Fix noise anchor and flickering in NoiseStyle and NoiseFilter by zfw1234567 · Pull Request #1433 · Tencent/tgfx

zfw1234567 · 2026-05-15T07:32:37Z

问题描述

噪声锚点偏移：
- NoiseFilter：在 Layer 下使用时，如果 inputImage 发生裁切，噪声采样原点会随之偏移，导致噪声图案不一致。
- NoiseStyle：在 Layer 下使用 path 模式时，噪声采样原点会随 path 的变化而偏移，导致噪声图案不稳定。
噪声闪烁：AlphaThresholdFragmentProcessor 的 GLSL 着色器使用 step() 函数进行 alpha 阈值判断，产生硬边界，导致噪声在不同帧之间出现闪烁。

主要变更

为 LayerFilter 添加带几何参数的 filterImage() 重载，接受 width/height/originOffset，使 NoiseFilter 能将噪声锚定到内容边界中心，而非随 inputImage 裁切而偏移
为 LayerStyle 的 draw()/onDraw() 添加 contentOffset 参数，使 NoiseStyle 能通过采样矩阵偏移将噪声锚定到内容位置，避免 path 模式下的偏移问题，同时消除 drawLayerStyleDefault 中的类型检查分发
引入 LayerImageFilter 基类，用于可表示为单个 ImageFilter 的滤镜（Blur、DropShadow、InnerShadow、ColorMatrix、Blend），提供 ImageFilter 缓存
重构 NoiseFilter 继承关系，NoiseFilter 直接继承 LayerFilter（因其效果依赖输入图像几何信息），getComposeFilter() 替换为 getImageFilter()，简化缓存机制
修复噪声闪烁：将 GLSLAlphaThresholdFragmentProcessor 中的 step() 替换为 smoothstep(threshold - 0.01, threshold + 0.01, alpha)，消除硬边界闪烁

…lip group. (Tencent#1429)

…tecture.

…red on content.

… modes.

…nds center.

Hparty · 2026-05-15T08:49:09Z

+
+  auto imageFilter = args.excludeEffects
+                         ? nullptr
+                         : layer->getImageFilter(contentMatrix.getMaxScale(), contentBounds.width(),


这里仍然走的是『先合成 ImageFilter → makeWithFilter』老路径,所以 NoiseFilter 不得不额外暴露 getComposeFilter(scale, w, h, oo) 把几何参数塞进 ImageFilter,并且在 NoiseFilter 内部维护一套只为这条路径存在的 composedFilter / composedDirty / composedScale 缓存。

而 Layer::createSubtreeCacheImage 那条路径已经迁到 applyFilters() 上,逐个 filter 调 filterImage() 把几何参数直接传进去,不需要 getComposeFilter。

建议这里也改成 applyFilters() 风格(把 ApplyImageFilterIfNeeded 里的 clipBounds 反向裁剪和 imageMatrix 偏移合并那段一起重构),配合给 LayerFilter::filterBounds 加 MapDirection 参数(默认 Forward,LayerImageFilter 转发到底层 ImageFilter,NoiseFilter 之类 identity 直接返回 srcRect),然后:

删掉 Layer::getImageFilter 整个入口(Layer 不再需要拿底层 ImageFilter,bounds 反推也走 LayerFilter::filterBounds(rect, scale, Reverse))

删掉 LayerFilter::getComposeFilter 这套虚函数

删掉 NoiseFilter 的 composedFilter / composedDirty / composedScale 缓存

这样能消掉『两条渲染路径要保持几何同步』的隐患,也能去掉只为 NoiseFilter 一个类存在的兜底机制。如果这次 PR 改动面太大,可以拆个 follow-up,但 getComposeFilter 这个名字和 composedFilter 缓存看起来像是临时方案,容易被忘掉。

…led.

…d rect.

…ld via path

…ck dispatch in Layer::drawLayerStyleDefault.

…_layer_noise

…and simplify NoiseFilter caching

Hparty · 2026-05-21T07:35:52Z

- * LayerFilter represents a filter that applies effects to a layer, such as blurs, shadows, or color
- * adjustments. It creates a new offscreen image that replaces the original layer content.
- * LayerFilters are mutable and can be changed at any time.
+ * LayerFilter is the abstract base class for filters that apply effects to a layer, such as blurs,


