From 27cc8742ce9d5a687a468186d647bc9fefa9fb21 Mon Sep 17 00:00:00 2001
From: Luke Wilde <lukew@serenityos.org>
Date: Sun, 10 Apr 2022 18:47:01 +0100
Subject: [PATCH] LibWeb: Implement CanvasRenderingContext2D.resetTransform

---
 .../Libraries/LibWeb/HTML/CanvasRenderingContext2D.cpp     | 7 +++++++
 Userland/Libraries/LibWeb/HTML/CanvasRenderingContext2D.h  | 1 +
 .../Libraries/LibWeb/HTML/CanvasRenderingContext2D.idl     | 1 +
 3 files changed, 9 insertions(+)

diff --git a/Userland/Libraries/LibWeb/HTML/CanvasRenderingContext2D.cpp b/Userland/Libraries/LibWeb/HTML/CanvasRenderingContext2D.cpp
index 95718a73be..15302c1230 100644
--- a/Userland/Libraries/LibWeb/HTML/CanvasRenderingContext2D.cpp
+++ b/Userland/Libraries/LibWeb/HTML/CanvasRenderingContext2D.cpp
@@ -719,6 +719,13 @@ void CanvasRenderingContext2D::set_transform(double a, double b, double c, doubl
     transform(a, b, c, d, e, f);
 }
 
+// https://html.spec.whatwg.org/multipage/canvas.html#dom-context-2d-resettransform
+void CanvasRenderingContext2D::reset_transform()
+{
+    // The resetTransform() method, when invoked, must reset the current transformation matrix to the identity matrix.
+    m_drawing_state.transform = {};
+}
+
 // https://html.spec.whatwg.org/multipage/canvas.html#check-the-usability-of-the-image-argument
 DOM::ExceptionOr<CanvasImageSourceUsability> check_usability_of_image(CanvasImageSource const& image)
 {
diff --git a/Userland/Libraries/LibWeb/HTML/CanvasRenderingContext2D.h b/Userland/Libraries/LibWeb/HTML/CanvasRenderingContext2D.h
index f00eca01c2..b86ee07ef0 100644
--- a/Userland/Libraries/LibWeb/HTML/CanvasRenderingContext2D.h
+++ b/Userland/Libraries/LibWeb/HTML/CanvasRenderingContext2D.h
@@ -100,6 +100,7 @@ public:
 
     void transform(double a, double b, double c, double d, double e, double f);
     void set_transform(double a, double b, double c, double d, double e, double f);
+    void reset_transform();
 
 private:
     explicit CanvasRenderingContext2D(HTMLCanvasElement&);
diff --git a/Userland/Libraries/LibWeb/HTML/CanvasRenderingContext2D.idl b/Userland/Libraries/LibWeb/HTML/CanvasRenderingContext2D.idl
index 36cebe7f05..6806b05658 100644
--- a/Userland/Libraries/LibWeb/HTML/CanvasRenderingContext2D.idl
+++ b/Userland/Libraries/LibWeb/HTML/CanvasRenderingContext2D.idl
@@ -58,5 +58,6 @@ interface CanvasRenderingContext2D {
     // FIXME: All these `double`s should be `unrestricted double`
     undefined transform(double a, double b, double c, double d, double e, double f);
     undefined setTransform(double a, double b, double c, double d, double e, double f);
+    undefined resetTransform();
 
 };