Technical FAQ

How does Drawangle calculate accuracy?

The target and the drawn attempt are represented using normalized canvas coordinates. Depending on the challenge, Drawangle compares direction, relative length, endpoint distance, and path shape. The scoring layer converts those deviations into component accuracies and an overall result.

Does position on the canvas matter?

For the core matching exercise, the comparison emphasizes shape, direction, and proportion rather than requiring the attempt to start at the target’s screen position. This lets the player focus on visual relationships instead of tracing.

How is angle deviation measured?

For a straight segment, the software derives a vector from its start and end coordinates. It compares the target and attempt vector directions, uses the smaller directional difference, and maps that deviation into the angle accuracy score.

How are curves compared?

Curved paths are normalized and sampled along their progression. The comparison considers corresponding points and overall path form instead of treating a curve as only one start-to-end line.

Why are later modes locked?

Arc, curve, polyline, and cross exercises are dynamically generated and fully implemented. They unlock after progression milestones so each mode builds on simpler observation skills. A locked card is a progression state, not an unfinished page.

What accuracy is needed to win?

The current thresholds are 70% for Easy, 80% for Medium, and 90% for Hard. Difficulty changes the win threshold while the detailed comparison still shows where the attempt differed.

Does Drawangle replace geometry lessons?

No. It practices visual estimation for art. It does not teach formal angle construction or replace measured work with rulers, compasses, or protractors.

Where is progress stored?

Anonymous progress is stored in the browser. Players who voluntarily sign in with Google can synchronize progress through Firebase. See the Privacy Policy for details.

Which browsers are supported?

Drawangle is designed for current browsers with JavaScript, Pointer Events, local storage, SVG, and HTML Canvas support. It is mobile-friendly and can be installed as a progressive web app on supported devices.