Change license + change style + misc

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

1 files changed, 221 insertions, 228 deletions

diff --git a/src/lib/gamma-quartz-cg.c b/src/lib/gamma-quartz-cg.c
index d2ceebc..b0e3a29 100644
--- a/src/lib/gamma-quartz-cg.c
+++ b/src/lib/gamma-quartz-cg.c
@@ -1,20 +1,4 @@
-/**
- * libgamma -- Display server abstraction layer for gamma ramp adjustments
- * Copyright (C) 2014, 2015  Mattias Andrée (maandree@member.fsf.org)
- * 
- * This library 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.
- * 
- * This library 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 this library.  If not, see <http://www.gnu.org/licenses/>.
- */
+/* See LICENSE file for copyright and license details. */
 #ifndef HAVE_LIBGAMMA_METHOD_QUARTZ_CORE_GRAPHICS
 # error Compiling gamma-quartz-cg.c without HAVE_LIBGAMMA_METHOD_QUARTZ_CORE_GRAPHICS
 #endif
@@ -28,7 +12,7 @@
 #else
 # include <ApplicationServices/ApplicationServices.h>
 # include <CoreGraphics/CGDirectDisplay.h>
-# define close_fake_quartz_cg() /* For compatibility with "fake-quartz-cg.h". */
+# define close_fake_quartz_cg() /* For compatibility with "fake-quartz-cg.h" */
 #endif
 
 #include <stdlib.h>
@@ -36,56 +20,56 @@
 
 
 /**
- * Return the capabilities of the adjustment method.
+ * Return the capabilities of the adjustment method
  * 
- * @param  this  The data structure to fill with the method's capabilities.
+ * @param  this  The data structure to fill with the method's capabilities
  */
-void libgamma_quartz_cg_method_capabilities(libgamma_method_capabilities_t* restrict this)
+void
+libgamma_quartz_cg_method_capabilities(libgamma_method_capabilities_t* restrict this)
 {
-  /* Gamma ramps size and depth can be queried. */
-  this->crtc_information = LIBGAMMA_CRTC_INFO_GAMMA_SIZE
-			 | LIBGAMMA_CRTC_INFO_GAMMA_DEPTH;
-  /* Quartz/CoreGraphics does not support sites or partitions. */
-  this->default_site_known = 1;
-  this->multiple_sites = 0;
-  this->multiple_partitions = 0;
-  /* Quartz/CoreGraphics does support CRTC:s. */
-  this->multiple_crtcs = 1;
-  /* Partitions are not support... */
-  this->partitions_are_graphics_cards = 0;
-  /* CoreGraphics have support for system restore. */
-  this->site_restore = 1;
-  this->partition_restore = 1;
-  /* But not for individual CRTC:s. */
-  this->crtc_restore = 0;
-  /* Gamma ramp sizes are identifical but not fixed. */
-  this->identical_gamma_sizes = 1;
-  this->fixed_gamma_size = 0;
-  /* Gamma ramp depths are fixed. */
-  this->fixed_gamma_depth = 1;
-  /* Quartz/CoreGraphics is a real adjustment method that can be faked. */
+	/* Gamma ramps size and depth can be queried */
+	this->crtc_information = LIBGAMMA_CRTC_INFO_GAMMA_SIZE | LIBGAMMA_CRTC_INFO_GAMMA_DEPTH;
+	/* Quartz/CoreGraphics does not support sites or partitions */
+	this->default_site_known = 1;
+	this->multiple_sites = 0;
+	this->multiple_partitions = 0;
+	/* Quartz/CoreGraphics does support CRTC:s */
+	this->multiple_crtcs = 1;
+	/* Partitions are not supported... */
+	this->partitions_are_graphics_cards = 0;
+	/* CoreGraphics have support for system restore */
+	this->site_restore = 1;
+	this->partition_restore = 1;
+	/* But not for individual CRTC:s */
+	this->crtc_restore = 0;
+	/* Gamma ramp sizes are identifical but not fixed */
+	this->identical_gamma_sizes = 1;
+	this->fixed_gamma_size = 0;
+	/* Gamma ramp depths are fixed */
+	this->fixed_gamma_depth = 1;
+	/* Quartz/CoreGraphics is a real adjustment method that can be faked */
 #ifdef FAKE_LIBGAMMA_METHOD_QUARTZ_CORE_GRAPHICS
-  /* It is considered real but fake if it is translated to X RandR. */
-  this->fake = 1;
+	/* It is considered real but fake if it is translated to X RandR */
+	this->fake = 1;
 # ifdef HAVE_LIBGAMMA_METHOD_X_RANDR
-  this->real = 1;
+	this->real = 1;
 # else
-  this->real = 0;
+	this->real = 0;
 # endif
 #else
-  /* It is real and not fake if we are running on Mac OS X. */
-  this->fake = 0;
-  this->real = 1;
+	/* It is real and not fake if we are running on Mac OS X */
+	this->fake = 0;
+	this->real = 1;
 #endif
-  /* Gamma ramp adjustments are non-persistent. */
-  this->auto_restore = 1;
+	/* Gamma ramp adjustments are non-persistent */
+	this->auto_restore = 1;
 }
 
