[PATCH v2 0/1] MR333: vkd3d-shader/hlsl: Add refract() function.

[Nikolay Sivov (＠nsivov)]

Signed-off-by: Nikolay Sivov

--
  v2: vkd3d-shader/hlsl: Add refract() function.

https://gitlab.winehq.org/wine/vkd3d/-/merge_requests/333

[PATCH v2 1/1] vkd3d-shader/hlsl: Add refract() function.

[Nikolay Sivov]

From: Nikolay Sivov

Signed-off-by: Nikolay Sivov 
---
 Makefile.am                    |  1 +
 libs/vkd3d-shader/hlsl.y       | 38 ++++++++++++++++++++++++++++++++++
 tests/hlsl/refract.shader_test | 19 +++++++++++++++++
 3 files changed, 58 insertions(+)
 create mode 100644 tests/hlsl/refract.shader_test

diff --git a/Makefile.am b/Makefile.am
index 14b5cf096..642e7d9df 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -143,6 +143,7 @@ vkd3d_shader_tests = \
    tests/hlsl/object-references.shader_test \
    tests/hlsl/pow.shader_test \
    tests/hlsl/reflect.shader_test \
+	tests/hlsl/refract.shader_test \
    tests/hlsl/register-reservations.shader_test \
    tests/hlsl/return-implicit-conversion.shader_test \
    tests/hlsl/return.shader_test \
diff --git a/libs/vkd3d-shader/hlsl.y b/libs/vkd3d-shader/hlsl.y
index 0e72a539e..f488ec047 100644
--- a/libs/vkd3d-shader/hlsl.y
+++ b/libs/vkd3d-shader/hlsl.y
@@ -3392,6 +3392,43 @@ static bool intrinsic_reflect(struct hlsl_ctx *ctx,
     return !!add_binary_arithmetic_expr(ctx, params->instrs, HLSL_OP2_ADD, i, neg, loc);
 }

+static bool intrinsic_refract(struct hlsl_ctx *ctx,
+        const struct parse_initializer *params, const struct vkd3d_shader_location *loc)
+{
+    struct hlsl_ir_node *r = params->args[0];
+    struct hlsl_ir_node *n = params->args[1];
+    struct hlsl_ir_function_decl *func;
+    struct hlsl_type *type;
+    char *body;
+
+    static const char template[] =
+            "%s refract(%s r, %s n, float i)\n"
+            "{\n"
+            "    float d = dot(r, n);\n"
+            "    float t = 1 - i * i * (1 - d * d);\n"
+            "    return t >= 0.0 ? i * r - (i * d + sqrt(t)) * n : 0;\n"
+            "}";
+
+    if (r->data_type->class == HLSL_CLASS_MATRIX
+            || n->data_type->class == HLSL_CLASS_MATRIX)
+    {
+        hlsl_error(ctx, loc, VKD3D_SHADER_ERROR_HLSL_INVALID_TYPE, "Invalid argument type.");
+        return false;
+    }
+
+    type = hlsl_get_vector_type(ctx, HLSL_TYPE_FLOAT, r->data_type->dimx);
+
+    if (!(body = hlsl_sprintf_alloc(ctx, template, type->name, type->name, type->name)))
+        return false;
+
+    func = hlsl_compile_internal_function(ctx, "refract", body);
+    vkd3d_free(body);
+    if (!func)
+        return false;
+
+    return add_user_call(ctx, func, params, loc);
+}
+
 static bool intrinsic_round(struct hlsl_ctx *ctx,
         const struct parse_initializer *params, const struct vkd3d_shader_location *loc)
 {
@@ -3811,6 +3848,7 @@ intrinsic_functions[] =
     {"normalize",                           1, true,  intrinsic_normalize},
     {"pow",                                 2, true,  intrinsic_pow},
     {"reflect",                             2, true,  intrinsic_reflect},
+    {"refract",                             3, true,  intrinsic_refract},
     {"round",                               1, true,  intrinsic_round},
     {"rsqrt",                               1, true,  intrinsic_rsqrt},
     {"saturate",                            1, true,  intrinsic_saturate},
diff --git a/tests/hlsl/refract.shader_test b/tests/hlsl/refract.shader_test
new file mode 100644
index 000000000..0ce84955c
--- /dev/null
+++ b/tests/hlsl/refract.shader_test
@@ -0,0 +1,19 @@
+[pixel shader]
+uniform float4 r;
+uniform float4 n;
+uniform float i;
+
+float4 main() : sv_target
+{
+    return refract(r, n, i);
+}
+
+[test]
+uniform 0 float4 0.5 -0.1 0.2 0.3
+uniform 4 float4 0.6 0.4 -0.3 1.0
+uniform 8 float 0.2
+todo(sm>=6) draw quad
+probe all rgba (-0.550931, -0.453954, 0.3654653, -1.0248856) 32
+uniform 8 float 100.0
+todo(sm>=6) draw quad
+probe all rgba (0.0, 0.0, 0.0, 0.0)

[Nikolay Sivov (＠nsivov)]

On Wed Nov  8 00:46:20 2023 +0000, Zebediah Figura wrote:
> This still has review that needs to be addressed.

It's still not clear to me where argument conversion needs to happen. I don't see any 'itof's  for example when called with int vectors. Unrelated to that, one thing we need to check is that dimensions for 'r' and 'n' are the same.

[Zebediah Figura (＠zfigura)]

On Wed Nov  8 00:46:19 2023 +0000, Nikolay Sivov wrote:
> It's still not clear to me where argument conversion needs to happen. I
> don't see any 'itof's  for example when called with int vectors.
> Unrelated to that, one thing we need to check is that dimensions for 'r'
> and 'n' are the same.

I see itof for all three arguments with the following shader:

```
int a, b, c;

float4 main() : sv_target
{
    return refract(a, b, c);
}
```

What are you testing?

[Nikolay Sivov (＠nsivov)]

On Wed Nov  8 01:05:15 2023 +0000, Zebediah Figura wrote:
> I see itof for all three arguments with the following shader:
> int a, b, c;
> float4 main() : sv_target
> {
>     return refract(a, b, c);
> }
>
> What are you testing?

That's a good question, I think I confused my test files. Contrary to what documentation suggests, this function only seems to support scalars/float1's or float4 vectors, nothing in between. Last argument is simply cast to a scalar. I'll update accordingly.

[Nikolay Sivov (＠nsivov)]

On Wed Nov  8 11:33:35 2023 +0000, Nikolay Sivov wrote:
> That's a good question, I think I confused my test files. Contrary to
> what documentation suggests, this function only seems to support
> scalars/float1's or float4 vectors, nothing in between. Last argument is
> simply cast to a scalar. I'll update accordingly.

Wrong again. The failure was about implicit cast of return value, it does accept any vector size.