LibWeb: Add DOMPoint matrixTransform and DOMMatrix transformPoint

Userland/Libraries/LibWeb/Geometry/DOMMatrixReadOnly.cpp

@@ -7,6 +7,7 @@
 #include <LibWeb/Bindings/Intrinsics.h>
 #include <LibWeb/Geometry/DOMMatrix.h>
 #include <LibWeb/Geometry/DOMMatrixReadOnly.h>
+#include <LibWeb/Geometry/DOMPoint.h>
 #include <LibWeb/WebIDL/ExceptionOr.h>
 
 namespace Web::Geometry {
@@ -240,6 +241,39 @@ JS::NonnullGCPtr<DOMMatrix> DOMMatrixReadOnly::inverse() const
     return result->invert_self();
 }
 
+// https://drafts.fxtf.org/geometry/#dom-dommatrixreadonly-transformpoint
+JS::NonnullGCPtr<DOMPoint> DOMMatrixReadOnly::transform_point(DOMPointInit const& point) const
+{
+    // Let pointObject be the result of invoking create a DOMPoint from the dictionary point.
+    auto point_object = DOMPoint::from_point(realm().vm(), point);
+
+    // Return the result of invoking transform a point with a matrix, given pointObject and the current matrix. The passed argument does not get modified.
+    return transform_point(point_object);
+}
+
+// https://drafts.fxtf.org/geometry/#transform-a-point-with-a-matrix
+JS::NonnullGCPtr<DOMPoint> DOMMatrixReadOnly::transform_point(DOMPointReadOnly const& point) const
+{
+    // 1. Let x be point’s x coordinate.
+    // 2. Let y be point’s y coordinate.
+    // 3. Let z be point’s z coordinate.
+    // 4. Let w be point’s w perspective.
+    // 5. Let pointVector be a new column vector with the elements being x, y, z, and w, respectively.
+    Vector4<double> point_vector { point.x(), point.y(), point.z(), point.w() };
+
+    // 6. Set pointVector to pointVector pre-multiplied by matrix.
+    // This is really a post multiply because of the transposed m_matrix.
+    point_vector = m_matrix.transpose() * point_vector;
+
+    // 7. Let transformedPoint be a new DOMPoint object.
+    // 8. Set transformedPoint’s x coordinate to pointVector’s first element.
+    // 9. Set transformedPoint’s y coordinate to pointVector’s second element.
+    // 10. Set transformedPoint’s z coordinate to pointVector’s third element.
+    // 11. Set transformedPoint’s w perspective to pointVector’s fourth element.
+    // 12. Return transformedPoint.
+    return DOMPoint::construct_impl(realm(), point_vector.x(), point_vector.y(), point_vector.z(), point_vector.w());
+}
+
 // https://drafts.fxtf.org/geometry/#dommatrixreadonly-stringification-behavior
 WebIDL::ExceptionOr<String> DOMMatrixReadOnly::to_string() const
 {

Userland/Libraries/LibWeb/Geometry/DOMMatrixReadOnly.h

@@ -83,6 +83,10 @@ public:
 
     JS::NonnullGCPtr<DOMMatrix> inverse() const;
 
+    JS::NonnullGCPtr<DOMPoint> transform_point(DOMPointInit const&) const;
+
+    JS::NonnullGCPtr<DOMPoint> transform_point(DOMPointReadOnly const&) const;
+
     WebIDL::ExceptionOr<String> to_string() const;
 
 protected:

Userland/Libraries/LibWeb/Geometry/DOMMatrixReadOnly.idl

@@ -1,4 +1,5 @@
 #import <Geometry/DOMMatrix.idl>
+#import <Geometry/DOMPoint.idl>
 
 // https://drafts.fxtf.org/geometry/#dommatrixreadonly
 [Exposed=(Window,Worker), Serializable, UseNewAKString]
@@ -52,7 +53,7 @@ interface DOMMatrixReadOnly {
     // FIXME: [NewObject] DOMMatrix flipY();
     [NewObject] DOMMatrix inverse();
 
-    // FIXME: [NewObject] DOMPoint transformPoint(optional DOMPointInit point = {});
+    [NewObject] DOMPoint transformPoint(optional DOMPointInit point = {});
     // FIXME: [NewObject] Float32Array toFloat32Array();
     // FIXME: [NewObject] Float64Array toFloat64Array();
 

Userland/Libraries/LibWeb/Geometry/DOMPointReadOnly.cpp

@@ -6,6 +6,7 @@
  */
 
 #include <LibWeb/Bindings/Intrinsics.h>
+#include <LibWeb/Geometry/DOMMatrix.h>
 #include <LibWeb/Geometry/DOMPointReadOnly.h>
 #include <LibWeb/WebIDL/ExceptionOr.h>
 
@@ -34,6 +35,19 @@ JS::NonnullGCPtr<DOMPointReadOnly> DOMPointReadOnly::from_point(JS::VM& vm, DOMP
 
 DOMPointReadOnly::~DOMPointReadOnly() = default;
 
+// https://drafts.fxtf.org/geometry/#dom-dompointreadonly-matrixtransform
+WebIDL::ExceptionOr<JS::NonnullGCPtr<DOMPoint>> DOMPointReadOnly::matrix_transform(DOMMatrixInit& matrix) const
+{
+    // 1. Let matrixObject be the result of invoking create a DOMMatrix from the dictionary matrix.
+    auto maybe_matrix_object = DOMMatrix::create_from_dom_matrix_2d_init(realm(), matrix);
+    if (maybe_matrix_object.is_exception())
+        return maybe_matrix_object.exception();
+    auto matrix_object = maybe_matrix_object.release_value();
+
+    // 2. Return the result of invoking transform a point with a matrix, given the current point and matrixObject. The current point does not get modified.
+    return matrix_object->transform_point(*this);
+}
+
 void DOMPointReadOnly::initialize(JS::Realm& realm)
 {
     Base::initialize(realm);

Userland/Libraries/LibWeb/Geometry/DOMPointReadOnly.h

@@ -36,6 +36,8 @@ public:
     double z() const { return m_z; }
     double w() const { return m_w; }
 
+    WebIDL::ExceptionOr<JS::NonnullGCPtr<DOMPoint>> matrix_transform(DOMMatrixInit&) const;
+
 protected:
     DOMPointReadOnly(JS::Realm&, double x, double y, double z, double w);
 

Userland/Libraries/LibWeb/Geometry/DOMPointReadOnly.idl

@@ -1,3 +1,6 @@
+#import <Geometry/DOMMatrixReadOnly.idl>
+#import <Geometry/DOMPoint.idl>
+
 // https://drafts.fxtf.org/geometry/#dompointreadonly
 [Exposed=(Window,Worker), Serializable]
 interface DOMPointReadOnly {
@@ -12,7 +15,7 @@ interface DOMPointReadOnly {
     readonly attribute unrestricted double z;
     readonly attribute unrestricted double w;
 
-    // FIXME: DOMPoint matrixTransform(optional DOMMatrixInit matrix = {});
+    [NewObject] DOMPoint matrixTransform(optional DOMMatrixInit matrix = {});
 
     [Default] object toJSON();
 };