add makefile + implement adjustment method common functions

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

2 files changed, 566 insertions, 0 deletions

diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..f1d2536
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,88 @@
+# Copying and distribution of this file, with or without modification,
+# are permitted in any medium without royalty provided the copyright
+# notice and this notice are preserved.  This file is offered as-is,
+# without any warranty.
+
+
+# The package path prefix, if you want to install to another root, set DESTDIR to that root.
+PREFIX ?= /usr
+# The library path excluding prefix.
+LIB ?= /lib
+# The resource path excluding prefix.
+DATA ?= /share
+# The library path including prefix.
+LIBDIR ?= $(PREFIX)$(LIB)
+# The resource path including prefix.
+DATADIR ?= $(PREFIX)$(DATA)
+# The generic documentation path including prefix.
+DOCDIR ?= $(DATADIR)/doc
+# The info manual documentation path including prefix.
+INFODIR ?= $(DATADIR)/info
+# The license base path including prefix.
+LICENSEDIR ?= $(DATADIR)/licenses
+
+# The name of the package as it should be installed.
+PKGNAME ?= libgamma
+
+
+# Optimisation level (and debug flags.)
+ifeq ($(DEBUG),y)
+OPTIMISE = -Og -g
+else
+OPTIMISE = -Ofast
+endif
+
+# Enabled warnings.
+WARN = -Wall -Wextra -pedantic -Wdouble-promotion -Wformat=2 -Winit-self       \
+       -Wmissing-include-dirs -Wtrampolines -Wfloat-equal -Wshadow             \
+       -Wmissing-prototypes -Wmissing-declarations -Wredundant-decls           \
+       -Wnested-externs -Winline -Wno-variadic-macros -Wsign-conversion        \
+       -Wswitch-default -Wconversion -Wsync-nand -Wunsafe-loop-optimizations   \
+       -Wcast-align -Wstrict-overflow -Wdeclaration-after-statement -Wundef    \
+       -Wbad-function-cast -Wcast-qual -Wwrite-strings -Wlogical-op            \
+       -Waggregate-return -Wstrict-prototypes -Wold-style-definition -Wpacked  \
+       -Wvector-operation-performance -Wunsuffixed-float-constants             \
+       -Wsuggest-attribute=const -Wsuggest-attribute=noreturn                  \
+       -Wsuggest-attribute=pure -Wsuggest-attribute=format -Wnormalized=nfkc
+
+# The C standard used in the code.
+STD = c99
+
+# C compiler debug flags.
+DEBUG_FLAGS =
+ifeq ($(DEBUG),y)
+DEBUG_FLAGS += -D'DEBUG'
+endif
+
+# Options for the C compiler.
+C_FLAGS = $(OPTIMISE) $(WARN) -std=$(STD) $(CPPFLAGS) $(CFLAGS) $(LDFLAGS)  \
+          -ftree-vrp -fstrict-aliasing -fipa-pure-const -fstack-usage       \
+          -fstrict-overflow -funsafe-loop-optimizations -fno-builtin        \
+	  $(DEBUG_FLAGS)
+
+
+# Object files for the library.
+LIBOBJ = libgamma-facade
+
+
+# Build rules.
+
+.PHONY: all
+all: bin/libgamma.so
+
+
+bin/libgamma.so: $(foreach O,$(LIBOBJ),obj/$(O).o)
+	mkdir -p $(shell dirname $@)
+	$(CC) $(C_FLAGS) -shared -o $@ $^
+
+obj/%.o: src/%.c src/*.h
+	mkdir -p $(shell dirname $@)
+	$(CC) $(C_FLAGS) -fPIC -c -o $@ $<
+
+
+# Clean rules.
+
+.PHONY: clean
+clean:
+	-rm -rf obj bin
+
diff --git a/src/libgamma-facade.c b/src/libgamma-facade.c
new file mode 100644
index 0000000..495b5f3
--- /dev/null
+++ b/src/libgamma-facade.c
@@ -0,0 +1,478 @@
+/**
+ * libgamma — Display server abstraction layer for gamma ramp adjustments
+ * Copyright © 2014  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/>.
+ */
+#include "libgamma-facade.h"
+
+#include "libgamma-method.h"
+
+#include <stddef.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+
+
+/**
+ * Return the capabilities of an adjustment method
+ * 
+ * @param  this    The data structure to fill with the method's capabilities
+ * @param  method  The adjustment method (display server and protocol)
+ */
+void libgamma_method_capabilities(libgamma_method_capabilities_t* restrict this, int method)
+{
+  /* TODO */
+}
+
+
+/**
+ * Return the capabilities of an adjustment method
+ * 
+ * @param   method  The adjustment method (display server and protocol)
+ * @return          The default site, `NULL` if it cannot be determined or
+ *                  if multiple sites are not supported by the adjustment
+ *                  method. This value should not be free:d.
