Flow can detect what you have just drawn and turn it into a perfect straight line or shape. It works with any drawing tool, and nothing needs to be turned on first, as it is enabled by default.
Snapping a line or shape
Draw your line or shape as you normally would, then hold still for a brief moment without lifting up. Flow looks at what you drew and snaps it into a clean version.
Flow detects:
- straight lines
- curved lines
- rectangles, including squares
- circles
- ellipses (ovals)
- triangles, both right angle and isosceles
You do not have to draw neatly. Detection is designed to cope with wobbly strokes, kinks, and corners that overlap or do not quite meet.
Straight lines
When you draw a nearly straight line and hold still, it snaps to being perfectly straight.
By default the line then stays attached to your pencil so you can drag the end point around until you are happy with it. Lift off to place it. While you are dragging, the line is drawn in front of everything else on the page so you can see it clearly. Once you let go, it settles back into its correct position in the layer stack.
As you drag, bringing the line close to exactly horizontal or vertical snaps it to that direction.
If you would rather have lines placed immediately instead of dragging them, turn off Allow straight lines to drag.
Curved lines
A line drawn as a deliberate curve is smoothed into a clean curve rather than being straightened. Flow applies a little extra smoothing at the start and end of a curve to reduce small flicks.
Shapes
Shapes snap to a tidied-up version of what you drew, and shapes that are close to being lined up straight with the page adjust to line up exactly.
Flow also tightens shapes that are nearly regular:
- A rectangle close to square becomes a square
- An ellipse close to circular becomes a circle
- A triangle close to isosceles or right angle snaps to that
Arrows and dots
Flow can offer to add arrowheads and dots to the ends of your lines. Turn on Add arrows to lines and a small menu pops up after you draw a line.
The menu gives you six options: an arrow at the start, at the end, or at both ends, and the same three for dots. Tap one to apply it, or carry on drawing to dismiss the menu and leave the line plain.
This is off by default.
Working with the Lasso Knife
By default, a shape is handed straight to the Lasso Knife as soon as it is created, so you can move, scale or rotate it right away. When you place the shape or cancel the selection, Flow switches you back to the tool you were using before.
Turn off Auto select shapes after making them if you would rather keep drawing without interruption.
Settings
All of these live under Straight Lines and Shapes in Drawing and Gestures.
| Setting | Default | What it does | | ------------------------------------ | ------- | --------------------------------------------------------------------------------- | | Enabled | On | Master switch for the whole feature | | Allow straight lines to drag | On | Keeps a snapped line attached to your pencil so you can drag its end point | | Snap alignment when close | On | Snaps a nearly horizontal or vertical line to be exactly aligned | | Smooth curved lines | On | Smooths deliberate curves instead of straightening them | | Add arrows to lines | Off | Shows a menu for adding arrowheads and dots to line ends | | Require holding still for longer | Off | Lengthens the pause needed before Flow snaps, if it triggers sooner than you want | | Auto select shapes after making them | On | Hands a new shape to the Lasso Knife so it can be moved straight away |
Allow straight lines to drag, Snap alignment when close and Require holding still for longer all depend on Enabled. Turning the master switch off disables them too.
Related
- The Ruler is the other way to draw precise lines and shapes, and is better suited to repeated or constrained work
- The Lasso Knife for adjusting shapes after they are created