![[tokkee]](http://tokkee.org/images/avatar.png){kind=avatar}
diff --git a/src/display/nr-filter-displacement-map.cpp b/src/display/nr-filter-displacement-map.cpp
index f4c29989fed1bf15fc66a725eef5236ccae353dd..863927f4b3f5d85e17ab851048c912d3501d26b0 100644 (file)
* feDisplacementMap filter primitive renderer
*
* Authors:
- * Felipe Corrêa da Silva Sanches <felipe.sanches@gmail.com>
+ * Felipe Corrêa da Silva Sanches <juca@members.fsf.org>
*
* Copyright (C) 2007 authors
*
#include "display/nr-filter-types.h"
#include "display/nr-filter-units.h"
#include "libnr/nr-blit.h"
-#include "libnr/nr-matrix-fns.h"
#include "libnr/nr-pixops.h"
-namespace NR {
+namespace Inkscape {
+namespace Filters {
FilterDisplacementMap::FilterDisplacementMap()
{}
FilterDisplacementMap::~FilterDisplacementMap()
{}
+struct pixel_t {
+ unsigned char channels[4];
+ inline unsigned char operator[](int c) const { return channels[c]; }
+ inline unsigned char& operator[](int c) { return channels[c]; }
+ static inline pixel_t blank() {
+ pixel_t p;
+ for(unsigned int i=0; i<4; i++) {
+ p[i] = 0;
+ }
+ return p;
+ }
+};
+
+static inline pixel_t pixelValue(NRPixBlock const* pb, int x, int y) {
+ 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)
+ pixel_t const* rowData = reinterpret_cast<pixel_t const*>(NR_PIXBLOCK_PX(pb) + (y-pb->area.y0)*pb->rs);
+ return rowData[x-pb->area.x0];
+}
+
+template<bool PREMULTIPLIED>
+static pixel_t interpolatePixels(NRPixBlock const* pb, double x, double y) {
+ // NOTE: The values of x and y are shifted by -0.5 (the "true" values would be x+0.5 and y+0.5).
+ // This is done because otherwise the pixel values first have to be shifted by +0.5 and then by -0.5 again...
+ unsigned int const sfl = 8u;
+ unsigned int const sf = 1u<<sfl;
+ unsigned int const sf2h = 1u<<(2u*sfl-1);
+ int xi = (int)floor(x), yi = (int)floor(y);
+ unsigned int xf = static_cast<unsigned int>(round(sf * (x - xi))),
+ yf = static_cast<unsigned int>(round(sf * (y - yi)));
+ pixel_t p00 = pixelValue(pb, xi+0, yi+0);
+ pixel_t p01 = pixelValue(pb, xi+1, yi+0);
+ pixel_t p10 = pixelValue(pb, xi+0, yi+1);
+ pixel_t p11 = pixelValue(pb, xi+1, yi+1);
+
+ /* It's a good idea to interpolate premultiplied colors:
+ *
+ * Consider two pixels, one being rgba(255,0,0,0), which is fully transparent,
+ * and the other being rgba(0,0,255,255), or blue (fully opaque).
+ * If these two colors are interpolated the expected result would be bluish pixels
+ * containing no red.
+ *
+ * However, if our final alpha value is zero, then the RGB values aren't really determinate.
+ * We might as well avoid premultiplication in this case, which still gives us a fully
+ * transparent result, but with interpolated RGB parts. */
+
+ pixel_t r;
+ if (PREMULTIPLIED) {
+ /* Premultiplied, so do simple interpolation. */
+ for (unsigned i = 0; i != 4; ++i) {
+ // y0,y1 have range [0,a*sf]
+ unsigned const y0 = sf*p00[i] + xf*((unsigned int)p01[i]-(unsigned int)p00[i]);
+ unsigned const y1 = sf*p10[i] + xf*((unsigned int)p11[i]-(unsigned int)p10[i]);
+
+ unsigned const ri = sf*y0 + yf*(y1-y0); // range [0,a*sf*sf]
+ r[i] = (ri + sf2h)>>(2*sfl); // range [0,a]
+ }
+ } else {
+ /* First calculate interpolated alpha value. */
+ unsigned const y0 = sf*p00[3] + xf*((unsigned int)p01[3]-(unsigned int)p00[3]); // range [0,a*sf]
+ unsigned const y1 = sf*p10[3] + xf*((unsigned int)p11[3]-(unsigned int)p10[3]);
+ unsigned const ra = sf*y0 + yf*(y1-y0); // range [0,a*sf*sf]
+
+ if (ra==0) {
+ /* Fully transparent, so do simple interpolation. */
+ for (unsigned i = 0; i != 3; ++i) {
+ // y0,y1 have range [0,255*sf]
+ unsigned const y0 = sf*p00[i] + xf*((unsigned int)p01[i]-(unsigned int)p00[i]);
+ unsigned const y1 = sf*p10[i] + xf*((unsigned int)p11[i]-(unsigned int)p10[i]);
+
+ unsigned const ri = sf*y0 + yf*(y1-y0); // range [0,255*sf*sf]
+ r[i] = (ri + sf2h)>>(2*sfl); // range [0,255]
+ }
+ r[3] = 0;
+ } else {
+ /* Do premultiplication ourselves. */
+ for (unsigned i = 0; i != 3; ++i) {
+ // Premultiplied versions. Range [0,255*a].