+ */
+char* libgamma_method_default_site(int method)
+{
+  const char* var = libgamma_method_default_site_variable(method);
+  char* env;
+  
+  if (var == NULL)
+    return NULL;
+  
+  env = getenv(var);
+  if ((env == NULL) || (*env == '\0'))
+    return NULL;
+  
+  return env;
+}
+
+
+/**
+ * Return the capabilities of an adjustment method
+ * 
+ * @param   method  The adjustment method (display server and protocol)
+ * @return          The environ variables that is used to determine the
+ *                  default site. `NULL` if there is none, that is, if
+ *                  the method does not support multiple sites.
+ *                  This value should not be free:d.
+ */
+const char* libgamma_method_default_site_variable(int method)
+{
+  /* TODO */
+}
+
+
+
+/**
+ * Initialise an allocated site state
+ * 
+ * @param   this    The site state to initialise
+ * @param   method  The adjustment method (display server and protocol)
+ * @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.
+ * @return          Zero on success, otherwise (negative) the value of an
+ *                  error identifier provided by this library
+ */
+int libgamma_site_initialise(libgamma_site_state_t* restrict this,
+			     int method, char* restrict site)
+{
+  /* TODO */
+}
+
+
+/**
+ * Release all resources held by a site state
+ * 
+ * @param  this  The site state
+ */
+void libgamma_site_destroy(libgamma_site_state_t* restrict this)
+{
+  /* TODO */
+}
+
+
+/**
+ * Release all resources held by a site state
+ * and free the site state pointer
+ * 
+ * @param  this  The site state
+ */
+void libgamma_site_free(libgamma_site_state_t* restrict this)
+{
+  libgamma_site_destroy(this);
+  free(this);
+}
+
+
+/**
+ * Restore the gamma ramps all CRTCS 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_site_restore(libgamma_site_state_t* restrict this)
+{
+  /* TODO */
+}
+
+
+
+/**
+ * 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_partition_initialise(libgamma_partition_state_t* restrict this,
+				  libgamma_site_state_t* restrict site, size_t partition)
+{
+  /* TODO */
+}
+
+
+/**
+ * Release all resources held by a partition state
+ * 
+ * @param  this  The partition state
+ */
+void libgamma_partition_destroy(libgamma_partition_state_t* restrict this)
+{
+  /* TODO */
+}
+
+
+/**
+ * Release all resources held by a partition state
+ * and free the partition state pointer
+ * 
+ * @param  this  The partition state
+ */
+void libgamma_partition_free(libgamma_partition_state_t* restrict this)
+{
+  libgamma_partition_destroy(this);
+  free(this);
+}
+
+
+/**
+ * Restore the gamma ramps all CRTCS 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_partition_restore(libgamma_site_state_t* restrict this)
+{
+  /* TODO */
+}
+
+
+
+/**
+ * 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_crtc_initialise(libgamma_crtc_state_t* restrict this,
+			     libgamma_partition_state_t* restrict partition, size_t crtc)
+{
+  /* TODO */
+}
+
+
+/**
+ * Release all resources held by a CRTC state
+ * 
+ * @param  this  The CRTC state
+ */
+void libgamma_crtc_destroy(libgamma_crtc_state_t* restrict this)
+{
+  /* TODO */
+}
+
+
+/**
+ * Release all resources held by a CRTC state
+ * and free the CRTC state pointer
+ * 
+ * @param  this  The CRTC state
+ */
+void libgamma_crtc_free(libgamma_crtc_state_t* restrict this)
+{
+  libgamma_crtc_destroy(this);
+  free(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_crtc_restore(libgamma_site_state_t* restrict this)
+{
+  /* 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   field  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_get_crtc_information(libgamma_crtc_information_t* restrict this,
+				  libgamma_crtc_state_t* restrict crtc, int32_t field)
+{
+  /* TODO */
+}
+
+
+/**
+ * Release all resources in an information data structure for a CRTC
+ * 
+ * @param  this  The CRTC information
+ */
+int libgamma_crtc_information_destroy(libgamma_crtc_information_t* restrict this)
+{
+  /* TODO */
+}
+
+
+/**
+ * Release all resources in an information data structure for a CRTC
+ * and free the data structure pointer
+ * 
+ * @param  this  The CRTC information
+ */
+int libgamma_crtc_information_free(libgamma_crtc_information_t* restrict this)
+{
+  libgamma_crtc_information_destroy(this);
+  free(this);
+}
+
+
+/**
+ * Convert a raw representation of an EDID to a lowercase hexadecimal representation
+ * 
+ * @param   edid    The EDID in raw representation
+ * @param   length  The length of `edid`
+ * @retrun          The EDID in lowercase hexadecimal representation,
+ *                  `NULL` on allocation error, `errno` will be set accordingly
+ */
+char* libgamma_behex_edid_lowercase(const unsigned char* restrict edid, size_t length)
+{
+  char* out = malloc((length * 2 + 1) * sizeof(char));
+  size_t i;
+  
+  if (out == NULL)
+    return NULL;
+  
+  for (i = 0; i < length; i++)
+    {
+      out[i * 2 + 0] = "0123456789abcdef"[(edid[i] >> 4) & 15];
+      out[i * 2 + 1] = "0123456789abcdef"[(edid[i] >> 0) & 15];
+    }
+  out[length * 2] = '\0';
+  
+  return out;
+}
+
+
+/**
+ * Convert a raw representation of an EDID to an uppercase hexadecimal representation
+ * 
+ * @param   edid    The EDID in raw representation
+ * @param   length  The length of `edid`
+ * @retrun          The EDID in uppercase hexadecimal representation,
+ *                  NULL` on allocation error, `errno` will be set accordingly
+ */
+char* libgamma_behex_edid_uppercase(const unsigned char* restrict edid, size_t length)
+{
+  char* out = malloc((length * 2 + 1) * sizeof(char));
+  size_t i;
+  
+  if (out == NULL)
+    return NULL;
+  
+  for (i = 0; i < length; i++)
+    {
+      out[i * 2 + 0] = "0123456789ABCDEF"[(edid[i] >> 4) & 15];
+      out[i * 2 + 1] = "0123456789ABCDEF"[(edid[i] >> 0) & 15];
+    }
+  out[length * 2] = '\0';
+  
+  return out;
+}
+
+
+/**
+ * Convert an hexadecimal representation of an EDID to a raw representation
+ * 
+ * @param   edid  The EDID in hexadecimal representation
+ * @retrun        The EDID in raw representation, it will be half the length
+ *                of `edid` (the input value). `NULL` on allocation error or
+ *                if the EDID is malformated, `errno` will be set accordingly.
