dom/canvas/WebGLBindableName.h

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
   2 /* This Source Code Form is subject to the terms of the Mozilla Public
   3  * License, v. 2.0. If a copy of the MPL was not distributed with this
   4  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   5
   6 #ifndef WEBGLBINDABLENAME_H_
   7 #define WEBGLBINDABLENAME_H_
   8
   9 #include "WebGLTypes.h"
  10
  11 #include "GLDefs.h"
  12 #include "mozilla/TypeTraits.h"
  13 #include "mozilla/Assertions.h"
  14
  15 namespace mozilla {
  16
  17 /** Represents a binding to a GL binding point
  18  */
  19 template<typename T>
  20 class WebGLBindable
  21 {
  22 public:
  23     WebGLBindable() : mTarget(LOCAL_GL_NONE) { }
  24     bool HasEverBeenBound() const { return mTarget != LOCAL_GL_NONE; }
  25
  26     void BindTo(T target) {
  27         MOZ_ASSERT(target != LOCAL_GL_NONE, "Can't bind to GL_NONE.");
  28         MOZ_ASSERT(!HasEverBeenBound() || mTarget == target, "Rebinding is illegal.");
  29
  30         bool targetChanged = (target != mTarget);
  31         mTarget = target;
  32         if (targetChanged)
  33             OnTargetChanged();
  34     }
  35
  36     T Target() const {
  37         MOZ_ASSERT(HasEverBeenBound());
  38         return mTarget;
  39     }
  40
  41 protected:
  42     //! Called after mTarget has been changed by BindTo(target).
  43     virtual void OnTargetChanged() {}
  44
  45     T mTarget;
  46 };
  47
  48
  49 /** Represents a GL name that can be bound to a target.
  50  */
  51 template<typename T>
  52 class WebGLBindableName
  53     : public WebGLBindable<T>
  54 {
  55 public:
  56
  57     explicit WebGLBindableName(GLuint aName)
  58         : WebGLBindable<T>()
  59         , mGLName(aName)
  60     { }
  61     GLuint GLName() const { return mGLName; }
  62
  63 protected:
  64     const GLuint mGLName;
  65 };
  66
  67
  68 } // namespace mozilla
  69
  70 #endif // !WEBGLBINDABLENAME_H_