render/color: add wlr_color_primaries_to_xyz()

include/render/color.h

@@ -45,4 +45,9 @@ struct wlr_color_transform_lut3d {
 struct wlr_color_transform_lut3d *wlr_color_transform_lut3d_from_base(
 	struct wlr_color_transform *tr);
 
+/**
+ * Compute the matrix to convert RGB color values to CIE 1931 XYZ.
+ */
+void wlr_color_primaries_to_xyz(const struct wlr_color_primaries *primaries, float matrix[static 9]);
+
 #endif

include/wlr/render/color.h

@@ -12,6 +12,20 @@
 #include <stdbool.h>
 #include <sys/types.h>
 
+/**
+ * CIE 1931 xy chromaticity coordinates.
+ */
+struct wlr_color_cie1931_xy {
+	float x, y;
+};
+
+/**
+ * Color primaries and white point describing a color volume.
+ */
+struct wlr_color_primaries {
+	struct wlr_color_cie1931_xy red, green, blue, white;
+};
+
 /**
  * A color transformation formula, which maps a linear color space with
  * sRGB primaries to an output color space.