added animation system (with skin support for now)

src/math/Quaternion.h

@@ -0,0 +1,83 @@
+#pragma once
+
+// TODO: actually implement this
+class CQuaternion
+{
+public:
+	float x, y, z, w;
+	CQuaternion(void) {}
+	CQuaternion(float x, float y, float z, float w) : x(x), y(y), z(z), w(w) {}
+
+	float Magnitude(void) const { return sqrt(x*x + y*y + z*z + w*w); }
+	float MagnitudeSqr(void) const { return x*x + y*y + z*z + w*w; }
+
+	const CQuaternion &operator+=(CQuaternion const &right) {
+		x += right.x;
+		y += right.y;
+		z += right.z;
+		w += right.w;
+		return *this;
+	}
+
+	const CQuaternion &operator-=(CQuaternion const &right) {
+		x -= right.x;
+		y -= right.y;
+		z -= right.z;
+		w -= right.w;
+		return *this;
+	}
+
+	const CQuaternion &operator*=(float right) {
+		x *= right;
+		y *= right;
+		z *= right;
+		w *= right;
+		return *this;
+	}
+
+	const CQuaternion &operator/=(float right) {
+		x /= right;
+		y /= right;
+		z /= right;
+		w /= right;
+		return *this;
+	}
+
+	CQuaternion operator-() const {
+		return CQuaternion(-x, -y, -z, -w);
+	}
+
+	void Slerp(const CQuaternion &q1, const CQuaternion &q2, float theta, float invSin, float t);
+	void Get(RwMatrix *matrix);
+};
+
+inline float
+DotProduct(const CQuaternion &q1, const CQuaternion &q2)
+{
+	return q1.x*q2.x + q1.y*q2.y + q1.z*q2.z + q1.w*q2.w;
+}
+
+inline CQuaternion operator+(const CQuaternion &left, const CQuaternion &right)
+{
+	return CQuaternion(left.x + right.x, left.y + right.y, left.z + right.z, left.w + right.w);
+}
+
+inline CQuaternion operator-(const CQuaternion &left, const CQuaternion &right)
+{
+	return CQuaternion(left.x - right.x, left.y - right.y, left.z - right.z, left.w - right.w);
+}
+
+inline CQuaternion operator*(const CQuaternion &left, float right)
+{
+	return CQuaternion(left.x * right, left.y * right, left.z * right, left.w * right);
+}
+
+inline CQuaternion operator*(float left, const CQuaternion &right)
+{
+	return CQuaternion(left * right.x, left * right.y, left * right.z, left * right.w);
+}
+
+inline CQuaternion operator/(const CQuaternion &left, float right)
+{
+	return CQuaternion(left.x / right, left.y / right, left.z / right, left.w / right);
+}