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Diffstat (limited to 'src/display/nr-filter-convolve-matrix.cpp')
| -rw-r--r-- | src/display/nr-filter-convolve-matrix.cpp | 243 |
1 files changed, 243 insertions, 0 deletions
diff --git a/src/display/nr-filter-convolve-matrix.cpp b/src/display/nr-filter-convolve-matrix.cpp new file mode 100644 index 0000000..1e9bdb0 --- /dev/null +++ b/src/display/nr-filter-convolve-matrix.cpp @@ -0,0 +1,243 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * feConvolveMatrix filter primitive renderer + * + * Authors: + * Felipe Corrêa da Silva Sanches <juca@members.fsf.org> + * Jasper van de Gronde <th.v.d.gronde@hccnet.nl> + * + * Copyright (C) 2007,2009 authors + * + * Released under GNU GPL v2+, read the file 'COPYING' for more information. + */ + +#include <vector> +#include "display/cairo-templates.h" +#include "display/cairo-utils.h" +#include "display/nr-filter-convolve-matrix.h" +#include "display/nr-filter-slot.h" +#include "display/nr-filter-units.h" +#include "display/nr-filter-utils.h" + +namespace Inkscape { +namespace Filters { + +FilterConvolveMatrix::FilterConvolveMatrix() += default; + +FilterPrimitive * FilterConvolveMatrix::create() { + return new FilterConvolveMatrix(); +} + +FilterConvolveMatrix::~FilterConvolveMatrix() += default; + +enum PreserveAlphaMode { + PRESERVE_ALPHA, + NO_PRESERVE_ALPHA +}; + +template <PreserveAlphaMode preserve_alpha> +struct ConvolveMatrix : public SurfaceSynth { + ConvolveMatrix(cairo_surface_t *s, int targetX, int targetY, int orderX, int orderY, + double divisor, double bias, std::vector<double> const &kernel) + : SurfaceSynth(s) + , _kernel(kernel.size()) + , _targetX(targetX) + , _targetY(targetY) + , _orderX(orderX) + , _orderY(orderY) + , _bias(bias) + { + for (unsigned i = 0; i < _kernel.size(); ++i) { + _kernel[i] = kernel[i] / divisor; + } + // the matrix is given rotated 180 degrees + // which corresponds to reverse element order + std::reverse(_kernel.begin(), _kernel.end()); + } + + guint32 operator()(int x, int y) const { + int startx = std::max(0, x - _targetX); + int starty = std::max(0, y - _targetY); + int endx = std::min(_w, startx + _orderX); + int endy = std::min(_h, starty + _orderY); + int limitx = endx - startx; + int limity = endy - starty; + double suma = 0.0, sumr = 0.0, sumg = 0.0, sumb = 0.0; + + for (int i = 0; i < limity; ++i) { + for (int j = 0; j < limitx; ++j) { + guint32 px = pixelAt(startx + j, starty + i); + double coeff = _kernel[i * _orderX + j]; + EXTRACT_ARGB32(px, a,r,g,b) + + sumr += r * coeff; + sumg += g * coeff; + sumb += b * coeff; + if (preserve_alpha == NO_PRESERVE_ALPHA) { + suma += a * coeff; + } + } + } + if (preserve_alpha == PRESERVE_ALPHA) { + suma = alphaAt(x, y); + } else { + suma += _bias * 255; + } + + guint32 ao = pxclamp(round(suma), 0, 255); + guint32 ro = pxclamp(round(sumr + ao * _bias), 0, ao); + guint32 go = pxclamp(round(sumg + ao * _bias), 0, ao); + guint32 bo = pxclamp(round(sumb + ao * _bias), 0, ao); + ASSEMBLE_ARGB32(pxout, ao,ro,go,bo); + return pxout; + } + +private: + std::vector<double> _kernel; + int _targetX, _targetY, _orderX, _orderY; + double _bias; +}; + +void FilterConvolveMatrix::render_cairo(FilterSlot &slot) +{ + static bool bias_warning = false; + static bool edge_warning = false; + + if (orderX<=0 || orderY<=0) { + g_warning("Empty kernel!"); + return; + } + if (targetX<0 || targetX>=orderX || targetY<0 || targetY>=orderY) { + g_warning("Invalid target!"); + return; + } + if (kernelMatrix.size()!=(unsigned int)(orderX*orderY)) { + //g_warning("kernelMatrix does not have orderX*orderY elements!"); + return; + } + + cairo_surface_t *input = slot.getcairo(_input); + cairo_surface_t *out = ink_cairo_surface_create_identical(input); + + // We may need to transform input surface to correct color interpolation space. The input surface + // might be used as input to another primitive but it is likely that all the primitives in a given + // filter use the same color interpolation space so we don't copy the input before converting. + SPColorInterpolation ci_fp = SP_CSS_COLOR_INTERPOLATION_AUTO; + if( _style ) { + ci_fp = (SPColorInterpolation)_style->color_interpolation_filters.computed; + set_cairo_surface_ci(out, ci_fp); + } + set_cairo_surface_ci( input, ci_fp ); + + if (bias!