 
 /**
- * Initialise an allocated site state.
+ * Initialise an allocated site state
  * 
- * @param   this    The site state to initialise.
+ * @param   this    The site state to initialise
  * @param   site    The site identifier, unless it is `NULL` it must a
  *                  `free`:able. Once the state is destroyed the library
  *                  will attempt to free it. There you should not free
@@ -93,274 +77,283 @@ void libgamma_quartz_cg_method_capabilities(libgamma_method_capabilities_t* rest
  *                  or allocate on the stack. Note however that it will
  *                  not be free:d if this function fails.
  * @return          Zero on success, otherwise (negative) the value of an
- *                  error identifier provided by this library.
+ *                  error identifier provided by this library
  */
-int libgamma_quartz_cg_site_initialise(libgamma_site_state_t* restrict this,
-				       char* restrict site)
+int
+libgamma_quartz_cg_site_initialise(libgamma_site_state_t *restrict this, char *restrict site)
 {
-  this->partitions_available = 1;
-  return site != NULL ? LIBGAMMA_NO_SUCH_SITE : 0;
+	this->partitions_available = 1;
+	return site ? 0 : LIBGAMMA_NO_SUCH_SITE;
 }
 
 
 /**
- * Release all resources held by a site state.
+ * Release all resources held by a site state
  * 
- * @param  this  The site state.
+ * @param  this  The site state
  */
-void libgamma_quartz_cg_site_destroy(libgamma_site_state_t* restrict this)
+void
+libgamma_quartz_cg_site_destroy(libgamma_site_state_t *restrict this)
 {
-  (void) this;
-  close_fake_quartz_cg();
+	(void) this;
+	close_fake_quartz_cg();
 }
 
 
 /**
- * Restore the gamma ramps all CRTC:s with a site to the system settings.
+ * Restore the gamma ramps all CRTC:s with a site to the system settings
  * 
- * @param   this  The site state.
+ * @param   this  The site state
  * @return        Zero on success, otherwise (negative) the value of an
- *                error identifier provided by this library.
+ *                error identifier provided by this library
  */
-int libgamma_quartz_cg_site_restore(libgamma_site_state_t* restrict this)
+int
+libgamma_quartz_cg_site_restore(libgamma_site_state_t *restrict this)
 {
-  (void) this;
-  CGDisplayRestoreColorSyncSettings();
-  return 0;
+	(void) this;
+	CGDisplayRestoreColorSyncSettings();
+	return 0;
 }
 
 
 
