/** \brief Create a view from imageNum of the provided file.
*
* \param file - file from which to read the image data.
* \param imageNum - subimage number for this view in the input file
* \param currToWorld - current -> world transformation matrix.
*/
CqShadowView(const boost::shared_ptr<IqTiledTexInputFile>& file, TqInt imageNum,
const CqMatrix& currToWorld)
: m_currToLight(),
m_currToRaster(),
m_currToRasterVec(),
m_viewDirec(),
m_pixels(file, imageNum)
{
// TODO refactor with CqShadowSampler, also refactor this function,
// since it's a bit unweildly...
if(!file)
AQSIS_THROW_XQERROR(XqInternal, EqE_NoFile,
"Cannot construct shadow map from NULL file handle");
const CqTexFileHeader& header = file->header(imageNum);
if(header.channelList().sharedChannelType() != Channel_Float32)
AQSIS_THROW_XQERROR(XqBadTexture, EqE_BadFile,
"Shadow maps must hold 32-bit floating point data");
// Get matrix which transforms the sample points to the light
// camera coordinates.
const CqMatrix* worldToLight
= header.findPtr<Attr::WorldToCameraMatrix>();
if(!worldToLight)
{
AQSIS_THROW_XQERROR(XqBadTexture, EqE_BadFile,
"No world -> camera matrix found in file \""
<< file->fileName() << "\"");
}
m_currToLight = (*worldToLight) * currToWorld;
// Get matrix which transforms the sample points to texture coordinates.
const CqMatrix* worldToLightScreen
= header.findPtr<Attr::WorldToScreenMatrix>();
if(!worldToLightScreen)
{
AQSIS_THROW_XQERROR(XqBadTexture, EqE_BadFile,
"No world -> screen matrix found in file \""
<< file->fileName() << "\"");
}
m_currToRaster = (*worldToLightScreen) * currToWorld;
// worldToLightScreen transforms world coordinates to "screen" coordinates,
// ie, onto the 2D box [-1,1]x[-1,1]. We instead want texture coordinates,
// which correspond to the box [0,width]x[0,height]. In
// addition, the direction of increase of the y-axis should be
// swapped, since texture coordinates define the origin to be in
// the top left of the texture rather than the bottom right.
m_currToRaster.Translate(CqVector3D(1,-1,0));
m_currToRaster.Scale(0.5f, -0.5f, 1);
// Transform the light origin to "current" space to use
// when checking the visibility of a point.
m_lightPos = m_currToLight.Inverse()*CqVector3D(0,0,0);
// Transform the normal (0,0,1) in light space into a normal in
// "current" space. The appropriate matrix is the inverse of the
// cam -> light normal transformation, which itself is the inverse
// transpose of currToLightVec.
CqMatrix currToLightVec = m_currToLight;
currToLightVec[3][0] = 0;
currToLightVec[3][1] = 0;
currToLightVec[3][2] = 0;
m_viewDirec = currToLightVec.Transpose()*CqVector3D(0,0,1);
m_viewDirec.Unit();
}
/** \brief Create a view from imageNum of the provided file.
*
* \param file - file from which to read the image data.
* \param imageNum - subimage number for this view in the input file
* \param currToWorld - current -> world transformation matrix.
*/
CqOccView(const boost::shared_ptr<IqTiledTexInputFile>& file, TqInt imageNum,
const CqMatrix& currToWorld)
: m_currToLight(),
m_currToRaster(),
m_currToRasterVec(),
m_negViewDirec(),
m_pixels(file, imageNum)
{
// TODO refactor with CqShadowSampler, also refactor this function,
// since it's a bit unweildly...
if(!file)
AQSIS_THROW_XQERROR(XqInternal, EqE_NoFile,
"Cannot construct shadow map from NULL file handle");
const CqTexFileHeader& header = file->header(imageNum);
if(header.channelList().sharedChannelType() != Channel_Float32)
AQSIS_THROW_XQERROR(XqBadTexture, EqE_BadFile,
"Shadow maps must hold 32-bit floating point data");
// Get matrix which transforms the sample points to the light
// camera coordinates.
const CqMatrix* worldToLight
= header.findPtr<Attr::WorldToCameraMatrix>();
if(!worldToLight)
{
AQSIS_THROW_XQERROR(XqBadTexture, EqE_BadFile,
"No world -> camera matrix found in file \""
<< file->fileName() << "\"");
}
m_currToLight = (*worldToLight) * currToWorld;
// Get matrix which transforms the sample points to texture coordinates.
const CqMatrix* worldToLightScreen
= header.findPtr<Attr::WorldToScreenMatrix>();
if(!worldToLightScreen)
{
AQSIS_THROW_XQERROR(XqBadTexture, EqE_BadFile,
"No world -> screen matrix found in file \""
<< file->fileName() << "\"");
}
m_currToRaster = (*worldToLightScreen) * currToWorld;
// worldToLightScreen transforms world coordinates to "screen" coordinates,
// ie, onto the 2D box [-1,1]x[-1,1]. We instead want texture coordinates,
// which correspond to the box [0,width]x[0,height]. In
// addition, the direction of increase of the y-axis should be
// swapped, since texture coordinates define the origin to be in
// the top left of the texture rather than the bottom right.
m_currToRaster.Translate(CqVector3D(1,-1,0));
m_currToRaster.Scale(0.5f*header.width(), -0.5f*header.height(), 1);
// This extra translation is by half a pixel width - it moves the
// raster coordinates
m_currToRaster.Translate(CqVector3D(-0.5,-0.5,0));
// Convert current -> texture transformation into a vector
// transform rather than a point transform.
// TODO: Put this stuff into the CqMatrix class?
m_currToRasterVec = m_currToRaster;
m_currToRasterVec[3][0] = 0;
m_currToRasterVec[3][1] = 0;
m_currToRasterVec[3][2] = 0;
// This only really makes sense when the matrix is affine rather
// than projective, ie, the last column is (0,0,0,h)
//
// TODO: Investigate whether this is really correct.
// assert(m_currToRasterVec[0][3] == 0);
// assert(m_currToRasterVec[1][3] == 0);
// assert(m_currToRasterVec[2][3] == 0);
m_currToRasterVec[0][3] = 0;
m_currToRasterVec[1][3] = 0;
m_currToRasterVec[2][3] = 0;
// Transform the normal (0,0,1) in light space into a normal in
// "current" space. The appropriate matrix is the inverse of the
// cam -> light normal transformation, which itself is the inverse
// transpose of currToLightVec.
CqMatrix currToLightVec = m_currToLight;
currToLightVec[3][0] = 0;
currToLightVec[3][1] = 0;
currToLightVec[3][2] = 0;
m_negViewDirec = currToLightVec.Transpose()*CqVector3D(0,0,-1);
m_negViewDirec.Unit();
}