+ unsigned const c00 = p00[i]*p00[3];
+ unsigned const c01 = p01[i]*p01[3];
+ unsigned const c10 = p10[i]*p10[3];
+ unsigned const c11 = p11[i]*p11[3];
+
+ // Interpolation.
+ unsigned const y0 = sf*c00 + xf*(c01-c00); // range [0,255*a*sf]
+ unsigned const y1 = sf*c10 + xf*(c11-c10); // range [0,255*a*sf]
+ unsigned const ri = sf*y0 + yf*(y1-y0); // range [0,255*a*sf*sf]
+ r[i] = (ri + ra/2) / ra; // range [0,255]
+ }
+ r[3] = (ra + sf2h)>>(2*sfl); // range [0,a]
+ }
+ }
+
+ return r;
+}
+
+template<bool MAP_PREMULTIPLIED, bool DATA_PREMULTIPLIED>
+static void performDisplacement(NRPixBlock const* texture, NRPixBlock const* map, int Xchannel, int Ychannel, NRPixBlock* out, double scalex, double scaley) {
+ bool Xneedsdemul = MAP_PREMULTIPLIED && Xchannel<3;
+ bool Yneedsdemul = MAP_PREMULTIPLIED && Ychannel<3;
+ if (!Xneedsdemul) scalex /= 255.0;
+ if (!Yneedsdemul) scaley /= 255.0;
+
+ for (int yout=out->area.y0; yout < out->area.y1; yout++){
+ pixel_t const* mapRowData = reinterpret_cast<pixel_t const*>(NR_PIXBLOCK_PX(map) + (yout-map->area.y0)*map->rs);
+ pixel_t* outRowData = reinterpret_cast<pixel_t*>(NR_PIXBLOCK_PX(out) + (yout-out->area.y0)*out->rs);
+ for (int xout=out->area.x0; xout < out->area.x1; xout++){
+ pixel_t const mapValue = mapRowData[xout-map->area.x0];
+
+ double xtex = xout + (Xneedsdemul ? // Although the value of the pixel corresponds to the MIDDLE of the pixel, no +0.5 is needed because we're interpolating pixels anyway (so to get the actual pixel locations 0.5 would have to be subtracted again).
+ (mapValue[3]==0?0:(scalex * (mapValue[Xchannel] - mapValue[3]*0.5) / mapValue[3])) :
+ (scalex * (mapValue[Xchannel] - 127.5)));
+ double ytex = yout + (Yneedsdemul ?
+ (mapValue[3]==0?0:(scaley * (mapValue[Ychannel] - mapValue[3]*0.5) / mapValue[3])) :
+ (scaley * (mapValue[Ychannel] - 127.5)));
+
+ outRowData[xout-out->area.x0] = interpolatePixels<DATA_PREMULTIPLIED>(texture, xtex, ytex);
+ }
+ }
+}
+
int FilterDisplacementMap::render(FilterSlot &slot, FilterUnits const &units) {
NRPixBlock *texture = slot.get(_input);
NRPixBlock *map = slot.get(_input2);
@@ -38,27 +158,26 @@ int FilterDisplacementMap::render(FilterSlot &slot, FilterUnits const &units) {
return 1;
}
- //TODO: check whether do we really need this check:
- if (map->area.x1 <= map->area.x0 || map->area.y1 <= map->area.y0) return 0; //nothing to do!
+ NR::IRect area = units.get_pixblock_filterarea_paraller();
+ int x0 = std::max(map->area.x0,area.min()[NR::X]);
+ int y0 = std::max(map->area.y0,area.min()[NR::Y]);
+ int x1 = std::min(map->area.x1,area.max()[NR::X]);
+ int y1 = std::min(map->area.y1,area.max()[NR::Y]);
- NRPixBlock *out = new NRPixBlock;
-
- out_x0 = map->area.x0;
- out_y0 = map->area.y0;
- out_w = map->area.x1 - map->area.x0;
- out_h = map->area.y1 - map->area.y0;
+ //TODO: check whether we really need this check:
+ if (x1 <= x0 || y1 <= y0) return 0; //nothing to do!
