d3dx8: Implement D3XMatrixInverse.

dlls/d3dx8/d3dx8.spec

@@ -23,7 +23,7 @@
 @ stdcall D3DXMatrixfDeterminant(ptr)
 @ stdcall D3DXMatrixMultiply(ptr ptr ptr)
 @ stdcall D3DXMatrixTranspose(ptr ptr)
-@ stub D3DXMatrixInverse
+@ stdcall D3DXMatrixInverse(ptr ptr ptr)
 @ stdcall D3DXMatrixScaling(ptr long long long)
 @ stdcall D3DXMatrixTranslation(ptr long long long)
 @ stdcall D3DXMatrixRotationX(ptr long)

dlls/d3dx8/math.c

@@ -47,6 +47,45 @@ FLOAT WINAPI D3DXMatrixfDeterminant(CONST D3DXMATRIX *pm)
     return det;
 }
 
+D3DXMATRIX* WINAPI D3DXMatrixInverse(D3DXMATRIX *pout, FLOAT *pdeterminant, CONST D3DXMATRIX *pm)
+{
+    int a, i, j;
+    D3DXVECTOR4 v, vec[3];
+    FLOAT cofactor, det;
+
+    det = D3DXMatrixfDeterminant(pm);
+    if ( !det ) return NULL;
+    if ( pdeterminant ) *pdeterminant = det;
+    for (i=0; i<4; i++)
+    {
+     for (j=0; j<4; j++)
+     {
+      if (j != i )
+      {
+       a = j;
+       if ( j > i ) a = a-1;
+       vec[a].x = pm->u.m[j][0];
+       vec[a].y = pm->u.m[j][1];
+       vec[a].z = pm->u.m[j][2];
+       vec[a].w = pm->u.m[j][3];
+      }
+     }
+    D3DXVec4Cross(&v, &vec[0], &vec[1], &vec[2]);
+    for (j=0; j<4; j++)
+    {
+     switch(j)
+     {
+      case 0: cofactor = v.x; break;
+      case 1: cofactor = v.y; break;
+      case 2: cofactor = v.z; break;
+      case 3: cofactor = v.w; break;
+     }
+    pout->u.m[j][i] = pow(-1.0f, i) * cofactor / det;
+    }
+   }
+    return pout;
+}
+
 D3DXMATRIX* WINAPI D3DXMatrixLookAtLH(D3DXMATRIX *pout, CONST D3DXVECTOR3 *peye, CONST D3DXVECTOR3 *pat, CONST D3DXVECTOR3 *pup)
 {
     D3DXVECTOR3 right, rightn, up, upn, vec, vec2;

dlls/d3dx8/tests/math.c

@@ -149,10 +149,11 @@ static void D3DXColorTest(void)
 static void D3DXMatrixTest(void)
 {
     D3DXMATRIX expectedmat, gotmat, mat, mat2, mat3;
+    LPD3DXMATRIX funcpointer;
     D3DXQUATERNION q;
     D3DXVECTOR3 at, axis, eye;
     BOOL expected, got;
-    FLOAT angle, expectedfloat, gotfloat;
+    FLOAT angle, determinant, expectedfloat, gotfloat;
 
     U(mat).m[0][1] = 5.0f; U(mat).m[0][2] = 7.0f; U(mat).m[0][3] = 8.0f;
     U(mat).m[1][0] = 11.0f; U(mat).m[1][2] = 16.0f; U(mat).m[1][3] = 33.0f;
@@ -181,6 +182,18 @@ static void D3DXMatrixTest(void)
     gotfloat = D3DXMatrixfDeterminant(&mat);
     ok(fabs( gotfloat - expectedfloat ) < admitted_error, "Expected: %f, Got: %f\n", expectedfloat, gotfloat);
 
+/*____________D3DXMatrixInverse______________*/
+    expectedmat.m[0][0] = 16067.0f/73944.0f; expectedmat.m[0][1] = -10165.0f/147888.0f; expectedmat.m[0][2] = -2729.0f/147888.0f; expectedmat.m[0][3] = -1631.0f/49296.0f;
+    expectedmat.m[1][0] = -565.0f/36972.0f; expectedmat.m[1][1] = 2723.0f/73944.0f; expectedmat.m[1][2] = -1073.0f/73944.0f; expectedmat.m[1][3] = 289.0f/24648.0f;
+    expectedmat.m[2][0] = -389.0f/2054.0f; expectedmat.m[2][1] = 337.0f/4108.0f; expectedmat.m[2][2] = 181.0f/4108.0f; expectedmat.m[2][3] = 317.0f/4108.0f;
+    expectedmat.m[3][0] = 163.0f/5688.0f; expectedmat.m[3][1] = -101.0f/11376.0f; expectedmat.m[3][2] = -73.0f/11376.0f; expectedmat.m[3][3] = -127.0f/3792.0f;
+    expectedfloat = -147888.0f;
+    D3DXMatrixInverse(&gotmat,&determinant,&mat);
+    expect_mat(expectedmat,gotmat);
+    ok(fabs( determinant - expectedfloat ) < admitted_error, "Expected: %f, Got: %f\n", expectedfloat, determinant);
+    funcpointer = D3DXMatrixInverse(&gotmat,NULL,&mat2);
+    ok(funcpointer == NULL, "Expected: %p, Got: %p\n", NULL, funcpointer);
+
 /*____________D3DXMatrixIsIdentity______________*/
     expected = FALSE;
     got = D3DXMatrixIsIdentity(&mat3);

include/d3dx8math.h

@@ -260,6 +260,7 @@ typedef struct D3DXCOLOR
 } D3DXCOLOR, *LPD3DXCOLOR;
 
 FLOAT WINAPI D3DXMatrixfDeterminant(CONST D3DXMATRIX *pm);
+D3DXMATRIX* WINAPI D3DXMatrixInverse(D3DXMATRIX *pout, FLOAT *pdeterminant, CONST D3DXMATRIX *pm);
 D3DXMATRIX* WINAPI D3DXMatrixLookAtLH(D3DXMATRIX *pout, CONST D3DXVECTOR3 *peye, CONST D3DXVECTOR3 *pat, CONST D3DXVECTOR3 *pup);
 D3DXMATRIX* WINAPI D3DXMatrixLookAtRH(D3DXMATRIX *pout, CONST D3DXVECTOR3 *peye, CONST D3DXVECTOR3 *pat, CONST D3DXVECTOR3 *pup);
 D3DXMATRIX* WINAPI D3DXMatrixMultiply(D3DXMATRIX *pout, CONST D3DXMATRIX *pm1, CONST D3DXMATRIX *pm2);