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From Jan Peciva, "attaching Matrix_implementation fix for two problems:

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- using m.getPerspective( fovy, tmp, tmp, tmp ) to get only FOV does not work.
The reason is that getPerspective is taking tmp as reference - thus all the three variables points to the same memory location. Then, zNear (third parameter) is used inside the method, while zNear content was spoiled by zFar that was written to the same place, resulting in fovy set to nan. I consider that it is the right of programmers to use 3 times tmp as parameter and I fixed the code in the method. I have done the same for getFrustum and getLookAt.

- I fixed makeFrustum to accept infinite zFar. (Some graphics techniques like shadow volumes require placing zFar to infinity to avoid visual artifacts.)"

Note from Robert Osfield, change the local near & far variable names to temp_near and temp_far MS Visual Studio has a record of using near and far names.
This commit is contained in:
Robert Osfield
2010-11-01 13:57:44 +00:00
parent 2ce4b9d8e9
commit fb4d6b16f9
1 changed files with 51 additions and 22 deletions
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73
src/osg/Matrix_implementation.cpp
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@@ -20,6 +20,7 @@
#include <limits>
#include <stdlib.h>
#include <float.h>
using namespace osg;
@@ -848,8 +849,8 @@ void Matrix_implementation::makeFrustum(double left, double right,
// note transpose of Matrix_implementation wr.t OpenGL documentation, since the OSG use post multiplication rather than pre.
double A = (right+left)/(right-left);
double B = (top+bottom)/(top-bottom);
double C = -(zFar+zNear)/(zFar-zNear);
double D = -2.0*zFar*zNear/(zFar-zNear);
double C = (fabs(zFar)>DBL_MAX) ? -1. : -(zFar+zNear)/(zFar-zNear);
double D = (fabs(zFar)>DBL_MAX) ? -2.*zNear : -2.0*zFar*zNear/(zFar-zNear);
SET_ROW(0, 2.0*zNear/(right-left), 0.0, 0.0, 0.0 )
SET_ROW(1, 0.0, 2.0*zNear/(top-bottom), 0.0, 0.0 )
SET_ROW(2, A, B, C, -1.0 )
@@ -860,18 +861,23 @@ bool Matrix_implementation::getFrustum(double& left, double& right,
double& bottom, double& top,
double& zNear, double& zFar) const
{
if (_mat[0][3]!=0.0 || _mat[1][3]!=0.0 || _mat[2][3]!=-1.0 || _mat[3][3]!=0.0) return false;
if (_mat[0][3]!=0.0 || _mat[1][3]!=0.0 || _mat[2][3]!=-1.0 || _mat[3][3]!=0.0)
return false;
// note: near and far must be used inside this method instead of zNear and zFar
// because zNear and zFar are references and they may point to the same variable.
double temp_near = _mat[3][2] / (_mat[2][2]-1.0);
double temp_far = _mat[3][2] / (1.0+_mat[2][2]);
zNear = _mat[3][2] / (_mat[2][2]-1.0);
zFar = _mat[3][2] / (1.0+_mat[2][2]);
left = temp_near * (_mat[2][0]-1.0) / _mat[0][0];
right = temp_near * (1.0+_mat[2][0]) / _mat[0][0];
top = temp_near * (1.0+_mat[2][1]) / _mat[1][1];
bottom = temp_near * (_mat[2][1]-1.0) / _mat[1][1];
left = zNear * (_mat[2][0]-1.0) / _mat[0][0];
right = zNear * (1.0+_mat[2][0]) / _mat[0][0];
zNear = temp_near;
zFar = temp_far;
top = zNear * (1.0+_mat[2][1]) / _mat[1][1];
bottom = zNear * (_mat[2][1]-1.0) / _mat[1][1];
return true;
}
@@ -895,13 +901,22 @@ bool Matrix_implementation::getPerspective(double& fovy,double& aspectRatio,
double left = 0.0;
double top = 0.0;
double bottom = 0.0;
if (getFrustum(left,right,bottom,top,zNear,zFar))
// note: near and far must be used inside this method instead of zNear and zFar
// because zNear and zFar are references and they may point to the same variable.
double temp_near = 0.0;
double temp_far = 0.0;
// get frustum and compute results
bool r = getFrustum(left,right,bottom,top,temp_near,temp_far);
if (r)
{
fovy = RadiansToDegrees(atan(top/zNear)-atan(bottom/zNear));
fovy = RadiansToDegrees(atan(top/temp_near)-atan(bottom/temp_near));
aspectRatio = (right-left)/(top-bottom);
return true;
}
return false;
zNear = temp_near;
zFar = temp_far;
return r;
}
void Matrix_implementation::makeLookAt(const Vec3d& eye,const Vec3d& center,const Vec3d& up)
@@ -927,22 +942,36 @@ void Matrix_implementation::getLookAt(Vec3f& eye,Vec3f& center,Vec3f& up,value_t
{
Matrix_implementation inv;
inv.invert(*this);
eye = osg::Vec3f(0.0,0.0,0.0)*inv;
// note: e and c variables must be used inside this method instead of eye and center
// because eye and center are references and they may point to the same variable.
Vec3f e = osg::Vec3f(0.0,0.0,0.0)*inv;
up = transform3x3(*this,osg::Vec3f(0.0,1.0,0.0));
center = transform3x3(*this,osg::Vec3f(0.0,0.0,-1));
center.normalize();
center = eye + center*lookDistance;
Vec3f c = transform3x3(*this,osg::Vec3f(0.0,0.0,-1));
c.normalize();
c = e + c*lookDistance;
// assign the results
eye = e;
center = c;
}
void Matrix_implementation::getLookAt(Vec3d& eye,Vec3d& center,Vec3d& up,value_type lookDistance) const
{
Matrix_implementation inv;
inv.invert(*this);
eye = osg::Vec3d(0.0,0.0,0.0)*inv;
// note: e and c variables must be used inside this method instead of eye and center
// because eye and center are references and they may point to the same variable.
Vec3d e = osg::Vec3d(0.0,0.0,0.0)*inv;
up = transform3x3(*this,osg::Vec3d(0.0,1.0,0.0));
center = transform3x3(*this,osg::Vec3d(0.0,0.0,-1));
center.normalize();
center = eye + center*lookDistance;
Vec3d c = transform3x3(*this,osg::Vec3d(0.0,0.0,-1));
c.normalize();
c = e + c*lookDistance;
// assign the results
eye = e;
center = c;
}
#undef SET_ROW