output: add color_format command

Allow configuring the output color format (RGB/YPbPr) via the
output config. Exposes the value in IPC JSON output.

include/sway/commands.h

@@ -286,6 +286,7 @@ sway_cmd input_cmd_xkb_variant;
 sway_cmd output_cmd_adaptive_sync;
 sway_cmd output_cmd_allow_tearing;
 sway_cmd output_cmd_background;
+sway_cmd output_cmd_color_format;
 sway_cmd output_cmd_color_profile;
 sway_cmd output_cmd_disable;
 sway_cmd output_cmd_dpms;

include/sway/config.h

@@ -8,6 +8,7 @@
 #include <wlr/types/wlr_tablet_tool.h>
 #include <wlr/util/box.h>
 #include <wlr/render/color.h>
+#include <wlr/types/wlr_output.h>
 #include <xkbcommon/xkbcommon.h>
 #include <xf86drmMode.h>
 #include "../include/config.h"
@@ -294,6 +295,7 @@ struct output_config {
 	int max_render_time; // In milliseconds
 	int adaptive_sync;
 	enum render_bit_depth render_bit_depth;
+	enum wlr_output_color_format color_format;
 	enum color_profile color_profile;
 	struct wlr_color_transform *color_transform;
 	int allow_tearing;

sway/commands/output.c

@@ -11,6 +11,7 @@ static const struct cmd_handler output_handlers[] = {
 	{ "allow_tearing", output_cmd_allow_tearing },
 	{ "background", output_cmd_background },
 	{ "bg", output_cmd_background },
+	{ "color_format", output_cmd_color_format },
 	{ "color_profile", output_cmd_color_profile },
 	{ "disable", output_cmd_disable },
 	{ "dpms", output_cmd_dpms },

sway/commands/output/color_format.c

@@ -0,0 +1,36 @@
+#include <strings.h>
+#include "sway/commands.h"
+#include "sway/config.h"
+
+struct cmd_results *output_cmd_color_format(int argc, char **argv) {
+	if (!config->handler_context.output_config) {
+		return cmd_results_new(CMD_FAILURE, "Missing output config");
+	}
+	if (!argc) {
+		return cmd_results_new(CMD_INVALID, "Missing color format argument.");
+	}
+
+	if (strcmp(*argv, "auto") == 0) {
+		config->handler_context.output_config->color_format =
+			WLR_OUTPUT_COLOR_FORMAT_AUTO;
+	} else if (strcmp(*argv, "rgb") == 0) {
+		config->handler_context.output_config->color_format =
+			WLR_OUTPUT_COLOR_FORMAT_RGB444;
+	} else if (strcmp(*argv, "yuv444") == 0) {
+		config->handler_context.output_config->color_format =
+			WLR_OUTPUT_COLOR_FORMAT_YCBCR444;
+	} else if (strcmp(*argv, "yuv422") == 0) {
+		config->handler_context.output_config->color_format =
+			WLR_OUTPUT_COLOR_FORMAT_YCBCR422;
+	} else if (strcmp(*argv, "yuv420") == 0) {
+		config->handler_context.output_config->color_format =
+			WLR_OUTPUT_COLOR_FORMAT_YCBCR420;
+	} else {
+		return cmd_results_new(CMD_INVALID,
+			"Invalid color format. Must be a value in (auto|rgb|yuv444|yuv422|yuv420).");
+	}
+
+	config->handler_context.leftovers.argc = argc - 1;
+	config->handler_context.leftovers.argv = argv + 1;
+	return NULL;
+}

sway/config/output.c

@@ -75,6 +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->color_format = WLR_OUTPUT_COLOR_FORMAT_AUTO;
 	oc->color_profile = COLOR_PROFILE_DEFAULT;
 	oc->color_transform = NULL;
 	oc->power = -1;
@@ -130,6 +131,9 @@ 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->color_format != WLR_OUTPUT_COLOR_FORMAT_AUTO) {
+		dst->color_format = WLR_OUTPUT_COLOR_FORMAT_AUTO;
+	}
 	if (src->color_profile != COLOR_PROFILE_DEFAULT) {
 		if (dst->color_transform) {
 			wlr_color_transform_unref(dst->color_transform);
@@ -207,6 +211,9 @@ 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->color_format != WLR_OUTPUT_COLOR_FORMAT_AUTO) {
+		dst->color_format = src->color_format;
+	}
 	if (src->color_profile != COLOR_PROFILE_DEFAULT) {
 		if (src->color_transform) {
 			wlr_color_transform_ref(src->color_transform);
@@ -553,6 +560,9 @@ static void queue_output_config(struct output_config *oc,
 	} else {
 		wlr_output_state_set_render_format(pending, DRM_FORMAT_XRGB8888);
 	}
+	if (oc && oc->color_format != WLR_OUTPUT_COLOR_FORMAT_AUTO) {
+		wlr_output_state_set_color_format(pending, oc->color_format);
+	}
 
 	bool hdr = oc && oc->hdr == 1;
 	bool color_profile = oc && (oc->color_transform != NULL

sway/desktop/output.c

@@ -628,6 +628,7 @@ static struct output_config *output_config_for_config_head(
 	oc->transform = config_head->state.transform;
 	oc->scale = config_head->state.scale;
 	oc->adaptive_sync = config_head->state.adaptive_sync_enabled;
+	oc->color_format = config_head->state.color_format;
 	return oc;
 }
 

sway/ipc-json.c

@@ -410,6 +410,17 @@ static void ipc_json_describe_enabled_output(struct sway_output *output,
 	json_object_object_add(object, "max_render_time", json_object_new_int(output->max_render_time));
 	json_object_object_add(object, "allow_tearing", json_object_new_boolean(output->allow_tearing));
 	json_object_object_add(object, "hdr", json_object_new_boolean(output->hdr));
+
+	const char *color_format_str = NULL;
+	switch (wlr_output->color_format) {
+	case WLR_OUTPUT_COLOR_FORMAT_AUTO: color_format_str = "auto"; break;
+	case WLR_OUTPUT_COLOR_FORMAT_RGB444: color_format_str = "rgb"; break;
+	case WLR_OUTPUT_COLOR_FORMAT_YCBCR444: color_format_str = "yuv444"; break;
+	case WLR_OUTPUT_COLOR_FORMAT_YCBCR422: color_format_str = "yuv422"; break;
+	case WLR_OUTPUT_COLOR_FORMAT_YCBCR420: color_format_str = "yuv420"; break;
+	}
+	json_object_object_add(object, "color_format",
+		json_object_new_string(color_format_str));
 }
 
 json_object *ipc_json_describe_disabled_output(struct sway_output *output) {

sway/meson.build

@@ -192,6 +192,7 @@ sway_sources = files(
 	'commands/output/adaptive_sync.c',
 	'commands/output/allow_tearing.c',
 	'commands/output/background.c',
+	'commands/output/color_format.c',
 	'commands/output/disable.c',
 	'commands/output/dpms.c',
 	'commands/output/enable.c',