From 7a4490c06248e03817faf85a49e48c04350bc4c7 Mon Sep 17 00:00:00 2001
From: David Adam <David.Adam@math.cnrs.fr>
Date: Tue, 20 Nov 2007 12:49:38 +0100
Subject: [PATCH] d3dx8: Implement D3DXQuaternionToAxisAngle.

---
 dlls/d3dx8/d3dx8.spec   |  2 +-
 dlls/d3dx8/math.c       | 21 +++++++++++++++++++++
 dlls/d3dx8/tests/math.c | 25 +++++++++++++++++++++++--
 include/d3dx8math.h     |  1 +
 4 files changed, 46 insertions(+), 3 deletions(-)

diff --git a/dlls/d3dx8/d3dx8.spec b/dlls/d3dx8/d3dx8.spec
index af78fb26d8b..1c57f53383a 100644
--- a/dlls/d3dx8/d3dx8.spec
+++ b/dlls/d3dx8/d3dx8.spec
@@ -49,7 +49,7 @@
 @ stdcall D3DXMatrixOrthoOffCenterLH(ptr long long long long long long)
 @ stdcall D3DXMatrixShadow(ptr ptr ptr)
 @ stdcall D3DXMatrixReflect(ptr ptr)
-@ stub D3DXQuaternionToAxisAngle
+@ stdcall D3DXQuaternionToAxisAngle(ptr ptr ptr)
 @ stub D3DXQuaternionRotationMatrix
 @ stub D3DXQuaternionRotationAxis
 @ stub D3DXQuaternionRotationYawPitchRoll
diff --git a/dlls/d3dx8/math.c b/dlls/d3dx8/math.c
index e907be14022..52e580d223c 100644
--- a/dlls/d3dx8/math.c
+++ b/dlls/d3dx8/math.c
@@ -665,6 +665,27 @@ D3DXQUATERNION* WINAPI D3DXQuaternionSquad(D3DXQUATERNION *pout, CONST D3DXQUATE
     return pout;
 }
 
+void WINAPI D3DXQuaternionToAxisAngle(CONST D3DXQUATERNION *pq, D3DXVECTOR3 *paxis, FLOAT *pangle)
+{
+    FLOAT norm;
+
+    *pangle = 0.0f;
+    norm = D3DXQuaternionLength(pq);
+    if ( norm )
+    {
+     paxis->x = pq->x / norm;
+     paxis->y = pq->y / norm;
+     paxis->z = pq->z / norm;
+     if ( fabs( pq->w ) <= 1.0f ) *pangle = 2.0f * acos(pq->w);
+    }
+    else
+    {
+     paxis->x = 1.0f;
+     paxis->y = 0.0f;
+     paxis->z = 0.0f;
+    }
+}
+
 /*_________________D3DXVec2_____________________*/
 
 D3DXVECTOR2* WINAPI D3DXVec2BaryCentric(D3DXVECTOR2 *pout, CONST D3DXVECTOR2 *pv1, CONST D3DXVECTOR2 *pv2, CONST D3DXVECTOR2 *pv3, FLOAT f, FLOAT g)
diff --git a/dlls/d3dx8/tests/math.c b/dlls/d3dx8/tests/math.c
index 229d0b7dc61..e3c6a28046b 100644
--- a/dlls/d3dx8/tests/math.c
+++ b/dlls/d3dx8/tests/math.c
@@ -552,9 +552,10 @@ static void D3DXPlaneTest(void)
 
 static void D3X8QuaternionTest(void)
 {
-    D3DXQUATERNION expectedquat, gotquat, nul, q, r, s, t, u;
+    D3DXQUATERNION expectedquat, gotquat, Nq, nul, q, r, s, t, u;
     LPD3DXQUATERNION funcpointer;
-    FLOAT expected, got, scale, scale2;
+    D3DXVECTOR3 axis, expectedvec;
+    FLOAT angle, expected, got, scale, scale2;
     BOOL expectedbool, gotbool;
 
