[PATCH] d3dx9: Implement D3DXComputeTangent().

[Zebediah Figura]

From: Alistair Leslie-Hughes <leslie_alistair(a)hotmail.com>

Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=41697
Signed-off-by: Alistair Leslie-Hughes <leslie_alistair(a)hotmail.com>
Signed-off-by: Zebediah Figura <z.figura12(a)gmail.com>
---
 dlls/d3dx9_24/d3dx9_24.spec |  2 +-
 dlls/d3dx9_25/d3dx9_25.spec |  2 +-
 dlls/d3dx9_26/d3dx9_26.spec |  2 +-
 dlls/d3dx9_27/d3dx9_27.spec |  2 +-
 dlls/d3dx9_28/d3dx9_28.spec |  2 +-
 dlls/d3dx9_29/d3dx9_29.spec |  2 +-
 dlls/d3dx9_30/d3dx9_30.spec |  2 +-
 dlls/d3dx9_31/d3dx9_31.spec |  2 +-
 dlls/d3dx9_32/d3dx9_32.spec |  2 +-
 dlls/d3dx9_33/d3dx9_33.spec |  2 +-
 dlls/d3dx9_34/d3dx9_34.spec |  2 +-
 dlls/d3dx9_35/d3dx9_35.spec |  2 +-
 dlls/d3dx9_36/d3dx9_36.spec |  2 +-
 dlls/d3dx9_36/mesh.c        | 16 ++++++++++++++++
 dlls/d3dx9_37/d3dx9_37.spec |  2 +-
 dlls/d3dx9_38/d3dx9_38.spec |  2 +-
 dlls/d3dx9_39/d3dx9_39.spec |  2 +-
 dlls/d3dx9_40/d3dx9_40.spec |  2 +-
 dlls/d3dx9_41/d3dx9_41.spec |  2 +-
 dlls/d3dx9_42/d3dx9_42.spec |  2 +-
 dlls/d3dx9_43/d3dx9_43.spec |  2 +-
 21 files changed, 36 insertions(+), 20 deletions(-)

