[Mesa-dev] [PATCH v4 02/22] mesa: Fix packing/unpacking of MESA_FORMAT_R5G6B5_UNORM

Anuj Phogat anuj.phogat at gmail.com
Thu Jan 8 12:02:24 PST 2015


On Wed, Jan 7, 2015 at 11:20 PM, Iago Toral Quiroga <itoral at igalia.com>
wrote:
> From: Jason Ekstrand <jason.ekstrand at intel.com>
>
> Aparently, the packing/unpacking functions for these formats have differed
> from the format description in formats.h.  Instead of fixing this, people
> simply left a comment saying it was broken.  Let's actually fix it for
> real.
>
> Signed-off-by: Jason Ekstrand <jason.ekstrand at intel.com>
>
> v2 by Samuel Iglesias <siglesias at igalia.com>:
> - Keep comment in unpack_R5G6B5_UNORM()
> ---
>  src/mesa/main/format_pack.c      | 10 ++--------
>  src/mesa/main/format_unpack.c    |  7 ++-----
>  src/mesa/main/formats.c          | 12 ++++++------
>  src/mesa/main/texstore.c         |  2 +-
>  src/mesa/swrast/s_texfetch_tmp.h |  8 ++++----
>  5 files changed, 15 insertions(+), 24 deletions(-)
>
> diff --git a/src/mesa/main/format_pack.c b/src/mesa/main/format_pack.c
> index 31c9f77..20d2b1a 100644
> --- a/src/mesa/main/format_pack.c
> +++ b/src/mesa/main/format_pack.c
> @@ -458,17 +458,11 @@ pack_row_float_B5G6R5_UNORM(GLuint n, const GLfloat
src[][4], void *dst)
>  }
>
>
> -/*
> - * MESA_FORMAT_R5G6B5_UNORM
> - * Warning: these functions do not match the current Mesa definition
> - * of MESA_FORMAT_R5G6B5_UNORM.
> - */
> -
>  static void
>  pack_ubyte_R5G6B5_UNORM(const GLubyte src[4], void *dst)
>  {
>     GLushort *d = ((GLushort *) dst);
> -   *d = PACK_COLOR_565_REV(src[RCOMP], src[GCOMP], src[BCOMP]);
> +   *d = PACK_COLOR_565(src[BCOMP], src[GCOMP], src[RCOMP]);
>  }
>
>  static void
> @@ -479,7 +473,7 @@ pack_float_R5G6B5_UNORM(const GLfloat src[4], void
*dst)
>     UNCLAMPED_FLOAT_TO_UBYTE(r, src[RCOMP]);
>     UNCLAMPED_FLOAT_TO_UBYTE(g, src[GCOMP]);
>     UNCLAMPED_FLOAT_TO_UBYTE(b, src[BCOMP]);
> -   *d = PACK_COLOR_565_REV(r, g, b);
> +   *d = PACK_COLOR_565(b, g, r);
>  }
>
>  static void
> diff --git a/src/mesa/main/format_unpack.c b/src/mesa/main/format_unpack.c
> index d5628a9..69c76d3 100644
> --- a/src/mesa/main/format_unpack.c
> +++ b/src/mesa/main/format_unpack.c
> @@ -2764,16 +2764,13 @@ unpack_ubyte_B5G6R5_UNORM(const void *src,
GLubyte dst[][4], GLuint n)
>  static void
>  unpack_ubyte_R5G6B5_UNORM(const void *src, GLubyte dst[][4], GLuint n)
>  {
> -   /* Warning: this function does not match the current Mesa definition
> -    * of MESA_FORMAT_R5G6B5_UNORM.
> -    */
>     const GLushort *s = ((const GLushort *) src);
>     GLuint i;
>     for (i = 0; i < n; i++) {
>        GLuint t = (s[i] >> 8) | (s[i] << 8); /* byte swap */
> -      dst[i][RCOMP] = EXPAND_5_8((t >> 11) & 0x1f);
> +      dst[i][RCOMP] = EXPAND_5_8( t        & 0x1f);
>        dst[i][GCOMP] = EXPAND_6_8((t >> 5 ) & 0x3f);
> -      dst[i][BCOMP] = EXPAND_5_8( t        & 0x1f);
> +      dst[i][BCOMP] = EXPAND_5_8((t >> 11) & 0x1f);
>        dst[i][ACOMP] = 0xff;
>     }
>  }
> diff --git a/src/mesa/main/formats.c b/src/mesa/main/formats.c
> index 58c32e2..1315d36 100644
> --- a/src/mesa/main/formats.c
> +++ b/src/mesa/main/formats.c
> @@ -1462,14 +1462,14 @@ _mesa_format_matches_format_and_type(mesa_format
