src/display/nr-filter-component-transfer.cpp

   1 /*
   2  * feComponentTransfer filter primitive renderer
   3  *
   4  * Authors:
   5  *   Felipe Corrêa da Silva Sanches <felipe.sanches@gmail.com>
   6  *   Jasper van de Gronde <th.v.d.gronde@hccnet.nl>
   7  *
   8  * Copyright (C) 2007 authors
   9  *
  10  * Released under GNU GPL, read the file 'COPYING' for more information
  11  */
  12
  13 #include "display/nr-filter-component-transfer.h"
  14 #include "display/nr-filter-units.h"
  15 #include "display/nr-filter-utils.h"
  16 #include "libnr/nr-pixblock.h"
  17 #include "libnr/nr-blit.h"
  18 #include "libnr/nr-pixops.h"
  19 #include <math.h>
  20
  21 namespace Inkscape {
  22 namespace Filters {
  23
  24 FilterComponentTransfer::FilterComponentTransfer()
  25 {
  26 }
  27
  28 FilterPrimitive * FilterComponentTransfer::create() {
  29     return new FilterComponentTransfer();
  30 }
  31
  32 FilterComponentTransfer::~FilterComponentTransfer()
  33 {}
  34
  35 int FilterComponentTransfer::render(FilterSlot &slot, FilterUnits const &/*units*/) {
  36     NRPixBlock *in = slot.get(_input);
  37
  38     if (!in) {
  39         g_warning("Missing source image for feComponentTransfer (in=%d)", _input);
  40         return 1;
  41     }
  42
  43     int x0=in->area.x0;
  44     int x1=in->area.x1;
  45     int y0=in->area.y0;
  46     int y1=in->area.y1;
  47
  48     NRPixBlock *out = new NRPixBlock;
  49     nr_pixblock_setup_fast(out, NR_PIXBLOCK_MODE_R8G8B8A8N, x0, y0, x1, y1, true);
  50
  51     // this primitive is defined for non-premultiplied RGBA values,
  52     // thus convert them to that format before blending
  53     bool free_in_on_exit = false;
  54     if (in->mode != NR_PIXBLOCK_MODE_R8G8B8A8N) {
  55         NRPixBlock *original_in = in;
  56         in = new NRPixBlock;
  57         nr_pixblock_setup_fast(in, NR_PIXBLOCK_MODE_R8G8B8A8N,
  58                                original_in->area.x0, original_in->area.y0,
  59                                original_in->area.x1, original_in->area.y1,
  60                                false);
  61         nr_blit_pixblock_pixblock(in, original_in);
  62         free_in_on_exit = true;
  63     }
  64
  65     unsigned char *in_data = NR_PIXBLOCK_PX(in);
  66     unsigned char *out_data = NR_PIXBLOCK_PX(out);
  67
  68     (void)in_data;
  69     (void)out_data;
  70
  71     int size = 4 * (y1-y0) * (x1-x0);
  72     int i;
  73
  74     for (int color=0;color<4;color++){
  75         int _vsize = tableValues[color].size();
  76         double _intercept = intercept[color];
  77         double _slope = slope[color];
  78         double _amplitude = amplitude[color];
  79         double _exponent = exponent[color];
  80         double _offset = offset[color];
  81         switch(type[color]){
  82             case COMPONENTTRANSFER_TYPE_IDENTITY:
  83                 for(i=color;i<size;i+=4){
  84                     out_data[i]=in_data[i];
  85                 }
  86                 break;
  87             case COMPONENTTRANSFER_TYPE_TABLE:
  88                 if (_vsize<=1){
  89                     if (_vsize==1) {
  90                         g_warning("A component transfer table has to have at least two values.");
  91                     }
  92                     for(i=color;i<size;i+=4){
  93                         out_data[i]=in_data[i];
  94                     }
  95                 } else {
  96                     std::vector<gdouble> _tableValues(tableValues[color]);
  97                     // Scale by 255 and add .5 to avoid having to add it later for rounding purposes
  98                     for(i=0;i<_vsize;i++) {
  99                         _tableValues[i] = std::max(0.,std::min(255.,255*_tableValues[i])) + .5;
 100                     }
 101                     for(i=color;i<size;i+=4){
 102                         int k = FAST_DIVIDE<255>((_vsize-1) * in_data[i]);
 103                         double dx = ((_vsize-1) * in_data[i])/255.0 - k;
 104                         out_data[i] = static_cast<unsigned char>(_tableValues[k] + dx * (_tableValues[k+1] - _tableValues[k]));
 105                     }
 106                 }
 107                 break;
 108             case COMPONENTTRANSFER_TYPE_DISCRETE:
 109                 if (_vsize==0){
 110                     for(i=color;i<size;i+=4){
 111                         out_data[i] = in_data[i];
 112                     }
 113                 } else {
 114                     std::vector<unsigned char> _tableValues(_vsize);
 115                     // Convert to unsigned char
 116                     for(i=0;i<_vsize;i++) {
 117                         _tableValues[i] = static_cast<unsigned char>(std::max(0.,std::min(255.,255*tableValues[color][i])) + .5);
 118                     }
 119                     for(i=color;i<size;i+=4){
 120                         int k = FAST_DIVIDE<255>((_vsize-1) * in_data[i]);
 121                         out_data[i] =  _tableValues[k];
 122                     }
 123                 }
 124                 break;
 125             case COMPONENTTRANSFER_TYPE_LINEAR:
 126                 _intercept = 255*_intercept + .5;
 127                 for(i=color;i<size;i+=4){
 128                     out_data[i] = CLAMP_D_TO_U8(_slope * in_data[i] + _intercept);
 129                 }
 130                 break;
 131             case COMPONENTTRANSFER_TYPE_GAMMA:
 132                 _amplitude *= pow(255.0, -_exponent+1);
 133                 _offset = 255*_offset + .5;
 134                 for(i=color;i<size;i+=4){
 135                     out_data[i] = CLAMP_D_TO_U8(_amplitude * pow((double)in_data[i], _exponent) + _offset);
 136                 }
 137                 break;
 138             case COMPONENTTRANSFER_TYPE_ERROR:
 139                 //TODO: report an error here
 140                 g_warning("Component tranfer type \"error\".");
 141                 break;
 142             default:
 143                 g_warning("Invalid tranfer type %d.", type[color]);
 144         }
 145     }
 146
 147     if (free_in_on_exit) {
 148         nr_pixblock_release(in);
 149         delete in;
 150     }
 151
 152     out->empty = FALSE;
 153     slot.set(_output, out);
 154     return 0;
 155 }
 156
 157 void FilterComponentTransfer::area_enlarge(NRRectL &/*area*/, Geom::Matrix const &/*trans*/)
 158 {
 159 }
 160
 161 } /* namespace Filters */
 162 } /* namespace Inkscape */
 163
 164 /*
 165   Local Variables:
 166   mode:c++
 167   c-file-style:"stroustrup"
 168   c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
 169   indent-tabs-mode:nil
 170   fill-column:99
 171   End:
 172 */
 173 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=99 :