mirror of
https://github.com/scratchfoundation/bgfx.git
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828 lines
24 KiB
C++
828 lines
24 KiB
C++
/*
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Copyright (c) 2014, Conor Stokes
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All rights reserved.
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Redistribution and use in source and binary forms, with or without
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modification, are permitted provided that the following conditions are met:
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1. Redistributions of source code must retain the above copyright notice, this
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list of conditions and the following disclaimer.
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2. Redistributions in binary form must reproduce the above copyright notice,
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this list of conditions and the following disclaimer in the documentation
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and/or other materials provided with the distribution.
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THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
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ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
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WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
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DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
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ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
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(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
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ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
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SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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#include "indexbuffercompression.h"
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#include "writebitstream.h"
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#include "indexcompressionconstants.h"
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#include <assert.h>
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#ifdef _MSC_VER
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#define IBC_INLINE __forceinline
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#else
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#define IBC_INLINE inline
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#endif
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// Individual vertex type classifications.
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enum VertexClassification
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{
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NEW_VERTEX = 0,
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CACHED_VERTEX = 1,
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FREE_VERTEX = 2
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};
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// Individual case for handling a combination of vertice classifications.
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struct VertexCompressionCase
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{
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IndexBufferTriangleCodes code;
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uint32_t vertexOrder[ 3 ];
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};
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// This is a table for looking up the appropriate code and rotation for a set of vertex classifications.
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const VertexCompressionCase CompressionCase[3][3][3] =
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{
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{ // new
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{ // new new
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{ // new new new
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IB_NEW_NEW_NEW, { 0, 1, 2 }
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},
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{ // new new cached
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IB_NEW_NEW_CACHED, { 0, 1, 2 }
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},
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{ // new new free
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IB_NEW_NEW_FREE, { 0, 1, 2 }
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}
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},
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{ // new cached
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{ // new cached new
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IB_NEW_NEW_CACHED, { 2, 0, 1 }
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},
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{ // new cached cached
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IB_NEW_CACHED_CACHED, { 0, 1, 2 }
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},
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{ // new cached free
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IB_NEW_CACHED_FREE, { 0, 1, 2 }
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}
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},
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{ // new free
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{ // new free new
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IB_NEW_NEW_FREE, { 2, 0, 1 }
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},
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{ // new free cached
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IB_NEW_FREE_CACHED, { 0, 1, 2 }
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},
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{ // new free free
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IB_NEW_FREE_FREE, { 0, 1, 2 }
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}
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}
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},
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{ // cached
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{ // cached new
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{ // cached new new
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IB_NEW_NEW_CACHED, { 1, 2, 0 }
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},
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{ // cached new cached
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IB_NEW_CACHED_CACHED, { 1, 2, 0 }
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},
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{ // cached new free
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IB_NEW_FREE_CACHED, { 1, 2, 0 }
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}
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},
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{ // cached cached
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{ // cached cached new
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IB_NEW_CACHED_CACHED, { 2, 0, 1 }
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},
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{ // cached cached cached
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IB_CACHED_CACHED_CACHED, { 0, 1, 2 }
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},
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{ // cached cached free
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IB_CACHED_CACHED_FREE, { 0, 1, 2 }
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}
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},
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{ // cached free
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{ // cached free new
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IB_NEW_CACHED_FREE, { 2, 0, 1 }
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},
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{ // cached free cached
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IB_CACHED_CACHED_FREE, { 2, 0, 1 }
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},
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{ // cached free free
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IB_CACHED_FREE_FREE, { 0, 1, 2 }
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}
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}
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},
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{ // free
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{ // free new
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{ // free new new
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IB_NEW_NEW_FREE, { 1, 2, 0 }
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},
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{ // free new cached
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IB_NEW_CACHED_FREE, { 1, 2, 0 }
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},
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{ // free new free
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IB_NEW_FREE_FREE, { 1, 2, 0 }
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}
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},
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{ // free cached
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{ // free cached new
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IB_NEW_FREE_CACHED, { 2, 0, 1 }
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},
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{ // free cached cached
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IB_CACHED_CACHED_FREE, { 1, 2, 0 }
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},
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{ // free cached free
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IB_CACHED_FREE_FREE, { 1, 2, 0 }
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}
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},
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{ // free free
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{ // free free new
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IB_NEW_FREE_FREE, { 2, 0, 1 }
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},
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{ // free free cached
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IB_CACHED_FREE_FREE, { 2, 0, 1 }
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},
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{ // free free free
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IB_FREE_FREE_FREE, { 0, 1, 2 }
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}
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}
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}
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};
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const uint32_t VERTEX_NOT_MAPPED = 0xFFFFFFFF;
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// Classify a vertex as new, cached or free, outputting the relative position in the vertex indice cache FIFO.
