color-representation-v1: Add wlr enums + converters

Add wlr-internal enums for the properties specified in
color-representation-v1 (encoding, range, chroma siting, alpha mode) so
that other parts of wlroots can use these without depending on the
protocol specifics and without needing to include the protocol headers.
Also add conversion functions to convert the protocol enum values into
the wlroots enum values.

include/wlr/render/color.h

@@ -30,6 +30,57 @@ enum wlr_color_transfer_function {
 	WLR_COLOR_TRANSFER_FUNCTION_EXT_LINEAR = 1 << 2,
 };
 
+/**
+ * Specifies alpha blending modes.  Note that premultiplied_electrical
+ * is the default, so there is no "none" or "unset" value.
+ */
+enum wlr_alpha_mode {
+	WLR_COLOR_ALPHA_MODE_PREMULTIPLIED_ELECTRICAL,
+	WLR_COLOR_ALPHA_MODE_PREMULTIPLIED_OPTICAL,
+	WLR_COLOR_ALPHA_MODE_STRAIGHT,
+};
+
+/**
+ * Well-known color encodings, each representing a set of matrix coefficients
+ * used to convert that particular YCbCr encoding to RGB.  NONE means the
+ * value is unset or unknown.
+ */
+enum wlr_color_encoding {
+	WLR_COLOR_ENCODING_NONE,
+	WLR_COLOR_ENCODING_IDENTITY,
+	WLR_COLOR_ENCODING_BT709,
+	WLR_COLOR_ENCODING_FCC,
+	WLR_COLOR_ENCODING_BT601,
+	WLR_COLOR_ENCODING_SMPTE240,
+	WLR_COLOR_ENCODING_BT2020,
+	WLR_COLOR_ENCODING_BT2020_CL,
+	WLR_COLOR_ENCODING_ICTCP,
+};
+
+/**
+ * Specifies whether a particular color-encoding uses full- or limited-range
+ * values.  NONE means the value is unset or unknown.
+ */
+enum wlr_color_range {
+	WLR_COLOR_RANGE_NONE,
+	WLR_COLOR_RANGE_LIMITED,
+	WLR_COLOR_RANGE_FULL,
+};
+
+/**
+ * Chroma sample locations, corresponding to Chroma420SampleLocType code
+ * points in H.273.  NONE means the value is unset or unknown.
+ */
+enum wlr_color_chroma_location {
+	WLR_COLOR_CHROMA_LOCATION_NONE,
+	WLR_COLOR_CHROMA_LOCATION_TYPE0,
+	WLR_COLOR_CHROMA_LOCATION_TYPE1,
+	WLR_COLOR_CHROMA_LOCATION_TYPE2,
+	WLR_COLOR_CHROMA_LOCATION_TYPE3,
+	WLR_COLOR_CHROMA_LOCATION_TYPE4,
+	WLR_COLOR_CHROMA_LOCATION_TYPE5,
+};
+
 /**
  * CIE 1931 xy chromaticity coordinates.
  */

include/wlr/types/wlr_color_representation_v1.h

@@ -82,4 +82,13 @@ struct wlr_color_representation_v1_surface_state {
 const struct wlr_color_representation_v1_surface_state *wlr_color_representation_v1_get_surface_state(
 	struct wlr_surface *surface);
 
+enum wlr_alpha_mode wlr_color_representation_v1_alpha_mode_to_wlr(
+	enum wp_color_representation_surface_v1_alpha_mode wp_val);
+enum wlr_color_encoding wlr_color_representation_v1_color_encoding_to_wlr(
+	enum wp_color_representation_surface_v1_coefficients wp_val);
+enum wlr_color_range wlr_color_representation_v1_color_range_to_wlr(
+	enum wp_color_representation_surface_v1_range wp_val);
+enum wlr_color_chroma_location wlr_color_representation_v1_chroma_location_to_wlr(
+	enum wp_color_representation_surface_v1_chroma_location wp_val);
+
 #endif // WLR_TYPES_WLR_COLOR_REPRESENTATION_V1_H