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  *
   7  * Copyright (C) 2007 authors
   8  *
   9  * Released under GNU GPL, read the file 'COPYING' for more information
  10  */
  11
  12 #include "display/nr-filter-component-transfer.h"
  13 #include "display/nr-filter-units.h"
  14 #include "display/nr-filter-utils.h"
  15 #include "libnr/nr-pixblock.h"
  16 #include "libnr/nr-blit.h"
  17 #include <math.h>
  18
  19 namespace NR {
  20
  21 FilterComponentTransfer::FilterComponentTransfer()
  22 {
  23 }
  24
  25 FilterPrimitive * FilterComponentTransfer::create() {
  26     return new FilterComponentTransfer();
  27 }
  28
  29 FilterComponentTransfer::~FilterComponentTransfer()
  30 {}
  31
  32 int FilterComponentTransfer::render(FilterSlot &slot, FilterUnits const &/*units*/) {
  33     NRPixBlock *in = slot.get(_input);
  34
  35     if (!in) {
  36         g_warning("Missing source image for feComponentTransfer (in=%d)", _input);
  37         return 1;
  38     }
  39
  40     int x0=in->area.x0;
  41     int x1=in->area.x1;
  42     int y0=in->area.y0;
  43     int y1=in->area.y1;
  44
  45     NRPixBlock *out = new NRPixBlock;
  46     nr_pixblock_setup_fast(out, NR_PIXBLOCK_MODE_R8G8B8A8N, x0, y0, x1, y1, true);
  47
  48     // this primitive is defined for non-premultiplied RGBA values,
  49     // thus convert them to that format before blending
  50     bool free_in_on_exit = false;
  51     if (in->mode != NR_PIXBLOCK_MODE_R8G8B8A8N) {
  52         NRPixBlock *original_in = in;
  53         in = new NRPixBlock;
  54         nr_pixblock_setup_fast(in, NR_PIXBLOCK_MODE_R8G8B8A8N,
  55                                original_in->area.x0, original_in->area.y0,
  56                                original_in->area.x1, original_in->area.y1,
  57                                false);
  58         nr_blit_pixblock_pixblock(in, original_in);
  59         free_in_on_exit = true;
  60     }
  61
  62     unsigned char *in_data = NR_PIXBLOCK_PX(in);
  63     unsigned char *out_data = NR_PIXBLOCK_PX(out);
  64
  65     (void)in_data;
  66     (void)out_data;
  67
  68     int size = 4 * (y1-y0) * (x1-x0);
  69     int i;
  70
  71     for (int color=0;color<4;color++){
  72         int _vsize = tableValues[color].size();
  73         std::vector<gdouble> _tableValues = tableValues[color];
  74         double _intercept = intercept[color];
  75         double _slope = slope[color];
  76         double _amplitude = amplitude[color];
  77         double _exponent = exponent[color];
  78         double _offset = offset[color];
  79         switch(type[color]){
  80             case COMPONENTTRANSFER_TYPE_IDENTITY:
  81                 for(i=color;i<size;i+=4){
  82                     out_data[i]=in_data[i];
  83                 }
  84                 break;
  85             case COMPONENTTRANSFER_TYPE_TABLE:
  86                 if (_vsize==0){
  87                     for(i=color;i<size;i+=4){
  88                         out_data[i]=in_data[i];
  89                     }
  90                 } else {
  91                     for(i=color;i<size;i+=4){
  92                         int k = (int)(((_vsize-1) * (double)in_data[i])/256);
  93                         double dx = ((_vsize-1) * (double)in_data[i])/256 - k;
  94                         out_data[i] = CLAMP_D_TO_U8(256 * (_tableValues[k] + dx * (_tableValues[k+1] - _tableValues[k]) ));
  95                     }
  96                 }
  97                 break;
  98             case COMPONENTTRANSFER_TYPE_DISCRETE:
  99                 if (_vsize==0){
 100                     for(i=color;i<size;i+=4){
 101                         out_data[i] = in_data[i];
 102                     }
 103                 } else {
 104                     for(i=color;i<size;i+=4){
 105                         out_data[i] = CLAMP_D_TO_U8(256 * _tableValues[(int)((_vsize-1)*(double)in_data[i]/256)] );
 106                     }
 107                 }
 108                 break;
 109             case COMPONENTTRANSFER_TYPE_LINEAR:
 110                 for(i=color;i<size;i+=4){
 111                     out_data[i] = CLAMP_D_TO_U8(256 * (_slope * (double)in_data[i]/256 + _intercept));
 112                 }
 113                 break;
 114             case COMPONENTTRANSFER_TYPE_GAMMA:
 115                 for(i=color;i<size;i+=4){
 116                     out_data[i] = CLAMP_D_TO_U8(256 * (_amplitude * pow((double)in_data[i]/256, _exponent) + _offset));
 117                 }
 118                 break;
 119             case COMPONENTTRANSFER_TYPE_ERROR:
 120                 //TODO: report an error here
 121                 break;
 122         }
 123     }
 124
 125     if (free_in_on_exit) {
 126         nr_pixblock_release(in);
 127         delete in;
 128     }
 129
 130     out->empty = FALSE;
 131     slot.set(_output, out);
 132     return 0;
 133 }
 134
 135 void FilterComponentTransfer::area_enlarge(NRRectL &/*area*/, Matrix const &/*trans*/)
 136 {
 137 }
 138
 139 } /* namespace NR */
 140
 141 /*
 142   Local Variables:
 143   mode:c++
 144   c-file-style:"stroustrup"
 145   c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
 146   indent-tabs-mode:nil
 147   fill-column:99
 148   End:
 149 */
 150 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=99 :