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static IBC_INLINE VertexClassification ClassifyVertex( uint32_t vertex, const uint32_t* vertexRemap, const uint32_t* vertexFifo, uint32_t verticesRead, uint32_t& cachedVertexIndex )
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{
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if ( vertexRemap[ vertex ] == VERTEX_NOT_MAPPED )
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{
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return NEW_VERTEX;
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}
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else
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{
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int32_t lowestVertexCursor = verticesRead >= VERTEX_FIFO_SIZE ? verticesRead - VERTEX_FIFO_SIZE : 0;
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// Probe backwards in the vertex FIFO for a cached vertex
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for ( int32_t vertexCursor = verticesRead - 1; vertexCursor >= lowestVertexCursor; --vertexCursor )
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{
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if ( vertexFifo[ vertexCursor & VERTEX_FIFO_MASK ] == vertex )
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{
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cachedVertexIndex = ( verticesRead - 1 ) - vertexCursor;
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return CACHED_VERTEX;
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}
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}
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return FREE_VERTEX;
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}
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}
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template <typename Ty>
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void CompressTriangleCodes1( const Ty* triangles,
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uint32_t triangleCount,
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uint32_t* vertexRemap,
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uint32_t vertexCount,
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WriteBitstream& output )
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{
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Edge edgeFifo[ EDGE_FIFO_SIZE ];
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uint32_t vertexFifo[ VERTEX_FIFO_SIZE ];
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uint32_t edgesRead = 0;
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uint32_t verticesRead = 0;
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uint32_t newVertices = 0;
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const Ty* triangleEnd = triangles + ( triangleCount * 3 );
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assert( vertexCount < 0xFFFFFFFF );
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uint32_t* vertexRemapEnd = vertexRemap + vertexCount;
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// clear the vertex remapping to "not found" value of 0xFFFFFFFF - dirty, but low overhead.
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for ( uint32_t* remappedVertex = vertexRemap; remappedVertex < vertexRemapEnd; ++remappedVertex )
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{
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*remappedVertex = VERTEX_NOT_MAPPED;
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}
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// iterate through the triangles
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for ( const Ty* triangle = triangles; triangle < triangleEnd; triangle += 3 )
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{
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int32_t lowestEdgeCursor = edgesRead >= EDGE_FIFO_SIZE ? edgesRead - EDGE_FIFO_SIZE : 0;
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int32_t edgeCursor = edgesRead - 1;
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bool foundEdge = false;
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int32_t spareVertex = 0;
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// check to make sure that there are no degenerate triangles.
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assert( triangle[ 0 ] != triangle[ 1 ] && triangle[ 1 ] != triangle[ 2 ] && triangle[ 2 ] != triangle[ 0 ] );
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// Probe back through the edge fifo to see if one of the triangle edges is in the FIFO
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for ( ; edgeCursor >= lowestEdgeCursor; --edgeCursor )
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{
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const Edge& edge = edgeFifo[ edgeCursor & EDGE_FIFO_MASK ];
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// check all the edges in order and save the free vertex.
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if ( edge.second == triangle[ 0 ] && edge.first == triangle[ 1 ] )
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{
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foundEdge = true;
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spareVertex = 2;
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break;
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}
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else if ( edge.second == triangle[ 1 ] && edge.first == triangle[ 2 ] )
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{
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foundEdge = true;
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spareVertex = 0;
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break;
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}
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else if ( edge.second == triangle[ 2 ] && edge.first == triangle[ 0 ] )
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{
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foundEdge = true;
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spareVertex = 1;
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break;
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}
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}
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// we found an edge so write it out, so classify a vertex and then write out the correct code.
