2 files changed, 140 insertions, 0 deletions

diff --git a/src/math/Quaternion.h b/src/math/Quaternion.h
new file mode 100644
index 00000000..702fc72f
--- /dev/null
+++ b/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);
+}
diff --git a/src/math/math.cpp b/src/math/math.cpp
new file mode 100644
index 00000000..b76db4ae
--- /dev/null
+++ b/src/math/math.cpp
@@ -0,0 +1,57 @@
+#include "common.h"
+#include "patcher.h"
+#include "Quaternion.h"
+
+// TODO: move more stuff into here
+
+void
+CQuaternion::Slerp(const CQuaternion &q1, const CQuaternion &q2, float theta, float invSin, float t)
+{
+	if(theta == 0.0f)
+		*this = q2;
+	else{
+		float w1, w2;
+		if(theta > PI/2){
+			theta = PI - theta;
+			w1 = sin((1.0f - t) * theta) * invSin;
+			w2 = -sin(t * theta) * invSin;
+		}else{
+			w1 = sin((1.0f - t) * theta) * invSin;
+			w2 = sin(t * theta) * invSin;
+		}
+		*this = w1*q1 + w2*q2;
+	}
+}
+
+void
+CQuaternion::Get(RwMatrix *matrix)
+{
+	float x2 = x+x;
+	float y2 = y+y;
+	float z2 = z+z;
+
+	float x_2x = x * x2;
+	float x_2y = x * y2;
+	float x_2z = x * z2;
+	float y_2y = y * y2;
+	float y_2z = y * z2;
+	float z_2z = z * z2;
+	float w_2x = w * x2;
+	float w_2y = w * y2;
+	float w_2z = w * z2;
+
+	matrix->right.x = 1.0f - (y_2y + z_2z);
+	matrix->up.x = x_2y - w_2z;
+	matrix->at.x = x_2z + w_2y;
+	matrix->right.y = x_2y + w_2z;
+	matrix->up.y = 1.0f - (x_2x + z_2z);
+	matrix->at.y = y_2z - w_2x;
+	matrix->right.z = x_2z - w_2y;
+	matrix->up.z = y_2z + w_2x;
+	matrix->at.z = 1.0f - (x_2x + y_2y);
+}
+
+STARTPATCHES
+	InjectHook(0x4BA1C0, &CQuaternion::Slerp, PATCH_JUMP);
+	InjectHook(0x4BA0D0, &CQuaternion::Get, PATCH_JUMP);
+ENDPATCHES