[Mesa-dev] [PATCH 4/8] glsl: Add new builtins required by GL_ARB_sample_shading
Anuj Phogat
anuj.phogat at gmail.com
Tue Oct 15 22:50:38 CEST 2013
On Tue, Oct 15, 2013 at 10:02 AM, Ian Romanick <idr at freedesktop.org> wrote:
> On 10/14/2013 10:12 AM, Anuj Phogat wrote:
>> New builtins added by GL_ARB_sample_shading:
>> in vec2 gl_SamplePosition
>> in int gl_SampleID
>> in int gl_NumSamples
>> out int gl_SampleMask[]
>>
>> Signed-off-by: Anuj Phogat <anuj.phogat at gmail.com>
>> ---
>> src/glsl/builtin_variables.cpp | 11 +++++++++++
>> src/glsl/link_varyings.cpp | 2 ++
>> src/mesa/main/mtypes.h | 7 ++++++-
>> src/mesa/program/prog_print.c | 5 +++++
>> 4 files changed, 24 insertions(+), 1 deletion(-)
>>
>> diff --git a/src/glsl/builtin_variables.cpp b/src/glsl/builtin_variables.cpp
>> index ae0a03f..c886840 100644
>> --- a/src/glsl/builtin_variables.cpp
>> +++ b/src/glsl/builtin_variables.cpp
>> @@ -30,6 +30,9 @@
>> #include "program/prog_statevars.h"
>> #include "program/prog_instruction.h"
>>
>> +static struct gl_builtin_uniform_element gl_NumSamples_elements[] = {
>> + {NULL, {STATE_NUM_SAMPLES, 0, 0}, SWIZZLE_XYZW}
>> +};
>>
>> static struct gl_builtin_uniform_element gl_DepthRange_elements[] = {
>> {"near", {STATE_DEPTH_RANGE, 0, 0}, SWIZZLE_XXXX},
>> @@ -236,6 +239,7 @@ static struct gl_builtin_uniform_element gl_NormalMatrix_elements[] = {
>> #define STATEVAR(name) {#name, name ## _elements, Elements(name ## _elements)}
>>
>> static const struct gl_builtin_uniform_desc _mesa_builtin_uniform_desc[] = {
>> + STATEVAR(gl_NumSamples),
>> STATEVAR(gl_DepthRange),
>> STATEVAR(gl_ClipPlane),
>> STATEVAR(gl_Point),
>> @@ -613,6 +617,7 @@ builtin_variable_generator::generate_constants()
>> void
>> builtin_variable_generator::generate_uniforms()
>> {
>> + add_uniform(int_t, "gl_NumSamples");
>> add_uniform(type("gl_DepthRangeParameters"), "gl_DepthRange");
>> add_uniform(array(vec4_t, VERT_ATTRIB_MAX), "gl_CurrentAttribVertMESA");
>> add_uniform(array(vec4_t, VARYING_SLOT_MAX), "gl_CurrentAttribFragMESA");
>> @@ -789,6 +794,12 @@ builtin_variable_generator::generate_fs_special_vars()
>> if (state->AMD_shader_stencil_export_warn)
>> var->warn_extension = "GL_AMD_shader_stencil_export";
>> }
>> +
>> + if (state->ARB_sample_shading_enable) {
>> + add_input(VARYING_SLOT_SAMPLE_ID, int_t, "gl_SampleID");
>> + add_input(VARYING_SLOT_SAMPLE_POS, vec2_t, "gl_SamplePosition");
>> + add_output(FRAG_RESULT_SAMPLE_MASK, array(int_t, 1), "gl_SampleMask");
>
> I don't see code anywhere in this patch series that correctly sizes this
> array. I thought gl_SampleMask.length() == gl_NumSamples... except you
> can't use .length() on gl_SampleMask because the size can't be known at
> compile-time. We should have a test that 'gl_SampleMask.length()' fails
> to compile. :)
>
I'll add a piglit compiler test for that.
> The only other array that works like this is gl_TexCoord. That array is
> sized to 0 (line 837 of builtin_variables.cpp). I believe gl_SampleMask
> should do the same.
>
Yes, I noticed gl_TexCoord is using array size of 0 and it works for
gl_SampleMask as well. But, It generates same glsl ir with array size
of 0 or 1:
(declare (shader_out ) (array int 1) gl_SampleMask)
what's the utility of using size 0?
I'll take care of rest of your comments in this patch.
