sway/commands/output: Add command to set color profile

This makes it possible to render output buffers in a different color
space, by specifying an ICC profile for the output.

13 files changed, 147 insertions, 1 deletions

diff --git a/.builds/alpine.yml b/.builds/alpine.yml
index 055e5ffa..7a1fa58e 100644
--- a/.builds/alpine.yml
+++ b/.builds/alpine.yml
@@ -4,6 +4,7 @@ packages:
   - eudev-dev
   - gdk-pixbuf-dev
   - json-c-dev
+  - lcms2-dev
   - libdisplay-info-dev
   - libevdev-dev
   - libinput-dev
diff --git a/.builds/archlinux.yml b/.builds/archlinux.yml
index 9972c01a..e249571e 100644
--- a/.builds/archlinux.yml
+++ b/.builds/archlinux.yml
@@ -3,6 +3,7 @@ packages:
   - cairo
   - gdk-pixbuf2
   - json-c
+  - lcms2
   - libdisplay-info
   - libegl
   - libinput
diff --git a/.builds/freebsd.yml b/.builds/freebsd.yml
index 29c6312a..8084574c 100644
--- a/.builds/freebsd.yml
+++ b/.builds/freebsd.yml
@@ -8,6 +8,7 @@ packages:
 - devel/pkgconf
 - graphics/cairo
 - graphics/gdk-pixbuf2
+- graphics/lcms2
 - graphics/wayland
 - graphics/wayland-protocols
 - textproc/scdoc
diff --git a/include/sway/commands.h b/include/sway/commands.h
index 27058587..0a9fdc70 100644
--- a/include/sway/commands.h
+++ b/include/sway/commands.h
@@ -283,6 +283,7 @@ sway_cmd input_cmd_xkb_variant;
 
 sway_cmd output_cmd_adaptive_sync;
 sway_cmd output_cmd_background;
+sway_cmd output_cmd_color_profile;
 sway_cmd output_cmd_disable;
 sway_cmd output_cmd_dpms;
 sway_cmd output_cmd_enable;
diff --git a/include/sway/config.h b/include/sway/config.h
index 5ccc3e77..3e3a104e 100644
--- a/include/sway/config.h
+++ b/include/sway/config.h
@@ -7,6 +7,7 @@
 #include <wlr/interfaces/wlr_switch.h>
 #include <wlr/types/wlr_tablet_tool.h>
 #include <wlr/util/box.h>
+#include <wlr/render/color.h>
 #include <xkbcommon/xkbcommon.h>
 #include <xf86drmMode.h>
 #include "../include/config.h"
@@ -285,6 +286,8 @@ struct output_config {
         int max_render_time; // In milliseconds
         int adaptive_sync;
         enum render_bit_depth render_bit_depth;
+        bool set_color_transform;
+        struct wlr_color_transform *color_transform;
 
         char *background;
         char *background_option;
diff --git a/include/sway/output.h b/include/sway/output.h
index d546d488..2189c6e8 100644
--- a/include/sway/output.h
+++ b/include/sway/output.h
@@ -66,6 +66,8 @@ struct sway_output {
                 struct wl_signal disable;
         } events;
 
