Uniform Speed

Description

Since the default behavior of this danmaku library does not ensure uniform speed for danmaku movements, users with uniform motion requirements can achieve this by using the following methods.

Important Notes

1. When you set the speed for danmaku, the configurations config.timeRange and config.duration will become invalid.
2. In uniform motion mode, this library only ensures that the speed of danmaku is consistent, but it does not guarantee that the spacing between danmaku is uniform. You can set the gap configuration, but this only ensures that the spacing between danmaku is not less than the value of gap, not that it is equal to it.
3. If you strongly require uniform spacing, you can reduce the speed to achieve an approximate result. See the explanation in this issue.

Setting Uniform Speed

There are two ways to enable uniform speed mode.

Principle

When the speed of danmaku is set, the motion duration of danmaku is calculated as follows, you can adjust the launching speed according to the desired duration:

1. $FacileDuration=(containter.width+danmaku.width)/v$
2. $FlexibleDuration=(danmaku.position.x+danmaku.width)/v$

// 1. Configure speed during initialization
const manager = create({
  speed: 0.1,
  speed: '100% / 1000', // The `duration` is approximately 1000ms
});

// 2. Use the `setSpeed` API to set speed
manager.setSpeed(0.1);
manager.setSpeed('100% / 2000'); // The `duration` is approximately 2000ms

Cancel Uniform Speed

Set speed to null to cancel uniform speed mode and revert to the default behavior.

manager.setSpeed(null);

Excluding Specific Danmaku from Uniform Speed Mode

If you want most danmaku to move at a uniform speed but exclude certain danmaku from this mode, you can specify the speed configuration as null when sending those danmaku. Alternatively, you can assign a speed value different from the global speed.

// 1. Facile danmaku
manager.push('content', {
  speed: null，
});

// 2. Flexible danmaku
manager.pushFlexibleDanmaku('content', {
  speed: null，
});

Relationship with config.mode

hen speed is set for danmaku, it will still be subject to the restrictions of config.mode.

• node No collision detection, danmaku will render immediately.
• strict Strict collision detection, rendering will be delayed if conditions are not met.
• adaptive Attempts collision detection while ensuring immediate rendering.