Now that we've added an RGBA property type to the kernel that handles RGBA values with a specific bit layout, let's add a userspace helper to allow userspace to easily build values in the proper format.
Cc: dri-devel@lists.freedesktop.org Signed-off-by: Matt Roper matthew.d.roper@intel.com --- xf86drmMode.c | 36 ++++++++++++++++++++++++++++++++++++ xf86drmMode.h | 7 +++++++ 2 files changed, 43 insertions(+)
diff --git a/xf86drmMode.c b/xf86drmMode.c index ab6b519..4bfd419 100644 --- a/xf86drmMode.c +++ b/xf86drmMode.c @@ -1445,3 +1445,39 @@ drmModeDestroyPropertyBlob(int fd, uint32_t id) destroy.blob_id = id; return DRM_IOCTL(fd, DRM_IOCTL_MODE_DESTROYPROPBLOB, &destroy); } + +/* + * Builds an RGBA 16bpc color value with bits laid out in the format expected + * by DRM RGBA properties. @bpc is the number of bits per component value + * being provided as parameters. + */ +uint64_t +drmModeRGBA(unsigned bpc, + uint16_t red, + uint16_t green, + uint16_t blue, + uint16_t alpha) +{ + int shift; + uint64_t val; + + if (bpc > 16) + return -ERANGE; + + /* + * If we were provided with fewer than 16 bpc, shift the value we + * received into the most significant bits. + */ + shift = 16 - bpc; + + val = red << shift; + val <<= 16; + val |= green << shift; + val <<= 16; + val |= blue << shift; + val <<= 16; + val |= alpha << shift; + + return val; +} + diff --git a/xf86drmMode.h b/xf86drmMode.h index 4de7bbb..4aa4917 100644 --- a/xf86drmMode.h +++ b/xf86drmMode.h @@ -507,6 +507,13 @@ extern int drmModeCreatePropertyBlob(int fd, const void *data, size_t size, uint32_t *id); extern int drmModeDestroyPropertyBlob(int fd, uint32_t id);
+extern uint64_t drmModeRGBA(unsigned bpc, + uint16_t red, + uint16_t green, + uint16_t blue, + uint16_t alpha); +#define DRM_RGBA8888(r, g, b, a) drmModeRGBA(8, r, g, b, a) +#define DRM_RGBA16161616(r, g, b, a) drmModeRGBA(16, r, g, b, a)
#if defined(__cplusplus) }