[PATCH 4/5] d3d10/effect: Support stream output declaration when creating geometry shaders.

[Matteo Bruni]

On Mon, Aug 30, 2021 at 7:07 AM Nikolay Sivov <nsivov at codeweavers.com> wrote:
>
> Signed-off-by: Nikolay Sivov <nsivov at codeweavers.com>
> ---
>  dlls/d3d10/effect.c | 172 ++++++++++++++++++++++++++++++++++++++++++--
>  1 file changed, 166 insertions(+), 6 deletions(-)

Patch is okay, a few notes below.

> diff --git a/dlls/d3d10/effect.c b/dlls/d3d10/effect.c
> index 113125e9cbd..c3c98a0da31 100644
> --- a/dlls/d3d10/effect.c
> +++ b/dlls/d3d10/effect.c

> @@ -566,6 +592,127 @@ static HRESULT get_fx10_shader_resources(struct d3d10_effect_variable *v, const
>      return S_OK;
>  }
>
> +struct d3d10_effect_so_decl
> +{
> +    D3D10_SO_DECLARATION_ENTRY *entries;
> +    SIZE_T capacity;
> +    SIZE_T count;
> +    unsigned int stride;
> +    char *decl;
> +};
> +
> +static void d3d10_effect_cleanup_so_decl(struct d3d10_effect_so_decl *so_decl)
> +{
> +    heap_free(so_decl->entries);
> +    heap_free(so_decl->decl);
> +    memset(so_decl, 0, sizeof(*so_decl));
> +}
> +
> +static HRESULT d3d10_effect_parse_stream_output_declaration(const char *decl,
> +        struct d3d10_effect_so_decl *so_decl)
> +{
> +    static const char * allmask = "xyzw";

Usually in HLSL you can use "rgba" in place of "xyzw" for swizzles /
writemasks, it might be worth checking if those also work (and are
passed through to the effect bytecode unchanged).

> +    char *p, *ptr, *end, *next, *mask, *m, *slot;
> +    unsigned int len = strlen(decl);
> +    D3D10_SO_DECLARATION_ENTRY e;
> +
> +    memset(so_decl, 0, sizeof(*so_decl));
> +
> +    if (!(so_decl->decl = heap_alloc(len + 1)))
> +        return E_OUTOFMEMORY;
> +    memcpy(so_decl->decl, decl, len + 1);
> +
> +    p = so_decl->decl;

I think it would be nice to have a small comment showing the expected
syntax of a stream out declaration (entry) somewhere around here. Just
something to quickly glance at while reading the following code.

> +
> +    while (p && *p)
> +    {
> +        memset(&e, 0, sizeof(e));
> +
> +        end = strchr(p, ';');
> +        next = end ? end + 1 : p + strlen(p);
> +
> +        len = next - p;
> +        if (end) len--;
> +
> +        /* Remove leading and trailing spaces. */
> +        while (len && isspace(*p)) { len--; p++; }
> +        while (len && isspace(p[len - 1])) len--;
> +
> +        p[len] = 0;
> +
> +        /* Output slot */
> +        if ((slot = strchr(p, ':')))
> +        {
> +            *slot = 0;
> +
> +            ptr = p;
> +            while (*ptr)
> +            {
> +                if (!isdigit(*ptr))
> +                {
> +                    WARN("Invalid output slot %s.\n", debugstr_a(p));
> +                    goto failed;
> +                }
> +                ptr++;
> +            }
> +
> +            e.OutputSlot = atoi(p);
> +            p = slot + 1;
> +        }
> +
> +        /* Mask */
> +        if ((mask = strchr(p, '.')))
> +        {
> +            *mask = 0; mask++;
> +
> +            if (!(m = strstr(allmask, mask)))
> +            {
> +                WARN("Invalid component mask %s.\n", debugstr_a(mask));
> +                goto failed;
> +            }
> +
> +            e.StartComponent = m - allmask;
> +            e.ComponentCount = strlen(mask);

Did you verify that it's illegal to have a wrongly ordered mask (e.g.
something like .wzyx)?
I expect that to be invalid but better to be sure.
Likewise for other assumptions involved here, like repeating the same
component twice.

In general, some more tests with interesting stream out declarations
would be nice. I guess you have more planned after the test in patch
5/5.

> +        }
> +        else
> +        {
> +            e.StartComponent = 0;
> +            e.ComponentCount = 4;
> +        }
> +
> +        /* Semantic index and name */
> +        len = strlen(p);
> +        while (isdigit(p[len - 1]))
> +            len--;
> +
> +        if (p[len])
> +        {
> +            e.SemanticIndex = atoi(&p[len]);
> +            p[len] = 0;
> +        }
> +
> +        e.SemanticName = p;
> +
> +        if (!d3d_array_reserve((void **)&so_decl->entries, &so_decl->capacity, so_decl->count + 1,
> +                sizeof(*so_decl->entries)))
> +            goto failed;
> +
> +        so_decl->entries[so_decl->count++] = e;
> +
> +        if (e.OutputSlot == 0)
> +            so_decl->stride += e.ComponentCount * sizeof(float);

This looks weird, but that's probably because the API for
ID3D10Device_CreateGeometryShaderWithStreamOutput() is confusing (just
one stride for up to 4 output buffers? What does it even mean?) and
neither the documentation nor our tests seem to clarify that. Any clue
what's supposed to happen with multiple output buffers?

FWIW that function's signature makes a lot more sense in d3d11.