scummvm/graphics/tinygl/zmath.h

#ifndef GRAPHICS_TINYGL_ZMATH_H
#define GRAPHICS_TINYGL_ZMATH_H

namespace TinyGL {

// Matrix & Vertex
class Vector3 {
public:
	Vector3();
	Vector3(const Vector3 &other);
	Vector3(float x, float y, float z);
	
	float getX() const { return _v[0]; }
	float getY() const { return _v[1]; }
	float getZ() const { return _v[2]; }

	void setX(float val) { _v[0] = val; }
	void setY(float val) { _v[1] = val; }
	void setZ(float val) { _v[2] = val; }

	void normalize();

	float getLength() const { return sqrt(_v[0] * _v[0] + _v[1] * _v[1] + _v[2] * _v[2]); }

	static float dot(const Vector3& a, const Vector3& b) {
		return a._v[0] * b._v[0] + a._v[1] * b._v[1] + a._v[2] * b._v[2]; 
	}

	bool operator==(const Vector3& other) const
	{
		return _v[0] == other._v[0] && _v[1] == other._v[1] && _v[2] == other._v[2];
	}

	bool operator!=(const Vector3& other) const
	{
		return _v[0] != other._v[0] || _v[1] != other._v[1] || _v[2] != other._v[2];
	}

	Vector3& operator=(const Vector3 &other)
	{
		memcpy(_v,other._v,sizeof(_v));
		return *this;
	}

	Vector3 operator-() const
	{
		return Vector3(-_v[0],-_v[1],-_v[2]);
	}

	Vector3 operator*(float factor) const {
		return Vector3(_v[0] * factor, _v[1] * factor, _v[2] * factor);
	}

	Vector3 operator+(const Vector3 &other) const {
		return Vector3(_v[0] + other._v[0], _v[1] + other._v[1], _v[2] + other._v[2]);
	}

	Vector3 operator-(const Vector3 &other) const {
		return Vector3(_v[0] - other._v[0], _v[1] - other._v[1], _v[2] - other._v[2]);
	}

	Vector3& operator*=(float factor) {
		_v[0] *= factor;
		_v[1] *= factor;
		_v[2] *= factor;
		return *this;
	}

	Vector3& operator+=(float value) {
		_v[0] += value;
		_v[1] += value;
		_v[2] += value;
		return *this;
	}

	Vector3& operator-=(float value) {
		_v[0] -= value;
		_v[1] -= value;
		_v[2] -= value;
		return *this;
	}
private:
	float _v[3];
};

class Vector4 {
public:
	Vector4();
	Vector4(const Vector3& vec, float w);
	Vector4(float x, float y, float z, float w);
	
	Vector4& operator=(const Vector4 &other)
	{
		memcpy(_v,other._v,sizeof(_v));
		return *this;
	}

	bool operator==(const Vector4& other) const
	{
		return _v[0] == other._v[0] && _v[1] == other._v[1] && _v[2] == other._v[2] && _v[3] == other._v[3];
	}

	bool operator!=(const Vector4& other) const
	{
		return _v[0] != other._v[0] || _v[1] != other._v[1] || _v[2] != other._v[2] || _v[3] != other._v[3];
	}

	Vector4 operator-() const
	{
		return Vector4(-_v[0],-_v[1],-_v[2],-_v[3]);
	}

	Vector4 operator*(float factor) const {
		return Vector4(_v[0] * factor, _v[1] * factor, _v[2] * factor,_v[3] * factor);
	}

	Vector4 operator+(const Vector4 &other) const {
		return Vector4(_v[0] + other._v[0], _v[1] + other._v[1], _v[2] + other._v[2], _v[3] + other._v[3]);
	}

	Vector4 operator-(const Vector4 &other) const {
		return Vector4(_v[0] - other._v[0], _v[1] - other._v[1], _v[2] - other._v[2], _v[3] - other._v[3]);
	}

	Vector4& operator*=(float factor) {
		_v[0] *= factor;
		_v[1] *= factor;
		_v[2] *= factor;
		_v[3] *= factor;
		return *this;
	}

	Vector4& operator+=(float value) {
		_v[0] += value;
		_v[1] += value;
		_v[2] += value;
		_v[3] += value;
		return *this;
	}

	Vector4& operator-=(float value) {
		_v[0] -= value;
		_v[1] -= value;
		_v[2] -= value;
		_v[3] -= value;
		return *this;
	}

	Vector3 toVector3() const {
		return Vector3(_v[0],_v[1],_v[2]);
	}

	float getX() const { return _v[0]; }
	float getY() const { return _v[1]; }
	float getZ() const { return _v[2]; }
	float getW() const { return _v[3]; }

	void setX(float val) { _v[0] = val; }
	void setY(float val) { _v[1] = val; }
	void setZ(float val) { _v[2] = val; }
	void setW(float val) { _v[3] = val; }

private:
	float _v[4];
};

class Matrix4 {
public:
	Matrix4();
	Matrix4(const Matrix4 &other);

	bool IsIdentity() const;

	Matrix4& operator=(const Matrix4 &other)
	{
		memcpy(_m,other._m,sizeof(_m));
		return *this;
	}
	
	Matrix4 operator+(const Matrix4& b) const
	{
		Matrix4 result;
		for(int i = 0; i < 4; i++) {
			for(int j = 0; j < 4; j++) {
				result.set(i,j, get(i,j) + b.get(i,j));
			}
		}
		return result;
	}

	Matrix4 operator-(const Matrix4& b) const
	{
		Matrix4 result;
		for(int i = 0; i < 4; i++) {
			for(int j = 0; j < 4; j++) {
				result.set(i,j, get(i,j) - b.get(i,j));
			}
		}
		return result;
	}

	Matrix4 operator*(const Matrix4 &b) const
	{
		Matrix4 result;
		float s;
		for (int i = 0; i < 4; i++) {
			for (int j = 0; j < 4; j++) {
				s = 0.0;
				for (int k = 0; k < 4; k++)
					s += this->get(i,k) * b.get(k,j);
				result.set(i,j,s);
			}
		}
		return result;
	}

	static Matrix4 identity();
	static Matrix4 rotation(float t, int u);

	void fill(float val) {
		for(int i = 0; i < 4; i++) {
			for(int j = 0; j < 4; j++) {
				_m[i][j] = val;
			}
		}
	}

	inline void set(int x,int y,float val) {
		_m[x][y] = val;
	}

	inline float get(int x, int y) const {
		return _m[x][y];
	}

	Matrix4 transpose() const;
	Matrix4 inverseOrtho() const;
	Matrix4 inverse() const;

	Vector3 transform(const Vector3 &vector) const;
	Vector3 transform3x3(const Vector3 &vector) const; // Transform the vector as if this were a 3x3 matrix.
	Vector4 transform3x4(const Vector4 &vector) const; // Transform the vector as if this were a 3x4 matrix.
	Vector4 transform(const Vector4 &vector) const;
private:
	float _m[4][4];
};

} // end of namespace TinyGL

#endif