60 lines
1.8 KiB
C
60 lines
1.8 KiB
C
/*
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* Copyright (c) 2016-2016 Irlan Robson http://www.irlan.net
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*
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* This software is provided 'as-is', without any express or implied
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* warranty. In no event will the authors be held liable for any damages
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* arising from the use of this software.
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* Permission is granted to anyone to use this software for any purpose,
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* including commercial applications, and to alter it and redistribute it
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* freely, subject to the following restrictions:
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* 1. The origin of this software must not be misrepresented; you must not
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* claim that you wrote the original software. If you use this software
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* in a product, an acknowledgment in the product documentation would be
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* appreciated but is not required.
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* 2. Altered source versions must be plainly marked as such, and must not be
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* misrepresented as being the original software.
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* 3. This notice may not be removed or altered from any source distribution.
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*/
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#ifndef B3_MAT_22_H
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#define B3_MAT_22_H
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#include <bounce\common\math\vec2.h>
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// A 2-by-2 matrix stored in column-major order.
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struct b3Mat22
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{
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// Does nothing for performance.
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b3Mat22() { }
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// Set this matrix from two vector elements.
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b3Mat22(const b3Vec2& _x, const b3Vec2& _y) : x(_x), y(_y) { }
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// Solve Ax = b.
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// It doesn't compute the inverse.
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// Therefore, is more efficient.
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// Returns the zero vector if the matrix is singular.
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b3Vec2 Solve(const b3Vec2& b) const;
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b3Vec2 x, y;
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};
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// Multiply a matrix times a vector.
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inline b3Vec2 operator*(const b3Mat22& A, const b3Vec2& v)
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{
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return v.x * A.x + v.y * A.y;
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}
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// Multiply a matrix times a vector.
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inline b3Vec2 b3Mul(const b3Mat22& A, const b3Vec2& v)
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{
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return v.x * A.x + v.y * A.y;
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}
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// Invert a matrix.
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// If the matrix determinant is zero this returns
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// the zero matrix.
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inline b3Mat22 b3Inverse(const b3Mat22& A);
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#endif
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