diff --git a/dlls/d3dx9_24/d3dx9_24.spec b/dlls/d3dx9_24/d3dx9_24.spec
index d617d766f85..bf7ec17e597 100644
--- a/dlls/d3dx9_24/d3dx9_24.spec
+++ b/dlls/d3dx9_24/d3dx9_24.spec
@@ -20,7 +20,7 @@
 @ stdcall D3DXComputeBoundingSphere(ptr long long ptr ptr)
 @ stdcall D3DXComputeNormalMap(ptr ptr ptr long long float)
 @ stdcall D3DXComputeNormals(ptr ptr)
-@ stub D3DXComputeTangent(ptr long long long long ptr)
+@ stdcall D3DXComputeTangent(ptr long long long long ptr)
 @ stub D3DXComputeTangentFrame(ptr long)
 @ stdcall D3DXComputeTangentFrameEx(ptr long long long long long long long long long ptr float float float ptr ptr)
 @ stub D3DXConcatenateMeshes(ptr long long ptr ptr ptr ptr ptr)
diff --git a/dlls/d3dx9_25/d3dx9_25.spec b/dlls/d3dx9_25/d3dx9_25.spec
index f13923dcb3a..3016ea8bee9 100644
--- a/dlls/d3dx9_25/d3dx9_25.spec
+++ b/dlls/d3dx9_25/d3dx9_25.spec
@@ -20,7 +20,7 @@
 @ stdcall D3DXComputeBoundingSphere(ptr long long ptr ptr)
 @ stdcall D3DXComputeNormalMap(ptr ptr ptr long long float)
 @ stdcall D3DXComputeNormals(ptr ptr)
-@ stub D3DXComputeTangent(ptr long long long long ptr)
+@ stdcall D3DXComputeTangent(ptr long long long long ptr)
 @ stub D3DXComputeTangentFrame(ptr long)
 @ stdcall D3DXComputeTangentFrameEx(ptr long long long long long long long long long ptr float float float ptr ptr)
 @ stub D3DXConcatenateMeshes(ptr long long ptr ptr ptr ptr ptr)
diff --git a/dlls/d3dx9_26/d3dx9_26.spec b/dlls/d3dx9_26/d3dx9_26.spec
index 286a9a094a0..1f3af10c1bb 100644
--- a/dlls/d3dx9_26/d3dx9_26.spec
+++ b/dlls/d3dx9_26/d3dx9_26.spec
@@ -24,7 +24,7 @@
 @ stub D3DXComputeIMTFromTexture(ptr ptr long long ptr ptr ptr)
 @ stdcall D3DXComputeNormalMap(ptr ptr ptr long long float)
 @ stdcall D3DXComputeNormals(ptr ptr)
-@ stub D3DXComputeTangent(ptr long long long long ptr)
+@ stdcall D3DXComputeTangent(ptr long long long long ptr)
 @ stub D3DXComputeTangentFrame(ptr long)
 @ stdcall D3DXComputeTangentFrameEx(ptr long long long long long long long long long ptr float float float ptr ptr)
 @ stub D3DXConcatenateMeshes(ptr long long ptr ptr ptr ptr ptr)
diff --git a/dlls/d3dx9_27/d3dx9_27.spec b/dlls/d3dx9_27/d3dx9_27.spec
index 286a9a094a0..1f3af10c1bb 100644
--- a/dlls/d3dx9_27/d3dx9_27.spec
+++ b/dlls/d3dx9_27/d3dx9_27.spec
@@ -24,7 +24,7 @@
 @ stub D3DXComputeIMTFromTexture(ptr ptr long long ptr ptr ptr)
 @ stdcall D3DXComputeNormalMap(ptr ptr ptr long long float)
 @ stdcall D3DXComputeNormals(ptr ptr)
-@ stub D3DXComputeTangent(ptr long long long long ptr)
+@ stdcall D3DXComputeTangent(ptr long long long long ptr)
 @ stub D3DXComputeTangentFrame(ptr long)
 @ stdcall D3DXComputeTangentFrameEx(ptr long long long long long long long long long ptr float float float ptr ptr)
 @ stub D3DXConcatenateMeshes(ptr long long ptr ptr ptr ptr ptr)
diff --git a/dlls/d3dx9_28/d3dx9_28.spec b/dlls/d3dx9_28/d3dx9_28.spec
index 06ced20df61..33703aa9687 100644
--- a/dlls/d3dx9_28/d3dx9_28.spec
+++ b/dlls/d3dx9_28/d3dx9_28.spec
@@ -24,7 +24,7 @@
 @ stub D3DXComputeIMTFromTexture(ptr ptr long long ptr ptr ptr)
 @ stdcall D3DXComputeNormalMap(ptr ptr ptr long long float)
