beginning of wayland support

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

5 files changed, 882 insertions, 1 deletions

diff --git a/src/lib/gamma-wayland.c b/src/lib/gamma-wayland.c
new file mode 100644
index 0000000..be41c7a
--- /dev/null
+++ b/src/lib/gamma-wayland.c
@@ -0,0 +1,602 @@
+/**
+ * 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/>.
+ */
+#ifndef HAVE_LIBGAMMA_METHOD_WAYLAND
+# error Compiling gamma-wayland.c without HAVE_LIBGAMMA_METHOD_WAYLAND
+#endif
+
+#include "gamma-wayland.h"
+#ifdef __GCC__
+# pragma GCC diagnostic push
+# pragma GCC diagnostic ignored "-Wcast-qual"
+#endif
+#include "wayland-gamma-control-client-protocol.h"
+#ifdef __GCC__
+# pragma GCC diagnostic pop
+#endif
+
+#include "libgamma-error.h"
+
+#include <stdlib.h>
+#include <errno.h>
+#include <string.h>
+#include <stdint.h>
+#ifdef DEBUG
+# include <stdio.h>
+#endif
+
+#include <wayland-client.h>
+
+
+
+/**
+ * This function is called when the display server
+ * announces global resources.
+ * 
+ * @param  site_state  The site state
+ * @param  registry    The event handler
+ * @param  id          The ID of the resource
+ * @param  interface   The name of the resource's type
+ * @param  version     The version of the resource's type
+ */
+static void registry_global_handler(void* site_state, struct wl_registry* registry, uint32_t id,
+				    const char* interface, uint32_t version);
+
+/**
+ * This function is called when the display server
+ * announces that global resources have been removed.
+ * 
+ * @param  site_state  The site state
+ * @param  registry    The event handler
+ * @param  id          The ID of the resource
+ */
+static void registry_global_remover(void* site_state, struct wl_registry* registry, uint32_t id);
+
+/**
+ * This function is invoked when the display
+ * server tells us the size of a gamma ramp.
+ * 
+ * @param  crtc_data  The protocol-specific data for the CRTC
+ * @param  control    The gamma ramp controll for the CRTC
+ * @param  size       The number of stops in the gamma ramps of the CRTC
+ */
+static void gamma_control_gamma_size(void* crtc, struct gamma_control* control, uint32_t size);
+
+
+
+/**
+ * Data structure for CRTC data.
+ */
+typedef struct libgamma_wayland_crtc_data
+{
+  /**
+   * Wayland-representation of the output.
+   */
+  struct wl_output* output;
+  
+  /**
+   * Gamma controller for the output.
+   */
+  struct gamma_control* gamma_control;
+  
+  /**
+   * The size of the gamma ramps.
+   */
+  uint32_t gamma_size;
+  
+  /**
+   * Whether `gamma_size` has been set.
+   * 
+   */
+  int gamma_size_announced;
+  
+  /**
+   * Whether gamma may be supported.
+   */
+  int gamma_maybe_supported;
+  
+  /**
+   * ID of the CRTC.
+   */
+  uint32_t global_id;
+  
+  /**
+   * Whether the CRTC has been removed;
+   */
+  int removed;
+  
+} libgamma_wayland_crtc_data_t;
+
+
+/**
+ * Data structure for site data.
+ */
+typedef struct libgamma_wayland_site_data
+{
+  /**
+   * Connection to the display.
+   */
+  struct wl_display* display;
+  
+  /**
+   * Event handlers for the display.
+   */
+  struct wl_registry* registry;
+  
+  /**
+   * Gamma controller for the display.
+   */
+  struct gamma_control_manager* gamma_control_manager;
+  
+  /**
+   * The number of CRTC:s that are available under this
+   * partition. Note that the CRTC:s are not necessarily
+   * online.
+   */
+  size_t crtcs_available;
+  
+  /**
+   * The number of CRTC:s that are available under this
+   * partition. Note that the CRTC:s are not necessarily
+   * online.
