@ue-too/board / convertUserInputDeltaToCameraDelta

Function: convertUserInputDeltaToCameraDelta()

convertUserInputDeltaToCameraDelta(delta, camera): Point

Defined in: packages/board/src/camera/camera-rig/pan-handler.ts:714

Converts a user input delta (viewport space) to camera movement delta (world space).

Parameters

delta

Point

Movement delta in viewport/screen coordinates (CSS pixels)

camera

BoardCamera

Current camera instance (provides rotation and zoom)

Returns

Point

Equivalent delta in world space

Remarks

This function performs the standard viewport-to-world delta conversion:

1. Rotate delta by camera rotation (convert screen direction to world direction)
2. Scale by inverse zoom (convert screen distance to world distance)

Formula: worldDelta = rotate(viewportDelta, cameraRotation) / zoomLevel

This is the core conversion used by DefaultCameraRig.panByViewPort.

Examples

// User drags mouse 100 pixels right, 50 pixels down
const viewportDelta = { x: 100, y: 50 };

// Camera at 2x zoom, no rotation
camera.zoomLevel = 2.0;
camera.rotation = 0;

const worldDelta = convertUserInputDeltaToCameraDelta(viewportDelta, camera);
// worldDelta = { x: 50, y: 25 } - half the viewport delta due to 2x zoom

// With camera rotation
camera.zoomLevel = 1.0;
camera.rotation = Math.PI / 2;  // 90 degrees

const viewportDelta = { x: 100, y: 0 };  // Drag right
const worldDelta = convertUserInputDeltaToCameraDelta(viewportDelta, camera);
// worldDelta ≈ { x: 0, y: -100 } - rotated 90 degrees in world space

See

DefaultCameraRig.panByViewPort for usage