, curve, curve });
+      cmsFreeToneCurve (curve);
+      space_array[GDK_NAMED_COLOR_SPACE_A98_RGB] = gdk_lcms_color_space_new_from_lcms_profile (lcms_profile);
+
+      curve = cmsBuildParametricToneCurve (NULL, 4, rec709_tonecurve);
+      lcms_profile = cmsCreateRGBProfile (cmsD50_xyY (),
+                                          &(cmsCIExyYTRIPLE) {
+                                            { 0.734699,        0.265301, 1.0 },
+                                            { 0.159597, 0.840403, 1.0 },
+                                            { 0.036598, 0.000105, 1.0 }
+                                          },
+                                          (cmsToneCurve*[3]) { curve, curve, curve });
+      cmsFreeToneCurve (curve);
+      space_array[GDK_NAMED_COLOR_SPACE_PROPHOTO_RGB] = gdk_lcms_color_space_new_from_lcms_profile 
(lcms_profile);
+
+      curve = cmsBuildParametricToneCurve (NULL, 4, rec709_tonecurve);
+      lcms_profile = cmsCreateRGBProfile (&D65,
+                                          &(cmsCIExyYTRIPLE) {
+                                            { 0.708, 0.292, 1.0 },
+                                            { 0.170, 0.797, 1.0 },
+                                            { 0.131, 0.046, 1.0 }
+                                          },
+                                          (cmsToneCurve*[3]) { curve, curve, curve });
+      cmsFreeToneCurve (curve);
+      space_array[GDK_NAMED_COLOR_SPACE_REC2020] = gdk_lcms_color_space_new_from_lcms_profile (lcms_profile);
+
+      g_once_init_leave (&color_spaces, space_array);
+    }
+
+  return color_spaces[name];
+}
+
 /**
  * gdk_color_space_supports_format:
  * @self: a `GdkColorSpace`
diff --git a/gdk/gdkcolorspace.h b/gdk/gdkcolorspace.h
index acf91b41e5..0eaff7c4d6 100644
--- a/gdk/gdkcolorspace.h
+++ b/gdk/gdkcolorspace.h
@@ -47,6 +47,8 @@ GType                   gdk_color_space_get_type                (void) G_GNUC_CO
 
 GDK_AVAILABLE_IN_4_6
 GdkColorSpace *         gdk_color_space_get_srgb                (void) G_GNUC_CONST;
+GDK_AVAILABLE_IN_4_6
+GdkColorSpace *         gdk_color_space_get_named               (GdkNamedColorSpace    name) G_GNUC_CONST;
 
 GDK_AVAILABLE_IN_4_6
 GdkColorSpace *         gdk_color_space_new_from_icc_profile    (GBytes               *icc_profile,
diff --git a/gdk/gdkenums.h b/gdk/gdkenums.h
index 11654a513f..c8b28b6a44 100644
--- a/gdk/gdkenums.h
+++ b/gdk/gdkenums.h
@@ -331,6 +331,50 @@ typedef enum {
   GDK_MEMORY_N_FORMATS
 } GdkMemoryFormat;
 
+/**
+ * GdkNamedColorSpace:
+ * @GDK_NAMED_COLOR_SPACE_SRGB: the sRGB color space,
+ *   see gdk_color_space_get_srgb() for details
+ * @GDK_NAMED_COLOR_SPACE_SRGB_LINEAR: the same sRGB color space, but
+ *   with a linear light tone curve
+ * @GDK_NAMED_COLOR_SPACE_XYZ_D50: the CIE XYZ color space, with the D50
+ *   white point
+ * @GDK_NAMED_COLOR_SPACE_XYZ_D65: the CIE CYZ color space, with the D65
+ *   white point
+ * @GDK_NAMED_COLOR_SPACE_DISPLAY_P3: the [DCI P3](https://en.wikipedia.org/wiki/DCI-P3)
+ *   color space with a D65 whitepoint as created by Apple
+ * @GDK_NAMED_COLOR_SPACE_A98_RGB: the [Adobe 1998 RGB](https://en.wikipedia.org/wiki/Adobe_RGB_color_space)
+ *   color space
+ * @GDK_NAMED_COLOR_SPACE_PROPHOTO_RGB: the [ProPhoto 
RGB](https://en.wikipedia.org/wiki/ProPhoto_RGB_color_space)
+ *   color space
+ * @GDK_NAMED_COLOR_SPACE_REC2020: the [Rec 2020](https://en.wikipedia.org/wiki/Rec._2020)
+ *   color space
+ * @GDK_NAMED_COLOR_SPACE_N_SPACES: The number of named color spaces.
+ *   This value will change as more color spaces get added, so do not
+ *   rely on its concrete integer.
+ * 
+ *
+ * The list of predefined color spaces. GDK provides the common
+ * color spaces used by CSS and other standards so applications can make
+ * use of them.
+ *
+ * More color spaces may be added in the future.
+ *
+ * Since: 4.6
+ **/
+typedef enum {
+  GDK_NAMED_COLOR_SPACE_SRGB,
+  GDK_NAMED_COLOR_SPACE_SRGB_LINEAR,
+  GDK_NAMED_COLOR_SPACE_XYZ_D50,
+  GDK_NAMED_COLOR_SPACE_XYZ_D65,
+  GDK_NAMED_COLOR_SPACE_DISPLAY_P3,
+  GDK_NAMED_COLOR_SPACE_A98_RGB,
+  GDK_NAMED_COLOR_SPACE_PROPHOTO_RGB,
+  GDK_NAMED_COLOR_SPACE_REC2020,
+
+  GDK_NAMED_COLOR_SPACE_N_SPACES
+} GdkNamedColorSpace;
+
 G_END_DECLS
 
 #endif /* __GDK_ENUMS_H__ */