+   */
+  size_t crtcs_allocated;
+  
+  /**
+   * CRTC information fields.
+   */
+  libgamma_wayland_crtc_data_t** crtcs;
+  
+  /**
+   * Error set from `registry_global_handler`.
+   */
+  int async_errno;
+  
+  /**
+   * Whether gamma may be supported.
+   */
+  int gamma_maybe_supported;
+  
+} libgamma_wayland_site_data_t;
+
+
+/**
+ * Event handlers for the display.
+ */
+static const struct wl_registry_listener registry_listener =
+  {
+    registry_global_handler,
+    registry_global_remover,
+  };
+
+/**
+ * Gamma event handlers for CRTC:s.
+ */
+static const struct gamma_control_listener gamma_control_listener =
+  {
+    gamma_control_gamma_size,
+  };
+
+
+
+/**
+ * Return the capabilities of the adjustment method.
+ * 
+ * @param  this  The data structure to fill with the method's capabilities.
+ */
+void libgamma_wayland_method_capabilities(libgamma_method_capabilities_t* restrict this)
+{
+  char* display = getenv("WAYLAND_DISPLAY");
+  /* TODO */
+  this->crtc_information = 0;
+  /* Wayland supports multiple sites and CRTC:s, but not paritions. */
+  this->default_site_known = (display && *display) ? 1 : 0;
+  this->multiple_sites = 1;
+  this->multiple_partitions = 0;
+  this->multiple_crtcs = 1;
+  this->partitions_are_graphics_cards = 0;
+  /* Wayland/Orbital has per-CRTC restore capabilities. */
+  this->site_restore = 0;
+  this->partition_restore = 0;
+  this->crtc_restore = 1;
+  /* 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;
+  /* Wayland/Orbital is a real non-faked adjustment method. */
+  this->real = 1;
+  this->fake = 0;
+}
+
+
+/**
+ * This function is called when the display server
+ * announces global resources.
+ * 
+ * @param  site_state  The site state
+ * @param  registry    The event handler
+ * @param  id          The ID of the resource
+ * @param  interface   The name of the resource's type
+ * @param  version     The version of the resource's type
+ */
+static void registry_global_handler(void* site_state, struct wl_registry* registry, uint32_t id,
+				    const char* interface, uint32_t version)
+{
+  libgamma_site_state_t* site = site_state;
+  libgamma_wayland_site_data_t* data = site->data;
+  libgamma_wayland_crtc_data_t** crtcs = data->crtcs;
+  libgamma_wayland_crtc_data_t* crtc;
+  size_t new_allocation, i;
+  
+  (void) version;
+  
+  /* Stop if an earlier call failed. */
+  if (data->async_errno)
+    return;
+  
+  if (!strcmp(interface, "gamma_control_manager"))
+    {
+      data->gamma_control_manager = wl_registry_bind(registry, id, &gamma_control_manager_interface, 1);
+      if (data->gamma_control_manager == NULL)
+	data->async_errno = errno;
+    }
+  else if (!strcmp(interface, "wl_output"))
+    {
+      /* Check that ID is not used. */
+      for (i = 0; i < data->crtcs_available; i++)
+	if (crtcs[i] && (crtcs[i]->global_id == id))
+	  return;
+      
+      /* Reallocate CRTC resource array. */
+      if (data->crtcs_available == data->crtcs_allocated)
+	{
+	  new_allocation = data->crtcs_allocated ? (data->crtcs_allocated << 1) : 1;
+	  crtcs = realloc(crtcs, new_allocation * sizeof(libgamma_wayland_crtc_data_t*));
+	  if (crtcs == NULL)
+	    {
+	      data->async_errno = errno;
+	      return;
+	    }
+	  data->crtcs = crtcs;
+	  data->crtcs_allocated = new_allocation;
+	}
+      
+      /* Allocate CRTC resource. */
+      crtc = calloc(1, sizeof(libgamma_wayland_crtc_data_t));
+      crtcs[data->crtcs_available] = crtc;
+      if (crtc == NULL)
+	{
+	  data->async_errno = errno;
+	  return;
+	}
+      
+      /* Set CRTC data. */
+      crtc->global_id = id;
+      crtc->output = wl_registry_bind(registry, id, &wl_output_interface, 1);
+      crtc->removed = 0;
+      
+      /* Increase CRTC cound and check for overflow. */
+      if (data->crtcs_available++ == (size_t)~0)
+	{
+	  free(crtc);
+	  data->async_errno = LIBGAMMA_IMPOSSIBLE_AMOUNT;
+	  return;
+	}
+    }
+}
+
+
+/**
+ * This function is called when the display server
+ * announces that global resources have been removed.
