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450 lines
13 KiB
C++
450 lines
13 KiB
C++
// Copyright (C) 2002-2012 Nikolaus Gebhardt
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// This file is part of the "Irrlicht Engine".
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// For conditions of distribution and use, see copyright notice in irrlicht.h
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#pragma once
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#include "plane3d.h"
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#include "vector3d.h"
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#include "line3d.h"
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#include "aabbox3d.h"
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#include "matrix4.h"
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#include "IVideoDriver.h"
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namespace irr
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{
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namespace scene
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{
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//! Defines the view frustum. That's the space visible by the camera.
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/** The view frustum is enclosed by 6 planes. These six planes share
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eight points. A bounding box around these eight points is also stored in
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this structure.
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*/
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struct SViewFrustum
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{
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enum VFPLANES
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{
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//! Far plane of the frustum. That is the plane furthest away from the eye.
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VF_FAR_PLANE = 0,
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//! Near plane of the frustum. That is the plane nearest to the eye.
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VF_NEAR_PLANE,
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//! Left plane of the frustum.
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VF_LEFT_PLANE,
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//! Right plane of the frustum.
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VF_RIGHT_PLANE,
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//! Bottom plane of the frustum.
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VF_BOTTOM_PLANE,
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//! Top plane of the frustum.
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VF_TOP_PLANE,
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//! Amount of planes enclosing the view frustum. Should be 6.
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VF_PLANE_COUNT
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};
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//! Default Constructor
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SViewFrustum() :
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BoundingRadius(0.f), FarNearDistance(0.f) {}
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//! Copy Constructor
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SViewFrustum(const SViewFrustum &other);
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//! This constructor creates a view frustum based on a projection and/or view matrix.
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//\param zClipFromZero: Clipping of z can be projected from 0 to w when true (D3D style) and from -w to w when false (OGL style).
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SViewFrustum(const core::matrix4 &mat, bool zClipFromZero);
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//! This constructor creates a view frustum based on a projection and/or view matrix.
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//\param zClipFromZero: Clipping of z can be projected from 0 to w when true (D3D style) and from -w to w when false (OGL style).
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inline void setFrom(const core::matrix4 &mat, bool zClipFromZero);
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//! transforms the frustum by the matrix
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/** \param mat: Matrix by which the view frustum is transformed.*/
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void transform(const core::matrix4 &mat);
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//! returns the point which is on the far left upper corner inside the the view frustum.
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core::vector3df getFarLeftUp() const;
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//! returns the point which is on the far left bottom corner inside the the view frustum.
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core::vector3df getFarLeftDown() const;
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//! returns the point which is on the far right top corner inside the the view frustum.
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core::vector3df getFarRightUp() const;
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//! returns the point which is on the far right bottom corner inside the the view frustum.
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core::vector3df getFarRightDown() const;
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//! returns the point which is on the near left upper corner inside the the view frustum.
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core::vector3df getNearLeftUp() const;
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//! returns the point which is on the near left bottom corner inside the the view frustum.
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core::vector3df getNearLeftDown() const;
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//! returns the point which is on the near right top corner inside the the view frustum.
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core::vector3df getNearRightUp() const;
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//! returns the point which is on the near right bottom corner inside the the view frustum.
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core::vector3df getNearRightDown() const;
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//! returns a bounding box enclosing the whole view frustum
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const core::aabbox3d<f32> &getBoundingBox() const;
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//! recalculates the bounding box and sphere based on the planes
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inline void recalculateBoundingBox();
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//! get the bounding sphere's radius (of an optimized sphere, not the AABB's)
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float getBoundingRadius() const;
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//! get the bounding sphere's radius (of an optimized sphere, not the AABB's)
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core::vector3df getBoundingCenter() const;
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//! the cam should tell the frustum the distance between far and near
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void setFarNearDistance(float distance);
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//! get the given state's matrix based on frustum E_TRANSFORMATION_STATE
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core::matrix4 &getTransform(video::E_TRANSFORMATION_STATE state);
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//! get the given state's matrix based on frustum E_TRANSFORMATION_STATE
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const core::matrix4 &getTransform(video::E_TRANSFORMATION_STATE state) const;
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//! clips a line to the view frustum.
