1 files changed, 74 insertions, 0 deletions
diff --git a/dom/canvas/WebGL2ContextRenderbuffers.cpp b/dom/canvas/WebGL2ContextRenderbuffers.cpp
new file mode 100644
index 0000000000..0203ad5c57
--- /dev/null
+++ b/dom/canvas/WebGL2ContextRenderbuffers.cpp
@@ -0,0 +1,74 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* 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 "WebGL2Context.h"
+
+#include "GLContext.h"
+#include "WebGLContextUtils.h"
+#include "WebGLFormats.h"
+
+namespace mozilla {
+
+Maybe<std::vector<int32_t>> WebGL2Context::GetInternalformatParameter(
+    GLenum target, GLenum internalformat, GLenum pname) const {
+  const FuncScope funcScope(*this, "getInternalfomratParameter");
+  if (IsContextLost()) return Nothing();
+
+  if (target != LOCAL_GL_RENDERBUFFER) {
+    ErrorInvalidEnum("`target` must be RENDERBUFFER.");
+    return Nothing();
+  }
+
+  // GLES 3.0.4 $4.4.4 p212:
+  // "An internal format is color-renderable if it is one of the formats from
+  // table 3.13
+  //  noted as color-renderable or if it is unsized format RGBA or RGB."
+
+  GLenum sizedFormat;
+  switch (internalformat) {
+    case LOCAL_GL_RGB:
+      sizedFormat = LOCAL_GL_RGB8;
+      break;
+    case LOCAL_GL_RGBA:
+      sizedFormat = LOCAL_GL_RGBA8;
+      break;
+    default:
+      sizedFormat = internalformat;
+      break;
+  }
+
+  // In RenderbufferStorage, we allow DEPTH_STENCIL. Therefore, it is accepted
+  // for internalformat as well. Please ignore the conformance test fail for
+  // DEPTH_STENCIL.
+
+  const auto usage = mFormatUsage->GetRBUsage(sizedFormat);
+  if (!usage) {
+    ErrorInvalidEnum(
+        "`internalformat` must be color-, depth-, or stencil-renderable, was: "
+        "0x%04x.",
+        internalformat);
+    return Nothing();
+  }
+
+  if (pname != LOCAL_GL_SAMPLES) {
+    ErrorInvalidEnum("`pname` must be SAMPLES.");
+    return Nothing();
+  }
+
+  std::vector<int32_t> ret;
+  GLint sampleCount = 0;
+  gl->fGetInternalformativ(LOCAL_GL_RENDERBUFFER, internalformat,
+                           LOCAL_GL_NUM_SAMPLE_COUNTS, 1, &sampleCount);
+  if (sampleCount) {
+    ret.resize(sampleCount);
+    gl->fGetInternalformativ(LOCAL_GL_RENDERBUFFER, internalformat,
+                             LOCAL_GL_SAMPLES, ret.size(), ret.data());
+  }
+
+  return Some(ret);
+}
+
+}  // namespace mozilla