1 files changed, 32 insertions, 0 deletions
diff --git a/dom/canvas/WebGLExtensionShaderTextureLod.cpp b/dom/canvas/WebGLExtensionShaderTextureLod.cpp
new file mode 100644
index 0000000000..bb6599910f
--- /dev/null
+++ b/dom/canvas/WebGLExtensionShaderTextureLod.cpp
@@ -0,0 +1,32 @@
+/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* 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 "WebGLExtensions.h"
+
+#include "GLContext.h"
+#include "mozilla/dom/WebGLRenderingContextBinding.h"
+#include "WebGLContext.h"
+
+namespace mozilla {
+
+WebGLExtensionShaderTextureLod::WebGLExtensionShaderTextureLod(
+    WebGLContext* webgl)
+    : WebGLExtensionBase(webgl) {
+  MOZ_ASSERT(IsSupported(webgl), "Don't construct extension if unsupported.");
+}
+
+bool WebGLExtensionShaderTextureLod::IsSupported(const WebGLContext* webgl) {
+  if (webgl->IsWebGL2()) return false;
+
+  gl::GLContext* gl = webgl->GL();
+  if (gl->IsGLES() && gl->Version() >= 300) {
+    // ANGLE's shader translator doesn't yet translate
+    // WebGL1+EXT_shader_texture_lod to ES3. (Bug 1491221)
+    return false;
+  }
+  return gl->IsSupported(gl::GLFeature::shader_texture_lod);
+}
+
+}  // namespace mozilla