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if ( foundEdge )
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{
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uint32_t cachedVertex;
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uint32_t spareVertexIndice = triangle[ spareVertex ];
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VertexClassification freeVertexClass = ClassifyVertex( spareVertexIndice, vertexRemap, vertexFifo, verticesRead, cachedVertex );
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uint32_t relativeEdge = ( edgesRead - 1 ) - edgeCursor;
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switch ( freeVertexClass )
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{
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case NEW_VERTEX:
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switch ( relativeEdge )
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{
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case 0:
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output.Write( IB_EDGE_0_NEW, IB_TRIANGLE_CODE_BITS );
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break;
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case 1:
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output.Write( IB_EDGE_1_NEW, IB_TRIANGLE_CODE_BITS );
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break;
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default:
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output.Write( IB_EDGE_NEW, IB_TRIANGLE_CODE_BITS );
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output.Write( relativeEdge, CACHED_EDGE_BITS );
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break;
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}
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vertexFifo[ verticesRead & VERTEX_FIFO_MASK ] = spareVertexIndice;
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vertexRemap[ spareVertexIndice ] = newVertices;
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++verticesRead;
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++newVertices;
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break;
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case CACHED_VERTEX:
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output.Write( IB_EDGE_CACHED, IB_TRIANGLE_CODE_BITS );
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output.Write( relativeEdge, CACHED_EDGE_BITS );
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output.Write( cachedVertex, CACHED_VERTEX_BITS );
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break;
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case FREE_VERTEX:
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output.Write( IB_EDGE_FREE, IB_TRIANGLE_CODE_BITS );
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output.Write( relativeEdge, CACHED_EDGE_BITS );
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vertexFifo[ verticesRead & VERTEX_FIFO_MASK ] = spareVertexIndice;
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++verticesRead;
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output.WriteVInt( ( newVertices - 1 ) - vertexRemap[ spareVertexIndice ] );
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break;
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}
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// Populate the edge fifo with the the remaining edges
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// Note - the winding order is important as we'll need to re-produce this on decompression.
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// The edges are put in as if the found edge is the first edge in the triangle (which it will be when we
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// reconstruct).
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switch ( spareVertex )
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{
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case 0:
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edgeFifo[ edgesRead & EDGE_FIFO_MASK ].set( triangle[ 2 ], triangle[ 0 ] );
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++edgesRead;
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edgeFifo[ edgesRead & EDGE_FIFO_MASK ].set( triangle[ 0 ], triangle[ 1 ] );
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++edgesRead;
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break;
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case 1:
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edgeFifo[ edgesRead & EDGE_FIFO_MASK ].set( triangle[ 0 ], triangle[ 1 ] );
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++edgesRead;
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edgeFifo[ edgesRead & EDGE_FIFO_MASK ].set( triangle[ 1 ], triangle[ 2 ] );
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++edgesRead;
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break;
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case 2:
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edgeFifo[ edgesRead & EDGE_FIFO_MASK ].set( triangle[ 1 ], triangle[ 2 ] );
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++edgesRead;
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edgeFifo[ edgesRead & EDGE_FIFO_MASK ].set( triangle[ 2 ], triangle[ 0 ] );
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++edgesRead;
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break;
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}
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}
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else
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{
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VertexClassification classifications[ 3 ];
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uint32_t cachedVertexIndices[ 3 ];
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// classify each vertex as new, cached or free, potentially extracting a cached indice.
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classifications[ 0 ] = ClassifyVertex( triangle[ 0 ], vertexRemap, vertexFifo, verticesRead, cachedVertexIndices[ 0 ] );
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classifications[ 1 ] = ClassifyVertex( triangle[ 1 ], vertexRemap, vertexFifo, verticesRead, cachedVertexIndices[ 1 ] );
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classifications[ 2 ] = ClassifyVertex( triangle[ 2 ], vertexRemap, vertexFifo, verticesRead, cachedVertexIndices[ 2 ] );
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// use the classifications to lookup the matching compression code and potentially rotate the order of the vertices.
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const VertexCompressionCase& compressionCase = CompressionCase[ classifications[ 0 ] ][ classifications[ 1 ] ][ classifications[ 2 ] ];
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// rotate the order of the vertices based on the compression classification.