- out->area.x0 = out_x0;
- out->area.y0 = out_y0;
- out->area.x1 = out_x0 + out_w;
- out->area.y1 = out_y0 + out_h;
+ if (texture->mode != NR_PIXBLOCK_MODE_R8G8B8A8N && texture->mode != NR_PIXBLOCK_MODE_R8G8B8A8P) {
+ g_warning("Source images without an alpha channel are not supported by feDisplacementMap at the moment.");
+ return 1;
+ }
- nr_pixblock_setup_fast(out, texture->mode, out->area.x0, out->area.y0, out->area.x1, out->area.y1, true);
+ NRPixBlock *out = new NRPixBlock;
+ nr_pixblock_setup_fast(out, texture->mode, x0, y0, x1, y1, true);
- // this primitive is defined for non-premultiplied RGBA values,
- // thus convert them to that format
+ // convert to a suitable format
bool free_map_on_exit = false;
- if (map->mode != NR_PIXBLOCK_MODE_R8G8B8A8N) {
+ if (map->mode != NR_PIXBLOCK_MODE_R8G8B8A8N && map->mode != NR_PIXBLOCK_MODE_R8G8B8A8P) {
NRPixBlock *original_map = map;
map = new NRPixBlock;
nr_pixblock_setup_fast(map, NR_PIXBLOCK_MODE_R8G8B8A8N,
@@ -68,44 +187,21 @@ int FilterDisplacementMap::render(FilterSlot &slot, FilterUnits const &units) {
nr_blit_pixblock_pixblock(map, original_map);
free_map_on_exit = true;
}
-
- unsigned char *map_data = NR_PIXBLOCK_PX(map);
- unsigned char *texture_data = NR_PIXBLOCK_PX(texture);
- unsigned char *out_data = NR_PIXBLOCK_PX(out);
- int x, y;
- int in_w = map->area.x1 - map->area.x0;
- int in_h = map->area.y1 - map->area.y0;
- double coordx, coordy;
+ bool map_premultiplied = (map->mode == NR_PIXBLOCK_MODE_R8G8B8A8P);
+ bool data_premultiplied = (out->mode == NR_PIXBLOCK_MODE_R8G8B8A8P);
Geom::Matrix trans = units.get_matrix_primitiveunits2pb();
double scalex = scale * trans.expansionX();
double scaley = scale * trans.expansionY();
-
- for (x=0; x < out_w; x++){
- for (y=0; y < out_h; y++){
- int xmap = x+out_x0-map->area.x0;
- int ymap = y+out_y0-map->area.y0;
- if (xmap >= 0 &&
- xmap < in_w &&
- ymap >= 0 &&
- ymap < in_h){
-
- coordx = xmap + scalex * ( double(map_data[4*(xmap + in_w*ymap) + Xchannel]-128.)/256);
- coordy = ymap + scaley * ( double(map_data[4*(xmap + in_w*ymap) + Ychannel]-128.)/256);
-
- if (coordx>=0 && coordx<in_w && coordy>=0 && coordy<in_h){
- out_data[4*(x + out_w*y) ] = texture_data[4*(int(coordx) + int(coordy)*in_w) ];
- out_data[4*(x + out_w*y) + 1] = texture_data[4*(int(coordx) + int(coordy)*in_w) + 1];
- out_data[4*(x + out_w*y) + 2] = texture_data[4*(int(coordx) + int(coordy)*in_w) + 2];
- out_data[4*(x + out_w*y) + 3] = texture_data[4*(int(coordx) + int(coordy)*in_w) + 3];
- } else {
- out_data[4*(x + out_w*y) ] = 255;
- out_data[4*(x + out_w*y) + 1] = 255;
- out_data[4*(x + out_w*y) + 2] = 255;
- out_data[4*(x + out_w*y) + 3] = 0;
- }
- }
- }
+
+ if (map_premultiplied && data_premultiplied) {
+ performDisplacement<true,true>(texture, map, Xchannel, Ychannel, out, scalex, scaley);
+ } else if (map_premultiplied && !data_premultiplied) {
+ performDisplacement<true,false>(texture, map, Xchannel, Ychannel, out, scalex, scaley);
+ } else if (data_premultiplied) {
+ performDisplacement<false,true>(texture, map, Xchannel, Ychannel, out, scalex, scaley);
+ } else {
+ performDisplacement<false,false>(texture, map, Xchannel, Ychannel, out, scalex, scaley);
}
if (free_map_on_exit) {
@@ -141,7 +237,7 @@ void FilterDisplacementMap::set_channel_selector(int s, FilterDisplacementMapCha
if (s == 1) Ychannel = channel;
}
-void FilterDisplacementMap::area_enlarge(NRRectL &area, Matrix const &trans)
+void FilterDisplacementMap::area_enlarge(NRRectL &area, Geom::Matrix const &trans)
{
//I assume scale is in user coordinates (?!?)
//FIXME: trans should be multiplied by some primitiveunits2user, shouldn't it?
return TRAIT_PARALLER;
}
-} /* namespace NR */
+} /* namespace Filters */
+} /* namespace Inkscape */
/*
Local Variables:
fill-column:99
End:
*/
-// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=99 :
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :