sway/commands/output: add color_profile "--device-primaries"

When a display is connected, create a color transform from its
self-reported color characteristics

include/sway/config.h

@@ -267,6 +267,12 @@ enum render_bit_depth {
 	RENDER_BIT_DEPTH_10,
 };
 
+enum color_profile {
+	COLOR_PROFILE_DEFAULT, // default is Transform with NULL color_transform
+	COLOR_PROFILE_TRANSFORM, // use color_transform from output_config
+	COLOR_PROFILE_TRANSFORM_WITH_DEVICE_PRIMARIES, // create transform from wlr_output
+};
+
 /**
  * Size and position configuration for a particular output.
  *
@@ -288,7 +294,7 @@ struct output_config {
 	int max_render_time; // In milliseconds
 	int adaptive_sync;
 	enum render_bit_depth render_bit_depth;
-	bool set_color_transform;
+	enum color_profile color_profile;
 	struct wlr_color_transform *color_transform;
 	int allow_tearing;
 	int hdr;

sway/commands/output/color_profile.c

@@ -55,6 +55,14 @@ struct cmd_results *output_cmd_color_profile(int argc, char **argv) {
 	if (!config->handler_context.output_config) {
 		return cmd_results_new(CMD_FAILURE, "Missing output config");
 	}
+
+	enum color_profile new_mode = COLOR_PROFILE_TRANSFORM;
+	if (argc >= 2 && strcmp(*argv, "--device-primaries") == 0) {
+		new_mode = COLOR_PROFILE_TRANSFORM_WITH_DEVICE_PRIMARIES;
+		argc--;
+		argv++;
+	}
+
 	if (!argc) {
 		return cmd_results_new(CMD_INVALID, "Missing color_profile first argument.");
 	}
@@ -62,7 +70,7 @@ struct cmd_results *output_cmd_color_profile(int argc, char **argv) {
 	if (strcmp(*argv, "gamma22") == 0) {
 		wlr_color_transform_unref(config->handler_context.output_config->color_transform);
 		config->handler_context.output_config->color_transform = NULL;
-		config->handler_context.output_config->set_color_transform = true;
+		config->handler_context.output_config->color_profile = new_mode;
 
 		config->handler_context.leftovers.argc = argc - 1;
 		config->handler_context.leftovers.argv = argv + 1;
@@ -70,7 +78,7 @@ struct cmd_results *output_cmd_color_profile(int argc, char **argv) {
 		wlr_color_transform_unref(config->handler_context.output_config->color_transform);
 		config->handler_context.output_config->color_transform =
 			wlr_color_transform_init_linear_to_inverse_eotf(WLR_COLOR_TRANSFER_FUNCTION_SRGB);
-		config->handler_context.output_config->set_color_transform = true;
+		config->handler_context.output_config->color_profile = new_mode;
 
 		config->handler_context.leftovers.argc = argc - 1;
 		config->handler_context.leftovers.argv = argv + 1;
@@ -79,6 +87,10 @@ struct cmd_results *output_cmd_color_profile(int argc, char **argv) {
 			return cmd_results_new(CMD_INVALID,
 				"Invalid color profile specification: icc type requires a file");
 		}
+		if (new_mode != COLOR_PROFILE_TRANSFORM) {
+			return cmd_results_new(CMD_INVALID,
+				"Invalid color profile specification: --device-primaries cannot be used with icc");
+		}
 
 		char *icc_path = strdup(argv[1]);
 		if (!expand_path(&icc_path)) {
@@ -108,7 +120,7 @@ struct cmd_results *output_cmd_color_profile(int argc, char **argv) {
 
 		wlr_color_transform_unref(config->handler_context.output_config->color_transform);
 		config->handler_context.output_config->color_transform = tmp;
-		config->handler_context.output_config->set_color_transform = true;
+		config->handler_context.output_config->color_profile = COLOR_PROFILE_TRANSFORM;
 
 		config->handler_context.leftovers.argc = argc - 2;
 		config->handler_context.leftovers.argv = argv + 2;

sway/config/output.c

@@ -75,7 +75,7 @@ struct output_config *new_output_config(const char *name) {
 	oc->max_render_time = -1;
 	oc->adaptive_sync = -1;
 	oc->render_bit_depth = RENDER_BIT_DEPTH_DEFAULT;
-	oc->set_color_transform = false;
+	oc->color_profile = COLOR_PROFILE_DEFAULT;
 	oc->color_transform = NULL;
 	oc->power = -1;
 	oc->allow_tearing = -1;
@@ -130,12 +130,12 @@ static void supersede_output_config(struct output_config *dst, struct output_con
 	if (src->render_bit_depth != RENDER_BIT_DEPTH_DEFAULT) {
 		dst->render_bit_depth = RENDER_BIT_DEPTH_DEFAULT;
 	}
-	if (src->set_color_transform) {
+	if (src->color_profile != COLOR_PROFILE_DEFAULT) {
 		if (dst->color_transform) {
 			wlr_color_transform_unref(dst->color_transform);
 			dst->color_transform = NULL;
 		}
-		dst->set_color_transform = false;
+		dst->color_profile = COLOR_PROFILE_DEFAULT;
 	}
 	if (src->background) {
 		free(dst->background);
@@ -207,12 +207,12 @@ static void merge_output_config(struct output_config *dst, struct output_config
 	if (src->render_bit_depth != RENDER_BIT_DEPTH_DEFAULT) {
 		dst->render_bit_depth = src->render_bit_depth;
 	}
-	if (src->set_color_transform) {
+	if (src->color_profile != COLOR_PROFILE_DEFAULT) {
 		if (src->color_transform) {
 			wlr_color_transform_ref(src->color_transform);
 		}
 		wlr_color_transform_unref(dst->color_transform);
-		dst->set_color_transform = true;
+		dst->color_profile = src->color_profile;
 		dst->color_transform = src->color_transform;
 	}
 	if (src->background) {
@@ -570,13 +570,60 @@ static void config_output_state_finish(struct config_output_state *state) {
 	wlr_color_transform_unref(state->color_transform);
 }
 