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uint32_t reorderedTriangle[ 3 ];
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reorderedTriangle[ 0 ] = triangle[ compressionCase.vertexOrder[ 0 ] ];
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reorderedTriangle[ 1 ] = triangle[ compressionCase.vertexOrder[ 1 ] ];
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reorderedTriangle[ 2 ] = triangle[ compressionCase.vertexOrder[ 2 ] ];
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output.Write( compressionCase.code, IB_TRIANGLE_CODE_BITS );
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switch ( compressionCase.code )
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{
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case IB_NEW_NEW_NEW:
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{
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vertexFifo[ verticesRead & VERTEX_FIFO_MASK ] = triangle[ 0 ];
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vertexFifo[ ( verticesRead + 1 ) & VERTEX_FIFO_MASK ] = triangle[ 1 ];
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vertexFifo[ ( verticesRead + 2 ) & VERTEX_FIFO_MASK ] = triangle[ 2 ];
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vertexRemap[ triangle[ 0 ] ] = newVertices;
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vertexRemap[ triangle[ 1 ] ] = newVertices + 1;
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vertexRemap[ triangle[ 2 ] ] = newVertices + 2;
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verticesRead += 3;
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newVertices += 3;
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break;
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}
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case IB_NEW_NEW_CACHED:
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{
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vertexFifo[ verticesRead & VERTEX_FIFO_MASK ] = reorderedTriangle[ 0 ];
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vertexFifo[ ( verticesRead + 1 ) & VERTEX_FIFO_MASK ] = reorderedTriangle[ 1 ];
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output.Write( cachedVertexIndices[ compressionCase.vertexOrder[ 2 ] ], CACHED_VERTEX_BITS );
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vertexRemap[ reorderedTriangle[ 0 ] ] = newVertices;
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vertexRemap[ reorderedTriangle[ 1 ] ] = newVertices + 1;
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verticesRead += 2;
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newVertices += 2;
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break;
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}
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case IB_NEW_NEW_FREE:
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{
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vertexFifo[ verticesRead & VERTEX_FIFO_MASK ] = reorderedTriangle[ 0 ];
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vertexFifo[ ( verticesRead + 1 ) & VERTEX_FIFO_MASK ] = reorderedTriangle[ 1 ];
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vertexFifo[ ( verticesRead + 2 ) & VERTEX_FIFO_MASK ] = reorderedTriangle[ 2 ];
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output.WriteVInt( ( newVertices - 1 ) - vertexRemap[ reorderedTriangle[ 2 ] ] );
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vertexRemap[ reorderedTriangle[ 0 ] ] = newVertices;
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vertexRemap[ reorderedTriangle[ 1 ] ] = newVertices + 1;
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verticesRead += 3;
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newVertices += 2;
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break;
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}
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case IB_NEW_CACHED_CACHED:
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{
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vertexFifo[ verticesRead & VERTEX_FIFO_MASK ] = reorderedTriangle[ 0 ];
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output.Write( cachedVertexIndices[ compressionCase.vertexOrder[ 1 ] ], CACHED_VERTEX_BITS );
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output.Write( cachedVertexIndices[ compressionCase.vertexOrder[ 2 ] ], CACHED_VERTEX_BITS );
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vertexRemap[ reorderedTriangle[ 0 ] ] = newVertices;
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verticesRead += 1;
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newVertices += 1;
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break;
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}
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case IB_NEW_CACHED_FREE:
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{
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vertexFifo[ verticesRead & VERTEX_FIFO_MASK ] = reorderedTriangle[ 0 ];
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vertexFifo[ ( verticesRead + 1 ) & VERTEX_FIFO_MASK ] = reorderedTriangle[ 2 ];
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output.Write( cachedVertexIndices[ compressionCase.vertexOrder[ 1 ] ], CACHED_VERTEX_BITS );
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output.WriteVInt( ( newVertices - 1 ) - vertexRemap[ reorderedTriangle[ 2 ] ] );
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vertexRemap[ reorderedTriangle[ 0 ] ] = newVertices;
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verticesRead += 2;
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newVertices += 1;
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break;
