From: Brian Paul Date: Tue, 20 Sep 2016 22:05:48 +0000 (-0600) Subject: gallium/util: add comment on util_is_format_compatible() X-Git-Tag: upstream/17.1.0~6220 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=b35684543ed43c3ac2aa2710e3974fbfaf9c2f7c;p=platform%2Fupstream%2Fmesa.git gallium/util: add comment on util_is_format_compatible() From reading the code, it's not obvious what is src/dest compatible. The list of a->b copy-compatible formats comes from Jose's original check-in message, with some format name updates. Reviewed-by: Nicolai Hähnle Reviewed-by: Roland Scheidegger --- diff --git a/src/gallium/auxiliary/util/u_format.c b/src/gallium/auxiliary/util/u_format.c index cbdb5ce..72dd60f 100644 --- a/src/gallium/auxiliary/util/u_format.c +++ b/src/gallium/auxiliary/util/u_format.c @@ -457,6 +457,30 @@ util_format_write_4i(enum pipe_format format, format_desc->pack_rgba_sint(dst_row, dst_stride, src_row, src_stride, w, h); } +/** + * Check if we can safely memcopy from the source format to the dest format. + * This basically covers the cases of a "used" channel copied to a typeless + * channel, plus some 1-channel cases. + * Examples of compatible copy formats include: + * b8g8r8a8_unorm -> b8g8r8x8_unorm + * a8r8g8b8_unorm -> x8r8g8b8_unorm + * b5g5r5a1_unorm -> b5g5r5x1_unorm + * b4g4r4a4_unorm -> b4g4r4x4_unorm + * l8_unorm -> r8_unorm + * i8_unorm -> l8_unorm + * i8_unorm -> a8_unorm + * i8_unorm -> r8_unorm + * l16_unorm -> r16_unorm + * z24_unorm_s8_uint -> z24x8_unorm + * s8_uint_z24_unorm -> x8z24_unorm + * r8g8b8a8_unorm -> r8g8b8x8_unorm + * a8b8g8r8_srgb -> x8b8g8r8_srgb + * b8g8r8a8_srgb -> b8g8r8x8_srgb + * a8r8g8b8_srgb -> x8r8g8b8_srgb + * a8b8g8r8_unorm -> x8b8g8r8_unorm + * r10g10b10a2_uscaled -> r10g10b10x2_uscaled + * r10sg10sb10sa2u_norm -> r10g10b10x2_snorm + */ boolean util_is_format_compatible(const struct util_format_description *src_desc, const struct util_format_description *dst_desc)