Add tranformation matrix type and identity matrix

VERSION

@@ -1 +1 @@
-2.1.1
+2.2.0

src/Base.php

@@ -30,6 +30,15 @@
  * @license   http://www.gnu.org/copyleft/lesser.html GNU-LGPL v3 (see LICENSE.TXT)
  * @link      https://github.com/tecnickcom/tc-lib-pdf-graph
  *
+ * @phpstan-type TTMatrix array{
+ *          float,
+ *          float,
+ *          float,
+ *          float,
+ *          float,
+ *          float,
+ *       }
+ *
  * @phpstan-type StyleData array{
  *          'lineWidth': float,
  *          'lineCap': string,
@@ -82,6 +91,13 @@ abstract class Base
      */
     public const MPI = 3.14159265358979323846264338327950288419716939937510;
 
+    /**
+     * Identity matrix for transformations.
+     *
+     * @var TTMatrix
+     */
+    public const IDMATRIX = [1.0, 0.0, 0.0, 1.0, 0.0, 0.0];
+
     /**
      * Current PDF object number
      */

src/Transform.php

@@ -28,6 +28,8 @@
  * @copyright 2011-2024 Nicola Asuni - Tecnick.com LTD
  * @license   http://www.gnu.org/copyleft/lesser.html GNU-LGPL v3 (see LICENSE.TXT)
  * @link      https://github.com/tecnickcom/tc-lib-pdf-graph
+ *
+ * @phpstan-import-type TTMatrix from \Com\Tecnick\Pdf\Graph\Base
  */
 abstract class Transform extends \Com\Tecnick\Pdf\Graph\Style
 {
@@ -40,14 +42,14 @@ abstract class Transform extends \Com\Tecnick\Pdf\Graph\Style
      * Array (stack) of Current Transformation Matrix (CTM),
      * which maps user space coordinates used within a PDF content stream into output device coordinates.
      *
-     * @var array<int, array<int, array<float>>>
+     * @var array<int, array<int, TTMatrix>>
      */
     protected array $ctm = [];
 
     /**
      * Returns the transformation stack.
      *
-     * @return array<int, array<int, array<float>>>
+     * @return array<int, array<int, TTMatrix>>
      */
     public function getTransformStack(): array
     {
@@ -92,7 +94,7 @@ public function getStopTransform(): string
     /**
      * Get the tranformation matrix (CTM) PDF string
      *
-     * @param array<float> $ctm Transformation matrix array.
+     * @param TTMatrix $ctm Transformation matrix array.
      */
     public function getTransformation(array $ctm): string
     {
@@ -336,10 +338,10 @@ public function getVertSkewing(float $angy, float $posx, float $posy): string
     /**
      * Get the product of two Tranformation Matrix.
      *
-     * @param array<float> $tma First  Tranformation Matrix.
-     * @param array<float> $tmb Second Tranformation Matrix.
+     * @param TTMatrix $tma First  Tranformation Matrix.
+     * @param TTMatrix $tmb Second Tranformation Matrix.
      *
-     * @return array<float> CTM Transformation Matrix.
+     * @return TTMatrix CTM Transformation Matrix.
      */
     public function getCtmProduct(array $tma, array $tmb): array
     {