The CanvasRenderingContext2D
.clip()
method of the Canvas 2D API turns the current or given path into the current clipping region. It replaces any previous clipping region.
In the image below, the red outline represents a clipping region shaped like a star. Only those parts of the checkerboard pattern that are within the clipping region get drawn.
Note: Be aware that the clipping region is only constructed from shapes added to the path. It doesn't work with shape primitives drawn directly to the canvas, such as fillRect()
. Instead, you'd have to use rect()
to add a rectangular shape to the path before calling clip()
.
Syntax
void ctx.clip([fillRule]); void ctx.clip(path [, fillRule]);
Parameters
fillRule
- The algorithm by which to determine if a point is inside or outside the clipping region. Possible values:
"nonzero"
: The non-zero winding rule. Default rule."evenodd"
: The even-odd winding rule.
path
- A
Path2D
path to use as the clipping region.
Examples
A simple clipping region
This example uses the clip()
method to create a clipping region according to the shape of a circular arc. Two rectangles are then drawn; only those parts within the clipping region are rendered.
HTML
<canvas id="canvas"></canvas>
JavaScript
The clipping region is a full circle, with its center at (100, 75), and a radius of 50.
const canvas = document.getElementById('canvas'); const ctx = canvas.getContext('2d'); // Create circular clipping region ctx.beginPath(); ctx.arc(100, 75, 50, 0, Math.PI * 2); ctx.clip(); // Draw stuff that gets clipped ctx.fillStyle = 'blue'; ctx.fillRect(0, 0, canvas.width, canvas.height); ctx.fillStyle = 'orange'; ctx.fillRect(0, 0, 100, 100);
Result
Specifying a path and a fillRule
This example saves two rectangles to a Path2D object, which is then made the current clipping region using the clip()
method. The "evenodd"
rule creates a hole where the clipping rectangles intersect; by default (with the "nonzero"
rule), there would be no hole.
HTML
<canvas id="canvas"></canvas>
JavaScript
const canvas = document.getElementById('canvas'); const ctx = canvas.getContext('2d'); // Create clipping path let region = new Path2D(); region.rect(80, 10, 20, 130); region.rect(40, 50, 100, 50); ctx.clip(region, "evenodd"); // Draw stuff that gets clipped ctx.fillStyle = 'blue'; ctx.fillRect(0, 0, canvas.width, canvas.height);
Result
Specifications
Specification | Status | Comment |
---|---|---|
HTML Living Standard The definition of 'CanvasRenderingContext2D.clip' in that specification. |
Living Standard |
Browser compatibility
Desktop | Mobile | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
clip | Chrome Full support Yes | Edge Full support 12 | Firefox Full support 1.5 | IE Full support Yes | Opera Full support Yes | Safari Full support Yes | WebView Android Full support Yes | Chrome Android Full support Yes | Firefox Android Full support 4 | Opera Android Full support Yes | Safari iOS Full support Yes | Samsung Internet Android Full support Yes |
Path parameter | Chrome ? | Edge Full support ≤18 | Firefox Full support 31 | IE No support No | Opera ? | Safari Full support 7 | WebView Android ? | Chrome Android ? | Firefox Android Full support 31 | Opera Android ? | Safari iOS Full support 8 | Samsung Internet Android ? |
Legend
- Full support
- Full support
- No support
- No support
- Compatibility unknown
- Compatibility unknown
See also
- The interface defining this method:
CanvasRenderingContext2D