c0bd9f9fe5
Current strategy: everything from the top Things to look at first are the manual changes: - added tools/rewrite_includes.py - removed -Idirectives from BUILD.gn - various compile.sh simplifications - tweak tools/embed_resources.py - update gn/find_headers.py to write paths from the top - update gn/gn_to_bp.py SkUserConfig.h layout so that #include "include/config/SkUserConfig.h" always gets the header we want. No-Presubmit: true Change-Id: I73a4b181654e0e38d229bc456c0d0854bae3363e Reviewed-on: https://skia-review.googlesource.com/c/skia/+/209706 Commit-Queue: Mike Klein <mtklein@google.com> Reviewed-by: Hal Canary <halcanary@google.com> Reviewed-by: Brian Osman <brianosman@google.com> Reviewed-by: Florin Malita <fmalita@chromium.org>
61 lines
2.6 KiB
C++
61 lines
2.6 KiB
C++
/*
|
|
* Copyright 2013 Google Inc.
|
|
*
|
|
* Use of this source code is governed by a BSD-style license that can be
|
|
* found in the LICENSE file.
|
|
*/
|
|
|
|
#ifndef SkPerlinNoiseShader_DEFINED
|
|
#define SkPerlinNoiseShader_DEFINED
|
|
|
|
#include "include/core/SkShader.h"
|
|
|
|
/** \class SkPerlinNoiseShader
|
|
|
|
SkPerlinNoiseShader creates an image using the Perlin turbulence function.
|
|
|
|
It can produce tileable noise if asked to stitch tiles and provided a tile size.
|
|
In order to fill a large area with repeating noise, set the stitchTiles flag to
|
|
true, and render exactly a single tile of noise. Without this flag, the result
|
|
will contain visible seams between tiles.
|
|
|
|
The algorithm used is described here :
|
|
http://www.w3.org/TR/SVG/filters.html#feTurbulenceElement
|
|
*/
|
|
class SK_API SkPerlinNoiseShader {
|
|
public:
|
|
/**
|
|
* This will construct Perlin noise of the given type (Fractal Noise or Turbulence).
|
|
*
|
|
* Both base frequencies (X and Y) have a usual range of (0..1) and must be non-negative.
|
|
*
|
|
* The number of octaves provided should be fairly small, with a limit of 255 enforced.
|
|
* Each octave doubles the frequency, so 10 octaves would produce noise from
|
|
* baseFrequency * 1, * 2, * 4, ..., * 512, which quickly yields insignificantly small
|
|
* periods and resembles regular unstructured noise rather than Perlin noise.
|
|
*
|
|
* If tileSize isn't NULL or an empty size, the tileSize parameter will be used to modify
|
|
* the frequencies so that the noise will be tileable for the given tile size. If tileSize
|
|
* is NULL or an empty size, the frequencies will be used as is without modification.
|
|
*/
|
|
static sk_sp<SkShader> MakeFractalNoise(SkScalar baseFrequencyX, SkScalar baseFrequencyY,
|
|
int numOctaves, SkScalar seed,
|
|
const SkISize* tileSize = nullptr);
|
|
static sk_sp<SkShader> MakeTurbulence(SkScalar baseFrequencyX, SkScalar baseFrequencyY,
|
|
int numOctaves, SkScalar seed,
|
|
const SkISize* tileSize = nullptr);
|
|
/**
|
|
* Creates an Improved Perlin Noise shader. The z value is roughly equivalent to the seed of the
|
|
* other two types, but minor variations to z will only slightly change the noise.
|
|
*/
|
|
static sk_sp<SkShader> MakeImprovedNoise(SkScalar baseFrequencyX, SkScalar baseFrequencyY,
|
|
int numOctaves, SkScalar z);
|
|
|
|
static void RegisterFlattenables();
|
|
|
|
private:
|
|
SkPerlinNoiseShader() = delete;
|
|
};
|
|
|
|
#endif
|