src/display/nr-filter-composite.cpp

   1 /*
   2  * feComposite filter effect renderer
   3  *
   4  * Authors:
   5  *   Niko Kiirala <niko@kiirala.com>
   6  *
   7  * Copyright (C) 2007 authors
   8  *
   9  * Released under GNU GPL, read the file 'COPYING' for more information
  10  */
  11
  12 #include <cmath>
  13
  14 #include "isnan.h"
  15 #include "sp-fecomposite.h"
  16 #include "display/nr-filter-composite.h"
  17 #include "display/nr-filter-pixops.h"
  18 #include "display/nr-filter-slot.h"
  19 #include "libnr/nr-blit.h"
  20 #include "libnr/nr-pixblock.h"
  21 #include "libnr/nr-pixops.h"
  22 #include "libnr/nr-matrix.h"
  23
  24 inline void
  25 composite_over(unsigned char *r, unsigned char const *a, unsigned char const *b)
  26 {
  27     r[0] = a[0] + NR_NORMALIZE_21(b[0] * (255 - a[3]));
  28     r[1] = a[1] + NR_NORMALIZE_21(b[1] * (255 - a[3]));
  29     r[2] = a[2] + NR_NORMALIZE_21(b[2] * (255 - a[3]));
  30     r[3] = a[3] + NR_NORMALIZE_21(b[3] * (255 - a[3]));
  31 }
  32
  33 inline void
  34 composite_in(unsigned char *r, unsigned char const *a, unsigned char const *b)
  35 {
  36     r[0] = NR_NORMALIZE_21(a[0] * b[3]);
  37     r[1] = NR_NORMALIZE_21(a[1] * b[3]);
  38     r[2] = NR_NORMALIZE_21(a[2] * b[3]);
  39     r[3] = NR_NORMALIZE_21(a[3] * b[3]);
  40 }
  41
  42 inline void
  43 composite_out(unsigned char *r, unsigned char const *a, unsigned char const *b)
  44 {
  45     r[0] = NR_NORMALIZE_21(a[0] * (255 - b[3]));
  46     r[1] = NR_NORMALIZE_21(a[1] * (255 - b[3]));
  47     r[2] = NR_NORMALIZE_21(a[2] * (255 - b[3]));
  48     r[3] = NR_NORMALIZE_21(a[3] * (255 - b[3]));
  49 }
  50
  51 inline void
  52 composite_atop(unsigned char *r, unsigned char const *a, unsigned char const *b)
  53 {
  54     r[0] = NR_NORMALIZE_21(a[0] * b[3] + b[0] * (255 - a[3]));
  55     r[1] = NR_NORMALIZE_21(a[1] * b[3] + b[1] * (255 - a[3]));
  56     r[2] = NR_NORMALIZE_21(a[2] * b[3] + b[2] * (255 - a[3]));
  57     r[3] = b[3];
  58 }
  59
  60 inline void
  61 composite_xor(unsigned char *r, unsigned char const *a, unsigned char const *b)
  62 {
  63     r[0] = NR_NORMALIZE_21(a[0] * (255 - b[3]) + b[0] * (255 - a[3]));
  64     r[1] = NR_NORMALIZE_21(a[1] * (255 - b[3]) + b[1] * (255 - a[3]));
  65     r[2] = NR_NORMALIZE_21(a[2] * (255 - b[3]) + b[2] * (255 - a[3]));
  66     r[3] = NR_NORMALIZE_21(a[3] * (255 - b[3]) + b[3] * (255 - a[3]));
  67 }
  68
  69 static int clamp(int val) {
  70     if (val < 0) return 0;
  71     if (val > 255) return 255;
  72     return val;
  73 }
  74
  75 // BUGBUG / TODO
  76 // This makes arithmetic compositing non re-entrant and non thread safe.
