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Merge pull request #414 from l337r007/collada-tristrips

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Collada: tristrip support: helps a lot :-). Thanks for that!
This commit is contained in:
Kim Kulling
2014-12-01 20:48:10 +01:00
parent 7a31a68cfc 926b7e98cc
commit bc0fd00e96
3 changed files with 251 additions and 38 deletions
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111
code/ColladaParser.cpp
View File

@@ -1867,14 +1867,15 @@ void ColladaParser::ReadIndexData( Mesh* pMesh)
// read primitive count from the attribute
int attrCount = GetAttribute( "count");
size_t numPrimitives = (size_t) mReader->getAttributeValueAsInt( attrCount);
// some mesh types (e.g. tristrips) don't specify primitive count upfront,
// so we need to sum up the actual number of primitives while we read the <p>-tags
size_t actualPrimitives = 0;
// material subgroup
// material subgroup
int attrMaterial = TestAttribute( "material");
SubMesh subgroup;
if( attrMaterial > -1)
subgroup.mMaterial = mReader->getAttributeValue( attrMaterial);
subgroup.mNumFaces = numPrimitives;
pMesh->mSubMeshes.push_back( subgroup);
// distinguish between polys and triangles
std::string elementName = mReader->getNodeName();
@@ -1933,7 +1934,7 @@ void ColladaParser::ReadIndexData( Mesh* pMesh)
if( !mReader->isEmptyElement())
{
// now here the actual fun starts - these are the indices to construct the mesh data from
ReadPrimitives( pMesh, perIndexData, numPrimitives, vcount, primType);
actualPrimitives += ReadPrimitives(pMesh, perIndexData, numPrimitives, vcount, primType);
}
} else
{
@@ -1948,6 +1949,14 @@ void ColladaParser::ReadIndexData( Mesh* pMesh)
break;
}
}
// small sanity check
if (primType != Prim_TriFans && primType != Prim_TriStrips)
ai_assert(actualPrimitives == numPrimitives);
// only when we're done reading all <p> tags (and thus know the final vertex count) can we commit the submesh
subgroup.mNumFaces = actualPrimitives;
pMesh->mSubMeshes.push_back(subgroup);
}
// ------------------------------------------------------------------------------------------------
@@ -1995,7 +2004,7 @@ void ColladaParser::ReadInputChannel( std::vector<InputChannel>& poChannels)
// ------------------------------------------------------------------------------------------------
// Reads a <p> primitive index list and assembles the mesh data into the given mesh
void ColladaParser::ReadPrimitives( Mesh* pMesh, std::vector<InputChannel>& pPerIndexChannels,
size_t ColladaParser::ReadPrimitives( Mesh* pMesh, std::vector<InputChannel>& pPerIndexChannels,
size_t pNumPrimitives, const std::vector<size_t>& pVCount, PrimitiveType pPrimType)
{
// determine number of indices coming per vertex
@@ -2093,70 +2102,98 @@ void ColladaParser::ReadPrimitives( Mesh* pMesh, std::vector<InputChannel>& pPer
acc->mData = &ResolveLibraryReference( mDataLibrary, acc->mSource);
}
// now assemble vertex data according to those indices
std::vector<size_t>::const_iterator idx = indices.begin();
// For continued primitives, the given count does not come all in one <p>, but only one primitive per <p>
size_t numPrimitives = pNumPrimitives;
if( pPrimType == Prim_TriFans || pPrimType == Prim_Polygon)
numPrimitives = 1;
// For continued primitives, the given count is actually the number of <p>'s inside the parent tag
if ( pPrimType == Prim_TriStrips){
size_t numberOfVertices = indices.size() / numOffsets;
numPrimitives = numberOfVertices - 2;
}
pMesh->mFaceSize.reserve( numPrimitives);
pMesh->mFacePosIndices.reserve( indices.size() / numOffsets);
for( size_t a = 0; a < numPrimitives; a++)
size_t polylistStartVertex = 0;
for (size_t currentPrimitive = 0; currentPrimitive < numPrimitives; currentPrimitive++)
{
// determine number of points for this primitive
size_t numPoints = 0;
switch( pPrimType)
{
case Prim_Lines:
numPoints = 2;
numPoints = 2;
for (size_t currentVertex = 0; currentVertex < numPoints; currentVertex++)
CopyVertex(currentVertex, numOffsets, numPoints, perVertexOffset, pMesh, pPerIndexChannels, currentPrimitive, indices);
break;
case Prim_Triangles:
numPoints = 3;
case Prim_Triangles:
numPoints = 3;
for (size_t currentVertex = 0; currentVertex < numPoints; currentVertex++)
CopyVertex(currentVertex, numOffsets, numPoints, perVertexOffset, pMesh, pPerIndexChannels, currentPrimitive, indices);
break;
case Prim_TriStrips:
numPoints = 3;
ReadPrimTriStrips(numOffsets, perVertexOffset, pMesh, pPerIndexChannels, currentPrimitive, indices);
break;
case Prim_Polylist:
numPoints = pVCount[a];
numPoints = pVCount[currentPrimitive];
for (size_t currentVertex = 0; currentVertex < numPoints; currentVertex++)
CopyVertex(polylistStartVertex + currentVertex, numOffsets, 1, perVertexOffset, pMesh, pPerIndexChannels, 0, indices);
polylistStartVertex += numPoints;
break;
case Prim_TriFans:
case Prim_Polygon:
numPoints = indices.size() / numOffsets;
numPoints = indices.size() / numOffsets;
for (size_t currentVertex = 0; currentVertex < numPoints; currentVertex++)
CopyVertex(currentVertex, numOffsets, numPoints, perVertexOffset, pMesh, pPerIndexChannels, currentPrimitive, indices);
break;
default:
// LineStrip and TriStrip not supported due to expected index unmangling
// LineStrip is not supported due to expected index unmangling
ThrowException( "Unsupported primitive type.");
break;
}
// store the face size to later reconstruct the face from
pMesh->mFaceSize.push_back( numPoints);
// gather that number of vertices
for( size_t b = 0; b < numPoints; b++)
{
// read all indices for this vertex. Yes, in a hacky local array
ai_assert( numOffsets < 20 && perVertexOffset < 20);
size_t vindex[20];
for( size_t offsets = 0; offsets < numOffsets; ++offsets)
vindex[offsets] = *idx++;
// extract per-vertex channels using the global per-vertex offset
for( std::vector<InputChannel>::iterator it = pMesh->mPerVertexData.begin(); it != pMesh->mPerVertexData.end(); ++it)
ExtractDataObjectFromChannel( *it, vindex[perVertexOffset], pMesh);
// and extract per-index channels using there specified offset
for( std::vector<InputChannel>::iterator it = pPerIndexChannels.begin(); it != pPerIndexChannels.end(); ++it)
ExtractDataObjectFromChannel( *it, vindex[it->mOffset], pMesh);
// store the vertex-data index for later assignment of bone vertex weights
pMesh->mFacePosIndices.push_back( vindex[perVertexOffset]);
}
}
// if I ever get my hands on that guy who invented this steaming pile of indirection...
TestClosing( "p");
return numPrimitives;
}
void ColladaParser::CopyVertex(size_t currentVertex, size_t numOffsets, size_t numPoints, size_t perVertexOffset, Mesh* pMesh, std::vector<InputChannel>& pPerIndexChannels, size_t currentPrimitive, const std::vector<size_t>& indices){
// calculate the base offset of the vertex whose attributes we ant to copy
size_t baseOffset = currentPrimitive * numOffsets * numPoints + currentVertex * numOffsets;
// don't overrun the boundaries of the index list
size_t maxIndexRequested = baseOffset + numOffsets - 1;
ai_assert(maxIndexRequested < indices.size());
// extract per-vertex channels using the global per-vertex offset
for (std::vector<InputChannel>::iterator it = pMesh->mPerVertexData.begin(); it != pMesh->mPerVertexData.end(); ++it)
ExtractDataObjectFromChannel(*it, indices[baseOffset + perVertexOffset], pMesh);
// and extract per-index channels using there specified offset
for (std::vector<InputChannel>::iterator it = pPerIndexChannels.begin(); it != pPerIndexChannels.end(); ++it)
ExtractDataObjectFromChannel(*it, indices[baseOffset + it->mOffset], pMesh);
// store the vertex-data index for later assignment of bone vertex weights
pMesh->mFacePosIndices.push_back(indices[baseOffset + perVertexOffset]);
}
void ColladaParser::ReadPrimTriStrips(size_t numOffsets, size_t perVertexOffset, Mesh* pMesh, std::vector<InputChannel>& pPerIndexChannels, size_t currentPrimitive, const std::vector<size_t>& indices){
if (currentPrimitive % 2 != 0){
//odd tristrip triangles need their indices mangled, to preserve winding direction
CopyVertex(1, numOffsets, 1, perVertexOffset, pMesh, pPerIndexChannels, currentPrimitive, indices);
CopyVertex(0, numOffsets, 1, perVertexOffset, pMesh, pPerIndexChannels, currentPrimitive, indices);
CopyVertex(2, numOffsets, 1, perVertexOffset, pMesh, pPerIndexChannels, currentPrimitive, indices);
}
else {//for non tristrips or even tristrip triangles
CopyVertex(0, numOffsets, 1, perVertexOffset, pMesh, pPerIndexChannels, currentPrimitive, indices);
CopyVertex(1, numOffsets, 1, perVertexOffset, pMesh, pPerIndexChannels, currentPrimitive, indices);
CopyVertex(2, numOffsets, 1, perVertexOffset, pMesh, pPerIndexChannels, currentPrimitive, indices);
}
}
// ------------------------------------------------------------------------------------------------