 @ stdcall D3DXComputeNormals(ptr ptr)
-@ stub D3DXComputeTangent(ptr long long long long ptr)
+@ stdcall D3DXComputeTangent(ptr long long long long ptr)
 @ stub D3DXComputeTangentFrame(ptr long)
 @ stdcall D3DXComputeTangentFrameEx(ptr long long long long long long long long long ptr float float float ptr ptr)
 @ stub D3DXConcatenateMeshes(ptr long long ptr ptr ptr ptr ptr)
diff --git a/dlls/d3dx9_29/d3dx9_29.spec b/dlls/d3dx9_29/d3dx9_29.spec
index 06ced20df61..33703aa9687 100644
--- a/dlls/d3dx9_29/d3dx9_29.spec
+++ b/dlls/d3dx9_29/d3dx9_29.spec
@@ -24,7 +24,7 @@
 @ stub D3DXComputeIMTFromTexture(ptr ptr long long ptr ptr ptr)
 @ stdcall D3DXComputeNormalMap(ptr ptr ptr long long float)
 @ stdcall D3DXComputeNormals(ptr ptr)
-@ stub D3DXComputeTangent(ptr long long long long ptr)
+@ stdcall D3DXComputeTangent(ptr long long long long ptr)
 @ stub D3DXComputeTangentFrame(ptr long)
 @ stdcall D3DXComputeTangentFrameEx(ptr long long long long long long long long long ptr float float float ptr ptr)
 @ stub D3DXConcatenateMeshes(ptr long long ptr ptr ptr ptr ptr)
diff --git a/dlls/d3dx9_30/d3dx9_30.spec b/dlls/d3dx9_30/d3dx9_30.spec
index 06ced20df61..33703aa9687 100644
--- a/dlls/d3dx9_30/d3dx9_30.spec
+++ b/dlls/d3dx9_30/d3dx9_30.spec
@@ -24,7 +24,7 @@
 @ stub D3DXComputeIMTFromTexture(ptr ptr long long ptr ptr ptr)
 @ stdcall D3DXComputeNormalMap(ptr ptr ptr long long float)
 @ stdcall D3DXComputeNormals(ptr ptr)
-@ stub D3DXComputeTangent(ptr long long long long ptr)
+@ stdcall D3DXComputeTangent(ptr long long long long ptr)
 @ stub D3DXComputeTangentFrame(ptr long)
 @ stdcall D3DXComputeTangentFrameEx(ptr long long long long long long long long long ptr float float float ptr ptr)
 @ stub D3DXConcatenateMeshes(ptr long long ptr ptr ptr ptr ptr)
diff --git a/dlls/d3dx9_31/d3dx9_31.spec b/dlls/d3dx9_31/d3dx9_31.spec
index c9aca309a35..28727460d51 100644
--- a/dlls/d3dx9_31/d3dx9_31.spec
+++ b/dlls/d3dx9_31/d3dx9_31.spec
@@ -24,7 +24,7 @@
 @ stub D3DXComputeIMTFromTexture(ptr ptr long long ptr ptr ptr)
 @ stdcall D3DXComputeNormalMap(ptr ptr ptr long long float)
 @ stdcall D3DXComputeNormals(ptr ptr)
-@ stub D3DXComputeTangent(ptr long long long long ptr)
+@ stdcall D3DXComputeTangent(ptr long long long long ptr)
 @ stub D3DXComputeTangentFrame(ptr long)
 @ stdcall D3DXComputeTangentFrameEx(ptr long long long long long long long long long ptr float float float ptr ptr)
 @ stub D3DXConcatenateMeshes(ptr long long ptr ptr ptr ptr ptr)
diff --git a/dlls/d3dx9_32/d3dx9_32.spec b/dlls/d3dx9_32/d3dx9_32.spec
index f541f6f2ef1..f3ea989707b 100644
--- a/dlls/d3dx9_32/d3dx9_32.spec
+++ b/dlls/d3dx9_32/d3dx9_32.spec
@@ -24,7 +24,7 @@
 @ stub D3DXComputeIMTFromTexture(ptr ptr long long ptr ptr ptr)
 @ stdcall D3DXComputeNormalMap(ptr ptr ptr long long float)
 @ stdcall D3DXComputeNormals(ptr ptr)
-@ stub D3DXComputeTangent(ptr long long long long ptr)
+@ stdcall D3DXComputeTangent(ptr long long long long ptr)
 @ stub D3DXComputeTangentFrame(ptr long)
 @ stdcall D3DXComputeTangentFrameEx(ptr long long long long long long long long long ptr float float float ptr ptr)