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}
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case IB_NEW_FREE_CACHED:
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{
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vertexFifo[ verticesRead & VERTEX_FIFO_MASK ] = reorderedTriangle[ 0 ];
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vertexFifo[ ( verticesRead + 1 ) & VERTEX_FIFO_MASK ] = reorderedTriangle[ 1 ];
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output.WriteVInt( ( newVertices - 1 ) - vertexRemap[ reorderedTriangle[ 1 ] ] );
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output.Write( cachedVertexIndices[ compressionCase.vertexOrder[ 2 ] ], CACHED_VERTEX_BITS );
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vertexRemap[ reorderedTriangle[ 0 ] ] = newVertices;
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verticesRead += 2;
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newVertices += 1;
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break;
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}
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case IB_NEW_FREE_FREE:
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{
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vertexFifo[ verticesRead & VERTEX_FIFO_MASK ] = reorderedTriangle[ 0 ];
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vertexFifo[ ( verticesRead + 1 ) & VERTEX_FIFO_MASK ] = reorderedTriangle[ 1 ];
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vertexFifo[ ( verticesRead + 2 ) & VERTEX_FIFO_MASK ] = reorderedTriangle[ 2 ];
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output.WriteVInt( ( newVertices - 1 ) - vertexRemap[ reorderedTriangle[ 1 ] ] );
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output.WriteVInt( ( newVertices - 1 ) - vertexRemap[ reorderedTriangle[ 2 ] ] );
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vertexRemap[ reorderedTriangle[ 0 ] ] = newVertices;
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verticesRead += 3;
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newVertices += 1;
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break;
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}
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case IB_CACHED_CACHED_CACHED:
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{
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output.Write( cachedVertexIndices[ compressionCase.vertexOrder[ 0 ] ], CACHED_VERTEX_BITS );
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output.Write( cachedVertexIndices[ compressionCase.vertexOrder[ 1 ] ], CACHED_VERTEX_BITS );
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output.Write( cachedVertexIndices[ compressionCase.vertexOrder[ 2 ] ], CACHED_VERTEX_BITS );
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break;
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}
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case IB_CACHED_CACHED_FREE:
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{
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vertexFifo[ verticesRead & VERTEX_FIFO_MASK ] = reorderedTriangle[ 2 ];
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output.Write( cachedVertexIndices[ compressionCase.vertexOrder[ 0 ] ], CACHED_VERTEX_BITS );
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output.Write( cachedVertexIndices[ compressionCase.vertexOrder[ 1 ] ], CACHED_VERTEX_BITS );
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output.WriteVInt( ( newVertices - 1 ) - vertexRemap[ reorderedTriangle[ 2 ] ] );
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verticesRead += 1;
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break;
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}
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case IB_CACHED_FREE_FREE:
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{
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vertexFifo[ verticesRead & VERTEX_FIFO_MASK ] = reorderedTriangle[ 1 ];
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vertexFifo[ ( verticesRead + 1 ) & VERTEX_FIFO_MASK ] = reorderedTriangle[ 2 ];
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output.Write( cachedVertexIndices[ compressionCase.vertexOrder[ 0 ] ], CACHED_VERTEX_BITS );
|
|
output.WriteVInt( ( newVertices - 1 ) - vertexRemap[ reorderedTriangle[ 1 ] ] );
|
|
output.WriteVInt( ( newVertices - 1 ) - vertexRemap[ reorderedTriangle[ 2 ] ] );
|
|
|
|
verticesRead += 2;
|
|
|
|
break;
|
|
}
|
|
case IB_FREE_FREE_FREE:
|
|
{
|
|
vertexFifo[ verticesRead & VERTEX_FIFO_MASK ] = reorderedTriangle[ 0 ];
|
|
vertexFifo[ ( verticesRead + 1 ) & VERTEX_FIFO_MASK ] = reorderedTriangle[ 1 ];
|
|
vertexFifo[ ( verticesRead + 2 ) & VERTEX_FIFO_MASK ] = reorderedTriangle[ 2 ];
|
|
|
|
output.WriteVInt( ( newVertices - 1 ) - vertexRemap[ reorderedTriangle[ 0 ] ] );
|
|
output.WriteVInt( ( newVertices - 1 ) - vertexRemap[ reorderedTriangle[ 1 ] ] );
|
|
output.WriteVInt( ( newVertices - 1 ) - vertexRemap[ reorderedTriangle[ 2 ] ] );
|
|
|
|
verticesRead += 3;
|
|
break;
|
|
}
|
|
|
|
default: // IB_EDGE_NEW, IB_EDGE_CACHED, IB_EDGE_0_NEW, IB_EDGE_1_NEW
|
|
break;
|
|
}
|
|
|
|
// populate the edge fifo with the 3 most recent edges
|
|
edgeFifo[ edgesRead & EDGE_FIFO_MASK ].set( reorderedTriangle[ 0 ], reorderedTriangle[ 1 ] );
|
|
|
|
++edgesRead;
|
|
|
|
edgeFifo[ edgesRead & EDGE_FIFO_MASK ].set( reorderedTriangle[ 1 ], reorderedTriangle[ 2 ] );
|
|
|
|
++edgesRead;
|
|
|
|
edgeFifo[ edgesRead & EDGE_FIFO_MASK ].set( reorderedTriangle[ 2 ], reorderedTriangle[ 0 ] );
|
|
|
|
++edgesRead;
|
|
}
|
|
}
|
|
}
|
|
|
|
|
|
|
|
// Output the compression information for a single vertex, remapping any new vertices and updating the vertex fifo where needed.
