/* -*- 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/. */

#ifndef WEBGL_CONTEXT_UTILS_H_
#define WEBGL_CONTEXT_UTILS_H_

#include "WebGLContext.h"

#include "mozilla/Assertions.h"
#include "mozilla/dom/BindingUtils.h"

#include "WebGLStrongTypes.h"

namespace mozilla {

// For use with the different texture calls, i.e.
//   TexImage2D, CopyTex[Sub]Image2D, ...
// that take a "target" parameter. This parameter is not always the same as
// the texture binding location, like GL_TEXTURE_2D or GL_TEXTURE_CUBE_MAP.
// For example, cube maps would pass GL_TEXTURE_CUBE_MAP_[POS|NEG]_[X|Y|Z]
// instead of just GL_TEXTURE_CUBE_MAP.
//
// This function converts the texture image target to the texture target a.k.a.
// binding location. The returned binding location can be used to check that
// the currently bound texture is appropriate for this texImageTarget.
//
// Returns GL_NONE if passed an invalid texture image target
TexTarget TexImageTargetToTexTarget(TexImageTarget texImageTarget);

// Helper function to create a JS::Value from a C string
JS::Value StringValue(JSContext* cx, const char* str, ErrorResult& rv);

struct GLComponents {
  unsigned char mComponents;

  enum Components {
    Red = (1 << 0),
    Green = (1 << 1),
    Blue = (1 << 2),
    Alpha = (1 << 3),
    Stencil = (1 << 4),
    Depth = (1 << 5),
  };

  GLComponents() : mComponents(0) {}

  explicit GLComponents(TexInternalFormat format);

  // Returns true iff other has all (or more) of
  // the components present in this GLComponents
  bool IsSubsetOf(const GLComponents& other) const;
};

template <typename WebGLObjectType>
JS::Value WebGLContext::WebGLObjectAsJSValue(JSContext* cx,
                                             const WebGLObjectType* object,
                                             ErrorResult& rv) const {
  if (!object) return JS::NullValue();

  MOZ_ASSERT(this == object->mContext);
  JS::Rooted<JS::Value> v(cx);
  JS::Rooted<JSObject*> wrapper(cx, GetWrapper());
  JSAutoRealm ar(cx, wrapper);
  if (!dom::GetOrCreateDOMReflector(cx, const_cast<WebGLObjectType*>(object),
                                    &v)) {
    rv.Throw(NS_ERROR_FAILURE);
    return JS::NullValue();
  }
  return v;
}

template <typename WebGLObjectType>
JSObject* WebGLContext::WebGLObjectAsJSObject(JSContext* cx,
                                              const WebGLObjectType* object,
                                              ErrorResult& rv) const {
  JS::Value v = WebGLObjectAsJSValue(cx, object, rv);
  if (v.isNull()) return nullptr;

  return &v.toObject();
}

/**
 * Return the displayable name for the texture function that is the
 * source for validation.
 */
const char* InfoFrom(WebGLTexImageFunc func, WebGLTexDimensions dims);

JS::Value StringValue(JSContext* cx, const nsAString& str, ErrorResult& er);

}  // namespace mozilla

#endif  // WEBGL_CONTEXT_UTILS_H_