Hi Brian,
----- Original Message -----
> From: Brian Paul <bri...@vmware.com>
>
> ---
> src/gallium/auxiliary/util/u_format.c | 77
> +++++++++++++++++++++++++++++++++
> src/gallium/auxiliary/util/u_format.h | 16 +++++++
> 2 files changed, 93 insertions(+), 0 deletions(-)
>
> diff --git a/src/gallium/auxiliary/util/u_format.c
> b/src/gallium/auxiliary/util/u_format.c
> index 34922ab..2bd3737 100644
> --- a/src/gallium/auxiliary/util/u_format.c
> +++ b/src/gallium/auxiliary/util/u_format.c
> @@ -67,6 +67,83 @@ util_format_is_float(enum pipe_format format)
> }
>
>
> +/** Test if the format contains RGB, but not alpha */
> +boolean
It might be better to change the name to util_format_is_rgb_no_alpha, as
is_rgb sounds more like a RGB colorspace inquiry.
> +util_format_is_rgb(enum pipe_format format)
> +{
> + const struct util_format_description *desc =
> + util_format_description(format);
For callers that call these helpers a lot, all these internal calls to
util_format_description() will be inefficient. In such cases it might be
preferrable for these functions to be declared inline, and take a "const struct
util_format_description *desc" argument instead of "enum pipe_format format",
allowing the caller will call util_format_description only once.
> +
> + if ((desc->colorspace == UTIL_FORMAT_COLORSPACE_RGB ||
> + desc->colorspace == UTIL_FORMAT_COLORSPACE_SRGB) &&
> + desc->nr_channels == 4 &&
> + desc->swizzle[0] <= UTIL_FORMAT_SWIZZLE_W &&
> + desc->swizzle[1] <= UTIL_FORMAT_SWIZZLE_W &&
> + desc->swizzle[2] <= UTIL_FORMAT_SWIZZLE_W &&
> + desc->swizzle[3] == UTIL_FORMAT_SWIZZLE_1) {
> + return TRUE;
> + }
> + return FALSE;
> +}
The above logic will produce the following unexpected results:
- FALSE for PIPE_FORMAT_R8G8B8_UNORM, because nr_channels == 3.
- FALSE for PIPE_FORMAT_R8G8_UNORM, because nr_channels == 2.
- FALSE for PIPE_FORMAT_R8_UNORM, because nr_channels == 1.
- FALSE for PIPE_FORMAT_DXT1_RGB, becuase nr_channels == 1 (nr_channels is
always 1 for non PLAIN formats and not really very meaningful in such format
types).
- TRUE for signed and mixed signed formats such as
PIPE_FORMAT_R8SG8SB8UX8U_NORM (not sure if this is intended or matters)
It might be useful to extend/adapt a test like such as
src/gallium/tests/unit/u_format_compatible_test.c to ensure that this gives the
expected results for all formats.
> +boolean
> +util_format_is_luminance(enum pipe_format format)
> +{
> + const struct util_format_description *desc =
> + util_format_description(format);
> +
> + if ((desc->colorspace == UTIL_FORMAT_COLORSPACE_RGB ||
> + desc->colorspace == UTIL_FORMAT_COLORSPACE_SRGB) &&
> + desc->nr_channels == 1 &&
> + desc->swizzle[0] == UTIL_FORMAT_SWIZZLE_X &&
> + desc->swizzle[1] == UTIL_FORMAT_SWIZZLE_X &&
> + desc->swizzle[2] == UTIL_FORMAT_SWIZZLE_X &&
> + desc->swizzle[3] == UTIL_FORMAT_SWIZZLE_1) {
> + return TRUE;
> + }
> + return FALSE;
> +}
This will produce TRUE for PIPE_FORMAT_LATC1_UNORM...
> +
> +boolean
> +util_format_is_luminance_alpha(enum pipe_format format)
> +{
> + const struct util_format_description *desc =
> + util_format_description(format);
> +
> + if ((desc->colorspace == UTIL_FORMAT_COLORSPACE_RGB ||
> + desc->colorspace == UTIL_FORMAT_COLORSPACE_SRGB) &&
> + desc->nr_channels == 2 &&
> + desc->swizzle[0] == UTIL_FORMAT_SWIZZLE_X &&
> + desc->swizzle[1] == UTIL_FORMAT_SWIZZLE_X &&
> + desc->swizzle[2] == UTIL_FORMAT_SWIZZLE_X &&
> + desc->swizzle[3] == UTIL_FORMAT_SWIZZLE_Y) {
> + return TRUE;
> + }
> + return FALSE;
> +}
.. but this will produce FALSE for PIPE_FORMAT_LATC2_UNORM (nr_channels != 2).
> +
> +boolean
> +util_format_is_intensity(enum pipe_format format)
> +{
> + const struct util_format_description *desc =
> + util_format_description(format);
> +
> + if ((desc->colorspace == UTIL_FORMAT_COLORSPACE_RGB ||
> + desc->colorspace == UTIL_FORMAT_COLORSPACE_SRGB) &&
> + desc->nr_channels == 1 &&
> + desc->swizzle[0] == UTIL_FORMAT_SWIZZLE_X &&
> + desc->swizzle[1] == UTIL_FORMAT_SWIZZLE_X &&
> + desc->swizzle[2] == UTIL_FORMAT_SWIZZLE_X &&
> + desc->swizzle[3] == UTIL_FORMAT_SWIZZLE_X) {
> + return TRUE;
> + }
> + return FALSE;
> +}
This looks alright.
Jose
_______________________________________________
mesa-dev mailing list
mesa-dev@lists.freedesktop.org
http://lists.freedesktop.org/mailman/listinfo/mesa-dev
