dri: Add a flush control extension

[mesa.git] / include / GL / internal / dri_interface.h

/*
 * Copyright 1998-1999 Precision Insight, Inc., Cedar Park, Texas.
 * Copyright 2007-2008 Red Hat, Inc.
 * (C) Copyright IBM Corporation 2004
 * All Rights Reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * on the rights to use, copy, modify, merge, publish, distribute, sub
 * license, and/or sell copies of the Software, and to permit persons to whom
 * the Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice (including the next
 * paragraph) shall be included in all copies or substantial portions of the
 * Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.  IN NO EVENT SHALL
 * THE COPYRIGHT HOLDERS AND/OR THEIR SUPPLIERS BE LIABLE FOR ANY CLAIM,
 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
 * USE OR OTHER DEALINGS IN THE SOFTWARE.
 */

/**
 * \file dri_interface.h
 *
 * This file contains all the types and functions that define the interface
 * between a DRI driver and driver loader.  Currently, the most common driver
 * loader is the XFree86 libGL.so.  However, other loaders do exist, and in
 * the future the server-side libglx.a will also be a loader.
 * 
 * \author Kevin E. Martin <kevin@precisioninsight.com>
 * \author Ian Romanick <idr@us.ibm.com>
 * \author Kristian Høgsberg <krh@redhat.com>
 */

#ifndef DRI_INTERFACE_H
#define DRI_INTERFACE_H

#ifdef HAVE_LIBDRM
#include <drm.h>
#else
typedef unsigned int drm_context_t;
typedef unsigned int drm_drawable_t;
typedef struct drm_clip_rect drm_clip_rect_t;
#endif

#include <stdint.h>

/**
 * \name DRI interface structures
 *
 * The following structures define the interface between the GLX client
 * side library and the DRI (direct rendering infrastructure).
 */
/*@{*/
typedef struct __DRIdisplayRec          __DRIdisplay;
typedef struct __DRIscreenRec           __DRIscreen;
typedef struct __DRIcontextRec          __DRIcontext;
typedef struct __DRIdrawableRec         __DRIdrawable;
typedef struct __DRIconfigRec           __DRIconfig;
typedef struct __DRIframebufferRec      __DRIframebuffer;
typedef struct __DRIversionRec          __DRIversion;

typedef struct __DRIcoreExtensionRec            __DRIcoreExtension;
typedef struct __DRIextensionRec                __DRIextension;
typedef struct __DRIcopySubBufferExtensionRec   __DRIcopySubBufferExtension;
typedef struct __DRIswapControlExtensionRec     __DRIswapControlExtension;
typedef struct __DRIframeTrackingExtensionRec   __DRIframeTrackingExtension;
typedef struct __DRImediaStreamCounterExtensionRec      __DRImediaStreamCounterExtension;
typedef struct __DRItexOffsetExtensionRec       __DRItexOffsetExtension;
typedef struct __DRItexBufferExtensionRec       __DRItexBufferExtension;
typedef struct __DRIlegacyExtensionRec          __DRIlegacyExtension;
typedef struct __DRIswrastExtensionRec          __DRIswrastExtension;
typedef struct __DRIbufferRec                   __DRIbuffer;
typedef struct __DRIdri2ExtensionRec            __DRIdri2Extension;
typedef struct __DRIdri2LoaderExtensionRec      __DRIdri2LoaderExtension;
typedef struct __DRI2flushExtensionRec  __DRI2flushExtension;
typedef struct __DRI2throttleExtensionRec       __DRI2throttleExtension;
typedef struct __DRI2fenceExtensionRec          __DRI2fenceExtension;
typedef struct __DRI2interopExtensionRec        __DRI2interopExtension;


typedef struct __DRIimageLoaderExtensionRec     __DRIimageLoaderExtension;
typedef struct __DRIimageDriverExtensionRec     __DRIimageDriverExtension;

/*@}*/


/**
 * Extension struct.  Drivers 'inherit' from this struct by embedding
 * it as the first element in the extension struct.
 *
 * We never break API in for a DRI extension.  If we need to change
 * the way things work in a non-backwards compatible manner, we
 * introduce a new extension.  During a transition period, we can
 * leave both the old and the new extension in the driver, which
 * allows us to move to the new interface without having to update the
 * loader(s) in lock step.
 *
 * However, we can add entry points to an extension over time as long
 * as we don't break the old ones.  As we add entry points to an
 * extension, we increase the version number.  The corresponding
 * #define can be used to guard code that accesses the new entry
 * points at compile time and the version field in the extension
 * struct can be used at run-time to determine how to use the
 * extension.
 */
struct __DRIextensionRec {
    const char *name;
    int version;
};