 @ stub D3DXConcatenateMeshes(ptr long long ptr ptr ptr ptr ptr)
diff --git a/dlls/d3dx9_33/d3dx9_33.spec b/dlls/d3dx9_33/d3dx9_33.spec
index f541f6f2ef1..f3ea989707b 100644
--- a/dlls/d3dx9_33/d3dx9_33.spec
+++ b/dlls/d3dx9_33/d3dx9_33.spec
@@ -24,7 +24,7 @@
 @ stub D3DXComputeIMTFromTexture(ptr ptr long long ptr ptr ptr)
 @ stdcall D3DXComputeNormalMap(ptr ptr ptr long long float)
 @ stdcall D3DXComputeNormals(ptr ptr)
-@ stub D3DXComputeTangent(ptr long long long long ptr)
+@ stdcall D3DXComputeTangent(ptr long long long long ptr)
 @ stub D3DXComputeTangentFrame(ptr long)
 @ stdcall D3DXComputeTangentFrameEx(ptr long long long long long long long long long ptr float float float ptr ptr)
 @ stub D3DXConcatenateMeshes(ptr long long ptr ptr ptr ptr ptr)
diff --git a/dlls/d3dx9_34/d3dx9_34.spec b/dlls/d3dx9_34/d3dx9_34.spec
index f541f6f2ef1..f3ea989707b 100644
--- a/dlls/d3dx9_34/d3dx9_34.spec
+++ b/dlls/d3dx9_34/d3dx9_34.spec
@@ -24,7 +24,7 @@
 @ stub D3DXComputeIMTFromTexture(ptr ptr long long ptr ptr ptr)
 @ stdcall D3DXComputeNormalMap(ptr ptr ptr long long float)
 @ stdcall D3DXComputeNormals(ptr ptr)
-@ stub D3DXComputeTangent(ptr long long long long ptr)
+@ stdcall D3DXComputeTangent(ptr long long long long ptr)
 @ stub D3DXComputeTangentFrame(ptr long)
 @ stdcall D3DXComputeTangentFrameEx(ptr long long long long long long long long long ptr float float float ptr ptr)
 @ stub D3DXConcatenateMeshes(ptr long long ptr ptr ptr ptr ptr)
diff --git a/dlls/d3dx9_35/d3dx9_35.spec b/dlls/d3dx9_35/d3dx9_35.spec
index f541f6f2ef1..f3ea989707b 100644
--- a/dlls/d3dx9_35/d3dx9_35.spec
+++ b/dlls/d3dx9_35/d3dx9_35.spec
@@ -24,7 +24,7 @@
 @ stub D3DXComputeIMTFromTexture(ptr ptr long long ptr ptr ptr)
 @ stdcall D3DXComputeNormalMap(ptr ptr ptr long long float)
 @ stdcall D3DXComputeNormals(ptr ptr)
-@ stub D3DXComputeTangent(ptr long long long long ptr)
+@ stdcall D3DXComputeTangent(ptr long long long long ptr)
 @ stub D3DXComputeTangentFrame(ptr long)
 @ stdcall D3DXComputeTangentFrameEx(ptr long long long long long long long long long ptr float float float ptr ptr)
 @ stub D3DXConcatenateMeshes(ptr long long ptr ptr ptr ptr ptr)
diff --git a/dlls/d3dx9_36/d3dx9_36.spec b/dlls/d3dx9_36/d3dx9_36.spec
index e1f44261610..093cea01763 100644
--- a/dlls/d3dx9_36/d3dx9_36.spec
+++ b/dlls/d3dx9_36/d3dx9_36.spec
@@ -24,7 +24,7 @@
 @ stub D3DXComputeIMTFromTexture(ptr ptr long long ptr ptr ptr)
 @ stdcall D3DXComputeNormalMap(ptr ptr ptr long long float)
 @ stdcall D3DXComputeNormals(ptr ptr)
-@ stub D3DXComputeTangent(ptr long long long long ptr)
+@ stdcall D3DXComputeTangent(ptr long long long long ptr)
 @ stub D3DXComputeTangentFrame(ptr long)
 @ stdcall D3DXComputeTangentFrameEx(ptr long long long long long long long long long ptr float float float ptr ptr)
 @ stub D3DXConcatenateMeshes(ptr long long ptr ptr ptr ptr ptr)
diff --git a/dlls/d3dx9_36/mesh.c b/dlls/d3dx9_36/mesh.c
index 8f7c926c32a..a8b7b5e26e8 100644
--- a/dlls/d3dx9_36/mesh.c
+++ b/dlls/d3dx9_36/mesh.c
@@ -7507,6 +7507,22 @@ done:
     return hr;
 }
 
