m + m fixes + doc

Signed-off-by: Mattias Andrée <maandree@operamail.com>

1 files changed, 29 insertions, 11 deletions

diff --git a/src/lib/gamma-x-vidmode.c b/src/lib/gamma-x-vidmode.c
index a73f36f..170d3b4 100644
--- a/src/lib/gamma-x-vidmode.c
+++ b/src/lib/gamma-x-vidmode.c
@@ -38,19 +38,26 @@
 void libgamma_x_vidmode_method_capabilities(libgamma_method_capabilities_t* restrict this)
 {
   char* restrict display = getenv("DISPLAY");
+  /* Gamma ramps size anddepth can be queried. */
   this->crtc_information = LIBGAMMA_CRTC_INFO_GAMMA_SIZE
 			 | LIBGAMMA_CRTC_INFO_GAMMA_DEPTH;
+  /* X VidMode supports multiple sits and partitions but not CRTC:s. */
   this->default_site_known = (display && *display);
   this->multiple_sites = 1;
   this->multiple_partitions = 1;
-  this->multiple_crtcs = 1;
+  this->multiple_crtcs = 0;
+  /* Partitions are screens and not graphics cards in X. */
   this->partitions_are_graphics_cards = 0;
+  /* X does not have system restore capabilities. */
   this->site_restore = 0;
   this->partition_restore = 0;
   this->crtc_restore = 0;
+  /* Gamma ramp sizes are identical but not fixed. */
   this->identical_gamma_sizes = 1;
   this->fixed_gamma_size = 0;
+  /* Gamma ramp depths are fixed. */
   this->fixed_gamma_depth = 1;
+  /* X VidMode is a real non-faked adjustment method */
   this->real = 1;
   this->fake = 0;
 }
@@ -72,14 +79,17 @@ void libgamma_x_vidmode_method_capabilities(libgamma_method_capabilities_t* rest
 int libgamma_x_vidmode_site_initialise(libgamma_site_state_t* restrict this,
 				       char* restrict site)
 {
+  /* Connect to the display. */
   Display* restrict connection = XOpenDisplay(site);
   int _major, _minor, screens;
   if ((this->data = connection) == NULL)
     return LIBGAMMA_OPEN_SITE_FAILED;
+  /* Query X VidMode extension protocol version. */
   if (!XF86VidModeQueryVersion(connection, &_major, &_minor))
-    return LIBGAMMA_PROTOCOL_VERSION_QUERY_FAILED;
+    return XCloseDisplay(connection), LIBGAMMA_PROTOCOL_VERSION_QUERY_FAILED;
+  /* Query the number of available screens. */
   if ((screens = ScreenCount(connection)) < 0)
-    return LIBGAMMA_NEGATIVE_PARTITION_COUNT;
+    return XCloseDisplay(connection), LIBGAMMA_NEGATIVE_PARTITION_COUNT;
   this->partitions_available = (size_t)screens;
   return 0;
 }
@@ -123,10 +133,8 @@ int libgamma_x_vidmode_site_restore(libgamma_site_state_t* restrict this)
 int libgamma_x_vidmode_partition_initialise(libgamma_partition_state_t* restrict this,
 					    libgamma_site_state_t* restrict site, size_t partition)
 {
-  if (partition >= site->partitions_available)
-    return LIBGAMMA_NO_SUCH_PARTITION;
   this->crtcs_available = 1;
-  return 0;
+  return partition >= site->partitions_available ? LIBGAMMA_NO_SUCH_PARTITION : 0;
 }
 
 
@@ -213,35 +221,41 @@ int libgamma_x_vidmode_get_crtc_information(libgamma_crtc_information_t* restric
 {
 #define _E(FIELD)  ((fields & FIELD) ? LIBGAMMA_CRTC_INFO_NOT_SUPPORTED : 0)
   
+  /* X VidMode 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);
   this->gamma_size_error = 0;
+  /* X VidMode does support gamma ramp size query. The gamma
+     ramps are identical but not fixed, and the query can fail. */
   if ((fields & LIBGAMMA_CRTC_INFO_GAMMA_SUPPORT))
     {
       Display* restrict connection = crtc->partition->site->data;
-      int stops;
+      int stops = 0;
       if (!XF86VidModeGetGammaRampSize(connection, (int)(crtc->partition->partition), &stops))
 	this->gamma_size_error = LIBGAMMA_GAMMA_RAMPS_SIZE_QUERY_FAILED;
       else if (stops < 2)
 	this->gamma_size_error = LIBGAMMA_SINGLETON_GAMMA_RAMP;
-      else
-	this->red_gamma_size = this->green_gamma_size = this->blue_gamma_size = (size_t)stops;
+      this->red_gamma_size = this->green_gamma_size = this->blue_gamma_size = (size_t)stops;
     }
+  /* X VidMode uses 16-bit integer ramps. */
   this->gamma_depth = 16;
   this->gamma_depth_error = 0;
+  /* X VidMode does not support gamma ramp support queries. */
   this->gamma_support_error = _E(LIBGAMMA_CRTC_INFO_GAMMA_SUPPORT);
+  /* X VidMode 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);
   
-#undef _E
+  /* We failed if gamma ramp size query failed or if an unsupport field was queried. */
+  return this->gamma_size_error || (fields & ~(LIBGAMMA_CRTC_INFO_GAMMA_DEPTH | LIBGAMMA_CRTC_INFO_GAMMA_SIZE)) ? -1 : 0;
   
-  return (fields & ~(LIBGAMMA_CRTC_INFO_GAMMA_DEPTH | LIBGAMMA_CRTC_INFO_GAMMA_SIZE)) ? -1 : this->gamma_size_error;
+#undef _E
 }
 
 
@@ -257,10 +271,12 @@ int libgamma_x_vidmode_crtc_get_gamma_ramps(libgamma_crtc_state_t* restrict this
 					    libgamma_gamma_ramps_t* restrict ramps)
 {
 #ifdef DEBUG
+  /* Gamma ramp 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. */
   if (!XF86VidModeGetGammaRamp((Display*)(this->partition->site->data), (int)(this->partition->partition),
 			       (int)(ramps->red_size), ramps->red, ramps->green, ramps->blue))
     return LIBGAMMA_GAMMA_RAMP_READ_FAILED;
@@ -280,10 +296,12 @@ int libgamma_x_vidmode_crtc_set_gamma_ramps(libgamma_crtc_state_t* restrict this
 					    libgamma_gamma_ramps_t ramps)
 {
 #ifdef DEBUG
+  /* Gamma ramp 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. */
   if (!XF86VidModeSetGammaRamp((Display*)(this->partition->site->data), (int)(this->partition->partition),
 			       (int)(ramps.red_size), ramps.red, ramps.green, ramps.blue))
     return LIBGAMMA_GAMMA_RAMP_WRITE_FAILED;