74 lines
2.3 KiB
C++
74 lines
2.3 KiB
C++
// Adapted by Francesco Abbate for GSL Shell
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// Original code's copyright below.
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//----------------------------------------------------------------------------
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// Anti-Grain Geometry - Version 2.4
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// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
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//
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// Permission to copy, use, modify, sell and distribute this software
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// is granted provided this copyright notice appears in all copies.
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// This software is provided "as is" without express or implied
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// warranty, and with no claim as to its suitability for any purpose.
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//
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//----------------------------------------------------------------------------
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// Contact: mcseem@antigrain.com
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// mcseemagg@yahoo.com
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// http://www.antigrain.com
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//----------------------------------------------------------------------------
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#ifndef AGG_LCD_DISTRIBUTION_LUT_INCLUDED
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#define AGG_LCD_DISTRIBUTION_LUT_INCLUDED
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#include <cstdlib>
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#include "agg_basics.h"
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namespace agg
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{
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//=====================================================lcd_distribution_lut
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class lcd_distribution_lut
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{
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public:
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lcd_distribution_lut(double prim, double second, double tert)
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{
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double norm = 1.0 / (prim + second*2 + tert*2);
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prim *= norm;
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second *= norm;
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tert *= norm;
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for(unsigned i = 0; i < 256; i++)
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{
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unsigned b = (i << 8);
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unsigned s = round(second * b);
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unsigned t = round(tert * b);
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unsigned p = b - (2*s + 2*t);
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m_data[3*i + 1] = s; /* secondary */
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m_data[3*i + 2] = t; /* tertiary */
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m_data[3*i ] = p; /* primary */
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}
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}
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unsigned convolution(const int8u* covers, int i0, int i_min, int i_max) const
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{
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unsigned sum = 0;
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int k_min = (i0 >= i_min + 2 ? -2 : i_min - i0);
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int k_max = (i0 <= i_max - 2 ? 2 : i_max - i0);
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for (int k = k_min; k <= k_max; k++)
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{
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/* select the primary, secondary or tertiary channel */
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int channel = std::abs(k) % 3;
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int8u c = covers[i0 + k];
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sum += m_data[3*c + channel];
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}
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return (sum + 128) >> 8;
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}
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private:
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unsigned short m_data[256*3];
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};
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}
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#endif
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