 /**
- * Initialise an allocated partition state.
+ * Initialise an allocated partition state
  * 
- * @param   this       The partition state to initialise.
- * @param   site       The site state for the site that the partition belongs to.
- * @param   partition  The the index of the partition within the site.
+ * @param   this       The partition state to initialise
+ * @param   site       The site state for the site that the partition belongs to
+ * @param   partition  The the index of the partition within the site
  * @return             Zero on success, otherwise (negative) the value of an
- *                     error identifier provided by this library.
+ *                     error identifier provided by this library
  */
-int libgamma_quartz_cg_partition_initialise(libgamma_partition_state_t* restrict this,
-					    libgamma_site_state_t* restrict site, size_t partition)
+int
+libgamma_quartz_cg_partition_initialise(libgamma_partition_state_t *restrict this,
+                                       libgamma_site_state_t *restrict site, size_t partition)
 {
-  uint32_t cap = 4, n;
-  CGDirectDisplayID* crtcs;
-  CGDirectDisplayID* crtcs_old;
-  
-  (void) site;
-  
-  this->data = NULL;
-  
-  if (partition != 0)
-    return LIBGAMMA_NO_SUCH_PARTITION;
-  
-  /* Allocate array of CRTC ID:s. */
-  if ((crtcs = malloc((size_t)cap * sizeof(CGDirectDisplayID))) == NULL)
-    return LIBGAMMA_ERRNO_SET;
-  
-  /* It is not possible to ask CoreGraphics how many CRTC:s
-     are available. We have to ask it to give us a ID:s of
-     a number of CRTC:s and ask for more if we got as many
-     as we asked for. */
-  for (;;)
-    {
-      /* Ask for CRTC ID:s */
-      if (CGGetOnlineDisplayList(cap, crtcs, &n) != kCGErrorSuccess)
-	return free(crtcs), LIBGAMMA_LIST_CRTCS_FAILED;
-      /* If we did not get as many as we asked for then we have all. */
-      if (n < cap)
-	break;
-      /* Increase the number CRTC ID:s to ask for. */
-      if ((cap <<= 1) == 0) /* We could also test ~0, but it is still too many. */
-	return free(crtcs), LIBGAMMA_IMPOSSIBLE_AMOUNT;
-      /* Grow the array of CRTC ID:s so that it can fit all we are asking for. */
-      if ((crtcs = realloc(crtcs_old = crtcs, (size_t)cap * sizeof(CGDirectDisplayID))) == NULL)
-	return free(crtcs_old), LIBGAMMA_ERRNO_SET;
-    }
-  
-  /* Store CRTC ID:s and CRTC count. */
-  this->data = crtcs;
-  this->crtcs_available = (size_t)n;
-  return 0;
+	CGDirectDisplayID *crtcs, *crtcs_old;
+	uint32_t cap = 4, n;
+
+	(void) site;
+
+	this->data = NULL;
+
+	if (partition)
+		return LIBGAMMA_NO_SUCH_PARTITION;
+
+	/* Allocate array of CRTC ID:s */
+	crtcs = malloc((size_t)cap * sizeof(CGDirectDisplayID));
+	if (!crtcs)
+		return LIBGAMMA_ERRNO_SET;
+
+	/* It is not possible to ask CoreGraphics how many CRTC:s are
+	 * available. We have to ask it to give us a ID:s of a number
+	 * of CRTC:s and ask for more if we got as many as we asked for. */
+	for (;;) {
+		/* Ask for CRTC ID:s */
+		if (CGGetOnlineDisplayList(cap, crtcs, &n) != kCGErrorSuccess)
+			return free(crtcs), LIBGAMMA_LIST_CRTCS_FAILED;
+		/* If we did not get as many as we asked for then we have all */
+		if (n < cap)
+			break;
+		/* Increase the number CRTC ID:s to ask for */
+		if (cap > SIZE_MAX / 2) /* We could also test ~0, but it is still too many */
+			return free(crtcs), LIBGAMMA_IMPOSSIBLE_AMOUNT;
+		cap <<= 1;
+		/* Grow the array of CRTC ID:s so that it can fit all we are asking for */
+		crtcs = realloc(crtcs_old = crtcs, (size_t)cap * sizeof(CGDirectDisplayID));
+		if (!crtcs) {
+			free(crtcs_old);
+			return LIBGAMMA_ERRNO_SET;
+		}
+	}
+
+	/* Store CRTC ID:s and CRTC count */
+	this->data = crtcs;
+	this->crtcs_available = (size_t)n;
+	return 0;
 }
 
