agg/source/agg_line_profile_aa.cpp

   1 //----------------------------------------------------------------------------
   2 // Anti-Grain Geometry - Version 2.3
   3 // Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
   4 //
   5 // Permission to copy, use, modify, sell and distribute this software
   6 // is granted provided this copyright notice appears in all copies.
   7 // This software is provided "as is" without express or implied
   8 // warranty, and with no claim as to its suitability for any purpose.
   9 //
  10 //----------------------------------------------------------------------------
  11 // Contact: mcseem@antigrain.com
  12 //          mcseemagg@yahoo.com
  13 //          http://www.antigrain.com
  14 //----------------------------------------------------------------------------
  15
  16 #include "agg_renderer_outline_aa.h"
  17
  18 namespace agg
  19 {
  20
  21     //---------------------------------------------------------------------
  22     void line_profile_aa::width(double w)
  23     {
  24         if(w < 0.0) w = 0.0;
  25
  26         if(w < m_smoother_width) w += w;
  27         else                     w += m_smoother_width;
  28
  29         w *= 0.5;
  30
  31         w -= m_smoother_width;
  32         double s = m_smoother_width;
  33         if(w < 0.0)
  34         {
  35             s += w;
  36             w = 0.0;
  37         }
  38         set(w, s);
  39     }
  40
  41
  42     //---------------------------------------------------------------------
  43     line_profile_aa::value_type* line_profile_aa::profile(double w)
  44     {
  45         m_subpixel_width = int(w * subpixel_size);
  46         unsigned size = m_subpixel_width + subpixel_size * 6;
  47         if(size > m_size)
  48         {
  49             delete [] m_profile;
  50             m_profile = new value_type[m_size = size];
  51         }
  52         return m_profile;
  53     }
  54
  55
  56     //---------------------------------------------------------------------
  57     void line_profile_aa::set(double center_width, double _smoother_width)
  58     {
  59         double base_val = 1.0;
  60         if(center_width == 0.0)   center_width = 1.0 / subpixel_size;
  61         if(_smoother_width == 0.0) _smoother_width = 1.0 / subpixel_size;
  62
  63         double _width = center_width + _smoother_width;
  64         if(_width < m_min_width)
  65         {
  66             double k = _width / m_min_width;
  67             base_val *= k;
  68             center_width /= k;
  69             _smoother_width /= k;
  70         }
  71
  72         value_type* ch = profile(center_width + _smoother_width);
  73
  74         unsigned subpixel_center_width = unsigned(center_width * subpixel_size);
  75         unsigned subpixel_smoother_width = unsigned(_smoother_width * subpixel_size);
  76
  77         value_type* ch_center   = ch + subpixel_size*2;
  78         value_type* ch_smoother = ch_center + subpixel_center_width;
  79
  80         unsigned i;
  81
  82         unsigned val = m_gamma[unsigned(base_val * aa_mask)];
  83         ch = ch_center;
  84         for(i = 0; i < subpixel_center_width; i++)
  85         {
  86             *ch++ = (value_type)val;
  87         }
  88
  89         for(i = 0; i < subpixel_smoother_width; i++)
  90         {
  91             *ch_smoother++ =
  92                 m_gamma[unsigned((base_val -
  93                                   base_val *
  94                                   (double(i) / subpixel_smoother_width)) * aa_mask)];
  95         }
  96
  97         unsigned n_smoother = profile_size() -
  98                               subpixel_smoother_width -
  99                               subpixel_center_width -
 100                               subpixel_size*2;
 101
 102         val = m_gamma[0];
 103         for(i = 0; i < n_smoother; i++)
 104         {
 105             *ch_smoother++ = (value_type)val;
 106         }
 107
 108         ch = ch_center;
 109         for(i = 0; i < subpixel_size*2; i++)
 110         {
 111             *--ch = *ch_center++;
 112         }
 113     }
 114
 115
 116 }
 117