[Mesa-dev] [PATCH 04/12] main/formats: Add layout and swizzle information

[Marek Olšák]

On Thu, Jul 17, 2014 at 8:04 PM, Jason Ekstrand <jason at jlekstrand.net> wrote:
> Signed-off-by: Jason Ekstrand <jason.ekstrand at intel.com>
> ---
>  src/mesa/main/format_info.py | 11 +++++++++++
>  src/mesa/main/formats.c      | 46 ++++++++++++++++++++++++++++++++++++++++++++
>  src/mesa/main/formats.h      | 29 ++++++++++++++++++++++++++++
>  3 files changed, 86 insertions(+)
>
> diff --git a/src/mesa/main/format_info.py b/src/mesa/main/format_info.py
> index b8956a5..448bd00 100644
> --- a/src/mesa/main/format_info.py
> +++ b/src/mesa/main/format_info.py
> @@ -96,6 +96,14 @@ def get_gl_data_type(fmat):
>     else:
>        assert False
>
> +def get_mesa_layout(fmat):
> +   if fmat.layout == 'array':
> +      return 'MESA_FORMAT_LAYOUT_ARRAY'
> +   elif fmat.layout == 'packed':
> +      return 'MESA_FORMAT_LAYOUT_PACKED'
> +   else:
> +      return 'MESA_FORMAT_LAYOUT_OTHER'
> +
>  def get_channel_bits(fmat, chan_name):
>     if fmat.is_compressed():
>        # These values are pretty-much bogus, but OpenGL requires that we
> @@ -166,6 +174,7 @@ for fmat in formats:
>     print '   {'
>     print '      {0},'.format(fmat.name)
>     print '      "{0}",'.format(fmat.name)
> +   print '      {0},'.format(get_mesa_layout(fmat))
>     print '      {0},'.format(get_gl_base_format(fmat))
>     print '      {0},'.format(get_gl_data_type(fmat))
>
> @@ -176,6 +185,8 @@ for fmat in formats:
>
>     print '      {0}, {1}, {2},'.format(fmat.block_width, fmat.block_height,
>                                         int(fmat.block_size() / 8))
> +
> +   print '      {{ {0} }},'.format(', '.join(map(str, fmat.swizzle)))
>     print '   },'
>
>  print '};'
> diff --git a/src/mesa/main/formats.c b/src/mesa/main/formats.c
> index 39cc5f1..f03425e 100644
> --- a/src/mesa/main/formats.c
> +++ b/src/mesa/main/formats.c
> @@ -40,6 +40,8 @@ struct gl_format_info
>     /** text name for debugging */
>     const char *StrName;
>
> +   enum mesa_format_layout Layout;
> +
>     /**
>      * Base format is one of GL_RED, GL_RG, GL_RGB, GL_RGBA, GL_ALPHA,
>      * GL_LUMINANCE, GL_LUMINANCE_ALPHA, GL_INTENSITY, GL_YCBCR_MESA,
> @@ -67,6 +69,8 @@ struct gl_format_info
>      */
>     GLubyte BlockWidth, BlockHeight;
>     GLubyte BytesPerBlock;
> +
> +   uint8_t Swizzle[4];
>  };
>
>  #include "format_info.c"
> @@ -178,6 +182,21 @@ _mesa_get_format_max_bits(mesa_format format)
>
>
>  /**
> + * Return the layout type of the given format.
> + * The return value will be one of:
> + *    MESA_FORMAT_LAYOUT_ARRAY
> + *    MESA_FORMAT_LAYOUT_PACKED
> + *    MESA_FORMAT_LAYOUT_OTHER
> + */
> +extern enum mesa_format_layout
> +_mesa_get_format_layout(mesa_format format)
> +{
> +   const struct gl_format_info *info = _mesa_get_format_info(format);
> +   return info->Layout;
> +}
> +
> +
> +/**
>   * Return the data type (or more specifically, the data representation)
>   * for the given format.
>   * The return value will be one of:
> @@ -224,6 +243,33 @@ _mesa_get_format_block_size(mesa_format format, GLuint *bw, GLuint *bh)
>  }
>
>
> +/**
> + * Returns the an array of four numbers representing the transformation
> + * from the RGBA or SZ colorspace to the given format.  For array formats,
> + * the i'th RGBA component is given by:
> + *
> + * if (swizzle[i] <= MESA_FORMAT_SWIZZLE_W)
> + *    comp = data[swizzle[i]];
> + * else if (swizzle[i] == MESA_FORMAT_SWIZZLE_ZERO)
> + *    comp = 0;
> + * else if (swizzle[i] == MESA_FORMAT_SWIZZLE_ONE)
> + *    comp = 1;
> + * else if (swizzle[i] == MESA_FORMAT_SWIZZLE_NONE)
> + *    // data does not contain a channel of this format
> + *
> + * For packed formats, the swizzle gives the number of components left of
> + * the least significant bit.
> + *
> + * Compressed formats have no swizzle.
> + */
> +void
> +_mesa_get_format_swizzle(mesa_format format, uint8_t swizzle_out[4])
> +{
> +   const struct gl_format_info *info = _mesa_get_format_info(format);
> +   memcpy(swizzle_out, info->Swizzle, sizeof(info->Swizzle));
> +}
> +
> +
>  /** Is the given format a compressed format? */
>  GLboolean
>  _mesa_is_format_compressed(mesa_format format)
> diff --git a/src/mesa/main/formats.h b/src/mesa/main/formats.h
> index dc50bc8..48aad44 100644
> --- a/src/mesa/main/formats.h
> +++ b/src/mesa/main/formats.h
> @@ -56,6 +56,15 @@ extern "C" {
>   */
>  #define MAX_PIXEL_BYTES 16
>
> +/**
> + * Specifies the layout of a pixel format.  See the MESA_FORMAT
> + * documentation below.
> + */
> +enum mesa_format_layout {
> +   MESA_FORMAT_LAYOUT_ARRAY,
> +   MESA_FORMAT_LAYOUT_PACKED,
> +   MESA_FORMAT_LAYOUT_OTHER,
> +};
>
>  /**
>   * Mesa texture/renderbuffer image formats.
> @@ -419,6 +428,9 @@ _mesa_get_format_bits(mesa_format format, GLenum pname);
>  extern GLuint
>  _mesa_get_format_max_bits(mesa_format format);
>
> +extern enum mesa_format_layout
> +_mesa_get_format_layout(mesa_format format);
> +
>  extern GLenum
>  _mesa_get_format_datatype(mesa_format format);
>
> @@ -428,6 +440,23 @@ _mesa_get_format_base_format(mesa_format format);
>  extern void
>  _mesa_get_format_block_size(mesa_format format, GLuint *bw, GLuint *bh);
>
> +/**
> + * An enum representing different possible swizzling values.  This is used
> + * to interpret the output of _mesa_get_format_swizzle
> + */
> +enum {
> +   MESA_FORMAT_SWIZZLE_X = 0,
> +   MESA_FORMAT_SWIZZLE_Y = 1,
> +   MESA_FORMAT_SWIZZLE_Z = 2,
> +   MESA_FORMAT_SWIZZLE_W = 3,
> +   MESA_FORMAT_SWIZZLE_ZERO = 4,
> +   MESA_FORMAT_SWIZZLE_ONE = 5,
> +   MESA_FORMAT_SWIZZLE_NONE = 6,
> +};

It would be nicer to declare all enums at one place in the file (e.g.
at the beginning) and not between function prototypes.

Marek