 
 /**
- * Release all resources held by a partition state.
+ * Release all resources held by a partition state
  * 
- * @param  this  The partition state.
+ * @param  this  The partition state
  */
-void libgamma_quartz_cg_partition_destroy(libgamma_partition_state_t* restrict this)
+void
+libgamma_quartz_cg_partition_destroy(libgamma_partition_state_t *restrict this)
 {
-  free(this->data);
+	free(this->data);
 }
 
 
 /**
- * Restore the gamma ramps all CRTC:s with a partition to the system settings.
+ * Restore the gamma ramps all CRTC:s with a partition to the system settings
  * 
- * @param   this  The partition state.
+ * @param   this  The partition state
  * @return        Zero on success, otherwise (negative) the value of an
- *                error identifier provided by this library.
+ *                error identifier provided by this library
  */
-int libgamma_quartz_cg_partition_restore(libgamma_partition_state_t* restrict this)
+int
+libgamma_quartz_cg_partition_restore(libgamma_partition_state_t *restrict this)
 {
-  return libgamma_quartz_cg_site_restore(this->site);
+	return libgamma_quartz_cg_site_restore(this->site);
 }
 
 
 
 /**
- * Initialise an allocated CRTC state.
+ * Initialise an allocated CRTC state
  * 
- * @param   this       The CRTC state to initialise.
- * @param   partition  The partition state for the partition that the CRTC belongs to.
- * @param   crtc       The the index of the CRTC within the site.
+ * @param   this       The CRTC state to initialise
+ * @param   partition  The partition state for the partition that the CRTC belongs to
+ * @param   crtc       The the index of the CRTC within the site
  * @return             Zero on success, otherwise (negative) the value of an
- *                     error identifier provided by this library.
+ *                     error identifier provided by this library
  */
-int libgamma_quartz_cg_crtc_initialise(libgamma_crtc_state_t* restrict this,
-				       libgamma_partition_state_t* restrict partition, size_t crtc)
+int
+libgamma_quartz_cg_crtc_initialise(libgamma_crtc_state_t *restrict this,
+                                   libgamma_partition_state_t *restrict partition, size_t crtc)
 {
-  (void) this;
-  return crtc >= partition->crtcs_available ? LIBGAMMA_NO_SUCH_CRTC : 0;
+	(void) this;
+	return crtc < partition->crtcs_available ? 0 : LIBGAMMA_NO_SUCH_CRTC;
 }
 
 
 /**
- * Release all resources held by a CRTC state.
+ * Release all resources held by a CRTC state
  * 
- * @param  this  The CRTC state.
+ * @param  this  The CRTC state
  */
-void libgamma_quartz_cg_crtc_destroy(libgamma_crtc_state_t* restrict this)
+void
+libgamma_quartz_cg_crtc_destroy(libgamma_crtc_state_t *restrict this)
 {
-  (void) this;
+	(void) this;
 }
 
 
 /**
- * Restore the gamma ramps for a CRTC to the system settings for that CRTC.
+ * Restore the gamma ramps for a CRTC to the system settings for that CRTC
  * 
- * @param   this  The CRTC state.
+ * @param   this  The CRTC state
  * @return        Zero on success, otherwise (negative) the value of an
- *                error identifier provided by this library.
+ *                error identifier provided by this library
  */
-int libgamma_quartz_cg_crtc_restore(libgamma_crtc_state_t* restrict this)
+int
+libgamma_quartz_cg_crtc_restore(libgamma_crtc_state_t *restrict this)
 {
-  (void) this;
-  return errno = ENOTSUP, LIBGAMMA_ERRNO_SET;
+	(void) this;
+	errno = ENOTSUP;
+	return LIBGAMMA_ERRNO_SET;
 }
 
 
 
