Restore support for preserve-gamma, with corrected order of application

Signed-off-by: Mattias Andrée <m@maandree.se>

4 files changed, 24 insertions, 5 deletions

diff --git a/src/backend-direct.c b/src/backend-direct.c
index dd381fb..ea60676 100644
--- a/src/backend-direct.c
+++ b/src/backend-direct.c
@@ -571,7 +571,7 @@ direct_start(struct gamma_state *state)
 
 
 int
-direct_apply(struct gamma_state *state, const struct colour_setting *setting, int preserve /* TODO */)
+direct_apply(struct gamma_state *state, const struct colour_setting *setting, int preserve)
 {
 	size_t i, err_count = 0, crtc, part;
 	const char *errstr;
@@ -584,6 +584,9 @@ direct_apply(struct gamma_state *state, const struct colour_setting *setting, in
 			fill_ramps_##SUFFIX(state->crtcs[i].gamma_ramps.RAMPS.red,\
 			                    state->crtcs[i].gamma_ramps.RAMPS.green,\
 			                    state->crtcs[i].gamma_ramps.RAMPS.blue,\
+			                    preserve ? state->crtcs[i].saved_gamma_ramps.RAMPS.red : NULL,\
+			                    preserve ? state->crtcs[i].saved_gamma_ramps.RAMPS.green : NULL,\
+			                    preserve ? state->crtcs[i].saved_gamma_ramps.RAMPS.blue : NULL,\
 			                    state->crtcs[i].gamma_ramps.size.red,\
 			                    state->crtcs[i].gamma_ramps.size.green,\
 			                    state->crtcs[i].gamma_ramps.size.blue,\
diff --git a/src/colour.c b/src/colour.c
index ad65b5f..4d85cb5 100644
--- a/src/colour.c
+++ b/src/colour.c
@@ -49,6 +49,7 @@ colour_setting_diff_is_major(const struct colour_setting *a, const struct colour
 	 * Fill a gamma ramp
 	 * 
 	 * @param  ramp        The gamma ramp
+	 * @param  saved       Saved gamma ramp with calibrations to preserver, or `NULL`
 	 * @param  size        The gamma ramp size (number of stops)
 	 * @param  brightness  The brightness (between 0 and 1) of the channel, which is
 	 *                     the overall applied brightness multiplied but the effect
@@ -56,7 +57,7 @@ colour_setting_diff_is_major(const struct colour_setting *a, const struct colour
 	 * @param  gamma       The gamma to apply to the channel
 	 */\
 	static void\
-	fill_ramp_##SUFFIX(TYPE *ramp, size_t size, double brightness, double gamma)\
+	fill_ramp_##SUFFIX(TYPE *ramp, const TYPE *saved, size_t size, double brightness, double gamma)\
 	{\
 		size_t i;\
 		double v;\
@@ -72,18 +73,25 @@ colour_setting_diff_is_major(const struct colour_setting *a, const struct colour
 				ramp[i] = (TYPE)v;\
 			}\
 		}\
+		if (saved) {\
+			for (i = 0; i < size; i++) {\
+				v = (double)ramp[i] / (MAX) * (size - 1U);\
+				ramp[i] = saved[(size_t)v];\
+			}\
+		}\
 	}\
 	\
 	void\
 	fill_ramps_##SUFFIX(TYPE *gamma_r, TYPE *gamma_g, TYPE *gamma_b,\
+	                    const TYPE *saved_r, const TYPE *saved_g, const TYPE *saved_b,\
 	                    size_t size_r, size_t size_g, size_t size_b,\
 	                    const struct colour_setting *setting)\
 	{\
 		double r = 1, g = 1, b = 1;\
 		libred_get_colour(setting->temperature, &r, &g, &b);\
-		fill_ramp_##SUFFIX(gamma_r, size_r, setting->brightness * r, setting->gamma[0]);\
-		fill_ramp_##SUFFIX(gamma_g, size_g, setting->brightness * g, setting->gamma[1]);\
-		fill_ramp_##SUFFIX(gamma_b, size_b, setting->brightness * b, setting->gamma[2]);\
+		fill_ramp_##SUFFIX(gamma_r, saved_r, size_r, setting->brightness * r, setting->gamma[0]);\
+		fill_ramp_##SUFFIX(gamma_g, saved_g, size_g, setting->brightness * g, setting->gamma[1]);\
+		fill_ramp_##SUFFIX(gamma_b, saved_b, size_b, setting->brightness * b, setting->gamma[2]);\
 	}
 
 LIST_RAMPS_STOP_VALUE_TYPES(X,)
diff --git a/src/common.h b/src/common.h
index dc0312b..e6e1339 100644
--- a/src/common.h
+++ b/src/common.h
@@ -1327,12 +1327,19 @@ int colour_setting_diff_is_major(const struct colour_setting *a, const struct co
 	 * @param  gamma_r   The gamma ramp for the red channel
 	 * @param  gamma_g   The gamma ramp for the green channel
 	 * @param  gamma_b   The gamma ramp for the blue channel
+	 * @param  saved_r   Saved gamma ramp with calibrations for
+	 *                   the red channel to preserve, or `NULL`
+	 * @param  saved_g   Saved gamma ramp with calibrations for
+	 *                   the green channel to preserve, or `NULL`
+	 * @param  saved_b   Saved gamma ramp with calibrations for
+	 *                   the blue channel to preserve, or `NULL`
 	 * @param  size_r    The number of stops in `gamma_r`
 	 * @param  size_g    The number of stops in `gamma_g`
 	 * @param  size_b    The number of stops in `gamma_b`
 	 * @param  settings  The colour settings to apply (temperature, brightness, gamma)
 	 */\
 	void fill_ramps_##SUFFIX(TYPE *gamma_r, TYPE *gamma_g, TYPE *gamma_b,\
+	                         const TYPE *saved_r, const TYPE *saved_g, const TYPE *saved_b,\
 	                         size_t size_r, size_t size_g, size_t size_b,\
 	                         const struct colour_setting *setting)
 LIST_RAMPS_STOP_VALUE_TYPES(X, ;);
diff --git a/src/gamma-coopgamma.c b/src/gamma-coopgamma.c
index 9818a88..6025da7 100644
--- a/src/gamma-coopgamma.c
+++ b/src/gamma-coopgamma.c
@@ -517,6 +517,7 @@ coopgamma_apply(struct gamma_state *state, const struct colour_setting *setting,
 			fill_ramps_##SUFFIX((void *)(filter->ramps.u8.red),\
 			                    (void *)(filter->ramps.u8.green),\
 			                    (void *)(filter->ramps.u8.blue),\
+			                    NULL, NULL, NULL,\
 			                    filter->ramps.u8.red_size,\
 			                    filter->ramps.u8.green_size,\
 			                    filter->ramps.u8.blue_size,\