bool DVRClipper::setNumAddPerVertexAttr(
DVRVolume *volume,
UInt32 additionalPerVertexAttributes)
{
numAddPerVertexAttr = additionalPerVertexAttributes;
sliceVertexData = (GLdouble*) realloc(
sliceVertexData,
6 * (6 + additionalPerVertexAttributes) * sizeof(GLdouble));
if(!sliceVertexData)
return false;
// get clip objects
DVRClipObjectsPtr clipObjects = DVRVOLUME_PARAMETER(volume,
DVRClipObjects);
if(clipObjects == NullFC)
return true;
for(UInt32 i = 0; i < clipObjects->count(); i++)
{
DVRClipGeometryPtr clipObject = clipObjects->get(i);
if(!clipObject->setNumAddPerVertexAttr(additionalPerVertexAttributes))
return false;
}
return true;
}
void DVRClipper::reset(DVRVolume *volume)
{
if(volume == NULL || !hasTesselatorSupport)
return;
// get clip objects
DVRClipObjectsPtr clipObjects = DVRVOLUME_PARAMETER(volume,
DVRClipObjects);
if(clipObjects == NullFC)
return;
// set tesselator properties according to clip mode
if(clipObjects->getClipMode() == DVRClipObjects::Intersection)
{
gluTessProperty(myTess,
GLU_TESS_WINDING_RULE,
GLU_TESS_WINDING_ABS_GEQ_TWO);
}
else
{
gluTessProperty(myTess,
GLU_TESS_WINDING_RULE,
GLU_TESS_WINDING_POSITIVE);
}
// reset local data
for(UInt32 i = 0; i < clipObjects->count(); i++)
{
// reset i-th clip object
DVRClipGeometryPtr clipObject = clipObjects->get(i);
clipObject->resetLocalData ();
clipObject->computeSeedVertices();
}
}
void DVRClipper::clipSlice( DVRVolume *volume,
DVRSlice &unclippedSlice,
const Vec3f &slicingNormal,
Real32 dist2RefPlane,
DVRRenderSlice &clippedSlice)
{
const Vec3f &texScale = unclippedSlice.getTextureScale ();
const Vec3f &texTranslate = unclippedSlice.getTextureTranslate();
// get clip objects
DVRClipObjectsPtr clipObjects = DVRVOLUME_PARAMETER(volume,
DVRClipObjects);
// nothing to clip with?
if(clipObjects == NullFC)
{
DVRRenderSlicePrimitive *newPrimitive = new DVRRenderSlicePrimitive();
newPrimitive->type = GL_TRIANGLE_FAN;
for(UInt32 i = 0; i < unclippedSlice.getVertexCount(); i++)
{
UInt32 idx = (6+numAddPerVertexAttr)*i;
sliceVertexData[idx ] =
unclippedSlice.getVertex(i).getValues()[0];
sliceVertexData[idx + 1] =
unclippedSlice.getVertex(i).getValues()[1];
sliceVertexData[idx + 2] =
unclippedSlice.getVertex(i).getValues()[2];
// set (standard) texture coordinates
sliceVertexData[idx + 3] =
texScale[0] *
unclippedSlice.getVertex(i).getValues()[0] +
texTranslate[0];
sliceVertexData[idx + 4] =
texScale[1] *
unclippedSlice.getVertex(i).getValues()[1] +
texTranslate[1];
sliceVertexData[idx + 5] =
texScale[2] *
unclippedSlice.getVertex(i).getValues()[2] +
texTranslate[2];
newPrimitive->vertices.push_back(&sliceVertexData[idx]);
}
clippedSlice.push_back(newPrimitive);
return;
}
if(!hasTesselatorSupport)
return;
// render colored contours only (usefull for debugging)
if(clipObjects->getDoContours())
{
glDisable(GL_TEXTURE );
glDisable(GL_LIGHTING );
glBegin (GL_LINE_STRIP);
{
int col = 0;
for(UInt32 i = 0; i < unclippedSlice.getVertexCount(); i++)
{
glColor3f(col % 3 == 0 ? 1.0f : 0.0f,
col % 3 == 1 ? 1.0f : 0.0f,
col % 3 == 2 ? 1.0f : 0.0f);
col++;
glVertex3fv(unclippedSlice.getVertex(i).getValues());
}
}
glEnd();
bool clipAwayOutside =
clipObjects->getClipMode() == DVRClipObjects::Difference;
for(UInt32 i = 0; i < clipObjects->count(); i++)
{
// get i-th clip object
DVRClipGeometryPtr clipObject = clipObjects->get(i);