 /**
- * Read information about a CRTC.
+ * Read information about a CRTC
  * 
- * @param   this    Instance of a data structure to fill with the information about the CRTC.
- * @param   crtc    The state of the CRTC whose information should be read.
+ * @param   this    Instance of a data structure to fill with the information about the CRTC
+ * @param   crtc    The state of the CRTC whose information should be read
  * @param   fields  OR:ed identifiers for the information about the CRTC that should be read.
- * @return          Zero on success, -1 on error. On error refer to the error reports in `this`.
+ * @return          Zero on success, -1 on error. On error refer to the error reports in `this`
  */
-int libgamma_quartz_cg_get_crtc_information(libgamma_crtc_information_t* restrict this,
-					    libgamma_crtc_state_t* restrict crtc, int32_t fields)
+int
+libgamma_quartz_cg_get_crtc_information(libgamma_crtc_information_t *restrict this,
+                                        libgamma_crtc_state_t *restrict crtc, int32_t fields)
 {
-#define SUPPORTED_FIELDS  (LIBGAMMA_CRTC_INFO_GAMMA_SIZE | LIBGAMMA_CRTC_INFO_GAMMA_DEPTH)
-#define _E(FIELD)  ((fields & FIELD) ? LIBGAMMA_CRTC_INFO_NOT_SUPPORTED : 0)
-  
-  /* Quartz/CoreGraphics does not support EDID or monitor dimensions. */
-  this->edid_error = _E(LIBGAMMA_CRTC_INFO_EDID);
-  this->width_mm_error = _E(LIBGAMMA_CRTC_INFO_WIDTH_MM);
-  this->height_mm_error = _E(LIBGAMMA_CRTC_INFO_HEIGHT_MM);
-  this->width_mm_edid_error = _E(LIBGAMMA_CRTC_INFO_WIDTH_MM_EDID);
-  this->height_mm_edid_error = _E(LIBGAMMA_CRTC_INFO_HEIGHT_MM_EDID);
-  /* Quartz/CoreGraphics does support gamma ramp size query.
-     The gamma ramps are identical but not fixed, and the query can fail. */
-  this->gamma_size_error = 0;
-  if ((fields & LIBGAMMA_CRTC_INFO_GAMMA_SIZE))
-    {
-      CGDirectDisplayID* restrict crtcs = crtc->partition->data;
-      size_t gamma_size = CGDisplayGammaTableCapacity(crtcs[crtc->crtc]);
-      this->red_gamma_size = this->green_gamma_size = this->blue_gamma_size = (size_t)gamma_size;
-      this->gamma_size_error = gamma_size < 2 ? LIBGAMMA_SINGLETON_GAMMA_RAMP : 0;
-    }
-  /* Quartz/CoreGraphics uses `float` ramps. */
-  this->gamma_depth = -1;
-  this->gamma_depth_error = 0;
-  /* Quartz/CoreGraphics does not support gamma ramp support queries. */
-  this->gamma_support_error = _E(LIBGAMMA_CRTC_INFO_GAMMA_SUPPORT);
-  /* Quartz/CoreGraphics does not support EDID or connector information. */
-  this->subpixel_order_error = _E(LIBGAMMA_CRTC_INFO_SUBPIXEL_ORDER);
-  this->active_error = _E(LIBGAMMA_CRTC_INFO_ACTIVE);
-  this->connector_name_error = _E(LIBGAMMA_CRTC_INFO_CONNECTOR_NAME);
-  this->connector_type_error = _E(LIBGAMMA_CRTC_INFO_CONNECTOR_TYPE);
-  this->gamma_error = _E(LIBGAMMA_CRTC_INFO_GAMMA);
-  
-  /* We failed if gamma ramp size query failed or if an unsupport field was queried. */
-  return this->gamma_size_error || (fields & ~SUPPORTED_FIELDS) ? -1 : 0;
-  
+#define SUPPORTED_FIELDS (LIBGAMMA_CRTC_INFO_GAMMA_SIZE | LIBGAMMA_CRTC_INFO_GAMMA_DEPTH)
+#define _E(FIELD)        ((fields & FIELD) ? LIBGAMMA_CRTC_INFO_NOT_SUPPORTED : 0)
+
+	CGDirectDisplayID *restrict crtcs;
+	size_t gamma_size;
+
+	/* Quartz/CoreGraphics does not support EDID or monitor dimensions */
+	this->edid_error = _E(LIBGAMMA_CRTC_INFO_EDID);
+	this->width_mm_error = _E(LIBGAMMA_CRTC_INFO_WIDTH_MM);
+	this->height_mm_error = _E(LIBGAMMA_CRTC_INFO_HEIGHT_MM);
+	this->width_mm_edid_error = _E(LIBGAMMA_CRTC_INFO_WIDTH_MM_EDID);
+	this->height_mm_edid_error = _E(LIBGAMMA_CRTC_INFO_HEIGHT_MM_EDID);
+	/* Quartz/CoreGraphics does support gamma ramp size query
+	   The gamma ramps are identical but not fixed, and the query can fail */
+	this->gamma_size_error = 0;
+	if ((fields & LIBGAMMA_CRTC_INFO_GAMMA_SIZE)) {
+		crtcs = crtc->partition->data;
+		gamma_size = CGDisplayGammaTableCapacity(crtcs[crtc->crtc]);
+		this->red_gamma_size = this->green_gamma_size = this->blue_gamma_size = (size_t)gamma_size;
+		this->gamma_size_error = gamma_size < 2 ? LIBGAMMA_SINGLETON_GAMMA_RAMP : 0;
+	}
+	/* Quartz/CoreGraphics uses `float` ramps */
+	this->gamma_depth = -1;
+	this->gamma_depth_error = 0;
+	/* Quartz/CoreGraphics does not support gamma ramp support queries */
+	this->gamma_support_error = _E(LIBGAMMA_CRTC_INFO_GAMMA_SUPPORT);
+	/* Quartz/CoreGraphics does not support EDID or connector information */
+	this->subpixel_order_error = _E(LIBGAMMA_CRTC_INFO_SUBPIXEL_ORDER);
+	this->active_error = _E(LIBGAMMA_CRTC_INFO_ACTIVE);
+	this->connector_name_error = _E(LIBGAMMA_CRTC_INFO_CONNECTOR_NAME);
+	this->connector_type_error = _E(LIBGAMMA_CRTC_INFO_CONNECTOR_TYPE);
+	this->gamma_error = _E(LIBGAMMA_CRTC_INFO_GAMMA);
+
+	/* We failed if gamma ramp size query failed or if an unsupport field was queried */
+	return (this->gamma_size_error || (fields & ~SUPPORTED_FIELDS)) ? -1 : 0;
+
 #undef _E
 #undef SUPPORTED_FIELDS
 }
 