/**
 * The first set of extension are the screen extensions, returned by
 * __DRIcore::getExtensions().  This entry point will return a list of
 * extensions and the loader can use the ones it knows about by
 * casting them to more specific extensions and advertising any GLX
 * extensions the DRI extensions enables.
 */

/**
 * Used by drivers to indicate support for setting the read drawable.
 */
#define __DRI_READ_DRAWABLE "DRI_ReadDrawable"
#define __DRI_READ_DRAWABLE_VERSION 1

/**
 * Used by drivers that implement the GLX_MESA_copy_sub_buffer extension.
 */
#define __DRI_COPY_SUB_BUFFER "DRI_CopySubBuffer"
#define __DRI_COPY_SUB_BUFFER_VERSION 1
struct __DRIcopySubBufferExtensionRec {
    __DRIextension base;
    void (*copySubBuffer)(__DRIdrawable *drawable, int x, int y, int w, int h);
};

/**
 * Used by drivers that implement the GLX_SGI_swap_control or
 * GLX_MESA_swap_control extension.
 */
#define __DRI_SWAP_CONTROL "DRI_SwapControl"
#define __DRI_SWAP_CONTROL_VERSION 1
struct __DRIswapControlExtensionRec {
    __DRIextension base;
    void (*setSwapInterval)(__DRIdrawable *drawable, unsigned int inteval);
    unsigned int (*getSwapInterval)(__DRIdrawable *drawable);
};

/**
 * Used by drivers that implement the GLX_MESA_swap_frame_usage extension.
 */
#define __DRI_FRAME_TRACKING "DRI_FrameTracking"
#define __DRI_FRAME_TRACKING_VERSION 1
struct __DRIframeTrackingExtensionRec {
    __DRIextension base;

    /**
     * Enable or disable frame usage tracking.
     * 
     * \since Internal API version 20030317.
     */
    int (*frameTracking)(__DRIdrawable *drawable, GLboolean enable);

    /**
     * Retrieve frame usage information.
     * 
     * \since Internal API version 20030317.
     */
    int (*queryFrameTracking)(__DRIdrawable *drawable,
                              int64_t * sbc, int64_t * missedFrames,
                              float * lastMissedUsage, float * usage);
};


/**
 * Used by drivers that implement the GLX_SGI_video_sync extension.
 */
#define __DRI_MEDIA_STREAM_COUNTER "DRI_MediaStreamCounter"
#define __DRI_MEDIA_STREAM_COUNTER_VERSION 1
struct __DRImediaStreamCounterExtensionRec {
    __DRIextension base;

    /**
     * Wait for the MSC to equal target_msc, or, if that has already passed,
     * the next time (MSC % divisor) is equal to remainder.  If divisor is
     * zero, the function will return as soon as MSC is greater than or equal
     * to target_msc.
     */
    int (*waitForMSC)(__DRIdrawable *drawable,
                      int64_t target_msc, int64_t divisor, int64_t remainder,
                      int64_t * msc, int64_t * sbc);

    /**
     * Get the number of vertical refreshes since some point in time before
     * this function was first called (i.e., system start up).
     */
    int (*getDrawableMSC)(__DRIscreen *screen, __DRIdrawable *drawable,
                          int64_t *msc);
};


#define __DRI_TEX_OFFSET "DRI_TexOffset"
#define __DRI_TEX_OFFSET_VERSION 1
struct __DRItexOffsetExtensionRec {
    __DRIextension base;

    /**
     * Method to override base texture image with a driver specific 'offset'.
     * The depth passed in allows e.g. to ignore the alpha channel of texture
     * images where the non-alpha components don't occupy a whole texel.
     *
     * For GLX_EXT_texture_from_pixmap with AIGLX.
     */
    void (*setTexOffset)(__DRIcontext *pDRICtx, GLint texname,
                         unsigned long long offset, GLint depth, GLuint pitch);
};


/* Valid values for format in the setTexBuffer2 function below.  These
 * values match the GLX tokens for compatibility reasons, but we
 * define them here since the DRI interface can't depend on GLX. */
#define __DRI_TEXTURE_FORMAT_NONE        0x20D8
#define __DRI_TEXTURE_FORMAT_RGB         0x20D9
#define __DRI_TEXTURE_FORMAT_RGBA        0x20DA

#define __DRI_TEX_BUFFER "DRI_TexBuffer"
#define __DRI_TEX_BUFFER_VERSION 3
struct __DRItexBufferExtensionRec {
    __DRIextension base;

    /**
     * Method to override base texture image with the contents of a
     * __DRIdrawable. 
     *
     * For GLX_EXT_texture_from_pixmap with AIGLX.  Deprecated in favor of
     * setTexBuffer2 in version 2 of this interface
     */
    void (*setTexBuffer)(__DRIcontext *pDRICtx,
                         GLint target,
                         __DRIdrawable *pDraw);

