wlsunset/main.c

#define _XOPEN_SOURCE 700
#define _POSIX_C_SOURCE 200809L
#include <errno.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/mman.h>
#include <sys/types.h>
#include <unistd.h>
#include <wayland-client-protocol.h>
#include <wayland-client.h>
#include <time.h>
#include <poll.h>
#include "wlr-gamma-control-unstable-v1-client-protocol.h"

enum state {
	HIGH_TEMP,
	LOW_TEMP,
	ANIMATING_TO_HIGH,
	ANIMATING_TO_LOW,
};

struct context {
	double gamma;
	time_t start_time;
	time_t stop_time;
	int high_temp;
	int low_temp;
	int duration;

	int cur_temp;
	bool new_output;
	enum state state;
	time_t animation_start;

	struct wl_list outputs;
};

struct output {
	struct context *context;
	struct wl_output *wl_output;
	int id;
	struct zwlr_gamma_control_v1 *gamma_control;
	uint32_t ramp_size;
	int table_fd;
	uint16_t *table;
	struct wl_list link;
};

static struct zwlr_gamma_control_manager_v1 *gamma_control_manager = NULL;

static int create_anonymous_file(off_t size) {
	char template[] = "/tmp/wlroots-shared-XXXXXX";
	int fd = mkstemp(template);
	if (fd < 0) {
		return -1;
	}

	int ret;
	do {
		errno = 0;
		ret = ftruncate(fd, size);
	} while (errno == EINTR);
	if (ret < 0) {
		close(fd);
		return -1;
	}

	unlink(template);
	return fd;
}

static int create_gamma_table(uint32_t ramp_size, uint16_t **table) {
	size_t table_size = ramp_size * 3 * sizeof(uint16_t);
	int fd = create_anonymous_file(table_size);
	if (fd < 0) {
		fprintf(stderr, "failed to create anonymous file\n");
		return -1;
	}

	void *data =
		mmap(NULL, table_size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
	if (data == MAP_FAILED) {
		fprintf(stderr, "failed to mmap()\n");
		close(fd);
		return -1;
	}

	*table = data;
	return fd;
}

static void gamma_control_handle_gamma_size(void *data,
		struct zwlr_gamma_control_v1 *gamma_control, uint32_t ramp_size) {
	struct output *output = data;
	output->ramp_size = ramp_size;
	output->table_fd = create_gamma_table(ramp_size, &output->table);
	output->context->new_output = true;
	if (output->table_fd < 0) {
		exit(EXIT_FAILURE);
	}
}

static void gamma_control_handle_failed(void *data,
		struct zwlr_gamma_control_v1 *gamma_control) {
	fprintf(stderr, "failed to set gamma table\n");
}

static const struct zwlr_gamma_control_v1_listener gamma_control_listener = {
	.gamma_size = gamma_control_handle_gamma_size,
	.failed = gamma_control_handle_failed,
};

static bool setup_output(struct output *output) {
	if (gamma_control_manager == NULL || output->gamma_control != NULL) {
		return false;
	}
	output->gamma_control = zwlr_gamma_control_manager_v1_get_gamma_control(
		gamma_control_manager, output->wl_output);
	zwlr_gamma_control_v1_add_listener(output->gamma_control,
		&gamma_control_listener, output);
	return true;
}

static void registry_handle_global(void *data, struct wl_registry *registry,
		uint32_t name, const char *interface, uint32_t version) {
	struct context *ctx = (struct context *)data;
	if (strcmp(interface, wl_output_interface.name) == 0) {
		struct output *output = calloc(1, sizeof(struct output));
		output->id = name;
		output->wl_output = wl_registry_bind(registry, name,
				&wl_output_interface, 1);
		output->table_fd = -1;
		output->context = ctx;
		wl_list_insert(&ctx->outputs, &output->link);
		setup_output(output);
	} else if (strcmp(interface,
				zwlr_gamma_control_manager_v1_interface.name) == 0) {
		gamma_control_manager = wl_registry_bind(registry, name,
				&zwlr_gamma_control_manager_v1_interface, 1);
	}
}