 
 /**
- * Get the current gamma ramps for a CRTC, `float` version.
+ * Get the current gamma ramps for a CRTC, `float` version
  * 
- * @param   this   The CRTC state.
- * @param   ramps  The gamma ramps to fill with the current values.
+ * @param   this   The CRTC state
+ * @param   ramps  The gamma ramps to fill with the current values
  * @return         Zero on success, otherwise (negative) the value of an
- *                 error identifier provided by this library.
+ *                 error identifier provided by this library
  */
-int libgamma_quartz_cg_crtc_get_gamma_rampsf(libgamma_crtc_state_t* restrict this,
-					     libgamma_gamma_rampsf_t* restrict ramps)
+int
+libgamma_quartz_cg_crtc_get_gamma_rampsf(libgamma_crtc_state_t *restrict this, libgamma_gamma_rampsf_t *restrict ramps)
 {
-  CGDirectDisplayID* restrict crtcs = this->partition->data;
-  CGDirectDisplayID crtc_id = crtcs[this->crtc];
-  uint32_t gamma_size_out;
-  CGError r;
+	CGDirectDisplayID *restrict crtcs = this->partition->data;
+	CGDirectDisplayID crtc_id = crtcs[this->crtc];
+	uint32_t gamma_size_out;
+	CGError r;
 #ifdef DEBUG
-  /* Gamma ramps sizes are identical but not fixed. */
-  if ((ramps->red_size != ramps->green_size) ||
-      (ramps->red_size != ramps->blue_size))
-    return LIBGAMMA_MIXED_GAMMA_RAMP_SIZE;
+	/* Gamma ramps sizes are identical but not fixed */
+	if (ramps->red_size != ramps->green_size || ramps->red_size != ramps->blue_size)
+		return LIBGAMMA_MIXED_GAMMA_RAMP_SIZE;
 #endif
-  /* Read current gamma ramps. */
-  r = CGGetDisplayTransferByTable(crtc_id, (uint32_t)(ramps->red_size),
-				  ramps->red, ramps->green, ramps->blue, &gamma_size_out);
-  if (r != kCGErrorSuccess)
-    return LIBGAMMA_GAMMA_RAMP_READ_FAILED;
-  /* I hope that it will not actually ever change,
-     but it does return the the gamma ramp size despite
-     that it can be queried without querying for more. */
-  if (gamma_size_out != ramps->red_size)
-    return LIBGAMMA_GAMMA_RAMP_SIZE_CHANGED;
-  return 0;
+	/* Read current gamma ramps */
+	r = CGGetDisplayTransferByTable(crtc_id, (uint32_t)ramps->red_size, ramps->red, ramps->green, ramps->blue, &gamma_size_out);
+	if (r != kCGErrorSuccess)
+		return LIBGAMMA_GAMMA_RAMP_READ_FAILED;
+	/* I hope that it will not actually ever change,
+	   but it does return the the gamma ramp size despite
+	   that it can be queried without querying for more */
+	if (gamma_size_out != ramps->red_size)
+		return LIBGAMMA_GAMMA_RAMP_SIZE_CHANGED;
+	return 0;
 }
 