    /**
     * Method to override base texture image with the contents of a
     * __DRIdrawable, including the required texture format attribute.
     *
     * For GLX_EXT_texture_from_pixmap with AIGLX.
     *
     * \since 2
     */
    void (*setTexBuffer2)(__DRIcontext *pDRICtx,
                          GLint target,
                          GLint format,
                          __DRIdrawable *pDraw);
    /**
     * Method to release texture buffer in case some special platform
     * need this.
     *
     * For GLX_EXT_texture_from_pixmap with AIGLX.
     *
     * \since 3
     */
    void (*releaseTexBuffer)(__DRIcontext *pDRICtx,
                        GLint target,
                        __DRIdrawable *pDraw);
};

/**
 * Used by drivers that implement DRI2
 */
#define __DRI2_FLUSH "DRI2_Flush"
#define __DRI2_FLUSH_VERSION 4

#define __DRI2_FLUSH_DRAWABLE (1 << 0) /* the drawable should be flushed. */
#define __DRI2_FLUSH_CONTEXT  (1 << 1) /* glFlush should be called */
#define __DRI2_FLUSH_INVALIDATE_ANCILLARY (1 << 2)

enum __DRI2throttleReason {
   __DRI2_THROTTLE_SWAPBUFFER,
   __DRI2_THROTTLE_COPYSUBBUFFER,
   __DRI2_THROTTLE_FLUSHFRONT
};

struct __DRI2flushExtensionRec {
    __DRIextension base;
    void (*flush)(__DRIdrawable *drawable);

    /**
     * Ask the driver to call getBuffers/getBuffersWithFormat before
     * it starts rendering again.
     *
     * \param drawable the drawable to invalidate
     *
     * \since 3
     */
    void (*invalidate)(__DRIdrawable *drawable);

    /**
     * This function reduces the number of flushes in the driver by combining
     * several operations into one call.
     *
     * It can:
     * - throttle
     * - flush a drawable
     * - flush a context
     *
     * \param context           the context
     * \param drawable          the drawable to flush
     * \param flags             a combination of _DRI2_FLUSH_xxx flags
     * \param throttle_reason   the reason for throttling, 0 = no throttling
     *
     * \since 4
     */
    void (*flush_with_flags)(__DRIcontext *ctx,
                             __DRIdrawable *drawable,
                             unsigned flags,
                             enum __DRI2throttleReason throttle_reason);
};


/**
 * Extension that the driver uses to request
 * throttle callbacks.
 */

#define __DRI2_THROTTLE "DRI2_Throttle"
#define __DRI2_THROTTLE_VERSION 1

struct __DRI2throttleExtensionRec {
   __DRIextension base;
   void (*throttle)(__DRIcontext *ctx,
                    __DRIdrawable *drawable,
                    enum __DRI2throttleReason reason);
};


/**
 * Extension for fences / synchronization objects.
 */

#define __DRI2_FENCE "DRI2_Fence"
#define __DRI2_FENCE_VERSION 2

#define __DRI2_FENCE_TIMEOUT_INFINITE     0xffffffffffffffffull

#define __DRI2_FENCE_FLAG_FLUSH_COMMANDS  (1 << 0)

/**
 * \name Capabilities that might be returned by __DRI2fenceExtensionRec::get_capabilities
 */
/*@{*/
#define __DRI_FENCE_CAP_NATIVE_FD 1
/*@}*/

struct __DRI2fenceExtensionRec {
   __DRIextension base;

   /**
    * Create and insert a fence into the command stream of the context.
    */
   void *(*create_fence)(__DRIcontext *ctx);

   /**
    * Get a fence associated with the OpenCL event object.
    * This can be NULL, meaning that OpenCL interoperability is not supported.
    */
   void *(*get_fence_from_cl_event)(__DRIscreen *screen, intptr_t cl_event);

   /**
    * Destroy a fence.
    */
   void (*destroy_fence)(__DRIscreen *screen, void *fence);

   /**
    * This function waits and doesn't return until the fence is signalled
    * or the timeout expires. It returns true if the fence has been signaled.
    *
    * \param ctx     the context where commands are flushed
    * \param fence   the fence
    * \param flags   a combination of __DRI2_FENCE_FLAG_xxx flags
    * \param timeout the timeout in ns or __DRI2_FENCE_TIMEOUT_INFINITE
    */
   GLboolean (*client_wait_sync)(__DRIcontext *ctx, void *fence,
                                 unsigned flags, uint64_t timeout);