+ */
+unsigned char* libgamma_unhex_edid(const char* restrict edid)
+{
+#define not_range(lower, V, upper)  ((V < lower) || (upper < V))
+#define is_not_hex(V)  (not_range('0', V, '9') && not_range('a', V, 'f') && not_range('A', V, 'F'))
+  
+  unsigned char* out = NULL;
+  size_t n = strlen(edid);
+  size_t i;
+  
+  if ((n & 1))
+    return errno = EINVAL, NULL;
+  
+  out = malloc(n / 2 * sizeof(unsigned char));
+  if (out == NULL)
+    return NULL;
+  
+  for (i = 0; i < n; i++)
+    {
+      char a = edid[i * 2 + 0];
+      char b = edid[i * 2 + 1];
+      
+      if (is_not_hex(a) || is_not_hex(b))
+	{
+	  free(out);
+	  return errno = EINVAL, NULL;
+	}
+      
+      a = (char)((a & 15) + (a > '9' ? 9 : 0));
+      b = (char)((b & 15) + (b > '9' ? 9 : 0));
+      
+      out[i] = (unsigned char)((a << 4) | b);
+    }
+  
+  return out;
+  
+#undef is_hex
+#undef not_range
+}
+
+
+
+/**
+ * Set the gamma ramps for a CRTC, 16-bit gamma-depth version
+ * 
+ * @param   this   The CRTC state
+ * @parma   ramps  The gamma ramps to apply
+ * @return         Zero on success, otherwise (negative) the value of an
+ *                 error identifier provided by this library
+ */
+int libgamma_crtc_set_gamma_ramps(libgamma_crtc_state_t* restrict this,
+				  libgamma_gamma_ramps_t ramps)
+{
+  /* TODO */
+}
+
+
+/**
+ * Get current the gamma ramps for a CRTC, 16-bit gamma-depth version
+ * 
+ * @param   this   The CRTC state
+ * @parma   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_crtc_get_gamma_ramps(libgamma_crtc_state_t* restrict this,
+				  libgamma_gamma_ramps_t* restrict ramps)
+{
+  /* TODO */
+}
+
+
+
+/**
+ * Set the gamma ramps for a CRTC, 32-bit gamma-depth version
+ * 
+ * @param   this   The CRTC state
+ * @parma   ramps  The gamma ramps to apply
+ * @return         Zero on success, otherwise (negative) the value of an
+ *                 error identifier provided by this library
+ */
+int libgamma_crtc_set_gamma_ramps32(libgamma_crtc_state_t* restrict this,
+				    libgamma_gamma_ramps32_t ramps)
+{
+  /* TODO */
+}
+
+
+/**
+ * Get current the gamma ramps for a CRTC, 32-bit gamma-depth version
+ * 
+ * @param   this   The CRTC state
+ * @parma   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_crtc_get_gamma_ramps32(libgamma_crtc_state_t* restrict this,
+				    libgamma_gamma_ramps32_t* restrict ramps)
+{
+  /* TODO */
+}
+
+
+/**
+ * Set the gamma ramps for a CRTC, 64-bit gamma-depth version
+ * 
+ * @param   this   The CRTC state
+ * @parma   ramps  The gamma ramps to apply
+ * @return         Zero on success, otherwise (negative) the value of an
+ *                 error identifier provided by this library
+ */
+int libgamma_crtc_set_gamma_ramps64(libgamma_crtc_state_t* restrict this,
+				    libgamma_gamma_ramps64_t ramps)
+{
+  /* TODO */
+}
+
+
+/**
+ * Get current the gamma ramps for a CRTC, 64-bit gamma-depth version
+ * 
+ * @param   this   The CRTC state
+ * @parma   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_crtc_get_gamma_ramps64(libgamma_crtc_state_t* restrict this,
+				    libgamma_gamma_ramps64_t* restrict ramps)
+{
+  /* TODO */
+}
+