86 lines
2.0 KiB
C++
86 lines
2.0 KiB
C++
// Copyright (c) 2012-2022 Wojciech Figat. All rights reserved.
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#include "Math.h"
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#include "Mathd.h"
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#include "Vector3.h"
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void Math::SinCos(float angle, float& sine, float& cosine)
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{
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sine = Math::Sin(angle);
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cosine = Math::Cos(angle);
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}
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void Math::SinCos(double angle, double& sine, double& cosine)
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{
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sine = Math::Sin(angle);
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cosine = Math::Cos(angle);
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}
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uint32 Math::FloorLog2(uint32 value)
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{
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// References:
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// http://codinggorilla.domemtech.com/?p=81
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// http://en.wikipedia.org/wiki/Binary_logarithm
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uint32 pos = 0;
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if (value >= 1 << 16)
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{
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value >>= 16;
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pos += 16;
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}
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if (value >= 1 << 8)
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{
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value >>= 8;
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pos += 8;
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}
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if (value >= 1 << 4)
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{
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value >>= 4;
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pos += 4;
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}
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if (value >= 1 << 2)
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{
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value >>= 2;
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pos += 2;
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}
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if (value >= 1 << 1)
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{
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pos += 1;
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}
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return value == 0 ? 0 : pos;
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}
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Vector3 Math::RotateAboutAxis(const Vector3& normalizedRotationAxis, float angle, const Vector3& positionOnAxis, const Vector3& position)
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{
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const Vector3 closestPointOnAxis = positionOnAxis + normalizedRotationAxis * Vector3::Dot(normalizedRotationAxis, position - positionOnAxis);
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const Vector3 axisU = position - closestPointOnAxis;
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const Vector3 axisV = Vector3::Cross(normalizedRotationAxis, axisU);
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float cosAngle, sinAngle;
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Math::SinCos(angle, sinAngle, cosAngle);
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const Vector3 rotation = axisU * cosAngle + axisV * sinAngle;
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const Vector3 rotatedPosition = closestPointOnAxis + rotation;
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return rotatedPosition - position;
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}
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Vector3 Math::ExtractLargestComponent(const Vector3& v)
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{
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const Vector3 a = v.GetAbsolute();
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if (a.X > a.Y)
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{
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if (a.X > a.Z)
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{
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return Vector3(v.X > 0.0f ? 1.0f : -1.0f, 0.0f, 0.0f);
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}
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}
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else
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{
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if (a.Y > a.Z)
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{
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return Vector3(0.0f, v.Y > 0.0f ? 1.0f : -1.0f, 0.0f);
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}
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}
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return Vector3(0.0f, 0.0f, v.Z > 0 ? 1.0f : -1.0f);
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}
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