On Tue, Feb 18, 2014 at 11:01 AM, Ian Romanick <i...@freedesktop.org> wrote:
> On 02/10/2014 05:29 PM, Anuj Phogat wrote:
>> GLSL 1.50 spec says:
>> "If gl_FragCoord is redeclared in any fragment shader in a program,
>> it must be redeclared in all the fragment shaders in that
>> program that have a static use gl_FragCoord. All redeclarations of
>> gl_FragCoord in all fragment shaders in a single program must
>> have the same set of qualifiers."
>>
>> This patch makes the glsl compiler to generate an error if we have a
>> fragment shader defined with conflicting layout qualifier declarations
>> for gl_FragCoord. For example:
>>
>> layout(origin_upper_left, pixel_center_integer) in vec4 gl_FragCoord;
>> layout(pixel_center_integer) in vec4 gl_FragCoord;
>> void main()
>> {
>> gl_FragColor = gl_FragCoord.xyzz;
>> }
>>
>> Cc: <mesa-sta...@lists.freedesktop.org>
>> Signed-off-by: Anuj Phogat <anuj.pho...@gmail.com>
>> ---
>> src/glsl/ast_to_hir.cpp | 39 +++++++++++++++++++++++++++++++++++++++
>> src/glsl/glsl_parser_extras.cpp | 3 +++
>> src/glsl/glsl_parser_extras.h | 10 ++++++++++
>> 3 files changed, 52 insertions(+)
>>
>> diff --git a/src/glsl/ast_to_hir.cpp b/src/glsl/ast_to_hir.cpp
>> index c89a26b..7d7d89b 100644
>> --- a/src/glsl/ast_to_hir.cpp
>> +++ b/src/glsl/ast_to_hir.cpp
>> @@ -2374,6 +2374,45 @@ apply_type_qualifier_to_variable(const struct
>> ast_type_qualifier *qual,
>> qual_string);
>> }
>>
>> + /* Make sure all gl_FragCoord redeclarations specify the same layout
>> + * qualifier type.
>> + */
>> + bool conflicting_pixel_center_integer =
>> + state->fs_pixel_center_integer &&
>> + !qual->flags.q.pixel_center_integer;
>> +
>> + bool conflicting_origin_upper_left =
>> + state->fs_origin_upper_left &&
>> + !qual->flags.q.origin_upper_left;
>
> I don't think this catches all the cases. What about
>
> layout(origin_upper_left ) in vec4 gl_FragCoord;
> layout(origin_upper_left, pixel_center_integer) in vec4 gl_FragCoord;
>
Nice catch. I'll update my patch to include this case. What do you think
about following two cases?
case 1:
in vec4 gl_FragCoord;
layout(origin_upper_left, pixel_center_integer) in vec4 gl_FragCoord;
AMD produces no compilation error. This patch matches the behavior.
case 2:
layout(origin_upper_left, pixel_center_integer) in vec4 gl_FragCoord;
in vec4 gl_FragCoord;
AMD produces compilation error. This patch matches the behavior.
>> +
>> + if (conflicting_pixel_center_integer || conflicting_origin_upper_left) {
>> + const char *const qual_string =
>> + (conflicting_pixel_center_integer &&
>> conflicting_origin_upper_left) ?
>> + "pixel_center_integer, origin_upper_left" :
>> + (conflicting_pixel_center_integer ?
>> + "origin_upper_left" : "pixel_center_integer");
>> +
>> + const char *const state_string =
>> + (state->fs_pixel_center_integer &&
>> + state->fs_origin_upper_left) ?
>> + "pixel_center_integer, origin_upper_left" :
>> + (state->fs_origin_upper_left ?
>> + "origin_upper_left" : "pixel_center_integer");
>> +
>> + _mesa_glsl_error(loc, state,
>> + "different layout qualifiers were specified with "
>> + "`gl_FragCoord' (%s) and (%s) "
>> + "redeclare fragment shader input `gl_FragCoord'",
>> + state_string,
>> + qual_string);
>> + }
>> +
>> + if (qual->flags.q.pixel_center_integer)
>> + state->fs_pixel_center_integer = true;
>> +
>> + if (qual->flags.q.origin_upper_left)
>> + state->fs_origin_upper_left = true;
>> +
>> if (qual->flags.q.explicit_location) {
>> validate_explicit_location(qual, var, state, loc);
>> } else if (qual->flags.q.explicit_index) {
>> diff --git a/src/glsl/glsl_parser_extras.cpp
>> b/src/glsl/glsl_parser_extras.cpp
>> index b822d22..b06337e 100644
>> --- a/src/glsl/glsl_parser_extras.cpp
>> +++ b/src/glsl/glsl_parser_extras.cpp
>> @@ -193,6 +193,9 @@ _mesa_glsl_parse_state::_mesa_glsl_parse_state(struct
>> gl_context *_ctx,
>> this->default_uniform_qualifier->flags.q.shared = 1;
>> this->default_uniform_qualifier->flags.q.column_major = 1;
>>
>> + this->fs_origin_upper_left = false;
>> + this->fs_pixel_center_integer = false;
>> +
>> this->gs_input_prim_type_specified = false;
>> this->gs_input_prim_type = GL_POINTS;
>> this->gs_input_size = 0;
>> diff --git a/src/glsl/glsl_parser_extras.h b/src/glsl/glsl_parser_extras.h
>> index 7d66147..674dae5 100644
>> --- a/src/glsl/glsl_parser_extras.h
>> +++ b/src/glsl/glsl_parser_extras.h
>> @@ -182,6 +182,16 @@ struct _mesa_glsl_parse_state {
>> struct ast_type_qualifier *default_uniform_qualifier;
>>
>> /**
>> + * True if a fragment shader has an input layout for redeclaring the
>> + * built-in variable gl_FragCoord.
>> + *
>> + * Note: this value is computed at ast_to_hir time rather than at parse
>> + * time.
>> + */
>> + bool fs_origin_upper_left;
>> + bool fs_pixel_center_integer;
>> +
>> + /**
>> * True if a geometry shader input primitive type was specified using a
>> * layout directive.
>> *
>>
>
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