diff options
Diffstat (limited to 'src/libgamma-facade.c')
| -rw-r--r-- | src/libgamma-facade.c | 132 |
1 files changed, 132 insertions, 0 deletions
diff --git a/src/libgamma-facade.c b/src/libgamma-facade.c index 07dfd9b..81c6d8a 100644 --- a/src/libgamma-facade.c +++ b/src/libgamma-facade.c @@ -56,6 +56,7 @@ # endif #endif +#include <unistd.h> #include <stddef.h> #include <stdint.h> #include <stdlib.h> @@ -74,6 +75,137 @@ #endif + +#ifdef HAVE_GAMMA_METHODS +# ifdef HAVE_GAMMA_METHOD_LINUX_DRM +/** + * Test whether a file descriptor refers to a VT + * + * @param fd The file descriptor + * @return Whether the file descriptor refers to a VT + */ +static int libgamma_is_vt_proper(int fd) +{ + char buf[32]; + char digit0; + + if (ttyname_r(fd, buf, sizeof(buf) / sizeof(char))) + return 0; + + if (strstr(buf, "/dev/tty") != buf) + return 0; + + digit0 = buf[strlen("/dev/tty")]; + return ('1' <= digit0) && (digit0 <= '9'); +} +# endif + + +/** + * Test the availability of an adjustment method + * + * @param method The adjustment method + * @param operation Allowed values: + * 0: Pass if the environment suggests it will work but is not fake. + * 1: Pass if the environment suggests it will work. + * 2: Pass if real and not fake. + * 3: Pass if real. + * 4: Always pass. + * Other values invoke undefined behaviour. + * @return Whether the test passed + */ +static int libgamma_list_method_test(int method, int operation) +{ + libgamma_method_capabilities_t caps; + libgamma_method_capabilities(&caps, method); + + switch (operation) + { + case 0: /* Methods that the environment suggests will work, excluding fake. */ + if (caps.fake) + return 0; + /* Fall through. */ + + case 1: /* Methods that the environment suggests will work, including fake. */ + if (caps.real == 0) + return 0; +#ifdef HAVE_GAMMA_METHOD_LINUX_DRM + if (method == GAMMA_METHOD_LINUX_DRM) + return libgamma_is_vt_proper(STDIN_FILENO) || + libgamma_is_vt_proper(STDOUT_FILENO) || + libgamma_is_vt_proper(STDERR_FILENO); +#endif +#ifdef HAVE_GAMMA_METHOD_DUMMY + if (method == GAMMA_METHOD_DUMMY) + return 0; +#endif + return caps.default_site_known; + + case 2: /* All real non-fake methods. */ + return caps.real && (caps.fake == 0); + + case 3: /* All real methods. */ + return caps.real; + + default: /* All methods. */ + return 1; + } +} +#endif + + +/** + * List available adjustment methods by their order of preference based on the environment + * + * @param methods Output array of methods, should be able to hold `GAMMA_METHOD_COUNT` elements + * @param operation Allowed values: + * 0: Methods that the environment suggests will work, excluding fake. + * 1: Methods that the environment suggests will work, including fake. + * 2: All real non-fake methods. + * 3: All real methods. + * 4: All methods. + * Other values invoke undefined behaviour. + * @return The number of element that have been stored in `methods` + */ +size_t libgamma_list_methods(int* methods, int operation) +{ +#ifdef HAVE_NO_GAMMA_METHODS + (void) methods; + (void) operation; + return 0; +#else + size_t n = 0; + +#ifdef HAVE_GAMMA_METHOD_RANDR + if (libgamma_list_method_test(GAMMA_METHOD_RANDR, operation)) + methods[n++] = GAMMA_METHOD_RANDR; +#endif +#ifdef HAVE_GAMMA_METHOD_VIDMODE + if (libgamma_list_method_test(GAMMA_METHOD_VIDMODE, operation)) + methods[n++] = GAMMA_METHOD_VIDMODE; +#endif +#ifdef HAVE_GAMMA_METHOD_LINUX_DRM + if (libgamma_list_method_test(GAMMA_METHOD_LINUX_DRM, operation)) + methods[n++] = GAMMA_METHOD_LINUX_DRM; +#endif +#ifdef HAVE_GAMMA_METHOD_W32_GDI + if (libgamma_list_method_test(GAMMA_METHOD_W32_GDI, operation)) + methods[n++] = GAMMA_METHOD_W32_GDI; +#endif +#ifdef HAVE_GAMMA_METHOD_QUARTZ_CORE_GRAPHICS + if (libgamma_list_method_test(GAMMA_METHOD_QUARTZ_CORE_GRAPHICS, operation)) + methods[n++] = GAMMA_METHOD_QUARTZ_CORE_GRAPHICS; +#endif +#ifdef HAVE_GAMMA_METHOD_DUMMY + if (libgamma_list_method_test(GAMMA_METHOD_DUMMY, operation)) + methods[n++] = GAMMA_METHOD_DUMMY; +#endif + + return n; +#endif +} + + /** * Return the capabilities of an adjustment method * |