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Diffstat (limited to 'src/redshift.c')
| -rw-r--r-- | src/redshift.c | 246 |
1 files changed, 246 insertions, 0 deletions
diff --git a/src/redshift.c b/src/redshift.c new file mode 100644 index 0000000..70bc4fa --- /dev/null +++ b/src/redshift.c @@ -0,0 +1,246 @@ +/* redshift.c -- Main program source + This file is part of Redshift. + + Redshift is free software: you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation, either version 3 of the License, or + (at your option) any later version. + + Redshift is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with Redshift. If not, see <http://www.gnu.org/licenses/>. + + Copyright (c) 2009 Jon Lund Steffensen <jonlst@gmail.com> +*/ + +#include <stdio.h> +#include <stdlib.h> +#include <unistd.h> +#include <string.h> +#include <time.h> +#include <math.h> +#include <locale.h> + +#include "solar.h" +#include "randr.h" + + +/* Bounds for parameters. */ +#define MIN_LAT -90.0 +#define MAX_LAT 90.0 +#define MIN_LON -180.0 +#define MAX_LON 180.0 +#define MIN_TEMP 1000 +#define MAX_TEMP 10000 +#define MIN_GAMMA 0.1 +#define MAX_GAMMA 10.0 + +/* Default values for parameters. */ +#define DEFAULT_DAY_TEMP 5500 +#define DEFAULT_NIGHT_TEMP 3700 +#define DEFAULT_GAMMA 1.0 + +/* Angular elevation of the sun at which the color temperature + transition period starts and ends (in degress). + Transition during twilight, and while the sun is lower than + 3.0 degrees above the horizon. */ +#define TRANSITION_LOW SOLAR_CIVIL_TWILIGHT_ELEV +#define TRANSITION_HIGH 3.0 + + +#define USAGE \ + "Usage: %s -l LAT:LON -t DAY:NIGHT [OPTIONS...]\n" +#define HELP \ + USAGE \ + " Set color temperature of display according to time of day.\n" \ + " -g R:G:B\tAdditional gamma correction to apply\n" \ + " -h\t\tDisplay this help message\n" \ + " -l LAT:LON\tYour current location\n" \ + " -t DAY:NIGHT\tColor temperature to set at daytime/night\n" \ + " -v\t\tVerbose output\n" + +/* DEGREE SIGN is Unicode U+00b0 */ +#define DEG_CHAR 0xb0 + + +int +main(int argc, char *argv[]) +{ + /* Check extensions needed for color temperature adjustment. */ + int r = randr_check_extension(); + if (r < 0) { + fprintf(stderr, "Unable to set color temperature:" + " Needed extension is missing.\n"); + exit(EXIT_FAILURE); + } + + /* Init locale for degree symbol. */ + char *loc = setlocale(LC_CTYPE, ""); + if (loc == NULL) { + fprintf(stderr, "Unable to set locale.\n"); + exit(EXIT_FAILURE); + } + + /* Parse arguments. */ + float lat = NAN; + float lon = NAN; + int temp_day = DEFAULT_DAY_TEMP; + int temp_night = DEFAULT_NIGHT_TEMP; + float gamma[3] = { DEFAULT_GAMMA, DEFAULT_GAMMA, DEFAULT_GAMMA }; + int verbose = 0; + char *s; + + int opt; + while ((opt = getopt(argc, argv, "g:hl:t:v")) != -1) { + switch (opt) { + case 'g': + s = strchr(optarg, ':'); + if (s == NULL) { + /* Use value for all channels */ + float g = atof(optarg); + gamma[0] = gamma[1] = gamma[2] = g; + } else { + /* Parse separate value for each channel */ + *(s++) = '\0'; + gamma[0] = atof(optarg); /* Red */ + char *g_s = s; + s = strchr(s, ':'); + if (s == NULL) { + fprintf(stderr, USAGE, argv[0]); + exit(EXIT_FAILURE); + } + + *(s++) = '\0'; + gamma[1] = atof(g_s); /* Blue */ + gamma[2] = atof(s); /* Green */ + } + break; + case 'h': + printf(HELP, argv[0]); + exit(EXIT_SUCCESS); + break; + case 'l': + s = strchr(optarg, ':'); + if (s == NULL) { + fprintf(stderr, USAGE, argv[0]); + exit(EXIT_FAILURE); + } + *(s++) = '\0'; + lat = atof(optarg); + lon = atof(s); + break; + case 't': + s = strchr(optarg, ':'); + if (s == NULL) { + fprintf(stderr, USAGE, argv[0]); + exit(EXIT_FAILURE); + } + *(s++) = '\0'; + temp_day = atoi(optarg); + temp_night = atoi(s); + break; + case 'v': + verbose = 1; + break; + default: + fprintf(stderr, USAGE, argv[0]); + exit(EXIT_FAILURE); + } + } + + /* Latitude and longitude must be set */ + if (isnan(lat) || isnan(lon)) { + fprintf(stderr, USAGE, argv[0]); + fprintf(stderr, "Latitude and longitude must be set.\n"); + exit(EXIT_FAILURE); + } + + if (verbose) { + printf("Location: %f%lc, %f%lc\n", + lat, DEG_CHAR, lon, DEG_CHAR); + } + + /* Latitude */ + if (lat < MIN_LAT || lat > MAX_LAT) { + fprintf(stderr, + "Latitude must be between %.1f%lc and %.1f%lc.\n", + MIN_LAT, DEG_CHAR, MAX_LAT, DEG_CHAR); + exit(EXIT_FAILURE); + } + + /* Longitude */ + if (lon < MIN_LON || lon > MAX_LON) { + fprintf(stderr, + "Longitude must be between %.1f%lc and %.1f%lc.\n", + MIN_LON, DEG_CHAR, MAX_LON, DEG_CHAR); + exit(EXIT_FAILURE); + } + + /* Color temperature at daytime */ + if (temp_day < MIN_TEMP || temp_day >= MAX_TEMP) { + fprintf(stderr, "Temperature must be between %uK and %uK.\n", + MIN_TEMP, MAX_TEMP); + exit(EXIT_FAILURE); + } + + /* Color temperature at night */ + if (temp_night < MIN_TEMP || temp_night >= MAX_TEMP) { + fprintf(stderr, "Temperature must be between %uK and %uK.\n", + MIN_TEMP, MAX_TEMP); + exit(EXIT_FAILURE); + } + + /* Gamma */ + if (gamma[0] < MIN_GAMMA || gamma[0] > MAX_GAMMA || + gamma[1] < MIN_GAMMA || gamma[1] > MAX_GAMMA || + gamma[2] < MIN_GAMMA || gamma[2] > MAX_GAMMA) { + fprintf(stderr, "Gamma value must be between %.1f and %.1f.\n", + MIN_GAMMA, MAX_GAMMA); + exit(EXIT_FAILURE); + } + + /* Current angular elevation of the sun */ + time_t now = time(NULL); + double elevation = solar_elevation(now, lat, lon); + + if (verbose) { + printf("Solar elevation: %f%lc\n", elevation, DEG_CHAR); + } + + /* Use elevation of sun to set color temperature */ + int temp = 0; + if (elevation < TRANSITION_LOW) { + temp = temp_night; + if (verbose) printf("Period: Night\n"); + } else if (elevation < TRANSITION_HIGH) { + /* Transition period: interpolate */ + float a = (TRANSITION_LOW - elevation) / + (TRANSITION_LOW - TRANSITION_HIGH); + temp = (1.0-a)*temp_night + a*temp_day; + if (verbose) { + printf("Period: Transition (%.2f%% day)\n", a*100); + } + } else { + temp = temp_day; + if (verbose) printf("Period: Daytime\n"); + } + + if (verbose) { + printf("Color temperature: %uK\n", temp); + printf("Gamma: %.3f, %.3f, %.3f\n", + gamma[0], gamma[1], gamma[2]); + } + + /* Set color temperature */ + r = randr_set_temperature(temp, gamma); + if (r < 0) { + fprintf(stderr, "Unable to set color temperature.\n"); + exit(EXIT_FAILURE); + } + + return EXIT_SUCCESS; +} |