11
code/ColladaParser.h
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@@ -177,9 +177,18 @@ protected:
void ReadInputChannel( std::vector<Collada::InputChannel>& poChannels);
/** Reads a <p> primitive index list and assembles the mesh data into the given mesh */
void ReadPrimitives( Collada::Mesh* pMesh, std::vector<Collada::InputChannel>& pPerIndexChannels,
size_t ReadPrimitives( Collada::Mesh* pMesh, std::vector<Collada::InputChannel>& pPerIndexChannels,
size_t pNumPrimitives, const std::vector<size_t>& pVCount, Collada::PrimitiveType pPrimType);
/** Copies the data for a single primitive into the mesh, based on the InputChannels */
void CopyVertex(size_t currentVertex, size_t numOffsets, size_t numPoints, size_t perVertexOffset,
Collada::Mesh* pMesh, std::vector<Collada::InputChannel>& pPerIndexChannels,
size_t currentPrimitive, const std::vector<size_t>& indices);
/** Reads one triangle of a tristrip into the mesh */
void ReadPrimTriStrips(size_t numOffsets, size_t perVertexOffset, Collada::Mesh* pMesh,
std::vector<Collada::InputChannel>& pPerIndexChannels, size_t currentPrimitive, const std::vector<size_t>& indices);
/** Extracts a single object from an input channel and stores it in the appropriate mesh data array */
void ExtractDataObjectFromChannel( const Collada::InputChannel& pInput, size_t pLocalIndex, Collada::Mesh* pMesh);