diff --git a/include/PolyVox/CubicSurfaceExtractor.h b/include/PolyVox/CubicSurfaceExtractor.h index 993857b7..2879a630 100644 --- a/include/PolyVox/CubicSurfaceExtractor.h +++ b/include/PolyVox/CubicSurfaceExtractor.h @@ -86,6 +86,35 @@ namespace PolyVox uint32_t vertices[4]; }; + // This constant defines the maximum number of quads which can share a vertex in a cubic style mesh. + // + // We try to avoid duplicate vertices by checking whether a vertex has already been added at a given position. + // However, it is possible that vertices have the same position but different materials. In this case, the + // vertices are not true duplicates and both must be added to the mesh. As far as I can tell, it is possible to have + // at most eight vertices with the same position but different materials. For example, this worst-case scenario + // happens when we have a 2x2x2 group of voxels, all with different materials and some/all partially transparent. + // The vertex position at the center of this group is then going to be used by all eight voxels all with different + // materials. + const uint32_t MaxVerticesPerPosition = 8; + + template + struct IndexAndMaterial + { + int32_t iIndex; + typename VolumeType::VoxelType uMaterial; + }; + + enum FaceNames + { + PositiveX, + PositiveY, + PositiveZ, + NegativeX, + NegativeY, + NegativeZ, + NoOfFaces + }; + template bool mergeQuads(Quad& q1, Quad& q2, MeshType* m_meshCurrent) { @@ -155,27 +184,43 @@ namespace PolyVox return bDidMerge; } + + template + int32_t addVertex(uint32_t uX, uint32_t uY, uint32_t uZ, typename VolumeType::VoxelType uMaterialIn, Array<3, IndexAndMaterial >& existingVertices, MeshType* m_meshCurrent) + { + for (uint32_t ct = 0; ct < MaxVerticesPerPosition; ct++) + { + IndexAndMaterial& rEntry = existingVertices(uX, uY, ct); + + if (rEntry.iIndex == -1) + { + //No vertices matched and we've now hit an empty space. Fill it by creating a vertex. The 0.5f offset is because vertices set between voxels in order to build cubes around them. + CubicVertex cubicVertex; + cubicVertex.encodedPosition.setElements(static_cast(uX), static_cast(uY), static_cast(uZ)); + cubicVertex.data = uMaterialIn; + rEntry.iIndex = m_meshCurrent->addVertex(cubicVertex); + rEntry.uMaterial = uMaterialIn; + + return rEntry.iIndex; + } + + //If we have an existing vertex and the material matches then we can return it. + if (rEntry.uMaterial == uMaterialIn) + { + return rEntry.iIndex; + } + } + + // If we exit the loop here then apparently all the slots were full but none of them matched. + // This shouldn't ever happen, so if it does it is probably a bug in PolyVox. Please report it to us! + POLYVOX_THROW(std::runtime_error, "All slots full but no matches during cubic surface extraction. This is probably a bug in PolyVox"); + return -1; //Should never happen. + } /// Do not use this class directly. Use the 'extractCubicSurface' function instead (see examples). template class CubicSurfaceExtractor - { - struct IndexAndMaterial - { - int32_t iIndex; - typename VolumeType::VoxelType uMaterial; - }; - - enum FaceNames - { - PositiveX, - PositiveY, - PositiveZ, - NegativeX, - NegativeY, - NegativeZ, - NoOfFaces - }; + { public: CubicSurfaceExtractor(VolumeType* volData, Region region, MeshType* result, IsQuadNeeded isQuadNeeded = IsQuadNeeded(), bool bMergeQuads = true); @@ -183,8 +228,6 @@ namespace PolyVox void execute(); private: - int32_t addVertex(uint32_t uX, uint32_t uY, uint32_t uZ, typename VolumeType::VoxelType