1 /*
2 * feMerge 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 */
12 #include <cmath>
13 #include <vector>
15 #include "2geom/isnan.h"
16 #include "filters/merge.h"
17 #include "display/nr-filter-merge.h"
18 #include "display/nr-filter-pixops.h"
19 #include "display/nr-filter-slot.h"
20 #include "display/nr-filter-units.h"
21 #include "display/nr-filter-utils.h"
22 #include "libnr/nr-blit.h"
23 #include "libnr/nr-pixblock.h"
24 #include "libnr/nr-pixops.h"
26 inline void
27 composite_over(unsigned char *r, unsigned char const *a, unsigned char const *b)
28 {
29 r[0] = a[0] + NR_NORMALIZE_21(b[0] * (255 - a[3]));
30 r[1] = a[1] + NR_NORMALIZE_21(b[1] * (255 - a[3]));
31 r[2] = a[2] + NR_NORMALIZE_21(b[2] * (255 - a[3]));
32 r[3] = a[3] + NR_NORMALIZE_21(b[3] * (255 - a[3]));
33 }
35 namespace Inkscape {
36 namespace Filters {
38 FilterMerge::FilterMerge() :
39 _input_image(1, NR_FILTER_SLOT_NOT_SET)
40 {}
42 FilterPrimitive * FilterMerge::create() {
43 return new FilterMerge();
44 }
46 FilterMerge::~FilterMerge()
47 {}
49 int FilterMerge::render(FilterSlot &slot, FilterUnits const &/*units*/) {
50 NRPixBlock *in[_input_image.size()];
51 NRPixBlock *original_in[_input_image.size()];
53 for (unsigned int i = 0 ; i < _input_image.size() ; i++) {
54 in[i] = slot.get(_input_image[i]);
55 original_in[i] = in[i];
56 }
58 NRPixBlock *out;
60 // Bail out if one of source images is missing
61 for (unsigned int i = 0 ; i < _input_image.size() ; i++) {
62 bool missing = false;
63 if (!in[i]) {
64 g_warning("Missing source image for feMerge (number=%d slot=%d)", i, _input_image[i]);
65 missing = true;
66 }
67 if (missing) return 1;
68 }
70 out = new NRPixBlock;
71 NRRectL out_area = in[0]->area;
72 for (unsigned int i = 1 ; i < _input_image.size() ; i++) {
73 nr_rect_l_union(&out_area, &out_area, &in[i]->area);
74 }
75 nr_pixblock_setup_fast(out, NR_PIXBLOCK_MODE_R8G8B8A8P,
76 out_area.x0, out_area.y0, out_area.x1, out_area.y1,
77 true);
79 // Merge is defined for premultiplied RGBA values, thus convert them to
80 // that format before blending
81 for (unsigned int i = 0 ; i < _input_image.size() ; i++) {
82 if (in[i]->mode != NR_PIXBLOCK_MODE_R8G8B8A8P) {
83 in[i] = new NRPixBlock;
84 nr_pixblock_setup_fast(in[i], NR_PIXBLOCK_MODE_R8G8B8A8P,
85 original_in[i]->area.x0,
86 original_in[i]->area.y0,
87 original_in[i]->area.x1,
88 original_in[i]->area.y1,
89 false);
90 nr_blit_pixblock_pixblock(in[i], original_in[i]);
91 }
92 }
94 /* pixops_mix is defined in display/nr-filter-pixops.h
95 * It mixes the two input images with the function given as template
96 * and places the result in output image.
97 */
98 for (unsigned int i = 0 ; i < _input_image.size() ; i++) {
99 pixops_mix<composite_over>(*out, *in[i], *out);
100 }
102 for (unsigned int i = 0 ; i < _input_image.size() ; i++) {
103 if (in[i] != original_in[i]) {
104 nr_pixblock_release(in[i]);
105 delete in[i];
106 }
107 }
109 out->empty = FALSE;
110 slot.set(_output, out);
112 return 0;
113 }
115 void FilterMerge::set_input(int slot) {
116 _input_image[0] = slot;
117 }
119 void FilterMerge::set_input(int input, int slot) {
120 if (input < 0) return;
122 if (static_cast<int>(_input_image.size()) > input) {
123 _input_image[input] = slot;
124 } else {
125 for (int i = static_cast<int>(_input_image.size()) ; i < input ; i++) {
126 _input_image.push_back(NR_FILTER_SLOT_NOT_SET);
127 }
128 _input_image.push_back(slot);
129 }
130 }
132 } /* namespace Filters */
133 } /* namespace Inkscape */
135 /*
136 Local Variables:
137 mode:c++
138 c-file-style:"stroustrup"
139 c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
140 indent-tabs-mode:nil
141 fill-column:99
142 End:
143 */
144 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=99 :