summaryrefslogtreecommitdiffstats
path: root/dom/canvas/CanvasUtils.cpp
diff options
context:
space:
mode:
Diffstat (limited to 'dom/canvas/CanvasUtils.cpp')
-rw-r--r--dom/canvas/CanvasUtils.cpp130
1 files changed, 130 insertions, 0 deletions
diff --git a/dom/canvas/CanvasUtils.cpp b/dom/canvas/CanvasUtils.cpp
new file mode 100644
index 000000000..c7cfed83f
--- /dev/null
+++ b/dom/canvas/CanvasUtils.cpp
@@ -0,0 +1,130 @@
+/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include <stdlib.h>
+#include <stdarg.h>
+
+#include "prprf.h"
+
+#include "nsIServiceManager.h"
+
+#include "nsIConsoleService.h"
+#include "nsIDOMCanvasRenderingContext2D.h"
+#include "nsICanvasRenderingContextInternal.h"
+#include "nsIHTMLCollection.h"
+#include "mozilla/dom/HTMLCanvasElement.h"
+#include "nsIPrincipal.h"
+
+#include "nsGfxCIID.h"
+
+#include "nsTArray.h"
+
+#include "CanvasUtils.h"
+#include "mozilla/gfx/Matrix.h"
+#include "WebGL2Context.h"
+
+using namespace mozilla::gfx;
+
+namespace mozilla {
+namespace CanvasUtils {
+
+bool
+GetCanvasContextType(const nsAString& str, dom::CanvasContextType* const out_type)
+{
+ if (str.EqualsLiteral("2d")) {
+ *out_type = dom::CanvasContextType::Canvas2D;
+ return true;
+ }
+
+ if (str.EqualsLiteral("experimental-webgl")) {
+ *out_type = dom::CanvasContextType::WebGL1;
+ return true;
+ }
+
+#ifdef MOZ_WEBGL_CONFORMANT
+ if (str.EqualsLiteral("webgl")) {
+ /* WebGL 1.0, $2.1 "Context Creation":
+ * If the user agent supports both the webgl and experimental-webgl
+ * canvas context types, they shall be treated as aliases.
+ */
+ *out_type = dom::CanvasContextType::WebGL1;
+ return true;
+ }
+#endif
+
+ if (WebGL2Context::IsSupported()) {
+ if (str.EqualsLiteral("webgl2")) {
+ *out_type = dom::CanvasContextType::WebGL2;
+ return true;
+ }
+ }
+
+ if (str.EqualsLiteral("bitmaprenderer")) {
+ *out_type = dom::CanvasContextType::ImageBitmap;
+ return true;
+ }
+
+ return false;
+}
+
+/**
+ * This security check utility might be called from an source that never taints
+ * others. For example, while painting a CanvasPattern, which is created from an
+ * ImageBitmap, onto a canvas. In this case, the caller could set the CORSUsed
+ * true in order to pass this check and leave the aPrincipal to be a nullptr
+ * since the aPrincipal is not going to be used.
+ */
+void
+DoDrawImageSecurityCheck(dom::HTMLCanvasElement *aCanvasElement,
+ nsIPrincipal *aPrincipal,
+ bool forceWriteOnly,
+ bool CORSUsed)
+{
+ // Callers should ensure that mCanvasElement is non-null before calling this
+ if (!aCanvasElement) {
+ NS_WARNING("DoDrawImageSecurityCheck called without canvas element!");
+ return;
+ }
+
+ if (aCanvasElement->IsWriteOnly())
+ return;
+
+ // If we explicitly set WriteOnly just do it and get out
+ if (forceWriteOnly) {
+ aCanvasElement->SetWriteOnly();
+ return;
+ }
+
+ // No need to do a security check if the image used CORS for the load
+ if (CORSUsed)
+ return;
+
+ NS_PRECONDITION(aPrincipal, "Must have a principal here");
+
+ if (aCanvasElement->NodePrincipal()->Subsumes(aPrincipal)) {
+ // This canvas has access to that image anyway
+ return;
+ }
+
+ aCanvasElement->SetWriteOnly();
+}
+
+bool
+CoerceDouble(const JS::Value& v, double* d)
+{
+ if (v.isDouble()) {
+ *d = v.toDouble();
+ } else if (v.isInt32()) {
+ *d = double(v.toInt32());
+ } else if (v.isUndefined()) {
+ *d = 0.0;
+ } else {
+ return false;
+ }
+ return true;
+}
+
+} // namespace CanvasUtils
+} // namespace mozilla