+ * 
+ * @param  site_state  The site state
+ * @param  registry    The event handler
+ * @param  id          The ID of the resource
+ */
+static void registry_global_remover(void* site_state, struct wl_registry* registry, uint32_t id)
+{
+  libgamma_site_state_t* site = site_state;
+  libgamma_wayland_site_data_t* data = site->data;
+  libgamma_wayland_crtc_data_t* crtc;
+  size_t i;
+  
+  (void) registry;
+  
+  for (i = 0; i < data->crtcs_available; i++)
+    if ((crtc = data->crtcs[i]))
+      if (crtc->global_id == id)
+	{
+	  crtc->removed = 1;
+	  break;
+	}
+}
+
+
+/**
+ * Initialise an allocated site state.
+ * 
+ * @param   this    The site state to initialise.
+ * @param   site    The site identifier, unless it is `NULL` it must a
+ *                  `free`:able. One the state is destroyed the library
+ *                  will attempt to free it. There you should not free
+ *                  it yourself, and it must not be a string constant
+ *                  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.
+ */
+int libgamma_wayland_site_initialise(libgamma_site_state_t* restrict this,
+				     char* restrict site)
+{
+  libgamma_wayland_site_data_t* data;
+  
+  /* Allocate adjustment method dependent data memory area.
+     We use `calloc` because we want `data`'s pointers to be `NULL` if not allocated at `fail`. */
+  if ((this->data = data = calloc(1, sizeof(libgamma_wayland_site_data_t))) == NULL)
+    return LIBGAMMA_ERRNO_SET;
+  
+  /* Connect to the display server. */
+  data->display = wl_display_connect(site);
+  if (data->display == NULL)
+    return LIBGAMMA_OPEN_SITE_FAILED;
+  data->registry = wl_display_get_registry(data->display);
+  if (data->registry == NULL)
+    return LIBGAMMA_ERRNO_SET;
+  if (wl_registry_add_listener(data->registry, &registry_listener, this) < 0)
+    return LIBGAMMA_ERRNO_SET;
+  
+  /* Synchronise with display. */
+  if (wl_display_roundtrip(data->display) < 0)
+    return LIBGAMMA_ERRNO_SET;
+  
+  /* Check for errors. */
+  if (data->async_errno > 0)
+    return errno = data->async_errno, LIBGAMMA_ERRNO_SET;
+  if (data->async_errno < 0)
+    return data->async_errno;
+  
+  /* Check that we have a gamma controller. */
+  if (data->gamma_control_manager)
+    data->gamma_maybe_supported = 1;
+  
+  this->partitions_available = 1;
+  return 0;
+}
+
+
+/**
+ * Release all resources held by a site state.
+ * 
+ * @param  this  The site state.
+ */
+void libgamma_wayland_site_destroy(libgamma_site_state_t* restrict this)
+{
+  libgamma_wayland_site_data_t* data = this->data;
+  libgamma_wayland_crtc_data_t* crtc;
+  gamma_control_manager_destroy(data->gamma_control_manager);
+  wl_registry_destroy(data->registry);
+  wl_display_disconnect(data->display);
+  while (data->crtcs_available--)
+    {
+      crtc = data->crtcs[data->crtcs_available];
+      gamma_control_destroy(crtc->gamma_control);
+      wl_output_destroy(crtc->output);
+      free(crtc);
+    }
+  free(data->crtcs);
+  free(data);
+}
+
+
+/**
+ * Restore the gamma ramps all CRTC:s with a site to the system settings.
