Automatic multisampling: the source

since 0.7.0 Post-processing
Open the live demo · Read the guide · View on GitHub
Regions the guide quotes: ask (line 21), compete (line 27), declined (line 41).
1/// Automatic multisampling: smoothed edges from the scene pass itself, with
2/// no extra pass and no texture read back.
3///
4/// Quoted by `msaa.md` and shown whole in the Source tab.
5library;

7import 'package:flutter3d/flutter3d.dart';
8import 'package:flutter3d_showcase/pages/post/post_stage.dart';
9import 'package:flutter3d_showcase/src/demo/demo.dart';

11final class MsaaDemo extends ShowcaseDemo {
bool readSurface = false;

late final bool _deviceCanMsaa;

@override
void configureView(DemoContext context) => PostStage.frame(context);

@override
Scene build(DemoContext context) {
  _deviceCanMsaa = context.device.supportsOffscreenMsaa;
  return PostStage.build(context).scene;
}

@override
RenderSettings settings(DemoContext context) => RenderSettings(
  ambientOcclusion: AmbientOcclusionSettings(enabled: readSurface),
);

@override
List<DemoControl> controls(DemoContext context) => <DemoControl>[
  ToggleControl(
    'Ambient occlusion (reads the surface buffer)',
    value: () => readSurface,
    onChanged: (bool v) => readSurface = v,
  ),
];

@override
void verify(Scene scene, FrameResult frame) {
  final String? declined = frame.antiAliasing.msaaDeclined;
  if (!_deviceCanMsaa) {
    if (declined == null) {
      throw StateError(
        'this device cannot multisample and the frame '
        'did not say so',
      );
    }
  } else if (readSurface) {
    if (declined == null || frame.antiAliasing.msaaSamples > 1) {
      throw StateError(
        'the surface buffer is in use and the scene pass '
        'still multisampled',
      );
    }
  } else {
    if (declined != null || frame.antiAliasing.msaaSamples <= 1) {
      throw StateError(
        'nothing stopped multisampling and the scene pass '
        'did not use it',
      );
    }
  }
}
65}