  77 static int arith_k1, arith_k2, arith_k3, arith_k4;
  78 inline void
  79 composite_arithmetic(unsigned char *r, unsigned char const *a, unsigned char const *b)
  80 {
  81     r[0] = clamp(NR_NORMALIZE_31(arith_k1 * a[0] * b[0]
  82                  + arith_k2 * a[0] + arith_k3 * b[0] + arith_k4));
  83     r[1] = clamp(NR_NORMALIZE_31(arith_k1 * a[1] * b[1]
  84                  + arith_k2 * a[1] + arith_k3 * b[1] + arith_k4));
  85     r[2] = clamp(NR_NORMALIZE_31(arith_k1 * a[2] * b[2]
  86                  + arith_k2 * a[2] + arith_k3 * b[2] + arith_k4));
  87     r[3] = clamp(NR_NORMALIZE_31(arith_k1 * a[3] * b[3]
  88                  + arith_k2 * a[3] + arith_k3 * b[3] + arith_k4));
  89 }
  90
  91 namespace NR {
  92
  93 FilterComposite::FilterComposite() :
  94     op(COMPOSITE_DEFAULT), k1(0), k2(0), k3(0), k4(0),
  95     _input2(NR::NR_FILTER_SLOT_NOT_SET)
  96 {}
  97
  98 FilterPrimitive * FilterComposite::create() {
  99     return new FilterComposite();
 100 }
 101
 102 FilterComposite::~FilterComposite()
 103 {}
 104
 105 int FilterComposite::render(FilterSlot &slot, Matrix const &trans) {
 106     NRPixBlock *in1 = slot.get(_input);
 107     NRPixBlock *in2 = slot.get(_input2);
 108     NRPixBlock *original_in1 = in1;
 109     NRPixBlock *original_in2 = in2;
 110     NRPixBlock *out;
 111
 112     // Bail out if either one of source images is missing
 113     if (!in1 || !in2) {
 114         g_warning("Missing source image for feComposite (in=%d in2=%d)", _input, _input2);
 115         return 1;
 116     }
 117
 118     out = new NRPixBlock;
 119     NRRectL out_area;
 120     nr_rect_l_union(&out_area, &in1->area, &in2->area);
 121     nr_pixblock_setup_fast(out, NR_PIXBLOCK_MODE_R8G8B8A8P,
 122                            out_area.x0, out_area.y0, out_area.x1, out_area.y1,
 123                            true);
 124
 125     // Blending modes are defined for premultiplied RGBA values,
 126     // thus convert them to that format before blending
 127     if (in1->mode != NR_PIXBLOCK_MODE_R8G8B8A8P) {
 128         in1 = new NRPixBlock;
 129         nr_pixblock_setup_fast(in1, NR_PIXBLOCK_MODE_R8G8B8A8P,
 130                                original_in1->area.x0, original_in1->area.y0,
 131                                original_in1->area.x1, original_in1->area.y1,
 132                                false);
 133         nr_blit_pixblock_pixblock(in1, original_in1);
 134     }
 135     if (in2->mode != NR_PIXBLOCK_MODE_R8G8B8A8P) {
 136         in2 = new NRPixBlock;
 137         nr_pixblock_setup_fast(in2, NR_PIXBLOCK_MODE_R8G8B8A8P,
 138                                original_in2->area.x0, original_in2->area.y0,
 139                                original_in2->area.x1, original_in2->area.y1,
 140                                false);
 141         nr_blit_pixblock_pixblock(in2, original_in2);
 142     }
 143
 144     /* pixops_mix is defined in display/nr-filter-pixops.h
 145      * It mixes the two input images with the function given as template
 146      * and places the result in output image.
 147      */
 148     switch (op) {
 149         case COMPOSITE_IN:
 150             pixops_mix<composite_in>(*out, *in1, *in2);
 151             break;
 152         case COMPOSITE_OUT:
 153             pixops_mix<composite_out>(*out, *in1, *in2);
 154             break;
 155         case COMPOSITE_ATOP:
 156             pixops_mix<composite_atop>(*out, *in1, *in2);
 157             break;
 158         case COMPOSITE_XOR:
 159             pixops_mix<composite_xor>(*out, *in1, *in2);
 160             break;
 161         case COMPOSITE_ARITHMETIC:
 162             arith_k1 = (int)(k1 * 255);
 163             arith_k2 = (int)(k2 * 255 * 255);
 164             arith_k3 = (int)(k3 * 255 * 255);
 165             arith_k4 = (int)(k4 * 255 * 255 * 255);
 166             pixops_mix<composite_arithmetic>(*out, *in1, *in2);
 167             break;
 168         case COMPOSITE_DEFAULT:
 169         case COMPOSITE_OVER:
 170         default:
 171             pixops_mix<composite_over>(*out, *in1, *in2);
 172             break;
 173     }
 174
 175     if (in1 != original_in1) {
 176         nr_pixblock_release(in1);
 177         delete in1;
 178     }
 179     if (in2 != original_in2) {
 180         nr_pixblock_release(in2);
 181         delete in2;
 182     }
 183
 184     out->empty = FALSE;
 185     slot.set(_output, out);
 186
 187     return 0;
 188 }
 189
 190 void FilterComposite::set_input(int input) {
 191     _input = input;
 192 }
 193
 194 void FilterComposite::set_input(int input, int slot) {
 195     if (input == 0) _input = slot;
 196     if (input == 1) _input2 = slot;
 197 }
 198
 199 void FilterComposite::set_operator(FeCompositeOperator op) {
 200     if (op == COMPOSITE_DEFAULT) {
 201         this->op = COMPOSITE_OVER;
 202     } else if (op == COMPOSITE_OVER ||
 203                op == COMPOSITE_IN ||
 204                op == COMPOSITE_OUT ||
 205                op == COMPOSITE_ATOP ||
 206                op == COMPOSITE_XOR ||
 207                op == COMPOSITE_ARITHMETIC)
 208     {
 209         this->op = op;
 210     }
 211 }
 212
 213 void FilterComposite::set_arithmetic(double k1, double k2, double k3, double k4) {
 214     if (!isFinite(k1) || !isFinite(k2) || !isFinite(k3) || !isFinite(k4)) {
 215         g_warning("Non-finite parameter for feComposite arithmetic operator");
 216         return;
 217     }
 218     this->k1 = k1;
 219     this->k2 = k2;
 220     this->k3 = k3;
 221     this->k4 = k4;
 222 }
 223
 224 } /* namespace NR */
 225
 226 /*
 227   Local Variables:
 228   mode:c++
 229   c-file-style:"stroustrup"
 230   c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
 231   indent-tabs-mode:nil
 232   fill-column:99
 233   End:
 234 */
 235 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=99 :