uMaterial, Array<3, IndexAndMaterial>& existingVertices); - IsQuadNeeded m_funcIsQuadNeededCallback; //The volume data and a sampler to access it. @@ -197,8 +240,8 @@ namespace PolyVox MeshType* m_meshCurrent; //Used to avoid creating duplicate vertices. - Array<3, IndexAndMaterial> m_previousSliceVertices; - Array<3, IndexAndMaterial> m_currentSliceVertices; + Array<3, IndexAndMaterial > m_previousSliceVertices; + Array<3, IndexAndMaterial > m_currentSliceVertices; //During extraction we create a number of different lists of quads. All the //quads in a given list are in the same plane and facing in the same direction. @@ -207,10 +250,6 @@ namespace PolyVox //Controls whether quad merging should be performed. This might be undesirable //is the user needs per-vertex attributes, or to perform per vertex lighting. bool m_bMergeQuads; - - //This constant defines the maximum number of quads which can share a - //vertex in a cubic style mesh. See the initialisation for more details. - static const uint32_t MaxVerticesPerPosition; }; // This version of the function performs the extraction into a user-provided mesh rather than allocating a mesh automatically. diff --git a/include/PolyVox/CubicSurfaceExtractor.inl b/include/PolyVox/CubicSurfaceExtractor.inl index 2a7d6b71..12f1f795 100644 --- a/include/PolyVox/CubicSurfaceExtractor.inl +++ b/include/PolyVox/CubicSurfaceExtractor.inl @@ -25,16 +25,6 @@ freely, subject to the following restrictions: namespace PolyVox { - // We try to avoid duplicate vertices by checking whether a vertex has already been added at a given position. - // However, it is possible that vertices have the same position but different materials. In this case, the - // vertices are not true duplicates and both must be added to the mesh. As far as I can tell, it is possible to have - // at most eight vertices with the same position but different materials. For example, this worst-case scenario - // happens when we have a 2x2x2 group of voxels, all with different materials and some/all partially transparent. - // The vertex position at the center of this group is then going to be used by all eight voxels all with different - // materials. - template - const uint32_t CubicSurfaceExtractor::MaxVerticesPerPosition = 8; - template CubicSurfaceExtractor::CubicSurfaceExtractor(VolumeType* volData, Region region, MeshType* result, IsQuadNeeded isQuadNeeded, bool bMergeQuads) :m_volData(volData) @@ -65,8 +55,8 @@ namespace PolyVox //uint32_t arraySize[3]= {uArrayWidth, uArrayHeight, MaxVerticesPerPosition}; //m_previousSliceVertices.resize(arraySize); //m_currentSliceVertices.resize(arraySize); - memset(m_previousSliceVertices.getRawData(), 0xff, m_previousSliceVertices.getNoOfElements() * sizeof(IndexAndMaterial)); - memset(m_currentSliceVertices.getRawData(), 0xff, m_currentSliceVertices.getNoOfElements() * sizeof(IndexAndMaterial)); + memset(m_previousSliceVertices.getRawData(), 0xff, m_previousSliceVertices.getNoOfElements() * sizeof(IndexAndMaterial)); + memset(m_currentSliceVertices.getRawData(), 0xff, m_currentSliceVertices.getNoOfElements() * sizeof(IndexAndMaterial)); m_vecQuads[NegativeX].resize(m_regSizeInVoxels.getUpperX() - m_regSizeInVoxels.getLowerX() + 2); m_vecQuads[PositiveX].resize(m_regSizeInVoxels.getUpperX() - m_regSizeInVoxels.getLowerX() + 2); @@ -102,20 +92,20 @@ namespace PolyVox // X if(m_funcIsQuadNeededCallback(currentVoxel, negXVoxel, material)) { - uint32_t v0 = addVertex(regX , regY , regZ , material, m_previousSliceVertices); - uint32_t v1 = addVertex(regX , regY , regZ + 1, material, m_currentSliceVertices); - uint32_t v2 = addVertex(regX , regY + 1, regZ + 1, material, m_currentSliceVertices); - uint32_t v3 = addVertex(regX , regY + 1, regZ , material, m_previousSliceVertices); + uint32_t v0 = addVertex(regX , regY , regZ , material, m_previousSliceVertices, m_meshCurrent); + uint32_t v1 = addVertex(regX , regY , regZ + 1, material, m_currentSliceVertices, m_meshCurrent); + uint32_t v2 = addVertex(regX , regY + 1, regZ + 1, material, m_currentSliceVertices, m_meshCurrent); + uint32_t v3 = addVertex(regX , regY + 1, regZ , material, m_previousSliceVertices, m_meshCurrent); m_vecQuads[NegativeX][regX].push_back(Quad(v0, v1, v2, v3)); } if(m_funcIsQuadNeededCallback(negXVoxel, currentVoxel, material)) { - uint32_t v0 = addVertex(regX , regY , regZ , material, m_previousSliceVertices); - uint32_t v1 = addVertex(regX , regY , regZ + 1, material, m_currentSliceVertices); - uint32_t v2 = addVertex(regX , regY + 1, regZ + 1, material, m_currentSliceVertices); - uint32_t v3 = addVertex(regX , regY + 1, regZ , material, m_previousSliceVertices); + uint32_t v0 = addVertex(regX , regY , regZ , material, m_previousSliceVertices, m_meshCurrent); + uint32_t v1 = addVertex(regX , regY , regZ + 1, material, m_currentSliceVertices, m_meshCurrent); + uint32_t v2 = addVertex(regX , regY + 1, regZ + 1, material, m_currentSliceVertices, m_meshCurrent); + uint32_t v3 = addVertex(regX , regY + 1, regZ , material, m_previousSliceVertices, m_meshCurrent); m_vecQuads[PositiveX][regX].push_back(Quad(v0, v3, v2, v1)); } @@ -123,20 +113,20 @@ namespace PolyVox // Y if(m_funcIsQuadNeededCallback(currentVoxel, negYVoxel, material)) { - uint32_t v0 = addVertex(regX , regY , regZ , material, m_previousSliceVertices); - uint32_t v1 = addVertex(regX + 1, regY , regZ , material, m_previousSliceVertices); - uint32_t v2 = addVertex(regX + 1, regY , regZ + 1, material, m_currentSliceVertices); - uint32_t v3 = addVertex(regX , regY , regZ + 1, material, m_currentSliceVertices); + uint32_t v0 = addVertex(regX , regY , regZ , material, m_previousSliceVertices, m_meshCurrent); + uint32_t v1 = addVertex(regX + 1, regY , regZ , material, m_previousSliceVertices, m_meshCurrent); + uint32_t v2 = addVertex(regX + 1, regY , regZ + 1, material, m_currentSliceVertices, m_meshCurrent); + uint32_t v3 = addVertex(regX , regY , regZ + 1, material, m_currentSliceVertices, m_meshCurrent); m_vecQuads[NegativeY][regY].push_back(Quad(v0, v1, v2, v3)); } if(m_funcIsQuadNeededCallback(negYVoxel, currentVoxel, material)) { - uint32_t v0 = addVertex(regX , regY , regZ , material, m_previousSliceVertices); - uint32_t v1 = addVertex(regX + 1, regY , regZ , material, m_previousSliceVertices); - uint32_t v2 = addVertex(regX + 1, regY , regZ + 1, material, m_currentSliceVertices); - uint32_t v3 = addVertex(regX , regY , regZ + 1, material, m_currentSliceVertices); + uint32_t v0 = addVertex(regX , regY , regZ , material, m_previousSliceVertices, m_meshCurrent); + uint32_t v1 = addVertex(regX + 1, regY , regZ , material, m_previousSliceVertices, m_meshCurrent); + uint32_t v2 = addVertex(regX + 1, regY , regZ + 1, material, m_currentSliceVertices, m_meshCurrent); + uint32_t v3 = addVertex(regX , regY , regZ + 1, material, m_currentSliceVertices, m_meshCurrent); m_vecQuads[PositiveY][regY].push_back(Quad(v0, v3, v2, v1)); } @@ -144,20 +134,20 @@ namespace PolyVox // Z if(m_funcIsQuadNeededCallback(currentVoxel, negZVoxel, material)) { - uint32_t v0 = addVertex(regX , regY , regZ , material, m_previousSliceVertices); - uint32_t