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/** \return True if the line was clipped, false if not */
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bool clipLine(core::line3d<f32> &line) const;
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//! the position of the camera
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core::vector3df cameraPosition;
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//! all planes enclosing the view frustum.
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core::plane3d<f32> planes[VF_PLANE_COUNT];
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//! bounding box around the view frustum
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core::aabbox3d<f32> boundingBox;
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private:
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//! Hold a copy of important transform matrices
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enum E_TRANSFORMATION_STATE_FRUSTUM
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{
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ETS_VIEW = 0,
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ETS_PROJECTION = 1,
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ETS_COUNT_FRUSTUM
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};
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//! recalculates the bounding sphere based on the planes
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inline void recalculateBoundingSphere();
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//! Hold a copy of important transform matrices
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core::matrix4 Matrices[ETS_COUNT_FRUSTUM];
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float BoundingRadius;
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float FarNearDistance;
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core::vector3df BoundingCenter;
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};
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/*!
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Copy constructor ViewFrustum
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*/
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inline SViewFrustum::SViewFrustum(const SViewFrustum &other)
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{
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cameraPosition = other.cameraPosition;
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boundingBox = other.boundingBox;
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u32 i;
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for (i = 0; i < VF_PLANE_COUNT; ++i)
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planes[i] = other.planes[i];
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for (i = 0; i < ETS_COUNT_FRUSTUM; ++i)
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Matrices[i] = other.Matrices[i];
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BoundingRadius = other.BoundingRadius;
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FarNearDistance = other.FarNearDistance;
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BoundingCenter = other.BoundingCenter;
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}
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inline SViewFrustum::SViewFrustum(const core::matrix4 &mat, bool zClipFromZero)
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{
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setFrom(mat, zClipFromZero);
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}
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inline void SViewFrustum::transform(const core::matrix4 &mat)
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{
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for (u32 i = 0; i < VF_PLANE_COUNT; ++i)
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mat.transformPlane(planes[i]);
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mat.transformVect(cameraPosition);
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recalculateBoundingBox();
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}
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inline core::vector3df SViewFrustum::getFarLeftUp() const
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{
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core::vector3df p;
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planes[scene::SViewFrustum::VF_FAR_PLANE].getIntersectionWithPlanes(
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planes[scene::SViewFrustum::VF_TOP_PLANE],
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planes[scene::SViewFrustum::VF_LEFT_PLANE], p);
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return p;
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}
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inline core::vector3df SViewFrustum::getFarLeftDown() const
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{
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core::vector3df p;
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planes[scene::SViewFrustum::VF_FAR_PLANE].getIntersectionWithPlanes(
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planes[scene::SViewFrustum::VF_BOTTOM_PLANE],
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planes[scene::SViewFrustum::VF_LEFT_PLANE], p);
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return p;
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}
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inline core::vector3df SViewFrustum::getFarRightUp() const
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{
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core::vector3df p;
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planes[scene::SViewFrustum::VF_FAR_PLANE].getIntersectionWithPlanes(
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planes[scene::SViewFrustum::VF_TOP_PLANE],
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planes[scene::SViewFrustum::VF_RIGHT_PLANE], p);
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return p;
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}
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inline core::vector3df SViewFrustum::getFarRightDown() const
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{
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core::vector3df p;
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planes[scene::SViewFrustum::VF_FAR_PLANE].getIntersectionWithPlanes(
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planes[scene::SViewFrustum::VF_BOTTOM_PLANE],
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planes[scene::SViewFrustum::VF_RIGHT_PLANE], p);
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return p;
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}
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inline core::vector3df SViewFrustum::getNearLeftUp() const
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{
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core::vector3df p;
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planes[scene::SViewFrustum::VF_NEAR_PLANE].getIntersectionWithPlanes(
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planes[scene::SViewFrustum::VF_TOP_PLANE],
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planes[scene::SViewFrustum::VF_LEFT_PLANE], p);
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return p;
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}
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inline core::vector3df SViewFrustum::getNearLeftDown() const
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{
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core::vector3df p;
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planes[scene::SViewFrustum::VF_NEAR_PLANE].getIntersectionWithPlanes(
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planes[scene::SViewFrustum::VF_BOTTOM_PLANE],
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planes[scene::SViewFrustum::VF_LEFT_PLANE], p);
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return p;
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}
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inline core::vector3df SViewFrustum::getNearRightUp() const
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{
