Add feature to adjust fade duration (with Elektra)

src/elektra/redshift.ni

@@ -94,6 +94,14 @@ opt = f
 opt/long = fade-fast
 opt/arg = none
 
+[fade/duration]
+type = unsigned_long
+description = Set length of the fade duration in full seconds for fading between color temperatures.
+default = 4
+example = 5
+opt/long = fade-duration
+opt/arg = required
+
 [brightness/day]
 type = float
 description = The screen brightness during daytime. If both day and night brightness are set, these will overrule the value of brightness.

src/options.c

@@ -93,8 +93,8 @@ static void
 print_method_list(const gamma_method_t *gamma_methods)
 {
     if (gamma_methods[0].name == NULL) {
-        printf("This build of redshift contains no adjustment methods that work on your system!");
-        return;
+	printf("This build of redshift contains no adjustment methods that work on your system!");
+	return;
     }
 
 	fputs(_("Available adjustment methods in this build of redshift:\n"), stdout);
@@ -112,8 +112,8 @@ static void
 print_provider_list(const location_provider_t location_providers[])
 {
     if (location_providers[0].name == NULL) {
-        printf("This build of redshift contains no adjustment methods that work on your system!");
-        return;
+	printf("This build of redshift contains no adjustment methods that work on your system!");
+	return;
     }
 
 	fputs(_("Available location providers in this build of redshift:\n"), stdout);
@@ -171,10 +171,10 @@ find_location_provider(
  */
 int
 options_load_from_elektra(
-        options_t *options,
-        Elektra *elektra,
-        const gamma_method_t *gamma_methods,
-        const location_provider_t *location_providers) {
+	options_t *options,
+	Elektra *elektra,
+	const gamma_method_t *gamma_methods,
+	const location_provider_t *location_providers) {
     /**
      * Before using Elektra, there were two sources for configuration: CLI options and config file.
      * From redshift's point of view there is only one source now, namely Elektra.
@@ -189,8 +189,8 @@ options_load_from_elektra(
 
     // Version
     if (elektraGetVersion(elektra)) {
-        printf("%s\n", PACKAGE_STRING);
-        return -1;
+		printf("%s\n", PACKAGE_STRING);
+		return -1;
     }
 
     // Verbose
@@ -302,6 +302,8 @@ options_load_from_elektra(
 
     // Fade
     options->use_fade = !elektraGetFadeFast(elektra);
+
+    options->fade_duration = elektraGetFadeDuration(elektra);
 
     // Temperature
     options->scheme.day.temperature = elektraGetTempDay(elektra);
@@ -378,6 +380,7 @@ options_init(options_t *options)
 	options->provider = NULL;
 
 	options->use_fade = -1;
+    options->fade_duration = -1;
 	options->preserve_gamma = 1;
 	options->mode = ELEKTRA_ENUM_MODE_CONTINUAL;
 	options->verbose = 0;

src/options.h

@@ -27,38 +27,35 @@ typedef struct {
 	/* Path to config file */
 	char *config_filepath;
 
+	/*
+	 * For description of these options, see Elektra specification file src/elektra/redshift.ni
+	 */
 	transition_scheme_t scheme;
 	ElektraEnumMode mode;
 	int verbose;
 
-	/* Temperature to set in manual mode. */
 	int temp_set;
-	/* Whether to fade between large skips in color temperature. */
 	int use_fade;
-	/* Whether to preserve gamma ramps if supported by gamma method. */
+	long fade_duration;
 	int preserve_gamma;
-
-	/* Selected gamma method. */
+
 	const gamma_method_t *method;
-    /* Options for adjustment methods */
-    unsigned short method_crtc;
-    unsigned short method_screen;
-    unsigned short method_drm_card;
-
-	/* Selected location provider. */
+	unsigned short method_crtc;
+	unsigned short method_screen;
+	unsigned short method_drm_card;
+
 	const location_provider_t *provider;
-	/* Lat, lon for location provider. */
 	float provider_manual_arg_lat;
-    float provider_manual_arg_lon;
+	float provider_manual_arg_lon;
 } options_t;
 
 
 int
 options_load_from_elektra(
-        options_t *options,
-        Elektra *elektra,
-        const gamma_method_t *gamma_methods,
-        const location_provider_t *location_providers);
+	options_t *options,
+	Elektra *elektra,
+	const gamma_method_t *gamma_methods,
+	const location_provider_t *location_providers);
 void options_init(options_t *options);
 
 #endif /* ! REDSHIFT_OPTIONS_H */

src/redshift.c

@@ -503,7 +503,8 @@ run_continual_mode(const location_provider_t *provider,
 		   const transition_scheme_t *scheme,
 		   const gamma_method_t *method,
 		   gamma_state_t *method_state,
-		   int use_fade, int preserve_gamma, int verbose)
+		   int use_fade, long fade_duration,
+		   int preserve_gamma, int verbose)
 {
 	int r;
 
@@ -656,8 +657,9 @@ run_continual_mode(const location_provider_t *provider,
 			     color_setting_diff_is_major(
 				     &target_interp,
 				     &prev_target_interp))) {
-				fade_length = FADE_LENGTH;
-				fade_time = 0;
+                // Scale fade_length according to desired fade_duration.
+                fade_length = (FADE_LENGTH * (fade_duration * 1000)) / (FADE_LENGTH * SLEEP_DURATION_SHORT);
+                fade_time = 0;
 				fade_start_interp = interp;
 			}
 		}
@@ -1172,7 +1174,8 @@ int main(int argc, const char * const *argv, const char * const *envp)
 		r = run_continual_mode(
 			options.provider, location_state, scheme,
 			options.method, method_state,
-			options.use_fade, options.preserve_gamma,
+			options.use_fade, options.fade_duration,
+			options.preserve_gamma,
 			options.verbose);
 		if (r < 0) exit(EXIT_FAILURE);
 	}