+static struct wlr_color_transform *color_profile_from_device(struct wlr_output *wlr_output,
+		struct wlr_color_transform *transfer_function) {
+	struct wlr_color_primaries srgb_primaries;
+	wlr_color_primaries_from_named(&srgb_primaries, WLR_COLOR_NAMED_PRIMARIES_SRGB);
+
+	const struct wlr_color_primaries *primaries = wlr_output->default_primaries;
+	if (primaries == NULL) {
+		sway_log(SWAY_INFO, "output has no reported color information");
+		if (transfer_function) {
+			wlr_color_transform_ref(transfer_function);
+		}
+		return transfer_function;
+	} else if (memcmp(primaries, &srgb_primaries, sizeof(*primaries)) == 0) {
+		sway_log(SWAY_INFO, "output reports sRGB colors, no correction needed");
+		if (transfer_function) {
+			wlr_color_transform_ref(transfer_function);
+		}
+		return transfer_function;
+	} else {
+		sway_log(SWAY_INFO, "Creating color profile from reported color primaries: "
+				"R(%f, %f) G(%f, %f) B(%f, %f) W(%f, %f)",
+			primaries->red.x, primaries->red.y, primaries->green.x, primaries->green.y,
+			primaries->blue.x, primaries->blue.y, primaries->white.x, primaries->white.y);
+		float matrix[9];
+		wlr_color_primaries_transform_absolute_colorimetric(&srgb_primaries, primaries, matrix);
+		struct wlr_color_transform *matrix_transform = wlr_color_transform_init_matrix(matrix);
+		if (matrix_transform == NULL) {
+			return NULL;
+		}
+		struct wlr_color_transform *resolved_tf = transfer_function ?
+			wlr_color_transform_ref(transfer_function) :
+			wlr_color_transform_init_linear_to_inverse_eotf(WLR_COLOR_TRANSFER_FUNCTION_GAMMA22);
+		if (resolved_tf == NULL) {
+			wlr_color_transform_unref(matrix_transform);
+			return NULL;
+		}
+		struct wlr_color_transform *transforms[] = { matrix_transform, resolved_tf };
+		size_t transforms_len = sizeof(transforms) / sizeof(transforms[0]);
+		struct wlr_color_transform *result = wlr_color_transform_init_pipeline(transforms, transforms_len);
+		wlr_color_transform_unref(matrix_transform);
+		wlr_color_transform_unref(resolved_tf);
+		return result;
+	}
+}
+
 static struct wlr_color_transform *get_color_profile(struct wlr_output *output,
 		struct output_config *oc) {
-	if (oc && oc->set_color_transform) {
+	if (oc && oc->color_profile == COLOR_PROFILE_TRANSFORM) {
 		if (oc->color_transform) {
 			wlr_color_transform_ref(oc->color_transform);
 		}
 		return oc->color_transform;
+	} else if (oc && oc->color_profile == COLOR_PROFILE_TRANSFORM_WITH_DEVICE_PRIMARIES) {
+		return color_profile_from_device(output, oc->color_transform);
 	} else {
 		return NULL;
 	}

sway/sway-output.5.scd

@@ -178,9 +178,19 @@ must be separated by one space. For example:
 	updated to work with different bit depths. This command is experimental,
 	and may be removed or changed in the future.
 
-*output* <name> color_profile gamma22|srgb|[icc <file>]
+*output* <name> color_profile [--device-primaries] gamma22|srgb
-	Sets the color profile for an output. The default is _gamma22_. <file> should be a
+	Sets the color profile for an output. The default is _gamma22_.
-	path to a display ICC profile.
+
+	_--device-primaries_ will use the output's self-reported color primaries
+	when available (e.g. from display EDID).
+
+	Not all renderers support this feature; currently it only works with the
+	the Vulkan renderer. It is not compatible with HDR support features.
+
+*output* <name> color_profile icc <file>
+	Sets the color profile for an output.
+
+	<file> should be a path to a display ICC profile.
 
 	Not all renderers support this feature; currently it only works with the
 	the Vulkan renderer. Even where supported, the application of the color