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core::vector3df p;
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planes[scene::SViewFrustum::VF_NEAR_PLANE].getIntersectionWithPlanes(
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planes[scene::SViewFrustum::VF_TOP_PLANE],
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planes[scene::SViewFrustum::VF_RIGHT_PLANE], p);
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return p;
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}
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inline core::vector3df SViewFrustum::getNearRightDown() const
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{
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core::vector3df p;
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planes[scene::SViewFrustum::VF_NEAR_PLANE].getIntersectionWithPlanes(
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planes[scene::SViewFrustum::VF_BOTTOM_PLANE],
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planes[scene::SViewFrustum::VF_RIGHT_PLANE], p);
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return p;
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}
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inline const core::aabbox3d<f32> &SViewFrustum::getBoundingBox() const
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{
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return boundingBox;
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}
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inline void SViewFrustum::recalculateBoundingBox()
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{
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boundingBox.reset(getNearLeftUp());
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boundingBox.addInternalPoint(getNearRightUp());
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boundingBox.addInternalPoint(getNearLeftDown());
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boundingBox.addInternalPoint(getNearRightDown());
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boundingBox.addInternalPoint(getFarRightUp());
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boundingBox.addInternalPoint(getFarLeftDown());
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boundingBox.addInternalPoint(getFarRightDown());
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boundingBox.addInternalPoint(getFarLeftUp());
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// Also recalculate the bounding sphere when the bbox changes
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recalculateBoundingSphere();
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}
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inline float SViewFrustum::getBoundingRadius() const
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{
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return BoundingRadius;
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}
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inline core::vector3df SViewFrustum::getBoundingCenter() const
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{
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return BoundingCenter;
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}
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inline void SViewFrustum::setFarNearDistance(float distance)
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{
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FarNearDistance = distance;
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}
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//! This constructor creates a view frustum based on a projection
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//! and/or view matrix.
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inline void SViewFrustum::setFrom(const core::matrix4 &mat, bool zClipFromZero)
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{
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// left clipping plane
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planes[VF_LEFT_PLANE].Normal.X = mat[3] + mat[0];
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planes[VF_LEFT_PLANE].Normal.Y = mat[7] + mat[4];
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planes[VF_LEFT_PLANE].Normal.Z = mat[11] + mat[8];
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planes[VF_LEFT_PLANE].D = mat[15] + mat[12];
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// right clipping plane
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planes[VF_RIGHT_PLANE].Normal.X = mat[3] - mat[0];
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planes[VF_RIGHT_PLANE].Normal.Y = mat[7] - mat[4];
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planes[VF_RIGHT_PLANE].Normal.Z = mat[11] - mat[8];
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planes[VF_RIGHT_PLANE].D = mat[15] - mat[12];
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// top clipping plane
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planes[VF_TOP_PLANE].Normal.X = mat[3] - mat[1];
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planes[VF_TOP_PLANE].Normal.Y = mat[7] - mat[5];
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planes[VF_TOP_PLANE].Normal.Z = mat[11] - mat[9];
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planes[VF_TOP_PLANE].D = mat[15] - mat[13];
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// bottom clipping plane
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planes[VF_BOTTOM_PLANE].Normal.X = mat[3] + mat[1];
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planes[VF_BOTTOM_PLANE].Normal.Y = mat[7] + mat[5];
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planes[VF_BOTTOM_PLANE].Normal.Z = mat[11] + mat[9];
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planes[VF_BOTTOM_PLANE].D = mat[15] + mat[13];
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// far clipping plane
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planes[VF_FAR_PLANE].Normal.X = mat[3] - mat[2];
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planes[VF_FAR_PLANE].Normal.Y = mat[7] - mat[6];
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planes[VF_FAR_PLANE].Normal.Z = mat[11] - mat[10];
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planes[VF_FAR_PLANE].D = mat[15] - mat[14];
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// near clipping plane
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if (zClipFromZero) {
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planes[VF_NEAR_PLANE].Normal.X = mat[2];
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planes[VF_NEAR_PLANE].Normal.Y = mat[6];
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planes[VF_NEAR_PLANE].Normal.Z = mat[10];
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planes[VF_NEAR_PLANE].D = mat[14];
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} else {
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// near clipping plane
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planes[VF_NEAR_PLANE].Normal.X = mat[3] + mat[2];
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planes[VF_NEAR_PLANE].Normal.Y = mat[7] + mat[6];
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planes[VF_NEAR_PLANE].Normal.Z = mat[11] + mat[10];
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planes[VF_NEAR_PLANE].D = mat[15] + mat[14];
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}
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// normalize normals
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u32 i;
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for (i = 0; i != VF_PLANE_COUNT; ++i) {
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const f32 len = -core::reciprocal_squareroot(
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planes[i].Normal.getLengthSQ());
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planes[i].Normal *= len;
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planes[i].D *= len;
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}
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// make bounding box
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recalculateBoundingBox();
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}
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/*!