 
 /**
- * Set the gamma ramps for a CRTC, `float` version.
+ * Set the gamma ramps for a CRTC, `float` version
  * 
- * @param   this   The CRTC state.
- * @param   ramps  The gamma ramps to apply.
+ * @param   this   The CRTC state
+ * @param   ramps  The gamma ramps to apply
  * @return         Zero on success, otherwise (negative) the value of an
- *                 error identifier provided by this library.
+ *                 error identifier provided by this library
  */
-int libgamma_quartz_cg_crtc_set_gamma_rampsf(libgamma_crtc_state_t* restrict this,
-					     libgamma_gamma_rampsf_t ramps)
+int
+libgamma_quartz_cg_crtc_set_gamma_rampsf(libgamma_crtc_state_t *restrict this, libgamma_gamma_rampsf_t ramps)
 {
-  CGDirectDisplayID* restrict crtcs = this->partition->data;
-  CGDirectDisplayID crtc_id = crtcs[this->crtc];
-  CGError r;
+	CGDirectDisplayID *restrict crtcs = this->partition->data;
+	CGDirectDisplayID crtc_id = crtcs[this->crtc];
+	CGError r;
 #ifdef DEBUG
-  /* Gamma ramps sizes are identical but not fixed. */
-  if ((ramps.red_size != ramps.green_size) ||
-      (ramps.red_size != ramps.blue_size))
-    return LIBGAMMA_MIXED_GAMMA_RAMP_SIZE;
+	/* Gamma ramps sizes are identical but not fixed */
+	if (ramps.red_size != ramps.green_size || ramps.red_size != ramps.blue_size)
+		return LIBGAMMA_MIXED_GAMMA_RAMP_SIZE;
 #endif
-  /* Apply gamma ramps. */
-  r = CGSetDisplayTransferByTable(crtc_id, (uint32_t)(ramps.red_size),
-				  ramps.red, ramps.green, ramps.blue);
-  return r == kCGErrorSuccess ? 0 : LIBGAMMA_GAMMA_RAMP_WRITE_FAILED;
+	/* Apply gamma ramps */
+	r = CGSetDisplayTransferByTable(crtc_id, (uint32_t)ramps.red_size, ramps.red, ramps.green, ramps.blue);
+	return r == kCGErrorSuccess ? 0 : LIBGAMMA_GAMMA_RAMP_WRITE_FAILED;
 }
-