static void registry_handle_global_remove(void *data,
		struct wl_registry *registry, uint32_t name) {
	struct context *ctx = (struct context *)data;
	struct output *output, *tmp;
	wl_list_for_each_safe(output, tmp, &ctx->outputs, link) {
		if (output->id == name) {
			if (output->gamma_control != NULL) {
				zwlr_gamma_control_v1_destroy(output->gamma_control);
			}
			if (output->table_fd != -1) {
				close(output->table_fd);
			}
			wl_list_remove(&output->link);
			break;
		}
	}
}

static const struct wl_registry_listener registry_listener = {
	.global = registry_handle_global,
	.global_remove = registry_handle_global_remove,
};

static void fill_gamma_table(uint16_t *table, uint32_t ramp_size, double rw, double gw, double bw, double gamma) {
	uint16_t *r = table;
	uint16_t *g = table + ramp_size;
	uint16_t *b = table + 2 * ramp_size;
	for (uint32_t i = 0; i < ramp_size; ++i) {
		double val = (double)i / (ramp_size - 1);
		r[i] = (uint16_t)(UINT16_MAX * pow(val * rw, 1.0 / gamma));
		g[i] = (uint16_t)(UINT16_MAX * pow(val * gw, 1.0 / gamma));
		b[i] = (uint16_t)(UINT16_MAX * pow(val * bw, 1.0 / gamma));
	}
}

static int illuminant_d(int temp, double *x, double *y) {
	// https://en.wikipedia.org/wiki/Standard_illuminant#Illuminant_series_D
	if (temp >= 4000 && temp <= 7000) {
		*x = 0.244063 + (0.09911e3/temp) + (2.9678e6/pow(temp, 2)) - (4.6070e9/pow(temp, 3));
	} else if (temp > 7000 && temp <= 25000) {
		*x = 0.237040 + (0.24748e3/temp) + (1.9018e6/pow(temp, 2)) - (2.0064e9/pow(temp, 3));
	} else {
		errno = EINVAL;
		return -1;
	}
	*y = (-3 * pow(*x, 2)) + (2.870 * (*x)) - 0.275;
	return 0;
}

static int planckian_locus(int temp, double *x, double *y) {
	if (temp >= 1667 && temp <= 4000) {
		*x = (-0.2661239e9/pow(temp, 3)) - (0.2343589e6/pow(temp, 2)) + (0.8776956e3/temp) + 0.179910;
		if (temp <= 2222) {
			*y = (-1.1064814 * pow(*x, 3)) - (1.34811020 * pow(*x, 2)) + (2.18555832 * (*x)) - 0.20219683;
		} else {
			*y = (-0.9549476 * pow(*x, 3)) - (1.37418593 * pow(*x, 2)) + (2.09137015 * (*x)) - 0.16748867;
		}
	} else if (temp > 4000 && temp < 25000) {
		*x = (-3.0258469e9/pow(temp, 3)) + (2.1070379e6/pow(temp, 2)) + (0.2226347e3/temp) + 0.240390;
		*y = (3.0817580 * pow(*x, 3)) - (5.87338670 * pow(*x, 2)) + (3.75112997 * (*x)) - 0.37001483;
	} else {
		errno = EINVAL;
		return -1;
	}
	return 0;
}

static double srgb_gamma(double value, double gamma) {
	// https://en.wikipedia.org/wiki/SRGB
	if (value <= 0.0031308) {
		return 12.92 * value;
	} else {
		return pow(1.055 * value, 1.0/gamma) - 0.055;
	}
}

static double clamp(double value) {
	if (value > 1.0) {
		return 1.0;
	} else if (value < 0.0) {
		return 0.0;
	} else {
		return value;
	}
}

static void xyz_to_srgb(double x, double y, double z, double *r, double *g, double *b) {
	// http://www.brucelindbloom.com/index.html?Eqn_RGB_XYZ_Matrix.html
	*r = srgb_gamma(clamp(3.2404542 * x - 1.5371385 * y - 0.4985314 * z), 2.2);
	*g = srgb_gamma(clamp(-0.9692660 * x + 1.8760108 * y + 0.0415560 * z), 2.2);
	*b = srgb_gamma(clamp(0.0556434 * x - 0.2040259 * y + 1.0572252 * z), 2.2);
}

