From 705986ebcdd24573791aa58c7a8f2b7549c918a3 Mon Sep 17 00:00:00 2001
From: Mikko Rasa <tdb@tdb.fi>
Date: Sun, 5 Dec 2010 18:56:03 +0000
Subject: [PATCH] Add conversion from Vector4 to Vector3 Add overloads of
 Matrix transformations with Vector3 parameters Add multiplication operator
 between Matrix and Vector4

---
 source/matrix.cpp | 19 +++++++++++++++++++
 source/matrix.h   |  8 ++++++++
 source/vector.h   |  7 +++++++
 3 files changed, 34 insertions(+)

diff --git a/source/matrix.cpp b/source/matrix.cpp
index a4b60dc6..4c3a7ee6 100644
--- a/source/matrix.cpp
+++ b/source/matrix.cpp
@@ -134,6 +134,25 @@ Matrix &Matrix::operator*=(const Matrix &other)
 	return *this;
 }
 
+Vector4 Matrix::operator*(const Vector4 &vec) const
+{
+	if(flags==IDENTITY)
+		return vec;
+	else if(flags==TRANSLATE)
+		return Vector4(vec.x+vec.w*matrix[12], vec.y+vec.w*matrix[13], vec.z+vec.w*matrix[14], vec.w);
+	else if(flags==SCALE)
+		return Vector4(vec.x*matrix[0], vec.y*matrix[5], vec.z*matrix[10], vec.w);
+	else
+	{
+		Vector4 result;
+		result.x = vec.x*matrix[0]+vec.y*matrix[4]+vec.z*matrix[8]+vec.w*matrix[12];
+		result.y = vec.x*matrix[1]+vec.y*matrix[5]+vec.z*matrix[9]+vec.w*matrix[13];
+		result.z = vec.x*matrix[2]+vec.y*matrix[6]+vec.z*matrix[10]+vec.w*matrix[14];
+		result.w = vec.x*matrix[3]+vec.y*matrix[7]+vec.z*matrix[11]+vec.w*matrix[15];
+		return result;
+	}
+}
+
 double Matrix::operator[](unsigned i) const
 {
 	if(i>=16)
diff --git a/source/matrix.h b/source/matrix.h
index a2194916..42e70c98 100644
--- a/source/matrix.h
+++ b/source/matrix.h
@@ -10,6 +10,7 @@ Distributed under the LGPL
 
 #include <list>
 #include "gl.h"
+#include "vector.h"
 
 namespace Msp {
 namespace GL {
@@ -41,18 +42,25 @@ public:
 
 	void multiply(const Matrix &);
 	void translate(double, double, double);
+	void translate(const Vector3 &t) { translate(t.x, t.y, t.z); }
 	void rotate(double, double, double, double);
+	void rotate(double a, const Vector3 &x) { rotate(a, x.x, x.y, x.z); }
 	void rotate_deg(double, double, double, double);
+	void rotate_deg(double a, const Vector3 & x) { rotate_deg(a, x.x, x.y, x.z); }
 	void scale(double);
 	void scale(double, double, double);
 
 	Matrix operator*(const Matrix &) const;
 	Matrix &operator*=(const Matrix &);
+	Vector4 operator*(const Vector4 &) const;
 	double operator[](unsigned) const;
 
 	static Matrix translation(double, double, double);
+	static Matrix translation(const Vector3 &t) { return translation(t.x, t.y, t.z); }
 	static Matrix rotation(double, double, double, double);
+	static Matrix rotation(double a, const Vector3 &x) { return rotation(a, x.x, x.y, x.z); }
 	static Matrix rotation_deg(double, double, double, double);
+	static Matrix rotation_deg(double a, const Vector3 &x) { return rotation_deg(a, x.x, x.y, x.z); }
 	static Matrix scaling(double);
 	static Matrix scaling(double, double, double);
 
diff --git a/source/vector.h b/source/vector.h
index d1693af1..25ebac11 100644
--- a/source/vector.h
+++ b/source/vector.h
@@ -11,12 +11,15 @@ Distributed under the LGPL
 namespace Msp {
 namespace GL {
 
+struct Vector4;
+
 struct Vector3
 {
 	float x, y, z;
 
 	Vector3(): x(0), y(0), z(0) { }
 	Vector3(float x_, float y_, float z_): x(x_), y(y_), z(z_) { }
+	Vector3(const Vector4 &);
 };
 
 struct Vector4
@@ -29,6 +32,10 @@ struct Vector4
 	Vector4(const Vector3 &v): x(v.x), y(v.y), z(v.z), w(1) { }
 };
 
+inline Vector3::Vector3(const Vector4 &v):
+	x(v.x/v.w), y(v.y/v.w), z(v.z/v.w)
+{ }
+
 } // namespace GL
 } // namespace Msp
 
-- 
2.45.2