|
|
static IBC_INLINE void OutputVertex( uint32_t vertex,
|
|
uint32_t* vertexRemap,
|
|
uint32_t& newVertexCount,
|
|
uint32_t* vertexFifo,
|
|
uint32_t& verticesRead,
|
|
WriteBitstream& output )
|
|
{
|
|
// Check if a vertex hasn't been remapped,
|
|
if ( vertexRemap[ vertex ] == VERTEX_NOT_MAPPED )
|
|
{
|
|
// no remap, so remap to the current high watermark and output a new vertex code.
|
|
vertexRemap[ vertex ] = newVertexCount;
|
|
|
|
output.Write( IB_NEW_VERTEX, IB_VERTEX_CODE_BITS );
|
|
|
|
++newVertexCount;
|
|
|
|
// new vertices go into the vertex FIFO
|
|
vertexFifo[ verticesRead & VERTEX_FIFO_MASK ] = vertex;
|
|
|
|
++verticesRead;
|
|
}
|
|
else
|
|
{
|
|
int32_t lowestVertexCursor = verticesRead >= VERTEX_FIFO_SIZE ? verticesRead - VERTEX_FIFO_SIZE : 0;
|
|
|
|
// Probe backwards in the vertex FIFO for a cached vertex
|
|
for ( int32_t vertexCursor = verticesRead - 1; vertexCursor >= lowestVertexCursor; --vertexCursor )
|
|
{
|
|
if ( vertexFifo[ vertexCursor & VERTEX_FIFO_MASK ] == vertex )
|
|
{
|
|
// found a cached vertex, so write out the code for a cached vertex, as the relative index into the fifo.
|
|
output.Write( IB_CACHED_VERTEX, IB_VERTEX_CODE_BITS );
|
|
output.Write( ( verticesRead - 1 ) - vertexCursor, CACHED_VERTEX_BITS );
|
|
|
|
return;
|
|
}
|
|
}
|
|
|
|
// no cached vertex found, so write out a free vertex
|
|
output.Write( IB_FREE_VERTEX, IB_VERTEX_CODE_BITS );
|
|
|
|
// free vertices are relative to the latest new vertex.
|
|
uint32_t vertexOutput = ( newVertexCount - 1 ) - vertexRemap[ vertex ];
|
|
|
|
// v-int encode the free vertex index.
|
|
output.WriteVInt( vertexOutput );
|
|
|
|
// free vertices go back into the vertex cache.
|
|
vertexFifo[ verticesRead & VERTEX_FIFO_MASK ] = vertex;
|
|
|
|
++verticesRead;
|
|
}
|
|
|
|
}
|
|
|
|
template <typename Ty>
|
|
void CompressIndiceCodes1( const Ty* triangles,
|
|
uint32_t triangleCount,
|
|
uint32_t* vertexRemap,
|
|
uint32_t vertexCount,
|
|
WriteBitstream& output )
|
|
{
|
|
Edge edgeFifo[ EDGE_FIFO_SIZE ];
|
|
uint32_t vertexFifo[ VERTEX_FIFO_SIZE ];
|
|
|
|
uint32_t edgesRead = 0;
|
|
uint32_t verticesRead = 0;
|
|
uint32_t newVertices = 0;
|
|
const Ty* triangleEnd = triangles + ( triangleCount * 3 );
|
|
|
|
assert( vertexCount < 0xFFFFFFFF );
|
|
|
|
uint32_t* vertexRemapEnd = vertexRemap + vertexCount;
|
|
|
|
// clear the vertex remapping to "not found" value of 0xFFFFFFFF - dirty, but low overhead.
