1 files changed, 157 insertions, 0 deletions
diff --git a/dom/canvas/WebGLQuery.cpp b/dom/canvas/WebGLQuery.cpp
new file mode 100644
index 0000000000..5290d69a50
--- /dev/null
+++ b/dom/canvas/WebGLQuery.cpp
@@ -0,0 +1,157 @@
+/* -*- 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 "WebGLQuery.h"
+
+#include "GLContext.h"
+#include "mozilla/dom/WebGL2RenderingContextBinding.h"
+#include "mozilla/StaticPrefs_webgl.h"
+#include "nsContentUtils.h"
+#include "WebGLContext.h"
+
+namespace mozilla {
+
+////
+
+static GLuint GenQuery(gl::GLContext* gl) {
+  GLuint ret = 0;
+  gl->fGenQueries(1, &ret);
+  return ret;
+}
+
+WebGLQuery::WebGLQuery(WebGLContext* webgl)
+    : WebGLContextBoundObject(webgl),
+      mGLName(GenQuery(mContext->gl)),
+      mTarget(0),
+      mActiveSlot(nullptr) {}
+
+WebGLQuery::~WebGLQuery() {
+  if (!mContext) return;
+  mContext->gl->fDeleteQueries(1, &mGLName);
+}
+
+////
+
+static GLenum TargetForDriver(const gl::GLContext* gl, GLenum target) {
+  switch (target) {
+    case LOCAL_GL_ANY_SAMPLES_PASSED:
+    case LOCAL_GL_ANY_SAMPLES_PASSED_CONSERVATIVE:
+      break;
+
+    default:
+      return target;
+  }
+
+  if (gl->IsSupported(gl::GLFeature::occlusion_query_boolean)) return target;
+
+  if (gl->IsSupported(gl::GLFeature::occlusion_query2))
+    return LOCAL_GL_ANY_SAMPLES_PASSED;
+
+  return LOCAL_GL_SAMPLES_PASSED;
+}
+
+void WebGLQuery::BeginQuery(GLenum target, RefPtr<WebGLQuery>& slot) {
+  mTarget = target;
+  mActiveSlot = &slot;
+  *mActiveSlot = this;
+
+  ////
+
+  const auto& gl = mContext->gl;
+
+  const auto driverTarget = TargetForDriver(gl, mTarget);
+  gl->fBeginQuery(driverTarget, mGLName);
+}
+
+void WebGLQuery::EndQuery() {
+  *mActiveSlot = nullptr;
+  mActiveSlot = nullptr;
+  mCanBeAvailable = false;
+
+  ////
+
+  const auto& gl = mContext->gl;
+
+  const auto driverTarget = TargetForDriver(gl, mTarget);
+  gl->fEndQuery(driverTarget);
+}
+
+Maybe<double> WebGLQuery::GetQueryParameter(GLenum pname) const {
+  switch (pname) {
+    case LOCAL_GL_QUERY_RESULT_AVAILABLE:
+    case LOCAL_GL_QUERY_RESULT:
+      break;
+
+    default:
+      mContext->ErrorInvalidEnumInfo("pname", pname);
+      return Nothing();
+  }
+
+  if (!mTarget) {
+    mContext->ErrorInvalidOperation("Query has never been active.");
+    return Nothing();
+  }
+
+  if (mActiveSlot) {
+    mContext->ErrorInvalidOperation("Query is still active.");
+    return Nothing();
+  }
+
+  // End of validation
+  ////
+
+  const auto& gl = mContext->gl;
+
+  uint64_t val = 0;
+  switch (pname) {
+    case LOCAL_GL_QUERY_RESULT_AVAILABLE:
+      gl->fGetQueryObjectuiv(mGLName, pname, (GLuint*)&val);
+      return Some(static_cast<bool>(val));
+
+    case LOCAL_GL_QUERY_RESULT:
+      switch (mTarget) {
+        case LOCAL_GL_TIME_ELAPSED_EXT:
+        case LOCAL_GL_TIMESTAMP_EXT:
+          if (mContext->Has64BitTimestamps()) {
+            gl->fGetQueryObjectui64v(mGLName, pname, &val);
+            break;
+          }
+          [[fallthrough]];
+
+        default:
+          gl->fGetQueryObjectuiv(mGLName, LOCAL_GL_QUERY_RESULT, (GLuint*)&val);
+          break;
+      }
+
+      switch (mTarget) {
+        case LOCAL_GL_ANY_SAMPLES_PASSED:
+        case LOCAL_GL_ANY_SAMPLES_PASSED_CONSERVATIVE:
+        case LOCAL_GL_TRANSFORM_FEEDBACK_PRIMITIVES_WRITTEN:
+        case LOCAL_GL_TIME_ELAPSED_EXT:
+        case LOCAL_GL_TIMESTAMP_EXT:
+          return Some(val);
+      }
+      MOZ_CRASH("Bad `mTarget`.");
+
+    default:
+      MOZ_CRASH("Bad `pname`.");
+  }
+}
+
+void WebGLQuery::QueryCounter() {
+  const GLenum target = LOCAL_GL_TIMESTAMP_EXT;
+  if (mTarget && target != mTarget) {
+    mContext->ErrorInvalidOperation("Queries cannot change targets.");
+    return;
+  }
+
+  mTarget = target;
+  mCanBeAvailable = false;
+
+  const auto& gl = mContext->gl;
+  gl->fQueryCounter(mGLName, mTarget);
+}
+
+}  // namespace mozilla