$canvasRotate

The $canvasRotate[degrees] function rotates the current canvas by a specified angle in degrees. The canvas is automatically resized to contain the entire image after rotation.

Syntax

$canvasRotate[degrees]

Parameters

Parameter	Description
degrees	Angle of rotation in degrees. Positive values = clockwise. Negative values = counterclockwise.

Return value

None. The canvas is rotated and resized if necessary.

Behavior

• The rotation is done around the center of the canvas.
• The canvas is automatically expanded to avoid clipping the image.
• Pixels outside the original image become transparent.
• Angle values are normalized modulo 360.

Examples

Simple 90° rotation

$canvasLoad[$attachment]
$canvasRotate[90]
$attachCanvas[]
$sendMessage[↪️ Image rotated by 90°!]

Complete flip (180°)

$canvasLoad[$attachment]
$canvasRotate[180]
$attachCanvas[]
$sendMessage[🔃 Image flipped!]

Counterclockwise rotation

$canvasLoad[$attachment]
$canvasRotate[-45]
$attachCanvas[]
$sendMessage[↩️ Counterclockwise rotation of 45°!]

User-controlled rotation

$canvasLoad[$attachment]
$canvasRotate[$message[1]]
$attachCanvas[]
$sendMessage[The image has been rotated by $message[1]°!]

Notes

• The canvas must be created or loaded before rotation.
• Rotations of 90°, 180°, or 270° are optimized and do not degrade the quality.
• Non-orthogonal rotations (e.g., 45°) require resampling.