static void srgb_normalize(double *r, double *g, double *b) {
	double maxw = fmaxl(*r, fmaxl(*g, *b));
	*r /= maxw;
	*g /= maxw;
	*b /= maxw;
}

static void calc_whitepoint(int temp, double *rw, double *gw, double *bw) {
	if (temp == 6500) {
		*rw = *gw = *bw = 1.0;
		return;
	}

	double x = 1.0, y = 1.0;
	if (temp > 1667 && temp <= 6500) {
		planckian_locus(temp, &x, &y);
	} else if (temp >= 6500 && temp <= 25000) {
		illuminant_d(temp, &x, &y);
	}
	double z = 1.0 - x - y;

	xyz_to_srgb(x, y, z, rw, gw, bw);
	srgb_normalize(rw, gw, bw);
}

static void set_temperature(struct context *ctx) {
	double rw, gw, bw;
	calc_whitepoint(ctx->cur_temp, &rw, &gw, &bw);

	struct output *output;
	wl_list_for_each(output, &ctx->outputs, link) {
		if (output->gamma_control == NULL || output->table_fd == -1) {
			continue;
		}
		fill_gamma_table(output->table, output->ramp_size,
				rw, gw, bw, ctx->gamma);
		lseek(output->table_fd, 0, SEEK_SET);
		zwlr_gamma_control_v1_set_gamma(output->gamma_control,
				output->table_fd);
	}
}

static void update_temperature(struct context *ctx) {
	time_t now = time(NULL);
	time_t t = now % 86400;
	int temp, temp_pos;
	double time_pos;

	switch (ctx->state) {
	case HIGH_TEMP:
		if (t > ctx->stop_time || t < ctx->start_time) {
			ctx->state = ANIMATING_TO_LOW;
			ctx->animation_start = now;
		}
		temp = ctx->high_temp;
		break;
	case LOW_TEMP:
		if (t > ctx->start_time || t < ctx->stop_time) {
			ctx->state = ANIMATING_TO_HIGH;
			ctx->animation_start = now;
		}
		temp = ctx->low_temp;
		break;
	case ANIMATING_TO_HIGH:
		if (now > ctx->animation_start + ctx->duration) {
			ctx->state = HIGH_TEMP;
		}
		time_pos = clamp(((double)now - (double)ctx->animation_start) / (double)ctx->duration);
		temp_pos = (double)(ctx->high_temp - ctx->low_temp) * time_pos;
		temp = ctx->low_temp + temp_pos;
		break;
	case ANIMATING_TO_LOW:
		if (now > ctx->animation_start + ctx->duration) {
			ctx->state = LOW_TEMP;
		}
		time_pos = clamp(((double)now - (double)ctx->animation_start) / (double)ctx->duration);
		temp_pos = (double)(ctx->high_temp - ctx->low_temp) * time_pos;
		temp = ctx->high_temp - temp_pos;
		break;
	}

	if (temp != ctx->cur_temp || ctx->new_output) {
		fprintf(stderr, "state: %d, temp: %d, cur: %d\n", ctx->state, temp, ctx->cur_temp);
		ctx->cur_temp = temp;
		set_temperature(ctx);
	}
}

static int increments(struct context *ctx) {
	int diff = ctx->high_temp - ctx->low_temp;
	diff /= 50;
	int time = (ctx->duration * 1000) / diff;
	return time;
}

static int time_to_next_event(struct context *ctx) {
	switch (ctx->state) {
	case ANIMATING_TO_HIGH:
	case ANIMATING_TO_LOW:
		return increments(ctx);
	default:
		return 300000;
	}
}

static int display_poll(struct wl_display *display, short int events, int timeout) {
	struct pollfd pfd[1];
	pfd[0].fd = wl_display_get_fd(display);
	pfd[0].events = events;