+/*************************************************************************
+ * D3DXComputeTangent    (D3DX9_36.@)
+ */
+HRESULT WINAPI D3DXComputeTangent(ID3DXMesh *mesh, DWORD stage_idx, DWORD tangent_idx,
+        DWORD binorm_idx, DWORD wrap, const DWORD *adjacency)
+{
+    TRACE("mesh %p, stage_idx %d, tangent_idx %d, binorm_idx %d, wrap %d, adjacency %p.\n",
+           mesh, stage_idx, tangent_idx, binorm_idx, wrap, adjacency);
+
+    return D3DXComputeTangentFrameEx(mesh, D3DDECLUSAGE_TEXCOORD, stage_idx,
+            (binorm_idx == D3DX_DEFAULT) ? D3DX_DEFAULT : D3DDECLUSAGE_BINORMAL, binorm_idx,
+            (tangent_idx == D3DX_DEFAULT) ? D3DX_DEFAULT : D3DDECLUSAGE_TANGENT, tangent_idx, D3DX_DEFAULT, 0,
+            (wrap ? D3DXTANGENT_WRAP_UV : 0) | D3DXTANGENT_GENERATE_IN_PLACE | D3DXTANGENT_ORTHOGONALIZE_FROM_U,
+            adjacency, -1.01f, -0.01f, -1.01f, NULL, NULL);
+}
+
 /*************************************************************************
  * D3DXComputeNormals    (D3DX9_36.@)
  */
diff --git a/dlls/d3dx9_37/d3dx9_37.spec b/dlls/d3dx9_37/d3dx9_37.spec
index e1f44261610..093cea01763 100644
--- a/dlls/d3dx9_37/d3dx9_37.spec
+++ b/dlls/d3dx9_37/d3dx9_37.spec
@@ -24,7 +24,7 @@
 @ stub D3DXComputeIMTFromTexture(ptr ptr long long ptr ptr ptr)
 @ stdcall D3DXComputeNormalMap(ptr ptr ptr long long float)
 @ stdcall D3DXComputeNormals(ptr ptr)
-@ stub D3DXComputeTangent(ptr long long long long ptr)
+@ stdcall D3DXComputeTangent(ptr long long long long ptr)
 @ stub D3DXComputeTangentFrame(ptr long)
 @ stdcall D3DXComputeTangentFrameEx(ptr long long long long long long long long long ptr float float float ptr ptr)
 @ stub D3DXConcatenateMeshes(ptr long long ptr ptr ptr ptr ptr)
diff --git a/dlls/d3dx9_38/d3dx9_38.spec b/dlls/d3dx9_38/d3dx9_38.spec
index e1f44261610..093cea01763 100644
--- a/dlls/d3dx9_38/d3dx9_38.spec
+++ b/dlls/d3dx9_38/d3dx9_38.spec
@@ -24,7 +24,7 @@
 @ stub D3DXComputeIMTFromTexture(ptr ptr long long ptr ptr ptr)
 @ stdcall D3DXComputeNormalMap(ptr ptr ptr long long float)
 @ stdcall D3DXComputeNormals(ptr ptr)
-@ stub D3DXComputeTangent(ptr long long long long ptr)
+@ stdcall D3DXComputeTangent(ptr long long long long ptr)
 @ stub D3DXComputeTangentFrame(ptr long)
 @ stdcall D3DXComputeTangentFrameEx(ptr long long long long long long long long long ptr float float float ptr ptr)
 @ stub D3DXConcatenateMeshes(ptr long long ptr ptr ptr ptr ptr)
diff --git a/dlls/d3dx9_39/d3dx9_39.spec b/dlls/d3dx9_39/d3dx9_39.spec
index e1f44261610..093cea01763 100644
--- a/dlls/d3dx9_39/d3dx9_39.spec
+++ b/dlls/d3dx9_39/d3dx9_39.spec
@@ -24,7 +24,7 @@
 @ stub D3DXComputeIMTFromTexture(ptr ptr long long ptr ptr ptr)
 @ stdcall D3DXComputeNormalMap(ptr ptr ptr long long float)
 @ stdcall D3DXComputeNormals(ptr ptr)
-@ stub D3DXComputeTangent(ptr long long long long ptr)
+@ stdcall D3DXComputeTangent(ptr long long long long ptr)
 @ stub D3DXComputeTangentFrame(ptr long)
 @ stdcall D3DXComputeTangentFrameEx(ptr long long long long long long long long long ptr float float float ptr ptr)
 @ stub D3DXConcatenateMeshes(ptr long long ptr ptr ptr ptr ptr)
diff --git a/dlls/d3dx9_40/d3dx9_40.spec b/dlls/d3dx9_40/d3dx9_40.spec
index e1f44261610..093cea01763 100644
--- a/dlls/d3dx9_40/d3dx9_40.spec
+++ b/dlls/d3dx9_40/d3dx9_40.spec
@@ -24,7 +24,7 @@
 @ stub D3DXComputeIMTFromTexture(ptr ptr long long ptr ptr ptr)
 @ stdcall D3DXComputeNormalMap(ptr ptr ptr long long float)
 @ stdcall D3DXComputeNormals(ptr ptr)
-@ stub D3DXComputeTangent(ptr long long long long ptr)
+@ stdcall D3DXComputeTangent(ptr long long long long ptr)
