synfig-core/trunk/src/modules/mod_filter/halftone.cpp

   1 /* === S Y N F I G ========================================================= */
   2 /*!     \file halftone.cpp
   3 **      \brief blehh
   4 **
   5 **      $Id: halftone.cpp,v 1.1.1.1 2005/01/04 01:23:10 darco Exp $
   6 **
   7 **      \legal
   8 **      Copyright (c) 2002 Robert B. Quattlebaum Jr.
   9 **
  10 **      This software and associated documentation
  11 **      are CONFIDENTIAL and PROPRIETARY property of
  12 **      the above-mentioned copyright holder.
  13 **
  14 **      You may not copy, print, publish, or in any
  15 **      other way distribute this software without
  16 **      a prior written agreement with
  17 **      the copyright holder.
  18 **      \endlegal
  19 */
  20 /* ========================================================================= */
  21
  22 /* === H E A D E R S ======================================================= */
  23
  24 #ifdef USING_PCH
  25 #       include "pch.h"
  26 #else
  27 #ifdef HAVE_CONFIG_H
  28 #       include <config.h>
  29 #endif
  30
  31 #include "halftone.h"
  32
  33 #endif
  34
  35 /* === M A C R O S ========================================================= */
  36
  37 using namespace synfig;
  38 using namespace std;
  39 using namespace etl;
  40
  41 /* === G L O B A L S ======================================================= */
  42
  43
  44 /* === P R O C E D U R E S ================================================= */
  45
  46 #define SQRT2   (1.414213562f)
  47
  48 /* === M E T H O D S ======================================================= */
  49
  50 float
  51 Halftone::operator()(const Point &point, const float& luma, float supersample)const
  52 {
  53         float halftone(mask(point));
  54
  55         if(supersample>=0.5f)
  56                 supersample=0.4999999999f;
  57
  58         halftone=(halftone-0.5f)*(1.0f-supersample*2.0f)+0.5f;
  59
  60         const float diff(halftone-luma);
  61
  62         if(supersample)
  63         {
  64                 const float amount(diff/(supersample*2.0f)+0.5f);
  65
  66                 if(amount<=0.0f+0.01f)
  67                         return 1.0f;
  68                 else if(amount>=1.0f-0.01f)
  69                         return 0.0f;
  70                 else
  71                         return 1.0f-amount;
  72         }
  73         else
  74         {
  75                 if(diff>=0)
  76                         return 0.0f;
  77                 else
  78                         return 1.0f;
  79         }
  80
  81         return 0.0f;
  82 }
  83
  84 float
  85 Halftone::mask(synfig::Point point)const
  86 {
  87         float radius1;
  88         float radius2;
  89
  90         point-=offset;
  91
  92         {
  93                 const float     a(Angle::sin(-angle).get()),    b(Angle::cos(-angle).get());
  94                 const float     u(point[0]),v(point[1]);
  95
  96                 point[0]=b*u-a*v;
  97                 point[1]=a*u+b*v;
  98         }
  99
 100         if(type==TYPE_STRIPE)
 101         {
 102                 Point pnt(fmod(point[0],size[0]),fmod(point[1],size[1]));
 103                 while(pnt[0]<0)pnt[0]+=abs(size[0]);
 104                 while(pnt[1]<0)pnt[1]+=abs(size[1]);
 105
 106                 float x(pnt[1]/size[1]);
 107                 if(x>0.5)x=1.0-x;
 108                 x*=2;
 109                 return x;
 110         }
 111
 112         {
 113                 Point pnt(fmod(point[0],size[0]),fmod(point[1],size[1]));
 114                 while(pnt[0]<0)pnt[0]+=abs(size[0]);
 115                 while(pnt[1]<0)pnt[1]+=abs(size[1]);
 116                 pnt-=Vector(size[0]*0.5,size[1]*0.5);
 117                 pnt*=2.0;
 118                 pnt[0]/=size[0];
 119                 pnt[1]/=size[1];
 120
 121                 radius1=pnt.mag()/SQRT2;
 122                 radius1*=radius1;
 123         }
 124         if(type==TYPE_DARKONLIGHT || type== TYPE_LIGHTONDARK)
 125                 return radius1;
 126
 127         {
 128                 Point pnt(fmod(point[0]+size[0]*0.5,size[0]),fmod(point[1]+size[0]*0.5,size[1]));
 129                 while(pnt[0]<0)pnt[0]+=abs(size[0]);
 130                 while(pnt[1]<0)pnt[1]+=abs(size[1]);
 131                 pnt-=Vector(size[0]*0.5,size[1]*0.5);
 132                 pnt*=2.0;
 133                 pnt[0]/=size[0];
 134                 pnt[1]/=size[1];
 135
 136                 radius2=pnt.mag()/SQRT2;
 137                 radius2*=radius2;
 138         }
 139
 140         if(type==TYPE_DIAMOND)
 141         {
 142                 //return (radius1+(1.0f-radius2))*0.5;
 143                 float x((radius1+(1.0f-radius2))*0.5);
 144                 //float x(((radius2-radius1)*((radius1+(1.0f-radius2))*0.5)+radius1)*2.0f);
 145                 x-=0.5;
 146                 x*=2.0;
 147                 if(x<0)x=-sqrt(-x);else x=sqrt(x);
 148                 x*=1.01f;
 149                 x/=2.0;
 150                 x+=0.5;
 151                 return x;
 152         }
 153
 154         if(type==TYPE_SYMMETRIC)
 155         {
 156                 float x(((radius2-radius1)*((radius1+(1.0f-radius2))*0.5)+radius1)*2.0f);
 157                 x-=0.5;
 158                 x*=2.0;
 159                 if(x<0)x=-sqrt(-x);else x=sqrt(x);
 160                 x*=1.01f;
 161                 x/=2.0;
 162                 x+=0.5;
 163                 return x;
 164         }
 165         return 0;
 166 }