+ * 
+ * @param   this  The site state.
+ * @return        Zero on success, otherwise (negative) the value of an
+ *                error identifier provided by this library.
+ */
+int libgamma_wayland_site_restore(libgamma_site_state_t* restrict this)
+{
+  (void) this;
+  return errno = ENOTSUP, LIBGAMMA_ERRNO_SET;
+}
+
+
+/**
+ * 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.
+ * @return             Zero on success, otherwise (negative) the value of an
+ *                     error identifier provided by this library.
+ */
+int libgamma_wayland_partition_initialise(libgamma_partition_state_t* restrict this,
+					  libgamma_site_state_t* restrict site, size_t partition)
+{
+  libgamma_wayland_site_data_t* data = site->data;
+  
+  this->data = NULL;
+  this->crtcs_available = 0;
+  
+  if (partition != 0)
+    return LIBGAMMA_NO_SUCH_PARTITION;
+  
+  this->crtcs_available = data->crtcs_available;
+  return 0;
+}
+
+
+/**
+ * Release all resources held by a partition state.
+ * 
+ * @param  this  The partition state.
+ */
+void libgamma_wayland_partition_destroy(libgamma_partition_state_t* restrict this)
+{
+  (void) this;
+}
+
+
+/**
+ * Restore the gamma ramps all CRTC:s with a partition to the system settings.
+ * 
+ * @param   this  The partition state.
+ * @return        Zero on success, otherwise (negative) the value of an
+ *                error identifier provided by this library.
+ */
+int libgamma_wayland_partition_restore(libgamma_partition_state_t* restrict this)
+{
+  return libgamma_wayland_site_restore(this->site);
+}
+
+
+/**
+ * This function is invoked when the display
+ * server tells us the size of a gamma ramp.
+ * 
+ * @param  crtc_data  The protocol-specific data for the CRTC
+ * @param  control    The gamma ramp controll for the CRTC
+ * @param  size       The number of stops in the gamma ramps of the CRTC
+ */
+static void gamma_control_gamma_size(void* crtc_data, struct gamma_control* control, uint32_t size)
+{
+  libgamma_wayland_crtc_data_t* data = crtc_data;
+  (void) control;
+  data->gamma_size = size;
+  data->gamma_size_announced = 1;
+}
+
+
+/**
+ * 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.
+ * @return             Zero on success, otherwise (negative) the value of an
+ *                     error identifier provided by this library.
+ */
+int libgamma_wayland_crtc_initialise(libgamma_crtc_state_t* restrict this,
+				     libgamma_partition_state_t* restrict partition, size_t crtc)
+{
+  libgamma_wayland_crtc_data_t* data;
+  libgamma_wayland_site_data_t* site = partition->site->data;
+  
+  this->data = NULL;
+  
+  if (crtc >= partition->crtcs_available)
+    return LIBGAMMA_NO_SUCH_CRTC;
+  
+  data = site->crtcs[crtc];
+  
+  data->gamma_control = gamma_control_manager_get_gamma_control(site->gamma_control_manager, data->output);
+  if (data->gamma_control)
+    {
+      data->gamma_maybe_supported = 1;
+      gamma_control_add_listener(data->gamma_control, &gamma_control_listener, data);
+    }
+  if (wl_display_roundtrip(site->display) < 0)
+    return LIBGAMMA_ERRNO_SET;
+  if (data->gamma_size_announced == 0)
+    data->gamma_maybe_supported = 0;
+  else if (data->gamma_size < 2)
+    return LIBGAMMA_SINGLETON_GAMMA_RAMP;
+  
+  this->data = data;
+  
+  return 0;
+}
+
+
+/**
+ * Release all resources held by a CRTC state.
