git-svn-id: svn://svn.code.sf.net/p/irrlicht/code/trunk@6000 dfc29bdd-3216-0410-991c-e03cc46cb475
		
			
				
	
	
		
			463 lines
		
	
	
		
			14 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
			
		
		
	
	
			463 lines
		
	
	
		
			14 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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| 
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| #ifndef __S_VIEW_FRUSTUM_H_INCLUDED__
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| #define __S_VIEW_FRUSTUM_H_INCLUDED__
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| 
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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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| 
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| namespace irr
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| {
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| namespace scene
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| {
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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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| 
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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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| 
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| 
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| 		//! Default Constructor
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| 		SViewFrustum() : BoundingRadius(0.f), FarNearDistance(0.f) {}
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| 
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| 		//! Copy Constructor
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| 		SViewFrustum(const SViewFrustum& other);
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| 
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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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| 
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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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| 
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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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| 
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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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| 
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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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| 
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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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| 
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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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| 
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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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| 
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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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| 
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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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| 
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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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| 
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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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| 
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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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| 
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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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| 
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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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| 
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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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| 
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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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| 
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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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| 
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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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| 
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| 		//! the position of the camera
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| 		core::vector3df cameraPosition;
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| 
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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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| 
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| 		//! bounding box around the view frustum
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| 		core::aabbox3d<f32> boundingBox;
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| 
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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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| 
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| 		//! recalculates the bounding sphere based on the planes
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| 		inline void recalculateBoundingSphere();
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| 
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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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| 
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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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| 
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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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| 
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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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| 
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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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| 
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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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| 
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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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| 
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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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| 
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| 		mat.transformVect(cameraPosition);
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| 		recalculateBoundingBox();
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| 	}
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| 
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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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| 
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| 		return p;
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| 	}
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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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| 
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| 		return p;
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| 	}
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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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| 
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| 		return p;
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| 	}
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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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| 
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| 		return p;
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| 	}
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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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| 
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| 		return p;
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| 	}
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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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| 
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| 		return p;
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| 	}
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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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| 
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| 		return p;
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| 	}
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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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| 
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| 		return p;
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| 	}
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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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| 
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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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| 
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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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| 
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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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| 
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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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| 
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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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| 
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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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| 
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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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| 
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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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| 
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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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| 
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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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| 
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| 		// near clipping plane
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| 		if ( zClipFromZero )
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| 		{
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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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| 		}
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| 		else
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| 		{
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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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| 
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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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| 		{
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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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| 
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| 		// make bounding box
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| 		recalculateBoundingBox();
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| 	}
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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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| 		{
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| 			case video::ETS_PROJECTION:
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| 				index = SViewFrustum::ETS_PROJECTION; break;
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| 			case video::ETS_VIEW:
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| 				index = SViewFrustum::ETS_VIEW; 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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| 	/*!
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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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| 		{
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| 			case video::ETS_PROJECTION:
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| 				index = SViewFrustum::ETS_PROJECTION; break;
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| 			case video::ETS_VIEW:
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| 				index = SViewFrustum::ETS_VIEW; 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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| 	//! 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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| 		{
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| 			if (planes[i].classifyPointRelation(line.start) == core::ISREL3D_FRONT)
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| 			{
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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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| 			{
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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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| 
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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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| 
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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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| 
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| 		BoundingCenter = cameraPosition + -planes[VF_NEAR_PLANE].Normal * neartocenter;
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| 
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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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| 
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| 		u32 i = 0;
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| 		float diam[8] = { 0.f };
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| 
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| 		for (i = 0; i < 8; ++i)
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| 			diam[i] = dir[i].getLengthSQ();
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| 
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| 		float longest = 0;
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| 
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| 		for (i = 0; i < 8; ++i)
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| 		{
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| 			if (diam[i] > longest)
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| 				longest = diam[i];
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| 		}
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| 
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| 		BoundingRadius = sqrtf(longest);
 | |
| 	}
 | |
| 
 | |
| } // end namespace scene
 | |
| } // end namespace irr
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| 
 | |
| #endif
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| 
 |