=0 && !bias_warning) { + g_warning("It is unknown whether Inkscape's implementation of bias in feConvolveMatrix " + "is correct!"); + bias_warning = true; + // The SVG specification implies that feConvolveMatrix is defined for premultiplied + // colors (which makes sense). It also says that bias should simply be added to the result + // for each color (without taking the alpha into account). However, it also says that one + // purpose of bias is "to have .5 gray value be the zero response of the filter". + // It seems sensible to indeed support the latter behaviour instead of the former, + // but this does appear to go against the standard. + // Note that Batik simply does not support bias!=0 + } + if (edgeMode!=CONVOLVEMATRIX_EDGEMODE_NONE && !edge_warning) { + g_warning("Inkscape only supports edgeMode=\"none\" (and a filter uses a different one)!"); + edge_warning = true; + } + + //guint32 *in_data = reinterpret_cast<guint32*>(cairo_image_surface_get_data(input)); + //guint32 *out_data = reinterpret_cast<guint32*>(cairo_image_surface_get_data(out)); + + //int width = cairo_image_surface_get_width(input); + //int height = cairo_image_surface_get_height(input); + + // Set up predivided kernel matrix + /*std::vector<double> kernel(kernelMatrix); + for(size_t i=0; i<kernel.size(); i++) { + kernel[i] /= divisor; // The code that creates this object makes sure that divisor != 0 + }*/ + + if (preserveAlpha) { + //convolve2D<true>(out_data, in_data, width, height, &kernel.front(), orderX, orderY, + // targetX, targetY, bias); + ink_cairo_surface_synthesize(out, ConvolveMatrix<PRESERVE_ALPHA>(input, + targetX, targetY, orderX, orderY, divisor, bias, kernelMatrix)); + } else { + //convolve2D<false>(out_data, in_data, width, height, &kernel.front(), orderX, orderY, + // targetX, targetY, bias); + ink_cairo_surface_synthesize(out, ConvolveMatrix<NO_PRESERVE_ALPHA>(input, + targetX, targetY, orderX, orderY, divisor, bias, kernelMatrix)); + } + + slot.set(_output, out); + cairo_surface_destroy(out); +} + +void FilterConvolveMatrix::set_targetX(int coord) { + targetX = coord; +} + +void FilterConvolveMatrix::set_targetY(int coord) { + targetY = coord; +} + +void FilterConvolveMatrix::set_orderX(int coord) { + orderX = coord; +} + +void FilterConvolveMatrix::set_orderY(int coord) { + orderY = coord; +} + +void FilterConvolveMatrix::set_divisor(double d) { + divisor = d; +} + +void FilterConvolveMatrix::set_bias(double b) { + bias = b; +} + +void FilterConvolveMatrix::set_kernelMatrix(std::vector<gdouble> &km) { + kernelMatrix = km; +} + +void FilterConvolveMatrix::set_edgeMode(FilterConvolveMatrixEdgeMode mode){ + edgeMode = mode; +} + +void FilterConvolveMatrix::set_preserveAlpha(bool pa){ + preserveAlpha = pa; +} + +void FilterConvolveMatrix::area_enlarge(Geom::IntRect &area, Geom::Affine const &/*trans*/) +{ + //Seems to me that since this filter's operation is resolution dependent, + // some spurious pixels may still appear at the borders when low zooming or rotating. Needs a better fix. + area.setMin(area.min() - Geom::IntPoint(targetX, targetY)); + // This makes sure the last row/column in the original image corresponds + // to the last row/column in the new image that can be convolved without + // adjusting the boundary conditions). + area.setMax(area.max() + Geom::IntPoint(orderX - targetX - 1, orderY - targetY -1)); +} + +double FilterConvolveMatrix::complexity(Geom::Affine const &) +{ + return kernelMatrix.size(); +} + +} /* namespace Filters */ +} /* namespace Inkscape */ + +/* + Local Variables: + mode:c++ + c-file-style:"stroustrup" + c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +)) + indent-tabs-mode:nil + fill-column:99 + End: +*/ +// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 : |