Changelog

All notable changes to this project will be documented in this file.

The format is based on Keep a Changelog, and this project adheres to Semantic Versioning.

[1.2.0] - 2026-01-20

initialMask prop: Added initialMask?: string prop to MaskEditor to pre-load a mask provided as a base64 data URL (e.g., saved from toMask()), enabling resuming editing sessions or switching between saved masks.
- The mask is applied once per unique value (to avoid redundant re-applications).
- When applied it overwrites the current mask canvas, saves the state in history (so undo/redo works from that base), and notifies onMaskChange immediately.
Storybook demo: Added a reliable "Pre-load existing mask" story demonstrating save → clear → load workflow (includes a forced reload mechanism so the same mask value can be re-applied).
Tests: Added tests (Vitest + Testing Library) to validate initialMask behavior and subsequent editing.

Improved zoom and pan: Fixed a critical issue where zoom didn't correctly maintain the point under the cursor.
Coordinate calculation correction: Implemented a new mathematical formula for zoom that correctly accounts for CSS transformation.
Keyboard zoom: Fixed zoom behavior via keyboard shortcuts to follow the current mouse position.
Zoom behavior: Eliminated axis inversion when zooming at different positions of the image.
Transformation consistency: Unified logic for all zoom operations (wheel, buttons, shortcuts) to ensure coherent behavior.

Performance: Optimized transformation calculations to reduce re-renders.
Code structure: Refactored the zoomToPoint function for better readability and maintainability.

The main technical change has been correcting the transformation calculation applied during zoom. The new implementation:

Applies an improved mathematical formula that considers the order of CSS transformations:

transform: translate(-50%, -50%) scale(effectiveScale)
  translate(translateX, translateY);

Uses the correct sign for translation values, considering that CSS translate moves the element in the specified direction, but to keep a point under the cursor requires the opposite movement

See commit history for more details about previous changes.