|
|
for ( uint32_t* remappedVertex = vertexRemap; remappedVertex < vertexRemapEnd; ++remappedVertex )
|
|
{
|
|
*remappedVertex = VERTEX_NOT_MAPPED;
|
|
}
|
|
|
|
// iterate through the triangles
|
|
for ( const Ty* triangle = triangles; triangle < triangleEnd; triangle += 3 )
|
|
{
|
|
int32_t lowestEdgeCursor = edgesRead >= EDGE_FIFO_SIZE ? edgesRead - EDGE_FIFO_SIZE : 0;
|
|
int32_t edgeCursor = edgesRead - 1;
|
|
bool foundEdge = false;
|
|
|
|
int32_t freeVertex = -1; // should not be negative 1 if found, this is not used as a signal, but for debugging.
|
|
|
|
// Probe back through the edge fifo to see if one of the triangle edges is in the FIFO
|
|
for ( ; edgeCursor >= lowestEdgeCursor; --edgeCursor )
|
|
{
|
|
const Edge& edge = edgeFifo[ edgeCursor & VERTEX_FIFO_MASK ];
|
|
|
|
// check all the edges in order and save the free vertex.
|
|
if ( edge.second == triangle[ 0 ] && edge.first == triangle[ 1 ] )
|
|
{
|
|
foundEdge = true;
|
|
freeVertex = 2;
|
|
break;
|
|
}
|
|
else if ( edge.second == triangle[ 1 ] && edge.first == triangle[ 2 ] )
|
|
{
|
|
foundEdge = true;
|
|
freeVertex = 0;
|
|
break;
|
|
}
|
|
else if ( edge.second == triangle[ 2 ] && edge.first == triangle[ 0 ] )
|
|
{
|
|
foundEdge = true;
|
|
freeVertex = 1;
|
|
break;
|
|
}
|
|
}
|
|
|
|
// we found an edge so write it out, then output the vertex
|
|
if ( foundEdge )
|
|
{
|
|
output.Write( IB_CACHED_EDGE, IB_VERTEX_CODE_BITS );
|
|
output.Write( ( edgesRead - 1 ) - edgeCursor, CACHED_EDGE_BITS );
|
|
|
|
const Edge& edge = edgeFifo[ edgeCursor & EDGE_FIFO_MASK ];
|
|
|
|
OutputVertex( triangle[ freeVertex ], vertexRemap, newVertices, vertexFifo, verticesRead, output );
|
|
|
|
// edge is in reverse order to last triangle it occured on (and it will only be a match if this is the case).
|
|
// so put the vertices into the fifo in that order.
|
|
vertexFifo[ verticesRead & VERTEX_FIFO_MASK ] = edge.second;
|
|
|
|
++verticesRead;
|
|
|
|
vertexFifo[ verticesRead & VERTEX_FIFO_MASK ] = edge.first;
|
|
|
|
++verticesRead;
|
|
|
|
// Populate the edge fifo with the the remaining edges
|
|
// Note - the winding order is important as we'll need to re-produce this on decompression.
|
|
// The edges are put in as if the found edge is the first edge in the triangle (which it will be when we
|
|
// reconstruct).
|
|
switch ( freeVertex )
|
|
{
|
|
case 0:
|
|
|
|
edgeFifo[ edgesRead & EDGE_FIFO_MASK ].set( triangle[ 2 ], triangle[ 0 ] );
|
|
|
|
++edgesRead;
|
|
|
|
edgeFifo[ edgesRead & EDGE_FIFO_MASK ].set( triangle[ 0 ], triangle[ 1 ] );
|
|
|
|
++edgesRead;
|
|
break;
|
|
|
|
case 1:
|
|
|
|
edgeFifo[ edgesRead & EDGE_FIFO_MASK ].set( triangle[ 0 ], triangle[ 1 ] );
|
|
|
|
++edgesRead;
|
|
|
|
edgeFifo[ edgesRead & EDGE_FIFO_MASK ].set( triangle[ 1 ], triangle[ 2 ] );
|
|
|
|
++edgesRead;
|
|
break;
|
|
|
|
case 2:
|
|
|
|
edgeFifo[ edgesRead & EDGE_FIFO_MASK ].set( triangle[ 1 ], triangle[ 2 ] );
|
|
|
|
++edgesRead;
|
|
|
|
edgeFifo[ edgesRead & EDGE_FIFO_MASK ].set( triangle[ 2 ], triangle[ 0 ] );
|
|
|
|
++edgesRead;
|
|
break;
|
|
}
|
|
}
|
|
else
|
|
{
|
|
// no edge, so we need to output all the vertices.