	int ret;
	do {
		ret = poll(pfd, 1, timeout);
	} while (ret == -1 && errno == EINTR);

	return ret;
}

int display_dispatch_with_timeout(struct wl_display *display, int timeout);
int display_dispatch_with_timeout(struct wl_display *display, int timeout) {
	if (wl_display_prepare_read(display) == -1) {
		return wl_display_dispatch_pending(display);
	}

	int ret;
	while (true) {
		ret = wl_display_flush(display);
		if (ret != -1 || errno != EAGAIN) {
			break;
		}

		if (display_poll(display, POLLOUT, -1) == -1) {
			wl_display_cancel_read(display);
			return -1;
		}
	}

	if (ret < 0 && errno != EPIPE) {
		wl_display_cancel_read(display);
		return -1;
	}

	if (display_poll(display, POLLIN, timeout) == -1) {
		wl_display_cancel_read(display);
		return -1;
	}

	if (wl_display_read_events(display) == -1) {
		return -1;
	}

	return wl_display_dispatch_pending(display);
}

static const char usage[] = "usage: %s [options]\n"
"  -h          show this help message\n"
"  -T <value>  set high temperature (default: 6500)\n"
"  -t <value>  set low temperature (default: 3500)\n"
"  -S <value>  set ramp up time (default: 6:00)\n"
"  -s <value>  set ramp down time (default: 18:00)\n"
"  -d <value>  set ramping duration in minutes (default: 30)\n"
"  -g <value>  set gamma (default: 1)\n";

int main(int argc, char *argv[]) {

	tzset();

	// Initialize defaults
	struct context ctx = {
		.gamma = 1.0,
		.start_time = 6 * 60 * 60,
		.stop_time = 18 * 60 * 60,
		.high_temp = 6500,
		.low_temp = 3500,
		.duration = 30 * 60,
		.state = HIGH_TEMP,
	};
	wl_list_init(&ctx.outputs);

	int opt;
	time_t now = time(NULL);
	struct tm tm = { 0 };
	struct tm current = { 0 };
	localtime_r(&now, &current);
	while ((opt = getopt(argc, argv, "hT:t:S:s:g:d:")) != -1) {
		switch (opt) {
			case 'T':
				ctx.high_temp = strtol(optarg, NULL, 10);
				break;
			case 't':
				ctx.low_temp = strtol(optarg, NULL, 10);
				break;
			case 'S':
				memcpy(&tm, &current, sizeof tm);
				if (strptime(optarg, "%H:%M", &tm) != NULL) {
					ctx.start_time = mktime(&tm) % 86400;
				}
				break;
			case 's':
				memcpy(&tm, &current, sizeof tm);
				if (strptime(optarg, "%H:%M", &tm) != NULL) {
					ctx.stop_time = mktime(&tm) % 86400;
				}
				break;
			case 'd':
				ctx.duration = strtod(optarg, NULL) * 60;
				break;
			case 'g':
				ctx.gamma = strtod(optarg, NULL);
				break;
			case 'h':
			default:
				fprintf(stderr, usage, argv[0]);
				return opt == 'h' ? EXIT_SUCCESS : EXIT_FAILURE;
		}
	}

	struct wl_display *display = wl_display_connect(NULL);
	if (display == NULL) {
		fprintf(stderr, "failed to create display\n");
		return -1;
	}

	struct wl_registry *registry = wl_display_get_registry(display);
	wl_registry_add_listener(registry, &registry_listener, &ctx);
	wl_display_roundtrip(display);

	if (gamma_control_manager == NULL) {
		fprintf(stderr,
				"compositor doesn't support wlr-gamma-control-unstable-v1\n");
		return EXIT_FAILURE;
	}

	struct output *output;
	wl_list_for_each(output, &ctx.outputs, link) {
		setup_output(output);
	}
	wl_display_roundtrip(display);


	update_temperature(&ctx);
	while (display_dispatch_with_timeout(display, time_to_next_event(&ctx)) != -1) {
		update_temperature(&ctx);
	}

	return EXIT_SUCCESS;
}