1 /*
2 -----------------------------------------------------------------------------
3 This source file is part of OGRE
4 (Object-oriented Graphics Rendering Engine)
5 For the latest info, see http://www.ogre3d.org/
6 
7 Copyright (c) 2000-2013 Torus Knot Software Ltd
8 Copyright (c) 2006 Matthias Fink, netAllied GmbH <matthias.fink@web.de>
9 
10 Permission is hereby granted, free of charge, to any person obtaining a copy
11 of this software and associated documentation files (the "Software"), to deal
12 in the Software without restriction, including without limitation the rights
13 to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
14 copies of the Software, and to permit persons to whom the Software is
15 furnished to do so, subject to the following conditions:
16 
17 The above copyright notice and this permission notice shall be included in
18 all copies or substantial portions of the Software.
19 
20 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
21 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
22 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
23 AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
24 LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
25 OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
26 THE SOFTWARE.
27 -----------------------------------------------------------------------------
28 */
29 
30 #include "OgreStableHeaders.h"
31 #include "OgreShadowCameraSetupPSSM.h"
32 #include "OgreSceneManager.h"
33 #include "OgreCamera.h"
34 
35 namespace Ogre
36 {
37 	//---------------------------------------------------------------------
PSSMShadowCameraSetup()38 	PSSMShadowCameraSetup::PSSMShadowCameraSetup()
39 		: mSplitPadding(1.0f), mCurrentIteration(0)
40 	{
41 		calculateSplitPoints(3, 100, 100000);
42 		setOptimalAdjustFactor(0, 5);
43 		setOptimalAdjustFactor(1, 1);
44 		setOptimalAdjustFactor(2, 0);
45 
46 
47 	}
48 	//---------------------------------------------------------------------
~PSSMShadowCameraSetup()49 	PSSMShadowCameraSetup::~PSSMShadowCameraSetup()
50 	{
51 	}
52 	//---------------------------------------------------------------------
calculateSplitPoints(uint splitCount,Real nearDist,Real farDist,Real lambda)53 	void PSSMShadowCameraSetup::calculateSplitPoints(uint splitCount, Real nearDist, Real farDist, Real lambda)
54 	{
55 		if (splitCount < 2)
56 			OGRE_EXCEPT(Exception::ERR_INVALIDPARAMS, "Cannot specify less than 2 splits",
57 			"PSSMShadowCameraSetup::calculateSplitPoints");
58 
59 		mSplitPoints.resize(splitCount + 1);
60 		mOptimalAdjustFactors.resize(splitCount);
61 		mSplitCount = splitCount;
62 
63 		mSplitPoints[0] = nearDist;
64 		for (size_t i = 1; i < mSplitCount; i++)
65 		{
66 			Real fraction = (Real)i / (Real)mSplitCount;
67 			Real splitPoint = lambda * nearDist * Math::Pow(farDist / nearDist, fraction) +
68 				(1.0f - lambda) * (nearDist + fraction * (farDist - nearDist));
69 
70 			mSplitPoints[i] = splitPoint;
71 		}
72 		mSplitPoints[splitCount] = farDist;
73 
74 	}
75 	//---------------------------------------------------------------------
setSplitPoints(const SplitPointList & newSplitPoints)76 	void PSSMShadowCameraSetup::setSplitPoints(const SplitPointList& newSplitPoints)
77 	{
78 		if (newSplitPoints.size() < 3) // 3, not 2 since splits + 1 points
79 			OGRE_EXCEPT(Exception::ERR_INVALIDPARAMS, "Cannot specify less than 2 splits",
80 			"PSSMShadowCameraSetup::setSplitPoints");
81 		mSplitCount = static_cast<uint>(newSplitPoints.size() - 1);
82 		mSplitPoints = newSplitPoints;
83 		mOptimalAdjustFactors.resize(mSplitCount);
84 	}
85 	//---------------------------------------------------------------------
setOptimalAdjustFactor(size_t splitIndex,Real factor)86 	void PSSMShadowCameraSetup::setOptimalAdjustFactor(size_t splitIndex, Real factor)
87 	{
88 		if (splitIndex >= mOptimalAdjustFactors.size())
89 			OGRE_EXCEPT(Exception::ERR_INVALIDPARAMS, "Split index out of range",
90 			"PSSMShadowCameraSetup::setOptimalAdjustFactor");
91 		mOptimalAdjustFactors[splitIndex] = factor;
92 
93 	}
94 	//---------------------------------------------------------------------
getOptimalAdjustFactor() const95 	Real PSSMShadowCameraSetup::getOptimalAdjustFactor() const
96 	{
97 		// simplifies the overriding of the LiSPSM opt adjust factor use
98 		return mOptimalAdjustFactors[mCurrentIteration];
99 	}
100 	//---------------------------------------------------------------------
getShadowCamera(const Ogre::SceneManager * sm,const Ogre::Camera * cam,const Ogre::Viewport * vp,const Ogre::Light * light,Ogre::Camera * texCam,size_t iteration) const101 	void PSSMShadowCameraSetup::getShadowCamera(const Ogre::SceneManager *sm, const Ogre::Camera *cam,
102 		const Ogre::Viewport *vp, const Ogre::Light *light, Ogre::Camera *texCam, size_t iteration) const
103 	{
104 		// apply the right clip distance.
105 		Real nearDist = mSplitPoints[iteration];
106 		Real farDist = mSplitPoints[iteration + 1];
107 
108 		// Add a padding factor to internal distances so that the connecting split point will not have bad artifacts.
109 		if (iteration > 0)
110 		{
111 			nearDist -= mSplitPadding;
112 		}
113 		if (iteration < mSplitCount - 1)
114 		{
115 			farDist += mSplitPadding;
116 		}
117 
118 		mCurrentIteration = iteration;
119 
120 		// Ouch, I know this is hacky, but it's the easiest way to re-use LiSPSM / Focused
121 		// functionality right now without major changes
122 		Camera* _cam = const_cast<Camera*>(cam);
123 		Real oldNear = _cam->getNearClipDistance();
124 		Real oldFar = _cam->getFarClipDistance();
125 		_cam->setNearClipDistance(nearDist);
126 		_cam->setFarClipDistance(farDist);
127 
128 		LiSPSMShadowCameraSetup::getShadowCamera(sm, cam, vp, light, texCam, iteration);
129 
130 		// restore near/far
131 		_cam->setNearClipDistance(oldNear);
132 		_cam->setFarClipDistance(oldFar);
133 
134 
135 	}
136 }
137