Support backward and forward snapping lines.

[mohsenD98]

PR Description:

This PR introduces support for the backward snapping feature, allowing snapping to common angles both backward (to the starting point) and forward (last digitized point).

How We Achieved This

1. Replacing Shape with Repeater for Snapping Lines: Instead of using a static Shape {} element, we now use a Repeater {} with dynamic model data to display the snapping lines. This approach provides flexibility and allows for more efficient handling of multiple snapping lines.

Props of each list element:

ListElement {
  beginCoordX: 0
  beginCoordY: 0
  endCoordX: 0
  endCoordY: 0
  snappedToAngle: false
}

The snapping line is only visible if snappedToAngle is true or if valid endCoords are provided.

2. Adding the forwardMode Parameter: We introduced a forwardMode parameter to three key functions:

• calculateSnapToAngleLineEndCoords
• snapPointToCommonAngle
• getCommonAngleInDegrees

The forwardMode parameter helps determine the direction of the snapping line by defining a targetPoint in each of these functions. This ensures that snapping lines are correctly oriented, whether snapping forward or backward.

3. Handling Both Forward and Backward Snapping: When both forward and backward snapping lines are present, we handle the intersection of these lines to ensure accurate snapping behavior in both directions.

Demo

You can view the feature in action in the following screencast:

Screencast.from.2024-11-14.12-39-27.webm

[qfield-fairy]

🎉 Ta-daaa, freshly created APKs are available for a7049b6: arm64-android

Other architectures

• arm-neon-android
• x64-android
• x86-android
• all access arm64-android
• all access arm-neon-android
• all access x64-android
• all access x86-android

[suricactus]

This change is dangerous unless you fix the comment above. == null will check for both null and undefined, now only checks for null.