The HTML5 <canvas> tag is used to draw graphics, on the fly, via scripting (usually JavaScript).
However, the <canvas> element has no drawing abilities of its own (it is only a container for graphics) - you must use a script to actually draw the graphics.
The getContext() method returns an object that provides methods and properties for drawing on the canvas.
This reference will cover the properties and methods of the getContext("2d") object, which can be used to draw text, lines, boxes, circles, and more - on the canvas.
Colors, Styles, and Shadows
| Property | Description |
|---|---|
| filStyle | Sets or returns the color, gradient, or pattern used to fill the drawing |
| strokeStyle | Sets or returns the color, gradient, or pattern used for strokes |
| shadowColor | Sets or returns the color to use for shadows |
| shadowBlur | Sets or returns the blur level for shadows |
| shadowOffsetX | Sets or returns the horizontal distance of the shadow from the shape |
| shadowOffsetY | Sets or returns the vertical distance of the shadow from the shape |
| Method | Description |
|---|---|
| createLinearGradient() | Creates a linear gradient (to use on canvas content) |
| createPattern() | Repeats a specified element in the specified direction |
| createRadialGradient() | Creates a radial/circular gradient (to use on canvas content) |
| addColorStop() | Specifies the colors and stop positions in a gradient object |
Line Styles
| Property | Description |
|---|---|
| lineCap | Sets or returns the style of the end caps for a line |
| lineJoin | Sets or returns the type of corner created, when two lines meet |
| lineWidth | Sets or returns the current line width |
| miterLimit | Sets or returns the maximum miter length |
Rectangles
| Method | Description |
|---|---|
| rect() | Creates a rectangle |
| fillRect() | Draws a "filled" rectangle |
| strokeRect() | Draws a rectangle (no fill) |
| clearRect() | Clears the specified pixels within a given rectangle |
Paths
| Method | Description |
|---|---|
| fill() | Fills the current drawing (path) |
| stroke() | Actually draws the path you have defined |
| beginPath() | Begins a path, or resets the current path |
| moveTo() | Moves the path to the specified point in the canvas, without creating a line |
| closePath() | Creates a path from the current point back to the starting point |
| lineTo() | Adds a new point and creates a line to that point from the last specified point in the canvas |
| clip() | Clips a region of any shape and size from the original canvas |
| quadraticCurveTo() | Creates a quadratic Bézier curve |
| bezierCurveTo() | Creates a cubic Bézier curve |
| arc() | Creates an arc/curve (used to create circles, or parts of circles) |
| arcTo() | Creates an arc/curve between two tangents |
| isPointInPath() | Returns true if the specified point is in the current path, otherwise false |
Transformations
Text
Image Drawing
Pixel Manipulation
Compositing
Other