int C_BspNode::ClassifyPolygon(C_Plane* plane , poly* polygon)
{
int front = 0, back = 0;
for(int i = 0; i < polygon->nVertices; i++) {
int whereIs = ClassifyVertex(plane , &(polygon->pVertices[i]));
if(whereIs == FRONT) {
front++;
} else if(whereIs == BACK) {
back++;
}
}
if(front && !back) {
return FRONT;
} else if(!front && back) {
return BACK;
} else if(!front && !back) {
return COINCIDENT;
} else {
return INTERSECTS;
}
}
void CompressTriangleCodes1( 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 spareVertex = 0;
// check to make sure that there are no degenerate triangles.
assert( triangle[ 0 ] != triangle[ 1 ] && triangle[ 1 ] != triangle[ 2 ] && triangle[ 2 ] != triangle[ 0 ] );
// 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 & EDGE_FIFO_MASK ];
// check all the edges in order and save the free vertex.
if ( edge.second == triangle[ 0 ] && edge.first == triangle[ 1 ] )
{
foundEdge = true;
spareVertex = 2;
break;
}
else if ( edge.second == triangle[ 1 ] && edge.first == triangle[ 2 ] )
{
foundEdge = true;
spareVertex = 0;
break;
}
else if ( edge.second == triangle[ 2 ] && edge.first == triangle[ 0 ] )
{
foundEdge = true;
spareVertex = 1;
break;
}
}
// we found an edge so write it out, so classify a vertex and then write out the correct code.
if ( foundEdge )
{
uint32_t cachedVertex;
uint32_t spareVertexIndice = triangle[ spareVertex ];
VertexClassification freeVertexClass = ClassifyVertex( spareVertexIndice, vertexRemap, vertexFifo, verticesRead, cachedVertex );
uint32_t relativeEdge = ( edgesRead - 1 ) - edgeCursor;
switch ( freeVertexClass )
{
case NEW_VERTEX:
switch ( relativeEdge )
{
case 0:
output.Write( IB_EDGE_0_NEW, IB_TRIANGLE_CODE_BITS );
break;
case 1:
output.Write( IB_EDGE_1_NEW, IB_TRIANGLE_CODE_BITS );
break;
default:
output.Write( IB_EDGE_NEW, IB_TRIANGLE_CODE_BITS );
output.Write( relativeEdge, CACHED_EDGE_BITS );
break;
}
vertexFifo[ verticesRead & VERTEX_FIFO_MASK ] = spareVertexIndice;
vertexRemap[ spareVertexIndice ] = newVertices;
++verticesRead;
++newVertices;
break;
case CACHED_VERTEX:
output.Write( IB_EDGE_CACHED, IB_TRIANGLE_CODE_BITS );
output.Write( relativeEdge, CACHED_EDGE_BITS );
output.Write( cachedVertex, CACHED_VERTEX_BITS );
break;
case FREE_VERTEX:
output.Write( IB_EDGE_FREE, IB_TRIANGLE_CODE_BITS );
output.Write( relativeEdge, CACHED_EDGE_BITS );
vertexFifo[ verticesRead & VERTEX_FIFO_MASK ] = spareVertexIndice;
++verticesRead;
output.WriteVInt( ( newVertices - 1 ) - vertexRemap[ spareVertexIndice ] );
break;
}
// 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 ( spareVertex )
{
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
{
VertexClassification classifications[ 3 ];
uint32_t cachedVertexIndices[ 3 ];
// classify each vertex as new, cached or free, potentially extracting a cached indice.
classifications[ 0 ] = ClassifyVertex( triangle[ 0 ], vertexRemap, vertexFifo, verticesRead, cachedVertexIndices[ 0 ] );
classifications[ 1 ] = ClassifyVertex( triangle[ 1 ], vertexRemap, vertexFifo, verticesRead, cachedVertexIndices[ 1 ] );
classifications[ 2 ] = ClassifyVertex( triangle[ 2 ], vertexRemap, vertexFifo, verticesRead, cachedVertexIndices[ 2 ] );
// use the classifications to lookup the matching compression code and potentially rotate the order of the vertices.
const VertexCompressionCase& compressionCase = CompressionCase[ classifications[ 0 ] ][ classifications[ 1 ] ][ classifications[ 2 ] ];
// rotate the order of the vertices based on the compression classification.
