1 files changed, 58 insertions, 0 deletions
diff --git a/dom/canvas/WebGLVertexArrayFake.cpp b/dom/canvas/WebGLVertexArrayFake.cpp
new file mode 100644
index 0000000000..2ab6e233fb
--- /dev/null
+++ b/dom/canvas/WebGLVertexArrayFake.cpp
@@ -0,0 +1,58 @@
+/* -*- Mode: C++; tab-width: 4; 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 "WebGLVertexArrayFake.h"
+
+#include "GLContext.h"
+#include "WebGLBuffer.h"
+#include "WebGLContext.h"
+
+namespace mozilla {
+
+WebGLVertexArrayFake::WebGLVertexArrayFake(WebGLContext* webgl)
+    : WebGLVertexArray(webgl) {}
+
+void WebGLVertexArrayFake::BindVertexArray() {
+  // Go through and re-bind all buffers and setup all
+  // vertex attribute pointers
+  const auto& gl = mContext->gl;
+
+  mContext->mBoundVertexArray = this;
+
+  static_assert(IsBufferTargetLazilyBound(LOCAL_GL_ARRAY_BUFFER));
+  static_assert(!IsBufferTargetLazilyBound(LOCAL_GL_ELEMENT_ARRAY_BUFFER));
+
+  const auto fnBind = [&](const GLenum target, WebGLBuffer* const buffer) {
+    gl->fBindBuffer(target, buffer ? buffer->mGLName : 0);
+  };
+
+  fnBind(LOCAL_GL_ELEMENT_ARRAY_BUFFER, mElementArrayBuffer);
+
+  const bool useDivisor =
+      mContext->IsWebGL2() ||
+      mContext->IsExtensionEnabled(WebGLExtensionID::ANGLE_instanced_arrays);
+
+  for (const auto i : IntegerRange(mContext->MaxVertexAttribs())) {
+    const auto& binding = mBindings[i];
+    const auto& desc = mDescs[i];
+
+    if (binding.layout.isArray) {
+      gl->fEnableVertexAttribArray(i);
+    } else {
+      gl->fDisableVertexAttribArray(i);
+    }
+
+    if (useDivisor) {
+      gl->fVertexAttribDivisor(i, binding.layout.divisor);
+    }
+
+    fnBind(LOCAL_GL_ARRAY_BUFFER, binding.buffer);
+    DoVertexAttribPointer(*gl, i, desc);
+  }
+
+  fnBind(LOCAL_GL_ARRAY_BUFFER, nullptr);
+}
+
+}  // namespace mozilla