     nul.x = 0.0f; nul.y = 0.0f; nul.z = 0.0f; nul.w = 0.0f;
@@ -667,6 +668,26 @@ static void D3X8QuaternionTest(void)
     expectedquat.x = -156.296f; expectedquat.y = 30.242f; expectedquat.z = -2.5022f; expectedquat.w = 7.3576f;
     D3DXQuaternionSquad(&gotquat,&q,&r,&t,&u,scale);
     expect_vec4(expectedquat,gotquat);
+
+/*_______________D3DXQuaternionToAxisAngle__________________*/
+    Nq.x = 1.0f/22.0f; Nq.y = 2.0f/22.0f; Nq.z = 4.0f/22.0f; Nq.w = 10.0f/22.0f;
+    expectedvec.x = 1.0f/11.0f; expectedvec.y = 2.0f/11.0f; expectedvec.z = 4.0f/11.0f;
+    expected = 2.197869f;
+    D3DXQuaternionToAxisAngle(&Nq,&axis,&angle);
+    expect_vec3(expectedvec,axis);
+    ok(fabs( angle - expected ) < admitted_error, "Expected: %f, Got: %f\n", expected, angle);
+    /* Test if |w|>1.0f */
+    expectedvec.x = 1.0f/11.0f; expectedvec.y = 2.0f/11.0f; expectedvec.z = 4.0f/11.0f;
+    expected = 0.0f;
+    D3DXQuaternionToAxisAngle(&q,&axis,&angle);
+    expect_vec3(expectedvec,axis);
+    ok(fabs( angle - expected ) < admitted_error, "Expected: %f, Got: %f\n", expected, angle);
+    /* Test the null quaternion */
+    expectedvec.x = 1.0f; expectedvec.y = 0.0f; expectedvec.z = 0.0f;
+    expected = 0.0f;
+    D3DXQuaternionToAxisAngle(&nul,&axis,&angle);
+    expect_vec3(expectedvec,axis);
+    ok(fabs( angle - expected ) < admitted_error, "Expected: %f, Got: %f\n", expected, angle);
 }
 
 static void D3X8Vector2Test(void)
diff --git a/include/d3dx8math.h b/include/d3dx8math.h
index 3e5581ebebe..dd85e3af4fa 100644
--- a/include/d3dx8math.h
+++ b/include/d3dx8math.h
@@ -308,6 +308,7 @@ D3DXQUATERNION* WINAPI D3DXQuaternionMultiply(D3DXQUATERNION *pout, CONST D3DXQU
 D3DXQUATERNION* WINAPI D3DXQuaternionNormalize(D3DXQUATERNION *pout, CONST D3DXQUATERNION *pq);
 D3DXQUATERNION* WINAPI D3DXQuaternionSlerp(D3DXQUATERNION *pout, CONST D3DXQUATERNION *pq1, CONST D3DXQUATERNION *pq2, FLOAT t);
 D3DXQUATERNION* WINAPI D3DXQuaternionSquad(D3DXQUATERNION *pout, CONST D3DXQUATERNION *pq1, CONST D3DXQUATERNION *pq2, CONST D3DXQUATERNION *pq3, CONST D3DXQUATERNION *pq4, FLOAT t);
+void WINAPI D3DXQuaternionToAxisAngle(CONST D3DXQUATERNION *pq, D3DXVECTOR3 *paxis, FLOAT *pangle);
 
 D3DXVECTOR2* WINAPI D3DXVec2BaryCentric(D3DXVECTOR2 *pout, CONST D3DXVECTOR2 *pv1, CONST D3DXVECTOR2 *pv2, CONST D3DXVECTOR2 *pv3, FLOAT f, FLOAT g);
 D3DXVECTOR2* WINAPI D3DXVec2CatmullRom(D3DXVECTOR2 *pout, CONST D3DXVECTOR2 *pv0, CONST D3DXVECTOR2 *pv1, CONST D3DXVECTOR2 *pv2, CONST D3DXVECTOR2 *pv3, FLOAT s);