|
|
OutputVertex( triangle[ 0 ], vertexRemap, newVertices, vertexFifo, verticesRead, output );
|
|
OutputVertex( triangle[ 1 ], vertexRemap, newVertices, vertexFifo, verticesRead, output );
|
|
OutputVertex( triangle[ 2 ], vertexRemap, newVertices, vertexFifo, verticesRead, output );
|
|
|
|
// populate the edge fifo with the 3 most recent edges
|
|
edgeFifo[ edgesRead & EDGE_FIFO_MASK ].set( triangle[ 0 ], triangle[ 1 ] );
|
|
|
|
++edgesRead;
|
|
|
|
edgeFifo[ edgesRead & EDGE_FIFO_MASK ].set( triangle[ 1 ], triangle[ 2 ] );
|
|
|
|
++edgesRead;
|
|
|
|
edgeFifo[ edgesRead & EDGE_FIFO_MASK ].set( triangle[ 2 ], triangle[ 0 ] );
|
|
|
|
++edgesRead;
|
|
}
|
|
}
|
|
}
|
|
|
|
// Detects if there are any degenerate triangles in a set of triangles, where there is 1 or more duplicate vertices.
|
|
template <typename Ty>
|
|
bool ContainsDegenerates( const Ty* triangles, uint32_t triangleCount )
|
|
{
|
|
const Ty* triangleEnd = triangles + ( triangleCount * 3 );
|
|
bool result = false;
|
|
|
|
for ( const Ty* triangle = triangles; triangle < triangleEnd; triangle += 3 )
|
|
{
|
|
if ( triangle[ 0 ] == triangle[ 1 ] || triangle[ 0 ] == triangle[ 2 ] || triangle[ 1 ] == triangle[ 2 ] )
|
|
{
|
|
result = true;
|
|
break;
|
|
}
|
|
}
|
|
|
|
return result;
|
|
}
|
|
|
|
template <typename Ty>
|
|
void CompressIndexBuffer( const Ty* triangles,
|
|
uint32_t triangleCount,
|
|
uint32_t* vertexRemap,
|
|
uint32_t vertexCount,
|
|
IndexBufferCompressionFormat format,
|
|
WriteBitstream& output )
|
|
{
|
|
switch ( format )
|
|
{
|
|
case IBCF_PER_INDICE_1:
|
|
|
|
output.WriteVInt( IBCF_PER_INDICE_1 );
|
|
CompressIndiceCodes1<Ty>( triangles, triangleCount, vertexRemap, vertexCount, output );
|
|
break;
|
|
|
|
case IBCF_PER_TRIANGLE_1:
|
|
|
|
output.WriteVInt( IBCF_PER_TRIANGLE_1 );
|
|
CompressTriangleCodes1<Ty>( triangles, triangleCount, vertexRemap, vertexCount, output );
|
|
break;
|
|
|
|
case ICBF_AUTO:
|
|
|
|
if ( ContainsDegenerates( triangles, triangleCount ) )
|
|
{
|
|
output.WriteVInt( IBCF_PER_INDICE_1 );
|
|
CompressIndiceCodes1<Ty>( triangles, triangleCount, vertexRemap, vertexCount, output );
|
|
}
|
|
else
|
|
{
|
|
output.WriteVInt( IBCF_PER_TRIANGLE_1 );
|
|
CompressTriangleCodes1<Ty>( triangles, triangleCount, vertexRemap, vertexCount, output );
|
|
}
|
|
|
|
break;
|
|
}
|
|
}
|
|
|
|
void CompressIndexBuffer( const uint16_t* triangles,
|
|
uint32_t triangleCount,
|
|
uint32_t* vertexRemap,
|
|
uint32_t vertexCount,
|
|
IndexBufferCompressionFormat format,
|
|
WriteBitstream& output )
|
|
{
|
|
|
|
CompressIndexBuffer<uint16_t>( triangles, triangleCount, vertexRemap, vertexCount, format, output );
|
|
}
|
|
|
|
void CompressIndexBuffer( const uint32_t* triangles,
|
|
uint32_t triangleCount,
|
|
uint32_t* vertexRemap,
|
|
uint32_t vertexCount,
|
|
IndexBufferCompressionFormat format,
|
|
WriteBitstream& output )
|
|
{
|
|
CompressIndexBuffer<uint32_t>( triangles, triangleCount, vertexRemap, vertexCount, format, output );
|
|
}
|
|
|