>> + }
>> }
>>
>>
>> diff --git a/src/glsl/link_varyings.cpp b/src/glsl/link_varyings.cpp
>> index 4ba6d8a..3595a58 100644
>> --- a/src/glsl/link_varyings.cpp
>> +++ b/src/glsl/link_varyings.cpp
>> @@ -938,6 +938,8 @@ is_varying_var(GLenum shaderType, const ir_variable *var)
>> case VARYING_SLOT_POS:
>> case VARYING_SLOT_FACE:
>> case VARYING_SLOT_PNTC:
>> + case VARYING_SLOT_SAMPLE_ID:
>> + case VARYING_SLOT_SAMPLE_POS:
>> return false;
>> default:
>> return true;
>> diff --git a/src/mesa/main/mtypes.h b/src/mesa/main/mtypes.h
>> index 5520e86..65ec829 100644
>> --- a/src/mesa/main/mtypes.h
>> +++ b/src/mesa/main/mtypes.h
>> @@ -236,6 +236,8 @@ typedef enum
>> VARYING_SLOT_LAYER, /* Appears as VS or GS output */
>> VARYING_SLOT_FACE, /* FS only */
>> VARYING_SLOT_PNTC, /* FS only */
>> + VARYING_SLOT_SAMPLE_ID, /* FS only */
>> + VARYING_SLOT_SAMPLE_POS, /* FS only */
>> VARYING_SLOT_VAR0, /* First generic varying slot */
>> VARYING_SLOT_MAX = VARYING_SLOT_VAR0 + MAX_VARYING
>> } gl_varying_slot;
>> @@ -272,6 +274,8 @@ typedef enum
>> #define VARYING_BIT_FACE BITFIELD64_BIT(VARYING_SLOT_FACE)
>> #define VARYING_BIT_PNTC BITFIELD64_BIT(VARYING_SLOT_PNTC)
>> #define VARYING_BIT_VAR(V) BITFIELD64_BIT(VARYING_SLOT_VAR0 + (V))
>> +#define VARYING_BIT_SAMPLE_ID BITFIELD64_BIT(VARYING_SLOT_SAMPLE_ID)
>> +#define VARYING_BIT_SAMPLE_POS BITFIELD64_BIT(VARYING_SLOT_SAMPLE_POS)
>> /*@}*/
>>
>>
>> @@ -306,12 +310,13 @@ typedef enum
>> * register is written. No FRAG_RESULT_DATAn will be written.
>> */
>> FRAG_RESULT_COLOR = 2,
>> + FRAG_RESULT_SAMPLE_MASK = 3,
>>
>> /* FRAG_RESULT_DATAn are the per-render-target (GLSL gl_FragData[n]
>> * or ARB_fragment_program fragment.color[n]) color results. If
>> * any are written, FRAG_RESULT_COLOR will not be written.
>> */
>> - FRAG_RESULT_DATA0 = 3,
>> + FRAG_RESULT_DATA0 = 4,
>> FRAG_RESULT_MAX = (FRAG_RESULT_DATA0 + MAX_DRAW_BUFFERS)
>> } gl_frag_result;
>>
>> diff --git a/src/mesa/program/prog_print.c b/src/mesa/program/prog_print.c
>> index cf85213..0c56ae6 100644
>> --- a/src/mesa/program/prog_print.c
>> +++ b/src/mesa/program/prog_print.c
>> @@ -150,6 +150,8 @@ arb_input_attrib_string(GLint index, GLenum progType)
>> "fragment.(twenty)", /* VARYING_SLOT_LAYER */
>> "fragment.(twenty-one)", /* VARYING_SLOT_FACE */
>> "fragment.(twenty-two)", /* VARYING_SLOT_PNTC */
>> + "fragment.(twenty-three)", /* VARYING_SLOT_SAMPLE_ID */
>> + "fragment.(twenty-four)", /* VARYING_SLOT_SAMPLE_POS */
>
> Can we just call these "fragment.sampleid" and "fragment.samplepos"?
>
>> "fragment.varying[0]",
>> "fragment.varying[1]",
>> "fragment.varying[2]",
>> @@ -274,6 +276,8 @@ arb_output_attrib_string(GLint index, GLenum progType)
>> "result.(twenty)", /* VARYING_SLOT_LAYER */
>> "result.(twenty-one)", /* VARYING_SLOT_FACE */
>> "result.(twenty-two)", /* VARYING_SLOT_PNTC */
>> + "result.(twenty-three)", /* VARYING_SLOT_SAMPLE_ID */
>> + "result.(twenty-four)", /* VARYING_SLOT_SAMPLE_POS */
>
> Since these should never appear in a vertex shader, I think it's okay to
> leave these as "result.(twenty-...)".
>
>> "result.varying[0]",
>> "result.varying[1]",
>> "result.varying[2]",
>> @@ -311,6 +315,7 @@ arb_output_attrib_string(GLint index, GLenum progType)
>> "result.depth", /* FRAG_RESULT_DEPTH */
>> "result.(one)", /* FRAG_RESULT_STENCIL */
>> "result.color", /* FRAG_RESULT_COLOR */
>> + "result.sample_mask", /* FRAG_RESULT_SAMPLE_MASK */
>
> NV_gpu_shader5 doesn't have the _, so I think "result.samplemask" is
> slightly better.
>
>> "result.color[0]", /* FRAG_RESULT_DATA0 (named for GLSL's gl_FragData) */
>> "result.color[1]",
>> "result.color[2]",
>>
>
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