注释内容面向使用者，不用说太多内部细节

Hparty · 2026-05-21T07:37:06Z

 class LayerFilter : public LayerProperty {
 public:
  /**
   * Applies this filter to the given input image at the specified scale factor. The offset stores


filterImage只留一个，不要留两个对外接口

Hparty · 2026-05-21T07:40:48Z

+   * @param offset If non-null, receives the (x, y) translation of the filtered image.
+   * @return The filtered image, or nullptr on failure.
+   */
+  std::shared_ptr<Image> filterImage(std::shared_ptr<Image> input, float scale, float width,


width，height,originOffset看下能不能组装成一个Rect行为，有点太散了

Hparty · 2026-05-21T07:41:29Z

+   * forwards to this method when subclasses do not override the 5-arg version.
   */
-  virtual std::shared_ptr<ImageFilter> onCreateImageFilter(float scale);
+  virtual std::shared_ptr<Image> onFilterImage(std::shared_ptr<Image> input, float, Point*) {


onFilterImage也不需要两个

Hparty · 2026-05-21T07:45:53Z

+   * grow or shrink the visible region. The default implementation returns nullptr.
   */
-  void invalidateFilter();
+  virtual std::shared_ptr<ImageFilter> getImageFilter(float scale);


getImageFilter不在这个基类里暴露，放在LayerImageFilter里

Hparty · 2026-05-21T07:51:09Z


 protected:
-  std::shared_ptr<ImageFilter> onBuildNoiseImageFilter(float scale, int width, int height) override;
+  std::shared_ptr<ImageFilter> onBuildNoiseImageFilter(float scale, Point shift) override;


const Point& shift

Hparty · 2026-05-21T08:05:02Z

                                     float contentScale, std::shared_ptr<Image> extraSource,
                                     const Point& extraSourceOffset, float alpha,
-                                     BlendMode blendMode);
+                                     BlendMode blendMode, const Point& contentOffset);


contentOffset是否可以放在canvas上处理，这里有extraSourceOffset+contentOffset两个，是否用1个就能解决

contentoffset是用于补偿因path导致的shader采样锚点的偏移，和cavas无关，extraSourceOffset和contentOffset这里是两个不同的东西

…mageFilter with isImageFilter

YGaurora and others added 6 commits May 13, 2026 19:04

Fix SVG export wrongly clipping short-circuited draws under a stale c…

e465de2

…lip group. (Tencent#1429)

Change LayerFilter from ImageFilter-based to image-in-image-out archi…

c28a25a

…tecture.

Add NoiseStyle layer styles with Mono Duo and Multi noise modes cente…

958ae50

…red on content.

Add NoiseFilter with Mono Duo and Multi modes centered on content image.

e71d153

Add test cases for NoiseStyle and NoiseFilter with Mono Duo and Multi…

c7b6482

… modes.

Fix unstable noise pattern in NoiseFilter by anchoring to content bou…

faca49a

…nds center.

zfw1234567 requested review from Hparty, YGaurora, domchen, kevingpqi123, richardshan0614 and shlzxjp as code owners May 15, 2026 07:32

Remove test files NoiseLayerTest and NoiseStyleTest from PR.

1361880

Hparty reviewed May 15, 2026

View reviewed changes

zfw1234567 added 8 commits May 18, 2026 10:27

Add tileSize 64 to NoiseStyleTest and log tileTasks count in renderTi…

2aab43e

…led.

Add NoiseStyleMovingRect test with parent shape layer and moving chil…

76acd01

…d rect.

Add global origin support for NoiseStyle sampling in tiled rendering.

7b2cba0

Update NoiseStyleMovingRect test to move parent via setMatrix and chi…

ef4237c

…ld via path

Add contentOffset to LayerStyle virtual methods to eliminate type-che…

e628f45

…ck dispatch in Layer::drawLayerStyleDefault.

Merge branch 'feature/partyhuang_layer_noise' into feature/fengweizou…

961b415

…_layer_noise

Refactor LayerFilter to replace getComposeFilter with getImageFilter …

beb3d1f

…and simplify NoiseFilter caching

Use smoothstep instead of step for alpha threshold to avoid hard edge

3dc2394

zfw1234567 changed the title ~~Fix unstable noise pattern in NoiseFilter by anchoring to content bounds center~~ Fix noise anchor and flickering in NoiseStyle and NoiseFilter May 21, 2026

Hparty reviewed May 21, 2026

View reviewed changes

zfw1234567 added 3 commits May 21, 2026 19:17

Remove debug LOGI from NoiseFilter::onFilterImage

ad01dd3

Simplify LayerFilter API by merging dual overloads and replacing getI…

a0330ae

…mageFilter with isImageFilter

Remove debug printf from Layer::drawDirectly.

3e853f0

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Fix noise anchor and flickering in NoiseStyle and NoiseFilter#1433

Fix noise anchor and flickering in NoiseStyle and NoiseFilter#1433
zfw1234567 wants to merge 18 commits into
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zfw1234567:feature/fengweizou_layer_noise

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zfw1234567 commented May 15, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

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问题描述

主要变更

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zfw1234567 commented May 15, 2026 •

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