29815abbb22a102123a8b80b174b80b4865d46e5
1 /*
2 * feDisplacementMap filter primitive renderer
3 *
4 * Authors:
5 * Felipe CorrĂȘa 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 */
12 #include "display/nr-filter-displacement-map.h"
13 #include "display/nr-filter-types.h"
14 #include "display/nr-filter-units.h"
15 #include "libnr/nr-blit.h"
16 #include "libnr/nr-pixops.h"
18 namespace Inkscape {
19 namespace Filters {
21 FilterDisplacementMap::FilterDisplacementMap()
22 {}
24 FilterPrimitive * FilterDisplacementMap::create() {
25 return new FilterDisplacementMap();
26 }
28 FilterDisplacementMap::~FilterDisplacementMap()
29 {}
31 struct pixel_t {
32 unsigned char channels[4];
33 inline unsigned char operator[](int c) const { return channels[c]; }
34 inline unsigned char& operator[](int c) { return channels[c]; }
35 static inline pixel_t blank() {
36 pixel_t p;
37 for(unsigned int i=0; i<4; i++) {
38 p[i] = 0;
39 }
40 return p;
41 }
42 };
44 static inline pixel_t pixelValue(NRPixBlock const* pb, int x, int y) {
45 if ( x < pb->area.x0 || x >= pb->area.x1 || y < pb->area.y0 || y >= pb->area.y1 ) return pixel_t::blank(); // This assumes anything outside the defined range is (0,0,0,0)
46 pixel_t const* data = reinterpret_cast<pixel_t const*>(NR_PIXBLOCK_PX(pb));
47 int offset = (x-pb->area.x0) + (pb->area.x1-pb->area.x0)*(y-pb->area.y0);
48 return data[offset];
49 }
51 template<bool PREMULTIPLIED>
52 static pixel_t interpolatePixels(NRPixBlock const* pb, double x, double y) {
53 unsigned int const sfl = 8u;
54 unsigned int const sf = 1u<<sfl;
55 unsigned int const sf2h = 1u<<(2u*sfl-1);
56 int xi = (int)floor(x), yi = (int)floor(y);
57 unsigned int xf = static_cast<unsigned int>(floor(sf*(x-xi)+.5)), yf = static_cast<unsigned int>(floor(sf*(y-yi)+.5));
58 pixel_t p00 = pixelValue(pb, xi+0, yi+0);
59 pixel_t p01 = pixelValue(pb, xi+1, yi+0);
60 pixel_t p10 = pixelValue(pb, xi+0, yi+1);
61 pixel_t p11 = pixelValue(pb, xi+1, yi+1);
63 pixel_t r;
64 if (PREMULTIPLIED) {
65 unsigned int p0[4]; // range [0,a*sf]
66 unsigned int p1[4];
67 for(size_t i=0; i<4; i++) {
68 p0[i] = sf*p00[i] + xf*((unsigned int)p01[i]-(unsigned int)p00[i]);
69 p1[i] = sf*p10[i] + xf*((unsigned int)p11[i]-(unsigned int)p10[i]);
70 }
71 for(size_t i=0; i<4; i++) {
72 unsigned int ru = sf*p0[i] + yf*(p1[i]-p0[i]); // range [0,a*sf^2]
73 r[i] = (ru + sf2h)>>(2u*sfl); // range [0,a]
74 }
75 } else {
76 // It's a good idea to interpolate premultiplied colors
77 // Consider two pixels, one being rgb(255,0,0,0), which is fully transparent,
78 // and the other being rgb(0,255,0,255), or green (fully opaque).
79 // If these two colors are interpolated the expected result would be greenish pixels containing no red.