v1 = addVertex(regX , regY + 1, regZ , material, m_previousSliceVertices); - uint32_t v2 = addVertex(regX + 1, regY + 1, regZ , material, m_previousSliceVertices); - uint32_t v3 = addVertex(regX + 1, regY , regZ , material, m_previousSliceVertices); + uint32_t v0 = addVertex(regX , regY , regZ , material, m_previousSliceVertices, m_meshCurrent); + uint32_t v1 = addVertex(regX , regY + 1, regZ , material, m_previousSliceVertices, m_meshCurrent); + uint32_t v2 = addVertex(regX + 1, regY + 1, regZ , material, m_previousSliceVertices, m_meshCurrent); + uint32_t v3 = addVertex(regX + 1, regY , regZ , material, m_previousSliceVertices, m_meshCurrent); m_vecQuads[NegativeZ][regZ].push_back(Quad(v0, v1, v2, v3)); } if(m_funcIsQuadNeededCallback(negZVoxel, currentVoxel, material)) { - uint32_t v0 = addVertex(regX , regY , regZ , material, m_previousSliceVertices); - uint32_t v1 = addVertex(regX , regY + 1, regZ , material, m_previousSliceVertices); - uint32_t v2 = addVertex(regX + 1, regY + 1, regZ , material, m_previousSliceVertices); - uint32_t v3 = addVertex(regX + 1, regY , regZ , material, m_previousSliceVertices); + uint32_t v0 = addVertex(regX , regY , regZ , material, m_previousSliceVertices, m_meshCurrent); + uint32_t v1 = addVertex(regX , regY + 1, regZ , material, m_previousSliceVertices, m_meshCurrent); + uint32_t v2 = addVertex(regX + 1, regY + 1, regZ , material, m_previousSliceVertices, m_meshCurrent); + uint32_t v3 = addVertex(regX + 1, regY , regZ , material, m_previousSliceVertices, m_meshCurrent); m_vecQuads[PositiveZ][regZ].push_back(Quad(v0, v3, v2, v1)); } @@ -167,7 +157,7 @@ namespace PolyVox } m_previousSliceVertices.swap(m_currentSliceVertices); - memset(m_currentSliceVertices.getRawData(), 0xff, m_currentSliceVertices.getNoOfElements() * sizeof(IndexAndMaterial)); + memset(m_currentSliceVertices.getRawData(), 0xff, m_currentSliceVertices.getNoOfElements() * sizeof(IndexAndMaterial)); } for(uint32_t uFace = 0; uFace < NoOfFaces; uFace++) @@ -202,36 +192,4 @@ namespace PolyVox "ms (Region size = ", m_regSizeInVoxels.getWidthInVoxels(), "x", m_regSizeInVoxels.getHeightInVoxels(), "x", m_regSizeInVoxels.getDepthInVoxels(), ")"); } - - template - int32_t CubicSurfaceExtractor::addVertex(uint32_t uX, uint32_t uY, uint32_t uZ, typename VolumeType::VoxelType uMaterialIn, Array<3, IndexAndMaterial>& existingVertices) - { - for(uint32_t ct = 0; ct < MaxVerticesPerPosition; ct++) - { - IndexAndMaterial& rEntry = existingVertices(uX, uY, ct); - - if(rEntry.iIndex == -1) - { - //No vertices matched and we've now hit an empty space. Fill it by creating a vertex. The 0.5f offset is because vertices set between voxels in order to build cubes around them. - CubicVertex cubicVertex; - cubicVertex.encodedPosition.setElements(static_cast(uX), static_cast(uY), static_cast(uZ)); - cubicVertex.data = uMaterialIn; - rEntry.iIndex = m_meshCurrent->addVertex(cubicVertex); - rEntry.uMaterial = uMaterialIn; - - return rEntry.iIndex; - } - - //If we have an existing vertex and the material matches then we can return it. - if(rEntry.uMaterial == uMaterialIn) - { - return rEntry.iIndex; - } - } - - // If we exit the loop here then apparently all the slots were full but none of them matched. - // This shouldn't ever happen, so if it does it is probably a bug in PolyVox. Please report it to us! - POLYVOX_THROW(std::runtime_error, "All slots full but no matches during cubic surface extraction. This is probably a bug in PolyVox"); - return -1; //Should never happen. - } }