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Diffstat (limited to 'drivers/squish/colourset.cpp')
| -rw-r--r-- | drivers/squish/colourset.cpp | 121 |
1 files changed, 121 insertions, 0 deletions
diff --git a/drivers/squish/colourset.cpp b/drivers/squish/colourset.cpp new file mode 100644 index 0000000000..97d29d9873 --- /dev/null +++ b/drivers/squish/colourset.cpp @@ -0,0 +1,121 @@ +/* ----------------------------------------------------------------------------- + + 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 "colourset.h" + +namespace squish { + +ColourSet::ColourSet( u8 const* rgba, int mask, int flags ) + : m_count( 0 ), + m_transparent( false ) +{ + // check the compression mode for dxt1 + bool isDxt1 = ( ( flags & kDxt1 ) != 0 ); + bool weightByAlpha = ( ( flags & kWeightColourByAlpha ) != 0 ); + + // create the minimal set + for( int i = 0; i < 16; ++i ) + { + // check this pixel is enabled + int bit = 1 << i; + if( ( mask & bit ) == 0 ) + { + m_remap[i] = -1; + continue; + } + + // check for transparent pixels when using dxt1 + if( isDxt1 && rgba[4*i + 3] < 128 ) + { + m_remap[i] = -1; + m_transparent = true; + continue; + } + + // loop over previous points for a match + for( int j = 0;; ++j ) + { + // allocate a new point + if( j == i ) + { + // normalise coordinates to [0,1] + float x = ( float )rgba[4*i] / 255.0f; + float y = ( float )rgba[4*i + 1] / 255.0f; + float z = ( float )rgba[4*i + 2] / 255.0f; + + // ensure there is always non-zero weight even for zero alpha + float w = ( float )( rgba[4*i + 3] + 1 ) / 256.0f; + + // add the point + m_points[m_count] = Vec3( x, y, z ); + m_weights[m_count] = ( weightByAlpha ? w : 1.0f ); + m_remap[i] = m_count; + + // advance + ++m_count; + break; + } + + // check for a match + int oldbit = 1 << j; + bool match = ( ( mask & oldbit ) != 0 ) + && ( rgba[4*i] == rgba[4*j] ) + && ( rgba[4*i + 1] == rgba[4*j + 1] ) + && ( rgba[4*i + 2] == rgba[4*j + 2] ) + && ( rgba[4*j + 3] >= 128 || !isDxt1 ); + if( match ) + { + // get the index of the match + int index = m_remap[j]; + + // ensure there is always non-zero weight even for zero alpha + float w = ( float )( rgba[4*i + 3] + 1 ) / 256.0f; + + // map to this point and increase the weight + m_weights[index] += ( weightByAlpha ? w : 1.0f ); + m_remap[i] = index; + break; + } + } + } + + // square root the weights + for( int i = 0; i < m_count; ++i ) + m_weights[i] = std::sqrt( m_weights[i] ); +} + +void ColourSet::RemapIndices( u8 const* source, u8* target ) const +{ + for( int i = 0; i < 16; ++i ) + { + int j = m_remap[i]; + if( j == -1 ) + target[i] = 3; + else + target[i] = source[j]; + } +} + +} // namespace squish |