JUCE/modules/juce_opengl/opengl/juce_OpenGLContext.h

/*
  ==============================================================================

   This file is part of the JUCE library - "Jules' Utility Class Extensions"
   Copyright 2004-11 by Raw Material Software Ltd.

  ------------------------------------------------------------------------------

   JUCE can be redistributed and/or modified under the terms of the GNU General
   Public License (Version 2), as published by the Free Software Foundation.
   A copy of the license is included in the JUCE distribution, or can be found
   online at www.gnu.org/licenses.

   JUCE is distributed in the hope that it will be useful, but WITHOUT ANY
   WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
   A PARTICULAR PURPOSE.  See the GNU General Public License for more details.

  ------------------------------------------------------------------------------

   To release a closed-source product which uses JUCE, commercial licenses are
   available: visit www.rawmaterialsoftware.com/juce for more information.

  ==============================================================================
*/

#ifndef __JUCE_OPENGLCONTEXT_JUCEHEADER__
#define __JUCE_OPENGLCONTEXT_JUCEHEADER__

#include "juce_OpenGLPixelFormat.h"


//==============================================================================
/**
    A base class for types of OpenGL context.

    An OpenGLComponent will supply its own context for drawing in its window.
*/
class JUCE_API  OpenGLContext
{
public:
    //==============================================================================
    /** Destructor. */
    virtual ~OpenGLContext();

    //==============================================================================
    /** Makes this context the currently active one. */
    virtual bool makeActive() const noexcept = 0;
    /** If this context is currently active, it is disactivated. */
    virtual bool makeInactive() const noexcept = 0;
    /** Returns true if this context is currently active. */
    virtual bool isActive() const noexcept = 0;

    /** Swaps the buffers (if the context can do this). */
    virtual void swapBuffers() = 0;

    /** Sets whether the context checks the vertical sync before swapping.

        The value is the number of frames to allow between buffer-swapping. This is
        fairly system-dependent, but 0 turns off syncing, 1 makes it swap on frame-boundaries,
        and greater numbers indicate that it should swap less often.

        Returns true if it sets the value successfully.
    */
    virtual bool setSwapInterval (int numFramesPerSwap) = 0;

    /** Returns the current swap-sync interval.
        See setSwapInterval() for info about the value returned.
    */
    virtual int getSwapInterval() const = 0;

    //==============================================================================
    /** Returns the pixel format being used by this context. */
    virtual OpenGLPixelFormat getPixelFormat() const = 0;

    /** For windowed contexts, this moves the context within the bounds of
        its parent window.
    */
    virtual void updateWindowPosition (const Rectangle<int>& bounds) = 0;

    /** For windowed contexts, this triggers a repaint of the window.

        (Not relevent on all platforms).
    */
    virtual void repaint() = 0;

    /** Returns an OS-dependent handle to the raw GL context.

        On win32, this will be a HGLRC; on the Mac, an AGLContext; on Linux,
        a GLXContext.
    */
    virtual void* getRawContext() const noexcept = 0;

    /** Deletes the context.

        This must only be called on the message thread, or will deadlock.
        On background threads, call getCurrentContext()->deleteContext(), but be careful not
        to call any other OpenGL function afterwards.
        This doesn't touch other resources, such as window handles, etc.
        You'll probably never have to call this method directly.
    */
    virtual void deleteContext() = 0;

    //==============================================================================
    /** Returns the context that's currently in active use by the calling thread.

        Returns 0 if there isn't an active context.
    */
    static OpenGLContext* getCurrentContext();

protected:
    //==============================================================================
    OpenGLContext() noexcept;

private:
    JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (OpenGLContext);
};


#endif   // __JUCE_OPENGLCONTEXT_JUCEHEADER__