Source/System/Window/Camera/OSGOffCenterPerspectiveCamera.cpp

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  37 \*---------------------------------------------------------------------------*/
  38
  39 //---------------------------------------------------------------------------
  40 //  Includes
  41 //---------------------------------------------------------------------------
  42
  43 #include <stdlib.h>
  44 #include <stdio.h>
  45 #include <math.h>
  46
  47 #include "OSGMatrixUtility.h"
  48 #include "OSGOffCenterPerspectiveCamera.h"
  49
  50 OSG_USING_NAMESPACE
  51
  52
  53 /***************************************************************************\
  54  *                            Description                                  *
  55 \***************************************************************************/
  56
  57 /*! \class OSG::OffCenterPerspectiveCamera
  58     \ingroup GrpSystemWindowCameras
  59
  60 The OffCenter Perspective Camera class.
  61
  62 The only new parameter is the _sfPrincipalPoint field.
  63
  64 The OffCenter Perspective Camera provides a more general camera than the
  65 Perspective Camera.
  66 The viewing frustrum is by default the same as given by the Perspective
  67 Camera.
  68 Iff principal points params are unequal zero the viewing frustrums parameters
  69 (left,right,top,bottom) are simple shifted in the camera's image plane.
  70 The principal point parameters are relative to left--right (or respectively
  71 bottom--top).
  72 A value of x=2 means the left value is equal to default
  73 right value.
  74 A value of x=-2 means the right value is equal to default
  75 left value.
  76 Marginal note: Iff the principal point is unequal zero the field of view
  77 value is unequal to the real field of view of the camera.
  78 (mail to: dherzog (at) mip.informatik.uni-kiel.de)
  79 */
  80
  81 /***************************************************************************\
  82  *                           Class methods                                 *
  83 \***************************************************************************/
  84
  85 /*-------------------------------------------------------------------------*\
  86  -  private                                                                -
  87 \*-------------------------------------------------------------------------*/
  88
  89 void OffCenterPerspectiveCamera::initMethod(InitPhase ePhase)
  90 {
  91     Inherited::initMethod(ePhase);
  92 }
  93
  94 /***************************************************************************\
  95  *                           Instance methods                              *
  96 \***************************************************************************/
  97
  98 /*-------------------------------------------------------------------------*\
  99  -  public                                                                 -
 100 \*-------------------------------------------------------------------------*/
 101
 102
 103 /*------------- constructors & destructors --------------------------------*/
 104
 105 OffCenterPerspectiveCamera::OffCenterPerspectiveCamera(void) :
 106     Inherited()
 107 {
 108 }
 109
 110 OffCenterPerspectiveCamera::OffCenterPerspectiveCamera(
 111     const OffCenterPerspectiveCamera &source) :
 112
 113     Inherited(source)
 114 {
 115 }
 116
 117 OffCenterPerspectiveCamera::~OffCenterPerspectiveCamera(void)
 118 {
 119 }
 120
 121 void OffCenterPerspectiveCamera::changed(ConstFieldMaskArg whichField,
 122                                          UInt32            origin,
 123                                          BitVector         details)
 124 {
 125     Inherited::changed(whichField, origin, details);
 126 }
 127
 128 /*-------------------------- your_category---------------------------------*/
 129
 130
 131 void OffCenterPerspectiveCamera::getProjection(Matrix &result,
 132                                                UInt32  width,
 133                                                UInt32  height)
 134 {
 135     Real32 fov = getFov();
 136
 137     // catch some illegal cases
 138     if(fov < 0 || width == 0 || height == 0)
 139     {
 140         result.setIdentity();
 141         return;
 142     }
 143
 144     // try to be nice to people giving degrees...
 145     if(fov > Pi)
 146         fov = osgDegree2Rad(fov);
 147
 148
 149     Real32 rNear  = getNear();
 150     Real32 rFar   = getFar();
 151     Real32 aspect = Real32(width) / Real32(height) * getAspect();
 152     Real32 ct     = osgTan(fov / 2.f);
 153
 154     if(rNear > rFar)
 155     {
 156         SWARNING << "MatrixPerspective: near " << rNear << " > far " << rFar
 157                  << "!\n" << std::endl;
 158         result.setIdentity();
 159         return;
 160     }
 161
 162     if(fov <= TypeTraits<Real32>::getDefaultEps())
 163     {
 164         SWARNING << "MatrixPerspective: fov " << fov << " very small!\n"
 165                  << std::endl;
 166         result.setIdentity();
 167         return;
 168     }
 169
 170     if(osgAbs(rNear - rFar) < TypeTraits<Real32>::getDefaultEps())
 171     {
 172         SWARNING << "MatrixPerspective: near " << rNear << " ~= far " << rFar
 173                  << "!\n" << std::endl;
 174         result.setIdentity();
 175         return;
 176     }
 177
 178     if(aspect < TypeTraits<Real32>::getDefaultEps())
 179     {
 180         SWARNING << "MatrixPerspective: aspect ratio " << aspect
 181                  << " very small!\n" << std::endl;
 182         result.setIdentity();
 183         return;
 184     }
 185
 186     Real32 x       = ct * rNear;
 187     Real32 y       = ct * rNear;
 188     UInt32 fovMode = getFovMode();
 189
 190     switch (fovMode)
 191     {
 192         case VerticalFoV:
 193             x *= aspect;
 194             break;
 195
 196         case HorizontalFoV:
 197             y /= aspect;
 198             break;
 199
 200         case SmallerFoV:
 201             if(width * getAspect() >= height)
 202             {
 203                 x *= aspect;
 204             }
 205             else
 206             {
 207                 y /= aspect;
 208             }
 209             break;
 210
 211         default:
 212             result.setIdentity();
 213             return;
 214     }
 215
 216     Real32 principalPointX = getPrincipalPoint()[0];
 217     Real32 principalPointY = getPrincipalPoint()[1];
 218
 219     // if principal point (x,y) is default (==(0,0)) everything works
 220     // like before or rather for an symmetical camera
 221     if ((principalPointX == 0.f) && (principalPointY == 0.f))
 222     {
 223         MatrixFrustum( result,
 224                       -x,
 225                        x,
 226                       -y,
 227                        y,
 228                        rNear,
 229                        rFar);
 230     }
 231     else
 232     {
 233         MatrixFrustum( result,
 234                       -x * (1.f + principalPointX),
 235                        x * (1.f - principalPointX),
 236                       -y * (1.f + principalPointY),
 237                        y * (1.f - principalPointY),
 238                        rNear,
 239                        rFar);
 240     }
 241 }
 242
 243
 244 /*------------------------------- dump ----------------------------------*/
 245
 246 void OffCenterPerspectiveCamera::dump(
 247           UInt32    OSG_CHECK_ARG(uiIndent),
 248     const BitVector OSG_CHECK_ARG(bvFlags)) const
 249 {
 250     SLOG << "Dump OffCenterPerspectiveCamera NI" << std::endl;
 251 }
 252
 253