uint32_t reorderedTriangle[ 3 ];
reorderedTriangle[ 0 ] = triangle[ compressionCase.vertexOrder[ 0 ] ];
reorderedTriangle[ 1 ] = triangle[ compressionCase.vertexOrder[ 1 ] ];
reorderedTriangle[ 2 ] = triangle[ compressionCase.vertexOrder[ 2 ] ];
output.Write( compressionCase.code, IB_TRIANGLE_CODE_BITS );
switch ( compressionCase.code )
{
case IB_NEW_NEW_NEW:
{
vertexFifo[ verticesRead & VERTEX_FIFO_MASK ] = triangle[ 0 ];
vertexFifo[ ( verticesRead + 1 ) & VERTEX_FIFO_MASK ] = triangle[ 1 ];
vertexFifo[ ( verticesRead + 2 ) & VERTEX_FIFO_MASK ] = triangle[ 2 ];
vertexRemap[ triangle[ 0 ] ] = newVertices;
vertexRemap[ triangle[ 1 ] ] = newVertices + 1;
vertexRemap[ triangle[ 2 ] ] = newVertices + 2;
verticesRead += 3;
newVertices += 3;
break;
}
case IB_NEW_NEW_CACHED:
{
vertexFifo[ verticesRead & VERTEX_FIFO_MASK ] = reorderedTriangle[ 0 ];
vertexFifo[ ( verticesRead + 1 ) & VERTEX_FIFO_MASK ] = reorderedTriangle[ 1 ];
output.Write( cachedVertexIndices[ compressionCase.vertexOrder[ 2 ] ], CACHED_VERTEX_BITS );
vertexRemap[ reorderedTriangle[ 0 ] ] = newVertices;
vertexRemap[ reorderedTriangle[ 1 ] ] = newVertices + 1;
verticesRead += 2;
newVertices += 2;
break;
}
case IB_NEW_NEW_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[ 2 ] ] );
vertexRemap[ reorderedTriangle[ 0 ] ] = newVertices;
vertexRemap[ reorderedTriangle[ 1 ] ] = newVertices + 1;
verticesRead += 3;
newVertices += 2;
break;
}
case IB_NEW_CACHED_CACHED:
{
vertexFifo[ verticesRead & VERTEX_FIFO_MASK ] = reorderedTriangle[ 0 ];
output.Write( cachedVertexIndices[ compressionCase.vertexOrder[ 1 ] ], CACHED_VERTEX_BITS );
output.Write( cachedVertexIndices[ compressionCase.vertexOrder[ 2 ] ], CACHED_VERTEX_BITS );
vertexRemap[ reorderedTriangle[ 0 ] ] = newVertices;
verticesRead += 1;
newVertices += 1;
break;
}
case IB_NEW_CACHED_FREE:
{
vertexFifo[ verticesRead & VERTEX_FIFO_MASK ] = reorderedTriangle[ 0 ];
vertexFifo[ ( verticesRead + 1 ) & VERTEX_FIFO_MASK ] = reorderedTriangle[ 2 ];
output.Write( cachedVertexIndices[ compressionCase.vertexOrder[ 1 ] ], CACHED_VERTEX_BITS );
output.WriteVInt( ( newVertices - 1 ) - vertexRemap[ reorderedTriangle[ 2 ] ] );
vertexRemap[ reorderedTriangle[ 0 ] ] = newVertices;
verticesRead += 2;
newVertices += 1;
break;
}
case IB_NEW_FREE_CACHED:
{
vertexFifo[ verticesRead & VERTEX_FIFO_MASK ] = reorderedTriangle[ 0 ];
vertexFifo[ ( verticesRead + 1 ) & VERTEX_FIFO_MASK ] = reorderedTriangle[ 1 ];
output.WriteVInt( ( newVertices - 1 ) - vertexRemap[ reorderedTriangle[ 1 ] ] );
output.Write( cachedVertexIndices[ compressionCase.vertexOrder[ 2 ] ], CACHED_VERTEX_BITS );
vertexRemap[ reorderedTriangle[ 0 ] ] = newVertices;
verticesRead += 2;
newVertices += 1;
break;
}
case IB_NEW_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[ 1 ] ] );
output.WriteVInt( ( newVertices - 1 ) - vertexRemap[ reorderedTriangle[ 2 ] ] );
vertexRemap[ reorderedTriangle[ 0 ] ] = newVertices;
verticesRead += 3;
newVertices += 1;
break;
}
case IB_CACHED_CACHED_CACHED:
{
output.Write( cachedVertexIndices[ compressionCase.vertexOrder[ 0 ] ], CACHED_VERTEX_BITS );
output.Write( cachedVertexIndices[ compressionCase.vertexOrder[ 1 ] ], CACHED_VERTEX_BITS );
output.Write( cachedVertexIndices[ compressionCase.vertexOrder[ 2 ] ], CACHED_VERTEX_BITS );
break;
}
case IB_CACHED_CACHED_FREE:
{
vertexFifo[ verticesRead & VERTEX_FIFO_MASK ] = reorderedTriangle[ 2 ];
output.Write( cachedVertexIndices[ compressionCase.vertexOrder[ 0 ] ], CACHED_VERTEX_BITS );
output.Write( cachedVertexIndices[ compressionCase.vertexOrder[ 1 ] ], CACHED_VERTEX_BITS );
output.WriteVInt( ( newVertices - 1 ) - vertexRemap[ reorderedTriangle[ 2 ] ] );
verticesRead += 1;
break;
}
case IB_CACHED_FREE_FREE:
{
vertexFifo[ verticesRead & VERTEX_FIFO_MASK ] = reorderedTriangle[ 1 ];
vertexFifo[ ( verticesRead + 1 ) & VERTEX_FIFO_MASK ] = reorderedTriangle[ 2 ];
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;
}
}
// 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;
}
}
}