+ * 
+ * @param  this  The CRTC state.
+ */
+void libgamma_wayland_crtc_destroy(libgamma_crtc_state_t* restrict this)
+{
+  (void) this;
+}
+
+
+/**
+ * Restore the gamma ramps for a CRTC to the system settings for that CRTC.
+ * 
+ * @param   this  The CRTC state.
+ * @return        Zero on success, otherwise (negative) the value of an
+ *                error identifier provided by this library.
+ */
+int libgamma_wayland_crtc_restore(libgamma_crtc_state_t* restrict this)
+{
+  libgamma_wayland_crtc_data_t* data = this->data;
+  libgamma_wayland_site_data_t* site = this->partition->site->data;
+  gamma_control_reset_gamma(data->gamma_control);
+  if (wl_display_flush(site->display) < 0)
+    return LIBGAMMA_ERRNO_SET;
+  return 0;
+}
+
+
+
+# pragma GCC diagnostic ignored "-Wsuggest-attribute=const" /* TODO */
+/**
+ * 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   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`..
+ */
+int libgamma_wayland_get_crtc_information(libgamma_crtc_information_t* restrict this,
+					  libgamma_crtc_state_t* restrict crtc, int32_t fields)
+{
+  return 0; (void) this, (void) crtc, (void) fields; /* TODO */
+}
+
+
+/**
+ * Get the current gamma ramps for a CRTC, 16-bit gamma-depth version.
+ * 
+ * @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.
+ */
+int libgamma_wayland_crtc_get_gamma_ramps16(libgamma_crtc_state_t* restrict this,
+					    libgamma_gamma_ramps16_t* restrict ramps)
+{
+  return 0; (void) this, (void) ramps; /* TODO */
+}
+
+
+/**
+ * Set the gamma ramps for a CRTC, 16-bit gamma-depth version.
+ * 
+ * @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.
+ */
+int libgamma_wayland_crtc_set_gamma_ramps16(libgamma_crtc_state_t* restrict this,
+					    libgamma_gamma_ramps16_t ramps)
+{
+  return 0; (void) this, (void) ramps; /* TODO */
+}
+
diff --git a/src/lib/gamma-wayland.h b/src/lib/gamma-wayland.h
new file mode 100644
index 0000000..b8435b1
--- /dev/null
+++ b/src/lib/gamma-wayland.h
@@ -0,0 +1,163 @@
+/**
+ * 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/>.
+ */
+#ifndef LIBGAMMA_GAMMA_WAYLAND_H
+#define LIBGAMMA_GAMMA_WAYLAND_H
+
+#ifndef HAVE_LIBGAMMA_METHOD_WAYLAND
+# error Including gamma-wayland.h without HAVE_LIBGAMMA_METHOD_WAYLAND
+#endif
+
+
+#include "libgamma-method.h"
+
+
+/**
+ * Return the capabilities of the adjustment method.
+ * 
+ * @param  this  The data structure to fill with the method's capabilities.
+ */
+void libgamma_wayland_method_capabilities(libgamma_method_capabilities_t* restrict this);
+
+/**
+ * Initialise an allocated site state.
+ * 
+ * @param   this    The site state to initialise.
+ * @param   site    The site identifier, unless it is `NULL` it must a
+ *                  `free`:able. One the state is destroyed the library
+ *                  will attempt to free it. There you should not free
+ *                  it yourself, and it must not be a string constant
+ *                  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.
+ */
+int libgamma_wayland_site_initialise(libgamma_site_state_t* restrict this,
+				     char* restrict site);
+
+/**
+ * Release all resources held by a site state.
+ * 
+ * @param  this  The site state.
+ */
+void libgamma_wayland_site_destroy(libgamma_site_state_t* restrict this);
+
+/**
+ * Restore the gamma ramps all CRTC:s with a site to the system settings.