80 unsigned int p0[4];
81 unsigned int p1[4];
82 for(size_t i=0; i<3; i++) {
83 unsigned int c00 = p00[i]*p00[3], c01 = p01[i]*p01[3], c10 = p10[i]*p10[3], c11 = p11[i]*p11[3]; // range [0,255*a]
84 p0[i] = sf*c00 + xf*(c01-c00); // range [0,255*a*sf]
85 p1[i] = sf*c10 + xf*(c11-c10); // range [0,255*a*sf]
86 }
87 p0[3] = sf*p00[3] + xf*(p01[3]-p00[3]); // range [0,a*sf]
88 p1[3] = sf*p10[3] + xf*(p11[3]-p10[3]);
89 unsigned int ru = sf*p0[3] + yf*(p1[3]-p0[3]); // range [0,a*sf^2]
90 r[3] = (ru + sf2h)>>(2u*sfl); // range [0,a]
91 for(size_t i=0; i<3; i++) {
92 unsigned int ru = sf*p0[i] + yf*(p1[i]-p0[i]); // range [0,255*a*sf^2]
93 r[i] = (ru + ru/2u)/ru; // range [0,255]
94 }
95 }
97 return r;
98 }
100 template<bool MAP_PREMULTIPLIED, bool DATA_PREMULTIPLIED>
101 static void performDisplacement(NRPixBlock const* texture, NRPixBlock const* map, int Xchannel, int Ychannel, NRPixBlock* out, double scalex, double scaley) {
102 pixel_t *out_data = reinterpret_cast<pixel_t*>(NR_PIXBLOCK_PX(out));
104 bool Xneedsdemul = MAP_PREMULTIPLIED && Xchannel<3;
105 bool Yneedsdemul = MAP_PREMULTIPLIED && Ychannel<3;
106 if (!Xneedsdemul) scalex /= 255.0;
107 if (!Yneedsdemul) scaley /= 255.0;
109 for (int xout=out->area.x0; xout < out->area.x1; xout++){
110 for (int yout=out->area.y0; yout < out->area.y1; yout++){
111 int xmap = xout;
112 int ymap = yout;
114 pixel_t mapValue = pixelValue(map, xmap, ymap);
115 double xtex = xout + (Xneedsdemul ?
116 (mapValue[3]==0?0:(scalex * (mapValue[Xchannel] - mapValue[3]*0.5) / mapValue[3])) :
117 (scalex * (mapValue[Xchannel] - 127.5)));
118 double ytex = yout + (Yneedsdemul ?
119 (mapValue[3]==0?0:(scaley * (mapValue[Ychannel] - mapValue[3]*0.5) / mapValue[3])) :
120 (scaley * (mapValue[Ychannel] - 127.5)));
122 out_data[(xout-out->area.x0) + (out->area.x1-out->area.x0)*(yout-out->area.y0)] = interpolatePixels<DATA_PREMULTIPLIED>(texture, xtex, ytex);
123 }
124 }
125 }
127 int FilterDisplacementMap::render(FilterSlot &slot, FilterUnits const &units) {
128 NRPixBlock *texture = slot.get(_input);
129 NRPixBlock *map = slot.get(_input2);
131 // Bail out if either one of source images is missing
132 if (!map || !texture) {
133 g_warning("Missing source image for feDisplacementMap (map=%d texture=%d)", _input, _input2);
134 return 1;
135 }
137 //TODO: check whether do we really need this check:
138 if (map->area.x1 <= map->area.x0 || map->area.y1 <= map->area.y0) return 0; //nothing to do!
