flutter - 颤振/飞镖和抗锯齿
问题描述
我目前正在用 Flutter 编写一个室内导航应用程序,而且我对 Flutter 和 Dart 还很陌生。为此,我使用并希望扩展库 mapsforge_flutter,基于 mapsforge for Android。使用 mapsforge_flutter,我可以下载 OpenStreetMap 地图,然后在手机上呈现这些地图。问题在于,地图上的线条看起来像这样像素化:
在 mapsforge_flutter 中还没有实现 AntiAliasing,所以我认为问题可能出在那儿。在原始的 mapsforge 库中,地图看起来没有那么像素化。
AA 以这种方式在原始库中实现:
// in Parameters.java:
//If true will use anti-aliasing in rendering.
public static boolean ANTI_ALIASING = true;
// in AndroidPaint.java:
AndroidPaint() {
paint = new android.graphics.Paint();
this.paint.setAntiAlias(Parameters.ANTI_ALIASING);
this.paint.setStrokeCap(getAndroidCap(Cap.ROUND));
this.paint.setStrokeJoin(android.graphics.Paint.Join.ROUND);
this.paint.setStyle(getAndroidStyle(Style.FILL));
}
// in AwtCanvas.java:
AwtCanvas(Graphics2D graphics2D) {
this.graphics2D = graphics2D;
setAntiAlias(Parameters.ANTI_ALIASING);
createFilters();
}
public void setBitmap(Bitmap bitmap) {
if (bitmap == null) {
this.bufferedImage = null;
this.graphics2D = null;
} else {
this.bufferedImage = AwtGraphicFactory.getBitmap(bitmap);
this.graphics2D = this.bufferedImage.createGraphics();
setAntiAlias(Parameters.ANTI_ALIASING);
this.graphics2D.setRenderingHint(RenderingHints.KEY_RENDERING, RenderingHints.VALUE_RENDER_QUALITY);
this.graphics2D.setRenderingHint(RenderingHints.KEY_STROKE_CONTROL, RenderingHints.VALUE_STROKE_PURE);
}
}
在 mapsforge_flutter 中有两个类:Mapcanvas 和 Fluttercanvas,具有以下方法,必须实现:
// in Fluttercanvas.dart:
bool isAntiAlias() {
// TODO: implement isAntiAlias
return null;
}
@override
void setAntiAlias(bool aa) {
// TODO: implement setAntiAlias
}
// in Mapcanvas.dart:
bool isAntiAlias();
有谁知道如何在 Flutter/Dart 中实现这一点?文档中的方法(https://api.flutter.dev/flutter/dart-ui/Paint/isAntiAlias.html)似乎对我不起作用。
提前致谢!