+ * 
+ * @param   this  The site state.
+ * @return        Zero on success, otherwise (negative) the value of an
+ *                error identifier provided by this library.
+ */
+int libgamma_wayland_site_restore(libgamma_site_state_t* restrict this) __attribute__((const));
+
+
+/**
+ * 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.
+ * @return             Zero on success, otherwise (negative) the value of an
+ *                     error identifier provided by this library.
+ */
+int libgamma_wayland_partition_initialise(libgamma_partition_state_t* restrict this,
+					  libgamma_site_state_t* restrict site,
+					  size_t partition) __attribute__((pure));
+
+/**
+ * Release all resources held by a partition state.
+ * 
+ * @param  this  The partition state.
+ */
+void libgamma_wayland_partition_destroy(libgamma_partition_state_t* restrict this) __attribute__((const));
+
+/**
+ * Restore the gamma ramps all CRTC:s with a partition to the system settings.
+ * 
+ * @param   this  The partition state.
+ * @return        Zero on success, otherwise (negative) the value of an
+ *                error identifier provided by this library.
+ */
+int libgamma_wayland_partition_restore(libgamma_partition_state_t* restrict this) __attribute__((const));
+
+
+/**
+ * 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.
+ * @return             Zero on success, otherwise (negative) the value of an
+ *                     error identifier provided by this library.
+ */
+int libgamma_wayland_crtc_initialise(libgamma_crtc_state_t* restrict this,
+				     libgamma_partition_state_t* restrict partition, size_t crtc);
+
+/**
+ * Release all resources held by a CRTC state.
+ * 
+ * @param  this  The CRTC state.
+ */
+void libgamma_wayland_crtc_destroy(libgamma_crtc_state_t* restrict this) __attribute__((const));
+
+/**
+ * Restore the gamma ramps for a CRTC to the system settings for that CRTC.
+ * 
+ * @param   this  The CRTC state.
+ * @return        Zero on success, otherwise (negative) the value of an
+ *                error identifier provided by this library.
+ */
+int libgamma_wayland_crtc_restore(libgamma_crtc_state_t* restrict this);
+
+
+/**
+ * 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   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`.
+ */
+int libgamma_wayland_get_crtc_information(libgamma_crtc_information_t* restrict this,
+					  libgamma_crtc_state_t* restrict crtc, int32_t fields);
+
+/**
+ * Get the current gamma ramps for a CRTC, 16-bit gamma-depth version.
+ * 
+ * @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.
+ */
+int libgamma_wayland_crtc_get_gamma_ramps16(libgamma_crtc_state_t* restrict this,
+					    libgamma_gamma_ramps16_t* restrict ramps);
+
+/**
+ * Set the gamma ramps for a CRTC, 16-bit gamma-depth version.
+ * 
+ * @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.
+ */
+int libgamma_wayland_crtc_set_gamma_ramps16(libgamma_crtc_state_t* restrict this,
+					    libgamma_gamma_ramps16_t ramps);
+
+
+#endif
+
diff --git a/src/lib/libgamma-facade.c.gpp b/src/lib/libgamma-facade.c.gpp
index ccf60ee..9c31db6 100644
--- a/src/lib/libgamma-facade.c.gpp
+++ b/src/lib/libgamma-facade.c.gpp
@@ -334,6 +334,10 @@ const char* libgamma_method_default_site_variable(int method)
     case LIBGAMMA_METHOD_X_VIDMODE:
       return "DISPLAY";
 #endif
+#ifdef HAVE_LIBGAMMA_METHOD_WAYLAND
+    case LIBGAMMA_METHOD_WAYLAND:
+      return "WAYLAND_DISPLAY";
+#endif
     default:
       return NULL;
     }
diff --git a/src/lib/libgamma-method.h b/src/lib/libgamma-method.h
index 1ebea84..58598a4 100644
--- a/src/lib/libgamma-method.h
+++ b/src/lib/libgamma-method.h
@@ -85,13 +85,20 @@
  */
 #define LIBGAMMA_METHOD_QUARTZ_CORE_GRAPHICS  5
 
+/**
+ * The identifier for the adjustment method with
+ * uses the Orbital Wayland compositor's protocol
+ * for gamma ramp control.
