HTML Canvas Verwysing
Beskrywing
Die HTML5 <canvas>-merker word gebruik om grafika te teken, op die vlug, via scripting (gewoonlik JavaScript).
Die <canvas>-element het egter geen tekenvermoë van sy eie nie (dit is slegs 'n houer vir grafika) - jy moet 'n script gebruik om die grafika werklik te teken.
Die getContext() metode gee 'n objek terug wat metodes en eienskappe verskaf om op die doek te teken.
Hierdie verwysing sal die eienskappe en metodes van die getContext("2d") voorwerp dek, wat gebruik kan word om teks, lyne, bokse, sirkels en meer te teken - op die doek.
Blaaierondersteuning
Die nommers in die tabel spesifiseer die eerste blaaierweergawe wat die element ten volle ondersteun.
Element |
|
|
|
|
|
<canvas> |
4.0 |
9.0 |
2.0 |
3.1 |
9.0 |
Internet Explorer 9, Firefox, Opera, Chrome en Safari ondersteun <canvas> en sy eienskappe en metodes.
Let wel: Internet Explorer 8 en vroeër weergawes ondersteun nie die <canvas>-element nie.
Kleure, style en skaduwees
Property |
Description |
fillStyle |
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 |
Lynstyle
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 |
Reghoeke
Paadjies
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 |
Transformasies
Method |
Description |
scale() |
Scales the current drawing bigger or smaller |
rotate() |
Rotates the current drawing |
translate() |
Remaps the (0,0) position on the canvas |
transform() |
Replaces the current transformation matrix for the drawing |
setTransform() |
Resets the current transform to the identity matrix. Then runs
transform() |
Teks
Property |
Description |
font |
Sets or returns the current font properties for text content |
textAlign |
Sets or returns the current alignment for text content |
textBaseline |
Sets or returns the current text baseline used when drawing text |
Method |
Description |
fillText() |
Draws "filled" text on the canvas |
strokeText() |
Draws text on the canvas (no fill) |
measureText() |
Returns an object that contains the width of the specified text |
Beeldtekening
Method |
Description |
drawImage() |
Draws an image, canvas, or video onto the canvas |
Pixel manipulasie
Property |
Description |
width |
Returns the width of an ImageData object |
height |
Returns the height of an ImageData object |
data |
Returns an object that contains image data of a specified ImageData
object |
Method |
Description |
createImageData() |
Creates a new, blank ImageData object |
getImageData() |
Returns an ImageData object that copies the pixel data for the specified
rectangle on a canvas |
putImageData() |
Puts the image data (from a specified ImageData object) back onto the
canvas |
Samestelling
Property |
Description |
globalAlpha |
Sets or returns the current alpha or transparency value of the drawing |
globalCompositeOperation |
Sets or returns how a new image are drawn onto an existing image |
Ander
Method |
Description |
save() |
Saves the state of the current context |
restore() |
Returns previously saved path state and attributes |
createEvent() |
|
getContext() |
|
toDataURL() |
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