// compute the contours of the triangles intersecting the
// current slice
const DVRTriangleList &contours =
clipObject->getContours(dist2RefPlane,
!clipAwayOutside,
slicingNormal);
if(!contours.empty())
{
DVRTriangle *current;
DVRTriangle *contourStart;
// iterate over all contours
DVRTriangleList::const_iterator contoursIt;
for(contoursIt = contours.begin();
contoursIt != contours.end ();
contoursIt++)
{
contourStart = current = *contoursIt;
glBegin(GL_LINE_STRIP);
{
int col = 0;
// iterate over all triangles in the current contour
do
{
glColor3f(col % 3 == 0 ? 1.0f : 0.0f,
col % 3 == 1 ? 1.0f : 0.0f,
col % 3 == 2 ? 1.0f : 0.0f);
col++;
glVertex3dv(current->cutPoint);
current = current->contourNeighbour;
} while(current!= contourStart);
}
glEnd();
}
}
}
glEnable(GL_TEXTURE );
glEnable(GL_LIGHTING);
}
else
{
// tesselate and render the clipped slices
// set the slice normal for tesselation
gluTessNormal(myTess,
slicingNormal[0],
slicingNormal[1],
slicingNormal[2]);
clippedSlice.clear();
gluTessBeginPolygon(myTess, &clippedSlice);
// set the slice's base contour
gluTessBeginContour(myTess);
for(UInt32 i = 0; i < unclippedSlice.getVertexCount(); i++)
{
UInt32 idx = (6 + numAddPerVertexAttr) * i;
sliceVertexData[idx ] =
unclippedSlice.getVertex(i).getValues()[0];
sliceVertexData[idx + 1] =
unclippedSlice.getVertex(i).getValues()[1];
sliceVertexData[idx + 2] =
unclippedSlice.getVertex(i).getValues()[2];
// set (standard) texture coordinates
sliceVertexData[idx + 3] =
texScale[0] *
unclippedSlice.getVertex(i).getValues()[0] +
texTranslate[0];
sliceVertexData[idx + 4] =
texScale[1] *
unclippedSlice.getVertex(i).getValues()[1] +
texTranslate[1];
sliceVertexData[idx + 5] =
texScale[2] *
unclippedSlice.getVertex(i).getValues()[2] +
texTranslate[2];
gluTessVertex(myTess,
&sliceVertexData[idx],
&sliceVertexData[idx]);
}
gluTessEndContour(myTess);
// set contours of clip objects
if(clipObjects->getClipMode() != DVRClipObjects::Off)
{
// get clip mode
bool clipAwayOutside =
clipObjects->getClipMode() == DVRClipObjects::Difference;
// add the contours of the intersections of the clip geometries
// with the slice
for(UInt32 i = 0; i < clipObjects->count(); i++)
{
// get i-th clip object
DVRClipGeometryPtr clipObject = clipObjects->get(i);
// compute the contours of the triangles intersecting
// the current slice
const DVRTriangleList &contours =
clipObject->getContours( dist2RefPlane,
!clipAwayOutside,
slicingNormal);
if(!contours.empty())
{
DVRTriangle *current;
DVRTriangle *contourStart;
// iterate over all contours
DVRTriangleList::const_iterator contoursIt;
for(contoursIt = contours.begin();
contoursIt != contours.end ();
contoursIt++)
{
contourStart = current = *contoursIt;
// start new contour
gluTessBeginContour(myTess);
// iterate over all triangles in the current contour
do
{
// set (standard) texture coordinates
current->cutPoint[3] =
texScale[0] *
current->cutPoint[0] +
texTranslate[0];
current->cutPoint[4] =
texScale[1] *
current->cutPoint[1] +
texTranslate[1];
current->cutPoint[5] =
texScale[2] *
current->cutPoint[2] +
texTranslate[2];
if(!current->cutPoint)
std::cerr << "WTF: cutPoint is NULL"
<< std::endl;
gluTessVertex(myTess,
current->cutPoint,
current->cutPoint);
current = current->contourNeighbour;
} while(current != contourStart);
gluTessEndContour(myTess);
}
}
}
}
gluTessEndPolygon(myTess);
}
}