Calculate the listener matrix when a new orientation is specified

This is so the matrix isn't derived each time a source is updated, and it will
make supporting user-defined matrices easier.

3 files changed, 60 insertions, 1 deletions

diff --git a/OpenAL32/Include/alListener.h b/OpenAL32/Include/alListener.h
index 0f399e5f..0e69f6c5 100644
--- a/OpenAL32/Include/alListener.h
+++ b/OpenAL32/Include/alListener.h
@@ -13,6 +13,7 @@ typedef struct ALlistener_struct
     volatile ALfloat Velocity[3];
     volatile ALfloat Forward[3];
     volatile ALfloat Up[3];
+    volatile ALfloat Matrix[4][4];
     volatile ALfloat Gain;
     volatile ALfloat MetersPerUnit;
 } ALlistener;
diff --git a/OpenAL32/Include/alu.h b/OpenAL32/Include/alu.h
index ffc8fa39..a3584775 100644
--- a/OpenAL32/Include/alu.h
+++ b/OpenAL32/Include/alu.h
@@ -260,6 +260,34 @@ static __inline void RestoreFPUMode(int state)
 }
 
 
+static __inline void aluCrossproduct(const ALfloat *inVector1, const ALfloat *inVector2, ALfloat *outVector)
+{
+    outVector[0] = inVector1[1]*inVector2[2] - inVector1[2]*inVector2[1];
+    outVector[1] = inVector1[2]*inVector2[0] - inVector1[0]*inVector2[2];
+    outVector[2] = inVector1[0]*inVector2[1] - inVector1[1]*inVector2[0];
+}
+
+static __inline ALfloat aluDotproduct(const ALfloat *inVector1, const ALfloat *inVector2)
+{
+    return inVector1[0]*inVector2[0] + inVector1[1]*inVector2[1] +
+           inVector1[2]*inVector2[2];
+}
+
+static __inline void aluNormalize(ALfloat *inVector)
+{
+    ALfloat length, inverse_length;
+
+    length = aluSqrt(aluDotproduct(inVector, inVector));
+    if(length > 0.0f)
+    {
+        inverse_length = 1.0f/length;
+        inVector[0] *= inverse_length;
+        inVector[1] *= inverse_length;
+        inVector[2] *= inverse_length;
+    }
+}
+
+
 ALvoid aluInitPanning(ALCdevice *Device);
 ALint aluCart2LUTpos(ALfloat re, ALfloat im);
 
diff --git a/OpenAL32/alListener.c b/OpenAL32/alListener.c
index 37982b5c..32a12cfb 100644
--- a/OpenAL32/alListener.c
+++ b/OpenAL32/alListener.c
@@ -142,14 +142,44 @@ AL_API ALvoid AL_APIENTRY alListenerfv(ALenum eParam, const ALfloat *pflValues)
                    isfinite(pflValues[2]) && isfinite(pflValues[3]) &&
                    isfinite(pflValues[4]) && isfinite(pflValues[5]))
                 {
+                    ALfloat U[3], V[3], N[3];
+
+                    /* AT then UP */
+                    N[0] = pflValues[0];
+                    N[1] = pflValues[1];
+                    N[2] = pflValues[2];
+                    aluNormalize(N);
+                    V[0] = pflValues[3];
+                    V[1] = pflValues[4];
+                    V[2] = pflValues[5];
+                    aluNormalize(V);
+                    /* Build and normalize right-vector */
+                    aluCrossproduct(N, V, U);
+                    aluNormalize(U);
+
                     LockContext(Context);
-                    // AT then UP
                     Context->Listener.Forward[0] = pflValues[0];
                     Context->Listener.Forward[1] = pflValues[1];
                     Context->Listener.Forward[2] = pflValues[2];
                     Context->Listener.Up[0] = pflValues[3];
                     Context->Listener.Up[1] = pflValues[4];
                     Context->Listener.Up[2] = pflValues[5];
+                    Context->Listener.Matrix[0][0] =  U[0];
+                    Context->Listener.Matrix[0][1] =  V[0];
+                    Context->Listener.Matrix[0][2] = -N[0];
+                    Context->Listener.Matrix[0][3] =  0.0f;
+                    Context->Listener.Matrix[1][0] =  U[1];
+                    Context->Listener.Matrix[1][1] =  V[1];
+                    Context->Listener.Matrix[1][2] = -N[1];
+                    Context->Listener.Matrix[1][3] =  0.0f;
+                    Context->Listener.Matrix[2][0] =  U[2];
+                    Context->Listener.Matrix[2][1] =  V[2];
+                    Context->Listener.Matrix[2][2] = -N[2];
+                    Context->Listener.Matrix[2][3] =  0.0f;
+                    Context->Listener.Matrix[3][0] =  0.0f;
+                    Context->Listener.Matrix[3][1] =  0.0f;
+                    Context->Listener.Matrix[3][2] =  0.0f;
+                    Context->Listener.Matrix[3][3] =  1.0f;
                     Context->UpdateSources = AL_TRUE;
                     UnlockContext(Context);
                 }