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View Frustum depends on Projection & View Matrix
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*/
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inline core::matrix4 &SViewFrustum::getTransform(video::E_TRANSFORMATION_STATE state)
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{
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u32 index = 0;
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switch (state) {
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case video::ETS_PROJECTION:
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index = SViewFrustum::ETS_PROJECTION;
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break;
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case video::ETS_VIEW:
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index = SViewFrustum::ETS_VIEW;
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break;
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default:
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break;
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}
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return Matrices[index];
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}
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/*!
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View Frustum depends on Projection & View Matrix
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*/
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inline const core::matrix4 &SViewFrustum::getTransform(video::E_TRANSFORMATION_STATE state) const
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{
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u32 index = 0;
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switch (state) {
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case video::ETS_PROJECTION:
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index = SViewFrustum::ETS_PROJECTION;
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break;
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case video::ETS_VIEW:
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index = SViewFrustum::ETS_VIEW;
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break;
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default:
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break;
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}
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return Matrices[index];
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}
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//! Clips a line to the frustum
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inline bool SViewFrustum::clipLine(core::line3d<f32> &line) const
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{
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bool wasClipped = false;
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for (u32 i = 0; i < VF_PLANE_COUNT; ++i) {
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if (planes[i].classifyPointRelation(line.start) == core::ISREL3D_FRONT) {
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line.start = line.start.getInterpolated(line.end,
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1.f - planes[i].getKnownIntersectionWithLine(line.start, line.end));
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wasClipped = true;
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}
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if (planes[i].classifyPointRelation(line.end) == core::ISREL3D_FRONT) {
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line.end = line.start.getInterpolated(line.end,
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1.f - planes[i].getKnownIntersectionWithLine(line.start, line.end));
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wasClipped = true;
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}
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}
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return wasClipped;
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}
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inline void SViewFrustum::recalculateBoundingSphere()
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{
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// Find the center
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const float shortlen = (getNearLeftUp() - getNearRightUp()).getLength();
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const float longlen = (getFarLeftUp() - getFarRightUp()).getLength();
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const float farlen = FarNearDistance;
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const float fartocenter = (farlen + (shortlen - longlen) * (shortlen + longlen) / (4 * farlen)) / 2;
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const float neartocenter = farlen - fartocenter;
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BoundingCenter = cameraPosition + -planes[VF_NEAR_PLANE].Normal * neartocenter;
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// Find the radius
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core::vector3df dir[8];
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dir[0] = getFarLeftUp() - BoundingCenter;
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dir[1] = getFarRightUp() - BoundingCenter;
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dir[2] = getFarLeftDown() - BoundingCenter;
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dir[3] = getFarRightDown() - BoundingCenter;
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dir[4] = getNearRightDown() - BoundingCenter;
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dir[5] = getNearLeftDown() - BoundingCenter;
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dir[6] = getNearRightUp() - BoundingCenter;
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dir[7] = getNearLeftUp() - BoundingCenter;
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u32 i = 0;
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float diam[8] = {0.f};
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for (i = 0; i < 8; ++i)
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diam[i] = dir[i].getLengthSQ();
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float longest = 0;
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for (i = 0; i < 8; ++i) {
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if (diam[i] > longest)
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longest = diam[i];
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}
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BoundingRadius = sqrtf(longest);
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}
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} // end namespace scene
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} // end namespace irr
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