Transforms (HasTransforms)

The HasTransforms trait provides geometric transformations that modify how subsequent drawing operations are rendered. Transformations operate on the Current Transformation Matrix (CTM) and must be wrapped in startTransform() / stopTransform() pairs to isolate their effects.

All methods return static, so every call can be chained.

Quick Reference

Method	Effect
startTransform()	Save graphics state (push CTM)
stopTransform()	Restore graphics state (pop CTM)
rotate()	Rotate around a point
scale()	Scale horizontally and vertically
translate()	Move the coordinate origin
skew()	Shear along X and Y axes
mirrorH()	Mirror horizontally
mirrorV()	Mirror vertically
mirrorP()	Mirror about a point
mirrorL()	Mirror about an arbitrary line

Basic Example

use Yeeefang\TcpdfNext\Core\Document;

$pdf = Document::create()
    ->addPage()
    ->setFont('Helvetica', '', 12)

    // Rotated text
    ->startTransform()
    ->rotate(45, 105, 60)
    ->text(100, 55, 'Rotated 45°')
    ->stopTransform()

    // Scaled rectangle
    ->startTransform()
    ->scale(150, 150, 50, 150)
    ->rect(40, 140, 20, 20, 'DF')
    ->stopTransform()

    // Mirrored text
    ->startTransform()
    ->mirrorH(105)
    ->text(100, 200, 'Mirrored')
    ->stopTransform();

WARNING

Always wrap transformations in startTransform() / stopTransform() pairs. Forgetting stopTransform() leaves the graphics state modified for all subsequent operations.

startTransform / stopTransform

$pdf->startTransform();  // Push current graphics state
// ... drawing operations with transforms ...
$pdf->stopTransform();   // Pop and restore previous state

These calls can be nested. Each startTransform() pushes a new state onto the stack.

rotate()

$pdf->rotate(float $angle, float $x = '', float $y = '');

Rotates subsequent content by $angle degrees counter-clockwise around point (x, y). If x and y are omitted, the current position is used.

scale()

$pdf->scale(float $sx, float $sy, float $x = '', float $y = '');

Scales content by $sx percent horizontally and $sy percent vertically, relative to point (x, y). A value of 100 means no change; 200 doubles the size.

translate()

$pdf->translate(float $tx, float $ty);

Shifts the coordinate origin by $tx horizontally and $ty vertically. All subsequent coordinates are offset by this amount until the transform is stopped.

skew()

$pdf->skew(float $angleX, float $angleY, float $x = '', float $y = '');

Applies a shear transformation. $angleX skews along the X axis and $angleY along the Y axis, both in degrees.

Mirror Methods

$pdf->mirrorH(float $x = '');                              // Horizontal mirror about vertical axis at x
$pdf->mirrorV(float $y = '');                              // Vertical mirror about horizontal axis at y
$pdf->mirrorP(float $x = '', float $y = '');               // Mirror about a point
$pdf->mirrorL(float $angle, float $x = '', float $y = ''); // Mirror about a line through (x, y) at angle

$pdf->startTransform()
    ->mirrorH(105)
    ->setFont('Helvetica', '', 14)
    ->text(80, 50, 'Flipped horizontally')
    ->stopTransform();

Combining Transforms

Multiple transforms can be stacked within a single block. They are applied in the order called.

$pdf->startTransform()
    ->translate(20, 20)
    ->rotate(30)
    ->scale(120, 120)
    ->rect(10, 10, 40, 20, 'DF')
    ->stopTransform();

Full CTM Support

For advanced use cases, the underlying Current Transformation Matrix is fully accessible. The six-element matrix [a, b, c, d, e, f] maps to the standard PDF transformation matrix, giving complete control over affine transformations when the convenience methods are not sufficient.