The code works as intended! Change some names and comments in the meantime.

[xonotic/darkplaces.git] / matrixlib.c

diff --git a/matrixlib.c b/matrixlib.c
index 89c131144dd7e9e71df20dbdbca81b1ad0c20696..e15fb995f3248de63a8d35b7985ee533d4b09125 100644 (file)
--- a/matrixlib.c
+++ b/matrixlib.c
@@ -1430,6 +1430,7 @@ void Matrix4x4_FromOriginQuat(matrix4x4_t *m, double ox, double oy, double oz, d
 // see http://www.euclideanspace.com/maths/geometry/rotations/conversions/matrixToQuaternion/index.htm
 void Matrix4x4_ToOrigin3Quat4Float(const matrix4x4_t *m, float *origin, float *quat)
 {
+#if 0
        float s;
        quat[3] = sqrt(1.0f + m->m[0][0] + m->m[1][1] + m->m[2][2]) * 0.5f;
        s = 0.25f / quat[3];
@@ -1448,6 +1449,86 @@ void Matrix4x4_ToOrigin3Quat4Float(const matrix4x4_t *m, float *origin, float *q
        quat[1] = (m->m[0][2] - m->m[2][0]) * s;
        quat[2] = (m->m[1][0] - m->m[0][1]) * s;
 #endif
+
+#else
+
+#ifdef MATRIX4x4_OPENGLORIENTATION
+       float trace = m->m[0][0] + m->m[1][1] + m->m[2][2];
+       origin[0] = m->m[3][0];
+       origin[1] = m->m[3][1];
+       origin[2] = m->m[3][2];
+       if(trace > 0)
+       {
+               float r = sqrt(1.0f + trace), inv = 0.5f / r;
+               quat[0] = (m->m[1][2] - m->m[2][1]) * inv;
+               quat[1] = (m->m[2][0] - m->m[0][2]) * inv;
+               quat[2] = (m->m[0][1] - m->m[1][0]) * inv;
+               quat[3] = 0.5f * r;
+       }
+       else if(m->m[0][0] > m->m[1][1] && m->m[0][0] > m->m[2][2])
+       {
+               float r = sqrt(1.0f + m->m[0][0] - m->m[1][1] - m->m[2][2]), inv = 0.5f / r;
+               quat[0] = 0.5f * r;
+               quat[1] = (m->m[0][1] + m->m[1][0]) * inv;
+               quat[2] = (m->m[2][0] + m->m[0][2]) * inv;
+               quat[3] = (m->m[1][2] - m->m[2][1]) * inv;
+       }
+       else if(m->m[1][1] > m->m[2][2])
+       {
+               float r = sqrt(1.0f + m->m[1][1] - m->m[0][0] - m->m[2][2]), inv = 0.5f / r;
+               quat[0] = (m->m[0][1] + m->m[1][0]) * inv;
+               quat[1] = 0.5f * r;
+               quat[2] = (m->m[1][2] + m->m[2][1]) * inv;
+               quat[3] = (m->m[2][0] - m->m[0][2]) * inv;
+       }
+       else
+       {
+               float r = sqrt(1.0f + m->m[2][2] - m->m[0][0] - m->m[1][1]), inv = 0.5f / r;
+               quat[0] = (m->m[2][0] + m->m[0][2]) * inv;
+               quat[1] = (m->m[1][2] + m->m[2][1]) * inv;
+               quat[2] = 0.5f * r;
+               quat[3] = (m->m[0][1] - m->m[1][0]) * inv;
+       }
+#else
+       float trace = m->m[0][0] + m->m[1][1] + m->m[2][2];
+       origin[0] = m->m[0][3];
+       origin[1] = m->m[1][3];
+       origin[2] = m->m[2][3];
+       if(trace > 0)
+       {
+               float r = sqrt(1.0f + trace), inv = 0.5f / r;
+               quat[0] = (m->m[2][1] - m->m[1][2]) * inv;
+               quat[1] = (m->m[0][2] - m->m[2][0]) * inv;
+               quat[2] = (m->m[1][0] - m->m[0][1]) * inv;
+               quat[3] = 0.5f * r;
+       }
+       else if(m->m[0][0] > m->m[1][1] && m->m[0][0] > m->m[2][2])
+       {
+               float r = sqrt(1.0f + m->m[0][0] - m->m[1][1] - m->m[2][2]), inv = 0.5f / r;
+               quat[0] = 0.5f * r;
+               quat[1] = (m->m[1][0] + m->m[0][1]) * inv;
+               quat[2] = (m->m[0][2] + m->m[2][0]) * inv;
+               quat[3] = (m->m[2][1] - m->m[1][2]) * inv;
+       }
+       else if(m->m[1][1] > m->m[2][2])
+       {
+               float r = sqrt(1.0f + m->m[1][1] - m->m[0][0] - m->m[2][2]), inv = 0.5f / r;
+               quat[0] = (m->m[1][0] + m->m[0][1]) * inv;
+               quat[1] = 0.5f * r;
+               quat[2] = (m->m[2][1] + m->m[1][2]) * inv;
+               quat[3] = (m->m[0][2] - m->m[2][0]) * inv;
+       }
+       else
+       {
+               float r = sqrt(1.0f + m->m[2][2] - m->m[0][0] - m->m[1][1]), inv = 0.5f / r;
+               quat[0] = (m->m[0][2] + m->m[2][0]) * inv;
+               quat[1] = (m->m[2][1] + m->m[1][2]) * inv;
+               quat[2] = 0.5f * r;
+               quat[3] = (m->m[1][0] - m->m[0][1]) * inv;
+       }
+#endif
+
+#endif
 }
 
 // LordHavoc: I got this code from:
@@ -1488,26 +1569,20 @@ void Matrix4x4_ToBonePose6s(const matrix4x4_t *m, float origininvscale, short *p
 {
        float origin[3];
        float quat[4];
-       float s;
+       float quatscale;
        Matrix4x4_ToOrigin3Quat4Float(m, origin, quat);
        // normalize quaternion so that it is unit length
-       s = quat[0]*quat[0]+quat[1]*quat[1]+quat[2]*quat[2]+quat[3]*quat[3];
-       if (s)
-       {
-               s = 1.0f / sqrt(s);
-               quat[0] *= s;
-               quat[1] *= s;
-               quat[2] *= s;
-               quat[3] *= s;
-       }
+       quatscale = quat[0]*quat[0]+quat[1]*quat[1]+quat[2]*quat[2]+quat[3]*quat[3];
+       if (quatscale)
+               quatscale = (quat[3] >= 0 ? -32767.0f : 32767.0f) / sqrt(quatscale);
        // use a negative scale on the quat because the above function produces a
        // positive quat[3] and canonical quaternions have negative quat[3]
        pose6s[0] = origin[0] * origininvscale;
        pose6s[1] = origin[1] * origininvscale;
        pose6s[2] = origin[2] * origininvscale;
-       pose6s[3] = quat[0] * -32767.0f;
-       pose6s[4] = quat[1] * -32767.0f;
-       pose6s[5] = quat[2] * -32767.0f;
+       pose6s[3] = quat[0] * quatscale;
+       pose6s[4] = quat[1] * quatscale;
+       pose6s[5] = quat[2] * quatscale;
 }
 
 void Matrix4x4_Blend (matrix4x4_t *out, const matrix4x4_t *in1, const matrix4x4_t *in2, double blend)