Drawing together in webpaint.ing
By releases ·
webpaint.ing can put several people on one canvas. The feature is built and tested, but it is not switched on for the live site yet: it needs a small server running there, and "Draw together" appears in the More menu only once that is done. This note explains how it works, so you know what to expect.
How a shared drawing stays one picture
- A drawing is a list of changes. Each stroke, fill, move or new layer is one small message saying what was done, not which pixels changed. Replaying the list gives the same picture, which is already how saving and Undo work when you draw alone.
- Sharing is passing that list around. If everyone has the same changes in the same order, everyone sees the same drawing.
- A room keeps the list. The small server numbers each change, writes it down and sends it to everyone in the room. It never draws and holds no picture.
- Joining late works the same way. Open the link and you are sent the whole list, then draw it from nothing.
When two people draw at once
- Your own stroke appears at once, without waiting for the network.
- The room's order wins. If someone else's stroke reaches the room before yours, your screen slips theirs underneath and redraws that layer, so every screen ends up the same.
- New layers do not collide. Two people adding a layer in the same second get two layers.
- Undo takes back only your own work. Other people's later strokes stay.
Who can join
- The link is the key. There are no accounts for this yet. A room's address is long and random, and anyone who has it can draw, so share it only with people you want in.
- Up to eight people share a room.
- A shared drawing is also kept on your own device, like any other.
Not built yet
- Strokes show when the pen lifts, not while they are being drawn.
- You cannot see where other people's pens are.
- A lost connection is not picked up by itself. Open the link again and the drawing returns whole.
- A shared drawing starts blank. One you have already begun cannot be shared yet.
- Accounts, invitations and roles do not exist yet.