[Mesa-dev] [PATCH 11/16] glsl: Track matrix layout of structure fields using two bits

[Ian Romanick]

On 07/21/2014 03:17 PM, Matt Turner wrote:
> On Mon, Jul 21, 2014 at 2:04 PM, Ian Romanick <idr at freedesktop.org> wrote:
>> +enum glsl_matrix_layout {
>> +   GLSL_MATRIX_LAYOUT_DEFAULT,
> 
> Does this mean language-default, or does it really means the inherited
> layout? E.g., for
> 
> layout(row_major) uniform a {
>    mat4 m;
> };
> 
> m's .matrix_layout is GLSL_MATRIX_LAYOUT_DEFAULT, so we look to the
> outer row_major qualifier on uniform a?

Correct.  If some entity inside a block has GLSL_MATRIX_LAYOUT_DEFAULT
then it either is not (or cannot contain) a matrix, or its layout is
inherited from the next outer container.  The interface type itself will
never have GLSL_MATRIX_LAYOUT_DEFAULT.

> If so, could we name it _INHERITED or something?

That works.  I think I like that better than _NOT_SET.  The layout may
not be set for the interface type, but it will always have a layout of
either GLSL_MATRIX_LAYOUT_COLUMN_MAJOR or GLSL_MATRIX_LAYOUT_ROW_MAJOR.

> Maybe I've misunderstood.
> 
>> +   GLSL_MATRIX_LAYOUT_COLUMN_MAJOR,
>> +   GLSL_MATRIX_LAYOUT_ROW_MAJOR
>> +};
>