82 lines
1.4 KiB
C++
82 lines
1.4 KiB
C++
//-------------------------------------------------------------------------------------
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//
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// JGE++ is a hardware accelerated 2D game SDK for PSP/Windows.
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//
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// Licensed under the BSD license, see LICENSE in JGE root for details.
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//
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// Copyright (c) 2007 James Hui (a.k.a. Dr.Watson) <jhkhui@gmail.com>
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//
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//-------------------------------------------------------------------------------------
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#include "../include/Vector2D.h"
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float Vector2D::Length(void) const
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{
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return sqrtf(x*x + y*y);
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}
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float Vector2D::Normalize(void)
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{
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float fLength = Length();
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if (fLength == 0.0f)
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return 0.0f;
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(*this) *= (1.0f / fLength);
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return fLength;
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}
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Vector2D Vector2D::Direction(void) const
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{
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Vector2D temp(*this);
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temp.Normalize();
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return temp;
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}
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float Vector2D::Angle(const Vector2D& xE)
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{
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float dot = (*this) * xE;
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float cross = (*this) ^ xE;
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// angle between segments
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float angle = atan2f(cross, dot);
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return angle;
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}
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Vector2D& Vector2D::Rotate(float angle)
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{
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float tx = x;
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x = x * cosf(angle) - y * sinf(angle);
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y = tx * sinf(angle) + y * cosf(angle);
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return *this;
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}
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Vector2D& Vector2D::Rotate(const Vector2D& xCentre, float fAngle)
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{
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Vector2D D = *this - xCentre;
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D.Rotate(fAngle);
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*this = xCentre + D;
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return *this;
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}
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void Vector2D::Clamp(const Vector2D& min, const Vector2D& max)
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{
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x = (x < min.x)? min.x : (x > max.x)? max.x : x;
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x = (y < min.y)? min.y : (y > max.y)? max.y : y;
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}
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