mesa_format,
>        return format == GL_RGB && type == GL_UNSIGNED_BYTE &&
littleEndian;
>
>     case MESA_FORMAT_B5G6R5_UNORM:
> -      return format == GL_RGB && type == GL_UNSIGNED_SHORT_5_6_5 &&
!swapBytes;
> +      return ((format == GL_RGB && type == GL_UNSIGNED_SHORT_5_6_5) ||
> +              (format == GL_BGR && type == GL_UNSIGNED_SHORT_5_6_5_REV))
&&
> +              !swapBytes;
>
>     case MESA_FORMAT_R5G6B5_UNORM:
> -      /* Some of the 16-bit MESA_FORMATs that would seem to correspond to
> -       * GL_UNSIGNED_SHORT_* are byte-swapped instead of
channel-reversed,
> -       * according to formats.h, so they can't be matched.
> -       */
> -      return GL_FALSE;
> +      return ((format == GL_BGR && type == GL_UNSIGNED_SHORT_5_6_5) ||
> +              (format == GL_RGB && type == GL_UNSIGNED_SHORT_5_6_5_REV))
&&
> +              !swapBytes;
>
>     case MESA_FORMAT_B4G4R4A4_UNORM:
>        return format == GL_BGRA && type == GL_UNSIGNED_SHORT_4_4_4_4_REV
&&
> diff --git a/src/mesa/main/texstore.c b/src/mesa/main/texstore.c
> index 50aa1fd..b9407d2 100644
> --- a/src/mesa/main/texstore.c
> +++ b/src/mesa/main/texstore.c
> @@ -923,7 +923,7 @@ _mesa_texstore_rgb565(TEXSTORE_PARAMS)
>           }
>           else {
>              for (col = 0; col < srcWidth; col++) {
> -               dstUS[col] = PACK_COLOR_565_REV( srcUB[0], srcUB[1],
srcUB[2] );
> +               dstUS[col] = PACK_COLOR_565( srcUB[2], srcUB[1], srcUB[0]
);
>                 srcUB += 3;
>              }
>           }
> diff --git a/src/mesa/swrast/s_texfetch_tmp.h
b/src/mesa/swrast/s_texfetch_tmp.h
> index 7ff30f6..23db48d 100644
> --- a/src/mesa/swrast/s_texfetch_tmp.h
> +++ b/src/mesa/swrast/s_texfetch_tmp.h
> @@ -417,10 +417,10 @@ FETCH(R5G6B5_UNORM)(const struct
swrast_texture_image *texImage,
>                      GLint i, GLint j, GLint k, GLfloat *texel)
>  {
>     const GLushort *src = TEXEL_ADDR(GLushort, texImage, i, j, k, 1);
> -   const GLushort s = (*src >> 8) | (*src << 8); /* byte swap */
> -   texel[RCOMP] = UBYTE_TO_FLOAT( ((s >> 8) & 0xf8) | ((s >> 13) & 0x7)
);
> -   texel[GCOMP] = UBYTE_TO_FLOAT( ((s >> 3) & 0xfc) | ((s >>  9) & 0x3)
);
> -   texel[BCOMP] = UBYTE_TO_FLOAT( ((s << 3) & 0xf8) | ((s >>  2) & 0x7)
);
> +   const GLushort s = *src;
> +   texel[RCOMP] = ((s      ) & 0x1f) * (1.0F / 31.0F);
> +   texel[GCOMP] = ((s >> 5 ) & 0x3f) * (1.0F / 63.0F);
> +   texel[BCOMP] = ((s >> 11) & 0x1f) * (1.0F / 31.0F);
>     texel[ACOMP] = 1.0F;
>  }
>
> --
> 1.9.1
>
> _______________________________________________
> mesa-dev mailing list
> mesa-dev at lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/mesa-dev
Below comment in formats.h also needs a fix to show correct ordering of
components:

    *  examples:                   msb <------ TEXEL BITS -----------> lsb
    *  MESA_FORMAT_A8B8G8R8_UNORM, AAAA AAAA BBBB BBBB GGGG GGGG RRRR RRRR
    *  MESA_FORMAT_R5G6B5_UNORM                        RRRR RGGG GGGB BBBB
    *  MESA_FORMAT_B4G4R4X4_UNORM                      BBBB GGGG RRRR XXXX


With this comment fixed, this patch is:
Reviewed-by: Anuj Phogat <anuj.phogat at gmail.com>
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