 @ stub D3DXComputeTangentFrame(ptr long)
 @ stdcall D3DXComputeTangentFrameEx(ptr long long long long long long long long long ptr float float float ptr ptr)
 @ stub D3DXConcatenateMeshes(ptr long long ptr ptr ptr ptr ptr)
diff --git a/dlls/d3dx9_41/d3dx9_41.spec b/dlls/d3dx9_41/d3dx9_41.spec
index e1f44261610..093cea01763 100644
--- a/dlls/d3dx9_41/d3dx9_41.spec
+++ b/dlls/d3dx9_41/d3dx9_41.spec
@@ -24,7 +24,7 @@
 @ stub D3DXComputeIMTFromTexture(ptr ptr long long ptr ptr ptr)
 @ stdcall D3DXComputeNormalMap(ptr ptr ptr long long float)
 @ stdcall D3DXComputeNormals(ptr ptr)
-@ stub D3DXComputeTangent(ptr long long long long ptr)
+@ stdcall D3DXComputeTangent(ptr long long long long ptr)
 @ stub D3DXComputeTangentFrame(ptr long)
 @ stdcall D3DXComputeTangentFrameEx(ptr long long long long long long long long long ptr float float float ptr ptr)
 @ stub D3DXConcatenateMeshes(ptr long long ptr ptr ptr ptr ptr)
diff --git a/dlls/d3dx9_42/d3dx9_42.spec b/dlls/d3dx9_42/d3dx9_42.spec
index 0851945d36b..43c301763d9 100644
--- a/dlls/d3dx9_42/d3dx9_42.spec
+++ b/dlls/d3dx9_42/d3dx9_42.spec
@@ -24,7 +24,7 @@
 @ stub D3DXComputeIMTFromTexture(ptr ptr long long ptr ptr ptr)
 @ stdcall D3DXComputeNormalMap(ptr ptr ptr long long float)
 @ stdcall D3DXComputeNormals(ptr ptr)
-@ stub D3DXComputeTangent(ptr long long long long ptr)
+@ stdcall D3DXComputeTangent(ptr long long long long ptr)
 @ stub D3DXComputeTangentFrame(ptr long)
 @ stdcall D3DXComputeTangentFrameEx(ptr long long long long long long long long long ptr float float float ptr ptr)
 @ stub D3DXConcatenateMeshes(ptr long long ptr ptr ptr ptr ptr)
diff --git a/dlls/d3dx9_43/d3dx9_43.spec b/dlls/d3dx9_43/d3dx9_43.spec
index 0851945d36b..43c301763d9 100644
--- a/dlls/d3dx9_43/d3dx9_43.spec
+++ b/dlls/d3dx9_43/d3dx9_43.spec
@@ -24,7 +24,7 @@
 @ stub D3DXComputeIMTFromTexture(ptr ptr long long ptr ptr ptr)
 @ stdcall D3DXComputeNormalMap(ptr ptr ptr long long float)
 @ stdcall D3DXComputeNormals(ptr ptr)
-@ stub D3DXComputeTangent(ptr long long long long ptr)
+@ stdcall D3DXComputeTangent(ptr long long long long ptr)
 @ stub D3DXComputeTangentFrame(ptr long)
 @ stdcall D3DXComputeTangentFrameEx(ptr long long long long long long long long long ptr float float float ptr ptr)
 @ stub D3DXConcatenateMeshes(ptr long long ptr ptr ptr ptr ptr)
-- 
2.20.1

[Matteo Bruni]

A rare occasion where I can quote myself recursively, so I'll do just
that: https://www.winehq.org/pipermail/wine-devel/2019-April/143293.html

While it would be nice to have some nice and detailed tests along the
lines of mesh.c:test_compute_normals(), I'll settle for the minimum
necessary to confirm that the arguments to D3DXComputeTangentFrameEx()
are correct (or otherwise, e.g. if that can't be tested for whatever
reason, a small comment in the code).

[Zebediah Figura (she/her)]

On 3/2/21 1:27 AM, Matteo Bruni wrote:
> A rare occasion where I can quote myself recursively, so I'll do just
> that: https://www.winehq.org/pipermail/wine-devel/2019-April/143293.html
>
> While it would be nice to have some nice and detailed tests along the
> lines of mesh.c:test_compute_normals(), I'll settle for the minimum
> necessary to confirm that the arguments to D3DXComputeTangentFrameEx()
> are correct (or otherwise, e.g. if that can't be tested for whatever
> reason, a small comment in the code).

Yeah, sorry, I missed that somehow.

The reason (which I should probably have mentioned regardless) I didn't
write tests is that, as far as I can tell, the actual functionality of
D3DXComputeTangent() isn't implemented. I could probably address that
too, though...