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Diffstat (limited to 'thirdparty/squish/singlecolourfit.cpp')
| -rw-r--r-- | thirdparty/squish/singlecolourfit.cpp | 173 |
1 files changed, 173 insertions, 0 deletions
diff --git a/thirdparty/squish/singlecolourfit.cpp b/thirdparty/squish/singlecolourfit.cpp new file mode 100644 index 0000000000..bd02cc41ab --- /dev/null +++ b/thirdparty/squish/singlecolourfit.cpp @@ -0,0 +1,173 @@ +/* ----------------------------------------------------------------------------- + + Copyright (c) 2006 Simon Brown si@sjbrown.co.uk + + Permission is hereby granted, free of charge, to any person obtaining + a copy of this software and associated documentation files (the + "Software"), to deal in the Software without restriction, including + without limitation the rights to use, copy, modify, merge, publish, + distribute, sublicense, and/or sell copies of the Software, and to + permit persons to whom the Software is furnished to do so, subject to + the following conditions: + + The above copyright notice and this permission notice shall be included + in all copies or substantial portions of the Software. + + THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS + OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF + MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. + IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY + CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, + TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE + SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. + + -------------------------------------------------------------------------- */ + +#include "singlecolourfit.h" +#include "colourset.h" +#include "colourblock.h" +#include <climits> + +namespace squish { + +struct SourceBlock +{ + u8 start; + u8 end; + u8 error; +}; + +struct SingleColourLookup +{ + SourceBlock sources[2]; +}; + +#include "singlecolourlookup.inl" + +static int FloatToInt( float a, int limit ) +{ + // use ANSI round-to-zero behaviour to get round-to-nearest + int i = ( int )( a + 0.5f ); + + // clamp to the limit + if( i < 0 ) + i = 0; + else if( i > limit ) + i = limit; + + // done + return i; +} + +SingleColourFit::SingleColourFit( ColourSet const* colours, int flags ) + : ColourFit( colours, flags ) +{ + // grab the single colour + Vec3 const* values = m_colours->GetPoints(); + m_colour[0] = ( u8 )FloatToInt( 255.0f*values->X(), 255 ); + m_colour[1] = ( u8 )FloatToInt( 255.0f*values->Y(), 255 ); + m_colour[2] = ( u8 )FloatToInt( 255.0f*values->Z(), 255 ); + + // initialise the best error + m_besterror = INT_MAX; +} + +void SingleColourFit::Compress3( void* block ) +{ + // build the table of lookups + SingleColourLookup const* const lookups[] = + { + lookup_5_3, + lookup_6_3, + lookup_5_3 + }; + + // find the best end-points and index + ComputeEndPoints( lookups ); + + // build the block if we win + if( m_error < m_besterror ) + { + // remap the indices + u8 indices[16]; + m_colours->RemapIndices( &m_index, indices ); + + // save the block + WriteColourBlock3( m_start, m_end, indices, block ); + + // save the error + m_besterror = m_error; + } +} + +void SingleColourFit::Compress4( void* block ) +{ + // build the table of lookups + SingleColourLookup const* const lookups[] = + { + lookup_5_4, + lookup_6_4, + lookup_5_4 + }; + + // find the best end-points and index + ComputeEndPoints( lookups ); + + // build the block if we win + if( m_error < m_besterror ) + { + // remap the indices + u8 indices[16]; + m_colours->RemapIndices( &m_index, indices ); + + // save the block + WriteColourBlock4( m_start, m_end, indices, block ); + + // save the error + m_besterror = m_error; + } +} + +void SingleColourFit::ComputeEndPoints( SingleColourLookup const* const* lookups ) +{ + // check each index combination (endpoint or intermediate) + m_error = INT_MAX; + for( int index = 0; index < 2; ++index ) + { + // check the error for this codebook index + SourceBlock const* sources[3]; + int error = 0; + for( int channel = 0; channel < 3; ++channel ) + { + // grab the lookup table and index for this channel + SingleColourLookup const* lookup = lookups[channel]; + int target = m_colour[channel]; + + // store a pointer to the source for this channel + sources[channel] = lookup[target].sources + index; + + // accumulate the error + int diff = sources[channel]->error; + error += diff*diff; + } + + // keep it if the error is lower + if( error < m_error ) + { + m_start = Vec3( + ( float )sources[0]->start/31.0f, + ( float )sources[1]->start/63.0f, + ( float )sources[2]->start/31.0f + ); + m_end = Vec3( + ( float )sources[0]->end/31.0f, + ( float )sources[1]->end/63.0f, + ( float )sources[2]->end/31.0f + ); + m_index = ( u8 )( 2*index ); + m_error = error; + } + } +} + +} // namespace squish |