+ */
+#define LIBGAMMA_METHOD_WAYLAND  6
+
 
 /**
  * The index of the last gamma method, neither it
  * nor any index before it may actually be supported
  * as it could have been disabled at compile-time.
  */
-#define LIBGAMMA_METHOD_MAX  5
+#define LIBGAMMA_METHOD_MAX  6
 
 /**
  * The number adjustment methods provided by this library.
diff --git a/src/lib/wayland-gamma-control-protocol.xml b/src/lib/wayland-gamma-control-protocol.xml
new file mode 100644
index 0000000..291472d
--- /dev/null
+++ b/src/lib/wayland-gamma-control-protocol.xml
@@ -0,0 +1,105 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<protocol name="gamma_control">
+  <copyright>
+    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 &lt;http://www.gnu.org/licenses/&gt;.
+  </copyright>
+  
+  
+  <!--
+    - Gamma ramp controller for a display.
+    -->
+  <interface name="gamma_control_manager" version="1">
+    <!--
+      - Acquirer a gamma ramp controller for an output.
+      - 
+      - @param   :struct gamma_control_manager*  The gamma ramp controller for the display.
+      - @param   output:struct wl_output*        The output.
+      - @return  id:struct gamma_control*        Gamma ramp controller for the output.
+      -->
+    <request name="get_gamma_control">
+      <arg name="id"     type="new_id" interface="gamma_control"/>
+      <arg name="output" type="object" interface="wl_output"/>
+    </request>
+    
+    <!--
+      - Release a gamma ramp controller for a display.
+      - 
+      - @param  :struct gamma_control_manager*  The gamma ramp controller.
+      -->
+    <request name="destroy" type="destructor"/>
+  </interface>
+  
+  
+  <!--
+    - Gamma ramp controller for an output.
+    -->
+  <interface name="gamma_control" version="1">
+    <!--
+      - List of errors for `gamma_control` methods.
+      -->
+    <enum name="error">
+      <!--
+	- The gamma ramps do not have the same number of stops.
+        -->
+      <entry name="invalid_gamma" value="0"/>
+    </enum>
+    
+    <!--
+      - Event that notifies the program about the number
+      - of stops in the gamma ramps.
+      - 
+      - @param  user_data:void*         Data registered to be passsed to the
+      -                                 function to identify the event registry.
+      - @param  :struct gamma_control*  The gamma ramp control of the output.
+      - @param  size:uint32_t           The number of stops in the gamma ramps.
+      -->
+    <event name="gamma_size">
+      <arg name="size" type="uint"/>
+    </event>
+    
+    <!--
+      - Set the gamma ramps for an output.
+      - 
+      - @param  :struct gamma_control*            The gamma ramp control of the output.
+      - @param  red:struct wl_array*<uint16_t>    The gamma ramp for the red channel.
+      - @param  green:struct wl_array*<uint16_t>  The gamma ramp for the green channel.
+      - @param  blue:struct wl_array*<uint16_t>   The gamma ramp for the blue channel.
+      -->
+    <request name="set_gamma">
+      <arg name="red"   type="array"/>
+      <arg name="green" type="array"/>
+      <arg name="blue"  type="array"/>
+    </request>
+    
+    <!--
+      - Undo all modifications to an output's gamma ramps.
+      - 
+      - @param  :struct gamma_control*  The gamma ramp control of the output.
+      -->
+    <request name="reset_gamma"/>
+    
+    <!--
+      - Release a gamma ramp controller for an output.
+      - 
+      - @param  :struct gamma_control*  The gamma ramp controller.
+      -->
+    <request name="destroy" type="destructor"/>
+  </interface>
+  
+  
+</protocol>
+