140 if (texture->mode != NR_PIXBLOCK_MODE_R8G8B8A8N && texture->mode != NR_PIXBLOCK_MODE_R8G8B8A8P) {
141 g_warning("Source images without an alpha channel are not supported by feDisplacementMap at the moment.");
142 return 1;
143 }
145 NRPixBlock *out = new NRPixBlock;
147 out->area.x0 = map->area.x0;
148 out->area.y0 = map->area.y0;
149 out->area.x1 = map->area.x1;
150 out->area.y1 = map->area.y1;
152 nr_pixblock_setup_fast(out, texture->mode, out->area.x0, out->area.y0, out->area.x1, out->area.y1, true);
154 // convert to a suitable format
155 bool free_map_on_exit = false;
156 if (map->mode != NR_PIXBLOCK_MODE_R8G8B8A8N && map->mode != NR_PIXBLOCK_MODE_R8G8B8A8P) {
157 NRPixBlock *original_map = map;
158 map = new NRPixBlock;
159 nr_pixblock_setup_fast(map, NR_PIXBLOCK_MODE_R8G8B8A8N,
160 original_map->area.x0, original_map->area.y0,
161 original_map->area.x1, original_map->area.y1,
162 false);
163 nr_blit_pixblock_pixblock(map, original_map);
164 free_map_on_exit = true;
165 }
166 bool map_premultiplied = (map->mode == NR_PIXBLOCK_MODE_R8G8B8A8P);
167 bool data_premultiplied = (out->mode == NR_PIXBLOCK_MODE_R8G8B8A8P);
169 Geom::Matrix trans = units.get_matrix_primitiveunits2pb();
170 double scalex = scale * trans.expansionX();
171 double scaley = scale * trans.expansionY();
173 if (map_premultiplied && data_premultiplied) {
174 performDisplacement<true,true>(texture, map, Xchannel, Ychannel, out, scalex, scaley);
175 } else if (map_premultiplied && !data_premultiplied) {
176 performDisplacement<true,false>(texture, map, Xchannel, Ychannel, out, scalex, scaley);
177 } else if (data_premultiplied) {
178 performDisplacement<false,true>(texture, map, Xchannel, Ychannel, out, scalex, scaley);
179 } else {
180 performDisplacement<false,false>(texture, map, Xchannel, Ychannel, out, scalex, scaley);
181 }
183 if (free_map_on_exit) {
184 nr_pixblock_release(map);
185 delete map;
186 }
188 out->empty = FALSE;
189 slot.set(_output, out);
190 return 0;
191 }
193 void FilterDisplacementMap::set_input(int slot) {
194 _input = slot;
195 }
197 void FilterDisplacementMap::set_scale(double s) {
198 scale = s;
199 }
201 void FilterDisplacementMap::set_input(int input, int slot) {
202 if (input == 0) _input = slot;
203 if (input == 1) _input2 = slot;
204 }
206 void FilterDisplacementMap::set_channel_selector(int s, FilterDisplacementMapChannelSelector channel) {
207 if (channel > DISPLACEMENTMAP_CHANNEL_ALPHA || channel < DISPLACEMENTMAP_CHANNEL_RED) {
208 g_warning("Selected an invalid channel value. (%d)", channel);
209 return;
210 }
212 if (s == 0) Xchannel = channel;
213 if (s == 1) Ychannel = channel;
214 }
216 void FilterDisplacementMap::area_enlarge(NRRectL &area, Geom::Matrix const &trans)
217 {
218 //I assume scale is in user coordinates (?!?)
219 //FIXME: trans should be multiplied by some primitiveunits2user, shouldn't it?
221 double scalex = scale/2.*(std::fabs(trans[0])+std::fabs(trans[1]));
222 double scaley = scale/2.*(std::fabs(trans[2])+std::fabs(trans[3]));
224 //FIXME: no +2 should be there!... (noticable only for big scales at big zoom factor)
225 area.x0 -= (int)(scalex)+2;
226 area.x1 += (int)(scalex)+2;
227 area.y0 -= (int)(scaley)+2;
228 area.y1 += (int)(scaley)+2;
229 }
231 FilterTraits FilterDisplacementMap::get_input_traits() {
232 return TRAIT_PARALLER;
233 }
235 } /* namespace Filters */
236 } /* namespace Inkscape */
238 /*
239 Local Variables:
240 mode:c++
241 c-file-style:"stroustrup"
242 c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
243 indent-tabs-mode:nil
244 fill-column:99
245 End:
246 */
247 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=99 :