+        struct wlr_color_transform *color_transform;
+
         struct timespec last_presentation;
         uint32_t refresh_nsec;
         int max_render_time; // In milliseconds
diff --git a/sway/commands/output.c b/sway/commands/output.c
index 5e5d31b3..b822e770 100644
--- a/sway/commands/output.c
+++ b/sway/commands/output.c
@@ -10,6 +10,7 @@ static const struct cmd_handler output_handlers[] = {
         { "adaptive_sync", output_cmd_adaptive_sync },
         { "background", output_cmd_background },
         { "bg", output_cmd_background },
+        { "color_profile", output_cmd_color_profile },
         { "disable", output_cmd_disable },
         { "dpms", output_cmd_dpms },
         { "enable", output_cmd_enable },
diff --git a/sway/commands/output/color_profile.c b/sway/commands/output/color_profile.c
new file mode 100644
index 00000000..792bd55f
--- /dev/null
+++ b/sway/commands/output/color_profile.c
@@ -0,0 +1,101 @@
+#include <fcntl.h>
+#include <strings.h>
+#include <sys/stat.h>
+#include <unistd.h>
+#include <wlr/render/color.h>
+#include "sway/commands.h"
+#include "sway/config.h"
+
+static bool read_file_into_buf(const char *path, void **buf, size_t *size) {
+        /* Why not use fopen/fread directly? glibc will succesfully open directories,
+         * not just files, and supports seeking on them. Instead, we directly
+         * work with file descriptors and use the more consistent open/fstat/read. */
+        int fd = open(path, O_RDONLY | O_NOCTTY | O_CLOEXEC);
+        if (fd == -1) {
+                return false;
+        }
+        char *b = NULL;
+        struct stat info;
+        if (fstat(fd, &info) == -1) {
+                goto fail;
+        }
+        // only regular files, to avoid issues with e.g. opening pipes
+        if (!S_ISREG(info.st_mode)) {
+                goto fail;
+        }
+        off_t s = info.st_size;
+        if (s <= 0) {
+                goto fail;
+        }
+        b = calloc(1, s);
+        if (!b) {
+                goto fail;
+        }
+        size_t nread = 0;
+        while (nread < (size_t)s) {
+                size_t to_read = (size_t)s - nread;
+                ssize_t r = read(fd, b + nread, to_read);
+                if ((r == -1 && errno != EINTR) || r == 0) {
+                        goto fail;
+                }
+                nread += (size_t)r;
+        }
+        close(fd);
+        *buf = b;
+        *size = (size_t)s;
+        return true; // success
+fail:
+        free(b);
+        close(fd);
+        return false;
+}
+
+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");
+        }
+        if (!argc) {
+                return cmd_results_new(CMD_INVALID, "Missing color_profile first argument.");
+        }
+
+        if (strcmp(*argv, "srgb") == 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.leftovers.argc = argc - 1;
+                config->handler_context.leftovers.argv = argv + 1;
+        } else if (strcmp(*argv, "icc") == 0) {
+                if (argc < 2) {
+                        return cmd_results_new(CMD_INVALID,
+                                "Invalid color profile specification: icc type requires a file");
+                }
+                void *data = NULL;
+                size_t size = 0;
+                if (!read_file_into_buf(argv[1], &data, &size)) {
+                        return cmd_results_new(CMD_FAILURE,
+                                "Failed to load color profile: could not read ICC file");
+                }
+
+                struct wlr_color_transform *tmp =
+                        wlr_color_transform_init_linear_to_icc(data, size);
+                if (!tmp) {
+                        free(data);
+                        return cmd_results_new(CMD_FAILURE,
+                                "Failed to load color profile: failed to initialize transform from ICC");
+                }
+                free(data);
+
+                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.leftovers.argc = argc - 2;
+                config->handler_context.leftovers.argv = argv + 2;
+        } else {
+                return cmd_results_new(CMD_INVALID,
+                        "Invalid color profile specification: first argument should be icc|srgb");
+        }
+
+        return NULL;
+}
diff --git a/sway/config/output.c b/sway/config/output.c
index 9a447388..bcd21b9b 100644
--- a/sway/config/output.c
+++ b/sway/config/output.c
@@ -76,6 +76,8 @@ 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_transform = NULL;
         oc->power = -1;
         return oc;
 }
@@ -191,6 +193,14 @@ 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_transform) {
+                        wlr_color_transform_ref(src->color_transform);
+                }
+                wlr_color_transform_unref(dst->color_transform);
+                dst->set_color_transform = true;
+                dst->color_transform = src->color_transform;
+        }
         if (src->background) {
                 free(dst->background);
                 dst->background = strdup(src->background);
@@ -557,6 +567,13 @@ static bool finalize_output_config(struct output_config *oc, struct sway_output
                 output->max_render_time = oc->max_render_time;
         }
 
+        if (oc && oc->set_color_transform) {
+                if (oc->color_transform) {
+                        wlr_color_transform_ref(oc->color_transform);
+                }
+                wlr_color_transform_unref(output->color_transform);
+                output->color_transform = oc->color_transform;
+        }
         return true;
 }
 
@@ -997,6 +1014,7 @@ void free_output_config(struct output_config *oc) {
         free(oc->name);
         free(oc->background);
         free(oc->background_option);
+        wlr_color_transform_unref(oc->color_transform);
         free(oc);
 }
 
diff --git a/sway/desktop/output.c b/sway/desktop/output.c
index 2722e556..cfa53021 100644
--- a/sway/desktop/output.c
+++ b/sway/desktop/output.c
@@ -269,7 +269,10 @@ static int output_repaint_timer_handler(void *data) {
                 return 0;
         }
 
-        wlr_scene_output_commit(output->scene_output, NULL);
+        struct wlr_scene_output_state_options opts = {
+                .color_transform = output->color_transform,
+        };
+        wlr_scene_output_commit(output->scene_output, &opts);
         return 0;
 }
 
diff --git a/sway/meson.build b/sway/meson.build
index 47b51d0c..a189fe9a 100644
--- a/sway/meson.build
+++ b/sway/meson.build
@@ -202,6 +202,7 @@ sway_sources = files(
         'commands/output/toggle.c',
         'commands/output/transform.c',
         'commands/output/unplug.c',
+        'commands/output/color_profile.c',
 
         'tree/arrange.c',
         'tree/container.c',
diff --git a/sway/sway-output.5.scd b/sway/sway-output.5.scd
index 7d088d5d..6d7c0860 100644
--- a/sway/sway-output.5.scd
+++ b/sway/sway-output.5.scd
@@ -178,6 +178,18 @@ 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 srgb|[icc <file>]
+        Sets the color profile for an output. The default is _srgb_. <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
+        profile may be inaccurate.
+
+        This command is experimental, and may be removed or changed in the future. It
+        may have no effect or produce unexpected output when used together with future
+        HDR support features.
+
 # SEE ALSO
 
 *sway*(5) *sway-input*(5)
diff --git a/sway/tree/output.c b/sway/tree/output.c
index 2d11195e..6c8dd6dc 100644
--- a/sway/tree/output.c
+++ b/sway/tree/output.c
@@ -279,6 +279,7 @@ void output_destroy(struct sway_output *output) {
         list_free(output->workspaces);
         list_free(output->current.workspaces);
         wl_event_source_remove(output->repaint_timer);
+        wlr_color_transform_unref(output->color_transform);
         free(output);
 }