1
2#pragma once
3
4#include "Projection.h"
5#include "Shape.h"
6#include "BitmapRef.hpp"
7
8namespace msdfgen {
9
10/// Performs error correction on a computed MSDF to eliminate interpolation artifacts. This is a low-level class, you may want to use the API in msdf-error-correction.h instead.
11class MSDFErrorCorrection {
12
13public:
14 /// Stencil flags.
15 enum Flags {
16 /// Texel marked as potentially causing interpolation errors.
17 ERROR = 1,
18 /// Texel marked as protected. Protected texels are only given the error flag if they cause inversion artifacts.
19 PROTECTED = 2
20 };
21
22 MSDFErrorCorrection();
23 explicit MSDFErrorCorrection(const BitmapRef<byte, 1> &stencil, const Projection &projection, double range);
24 /// Sets the minimum ratio between the actual and maximum expected distance delta to be considered an error.
25 void setMinDeviationRatio(double minDeviationRatio);
26 /// Sets the minimum ratio between the pre-correction distance error and the post-correction distance error.
27 void setMinImproveRatio(double minImproveRatio);
28 /// Flags all texels that are interpolated at corners as protected.
29 void protectCorners(const Shape &shape);
30 /// Flags all texels that contribute to edges as protected.
31 template <int N>
32 void protectEdges(const BitmapConstRef<float, N> &sdf);
33 /// Flags all texels as protected.
34 void protectAll();
35 /// Flags texels that are expected to cause interpolation artifacts based on analysis of the SDF only.
36 template <int N>
37 void findErrors(const BitmapConstRef<float, N> &sdf);
38 /// Flags texels that are expected to cause interpolation artifacts based on analysis of the SDF and comparison with the exact shape distance.
39 template <template <typename> class ContourCombiner, int N>
40 void findErrors(const BitmapConstRef<float, N> &sdf, const Shape &shape);
41 /// Modifies the MSDF so that all texels with the error flag are converted to single-channel.
42 template <int N>
43 void apply(const BitmapRef<float, N> &sdf) const;
44 /// Returns the stencil in its current state (see Flags).
45 BitmapConstRef<byte, 1> getStencil() const;
46
47private:
48 BitmapRef<byte, 1> stencil;
49 Projection projection;
50 double invRange;
51 double minDeviationRatio;
52 double minImproveRatio;
53
54};
55
56}
57