Re: [PATCH] wined3d: Implement icb dcl support in GLSL.

[Józef Kucia]

This implementation has some issues, e.g. a generated GLSL shader will
produce a compilation error when the immediate constant buffer
contains an unsigned integer which represents NaN. Morever, from
testing a similar implementation, it seems that some drivers don't
handle shaders with huge arrays very well and such shaders perform
poorly. My current impression is that we should implement immediate
constant buffers using a uniform variable.

Also, a test would be nice.

On Mon, Jun 13, 2016 at 6:41 PM, Guillaume Charifi
 wrote:
> Signed-off-by: Guillaume Charifi
>
> dlls/wined3d/glsl_shader.c | 15 ++++++++++++++-
>  1 file changed, 14 insertions(+), 1 deletion(-)
>
> diff --git a/dlls/wined3d/glsl_shader.c b/dlls/wined3d/glsl_shader.c
> index 55affc1..def224c 100644
> --- a/dlls/wined3d/glsl_shader.c
> +++ b/dlls/wined3d/glsl_shader.c
> @@ -1886,6 +1886,19 @@ static void shader_generate_glsl_declarations(const struct wined3d_context *cont
>      if (shader->limits->constant_bool > 0 && reg_maps->boolean_constants)
>          shader_addline(buffer, "uniform bool %s_b[%u];\n", prefix, shader->limits->constant_bool);
> - if (reg_maps->icb)
> - {
> -
>    shader_addline(buffer, "const vec4 %s_icb[%u] = vec4[%u](\n",
> -
>            prefix, reg_maps->icb->element_count / 4, reg_maps->icb->element_count / 4);
> -
>    for (i = 0; i < reg_maps->icb->element_count / 4; i++) {
> -
>        shader_glsl_append_imm_vec4(buffer, (float *)&reg_maps->icb->data[4 * i]);
> -
>        if (i != reg_maps->icb->element_count / 4 - 1)
> -
>            shader_addline(buffer, ",");
> -
>        shader_addline(buffer, "\n");
> -
>    }
> -
>    shader_addline(buffer, ");\n");
> - }

I think it would be better to store the number of vectors instead of
the element count in "reg_maps->icb". Not that it matters much, but
this block of code would certainly look nicer.
> - for (i = 0; i < WINED3D_MAX_CBS; ++i)
>    {
>        if (reg_maps->cb_sizes[i])
>
> @@ -8561,7 +8574,7 @@ static const SHADER_HANDLER shader_glsl_instruction_handler_table[WINED3DSIH_TAB
>      /* WINED3DSIH_DCL_GLOBAL_FLAGS                 */ shader_glsl_nop,
>      /* WINED3DSIH_DCL_HS_FORK_PHASE_INSTANCE_COUNT */ NULL,
>      /* WINED3DSIH_DCL_HS_MAX_TESSFACTOR            */ NULL,
> - /* WINED3DSIH_DCL_IMMEDIATE_CONSTANT_BUFFER    */ NULL,
> - /* WINED3DSIH_DCL_IMMEDIATE_CONSTANT_BUFFER    */ shader_glsl_nop,
> /* WINED3DSIH_DCL_INPUT                        */ shader_glsl_nop,
> /* WINED3DSIH_DCL_INPUT_CONTROL_POINT_COUNT    */ NULL,
> /* WINED3DSIH_DCL_INPUT_PRIMITIVE              */ shader_glsl_nop,
>
> --
> 2.7.4