1 files changed, 69 insertions, 0 deletions
diff --git a/dom/canvas/WebGLExtensionDrawBuffers.cpp b/dom/canvas/WebGLExtensionDrawBuffers.cpp
new file mode 100644
index 000000000..27aa76cc7
--- /dev/null
+++ b/dom/canvas/WebGLExtensionDrawBuffers.cpp
@@ -0,0 +1,69 @@
+/* -*- Mode: C++; tab-width: 4; 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 "WebGLExtensions.h"
+
+#include <algorithm>
+#include "GLContext.h"
+#include "mozilla/dom/WebGLRenderingContextBinding.h"
+#include "WebGLContext.h"
+#include "WebGLFramebuffer.h"
+#include "WebGLRenderbuffer.h"
+#include "WebGLTexture.h"
+
+namespace mozilla {
+
+WebGLExtensionDrawBuffers::WebGLExtensionDrawBuffers(WebGLContext* webgl)
+    : WebGLExtensionBase(webgl)
+{
+    MOZ_ASSERT(IsSupported(webgl), "Don't construct extension if unsupported.");
+
+    // WEBGL_draw_buffers:
+    // "The value of the MAX_COLOR_ATTACHMENTS_WEBGL parameter must be greater than or
+    //  equal to that of the MAX_DRAW_BUFFERS_WEBGL parameter."
+    webgl->mImplMaxColorAttachments = webgl->mGLMaxColorAttachments;
+    webgl->mImplMaxDrawBuffers = std::min(webgl->mGLMaxDrawBuffers,
+                                          webgl->mImplMaxColorAttachments);
+}
+
+WebGLExtensionDrawBuffers::~WebGLExtensionDrawBuffers()
+{
+}
+
+void
+WebGLExtensionDrawBuffers::DrawBuffersWEBGL(const dom::Sequence<GLenum>& buffers)
+{
+    if (mIsLost) {
+        mContext->ErrorInvalidOperation("drawBuffersWEBGL: Extension is lost.");
+        return;
+    }
+
+    mContext->DrawBuffers(buffers);
+}
+
+bool
+WebGLExtensionDrawBuffers::IsSupported(const WebGLContext* webgl)
+{
+    gl::GLContext* gl = webgl->GL();
+
+    if (!gl->IsExtensionSupported(gl::GLContext::ARB_draw_buffers) &&
+        !gl->IsExtensionSupported(gl::GLContext::EXT_draw_buffers))
+    {
+        return false;
+    }
+
+    // WEBGL_draw_buffers requires at least 4 color attachments.
+    if (webgl->mGLMaxDrawBuffers < webgl->kMinMaxDrawBuffers ||
+        webgl->mGLMaxColorAttachments < webgl->kMinMaxColorAttachments)
+    {
+        return false;
+    }
+
+    return true;
+}
+
+IMPL_WEBGL_EXTENSION_GOOP(WebGLExtensionDrawBuffers, WEBGL_draw_buffers)
+
+} // namespace mozilla