   /**
    * This function enqueues a wait command into the command stream of
    * the context and then returns. When the execution reaches the wait
    * command, no further execution will be done in the context until
    * the fence is signaled. This is a no-op if the device doesn't support
    * parallel execution of contexts.
    *
    * \param ctx     the context where the waiting is done
    * \param fence   the fence
    * \param flags   a combination of __DRI2_FENCE_FLAG_xxx flags that make
    *                sense with this function (right now there are none)
    */
   void (*server_wait_sync)(__DRIcontext *ctx, void *fence, unsigned flags);

   /**
    * Query for general capabilities of the driver that concern fences.
    * Returns a bitmask of __DRI_FENCE_CAP_x
    *
    * \since 2
    */
   unsigned (*get_capabilities)(__DRIscreen *screen);

   /**
    * Create an fd (file descriptor) associated fence.  If the fence fd
    * is -1, this behaves similarly to create_fence() except that when
    * rendering is flushed the driver creates a fence fd.  Otherwise,
    * the driver wraps an existing fence fd.
    *
    * This is used to implement the EGL_ANDROID_native_fence_sync extension.
    *
    * \since 2
    *
    * \param ctx     the context associated with the fence
    * \param fd      the fence fd or -1
    */
   void *(*create_fence_fd)(__DRIcontext *ctx, int fd);

   /**
    * For fences created with create_fence_fd(), after rendering is flushed,
    * this retrieves the native fence fd.  Caller takes ownership of the
    * fd and will close() it when it is no longer needed.
    *
    * \since 2
    *
    * \param screen  the screen associated with the fence
    * \param fence   the fence
    */
   int (*get_fence_fd)(__DRIscreen *screen, void *fence);
};


/**
 * Extension for API interop.
 * See GL/mesa_glinterop.h.
 */

#define __DRI2_INTEROP "DRI2_Interop"
#define __DRI2_INTEROP_VERSION 1

struct mesa_glinterop_device_info;
struct mesa_glinterop_export_in;
struct mesa_glinterop_export_out;

struct __DRI2interopExtensionRec {
   __DRIextension base;

   /** Same as MesaGLInterop*QueryDeviceInfo. */
   int (*query_device_info)(__DRIcontext *ctx,
                            struct mesa_glinterop_device_info *out);

   /** Same as MesaGLInterop*ExportObject. */
   int (*export_object)(__DRIcontext *ctx,
                        struct mesa_glinterop_export_in *in,
                        struct mesa_glinterop_export_out *out);
};

/*@}*/

/**
 * The following extensions describe loader features that the DRI
 * driver can make use of.  Some of these are mandatory, such as the
 * getDrawableInfo extension for DRI and the DRI Loader extensions for
 * DRI2, while others are optional, and if present allow the driver to
 * expose certain features.  The loader pass in a NULL terminated
 * array of these extensions to the driver in the createNewScreen
 * constructor.
 */

typedef struct __DRIgetDrawableInfoExtensionRec __DRIgetDrawableInfoExtension;
typedef struct __DRIsystemTimeExtensionRec __DRIsystemTimeExtension;
typedef struct __DRIdamageExtensionRec __DRIdamageExtension;
typedef struct __DRIloaderExtensionRec __DRIloaderExtension;
typedef struct __DRIswrastLoaderExtensionRec __DRIswrastLoaderExtension;


/**
 * Callback to getDrawableInfo protocol
 */
#define __DRI_GET_DRAWABLE_INFO "DRI_GetDrawableInfo"
#define __DRI_GET_DRAWABLE_INFO_VERSION 1
struct __DRIgetDrawableInfoExtensionRec {
    __DRIextension base;

    /**
     * This function is used to get information about the position, size, and
     * clip rects of a drawable.
     */
    GLboolean (* getDrawableInfo) ( __DRIdrawable *drawable,
        unsigned int * index, unsigned int * stamp,
        int * x, int * y, int * width, int * height,
        int * numClipRects, drm_clip_rect_t ** pClipRects,
        int * backX, int * backY,
        int * numBackClipRects, drm_clip_rect_t ** pBackClipRects,
        void *loaderPrivate);
};

/**
 * Callback to get system time for media stream counter extensions.
 */
#define __DRI_SYSTEM_TIME "DRI_SystemTime"
#define __DRI_SYSTEM_TIME_VERSION 1
struct __DRIsystemTimeExtensionRec {
    __DRIextension base;

    /**
     * Get the 64-bit unadjusted system time (UST).
     */
    int (*getUST)(int64_t * ust);

    /**
     * Get the media stream counter (MSC) rate.
     * 
     * Matching the definition in GLX_OML_sync_control, this function returns
     * the rate of the "media stream counter".  In practical terms, this is
     * the frame refresh rate of the display.
     */
    GLboolean (*getMSCRate)(__DRIdrawable *draw,
                            int32_t * numerator, int32_t * denominator,
                            void *loaderPrivate);
};

/**
 * Damage reporting
 */
#define __DRI_DAMAGE "DRI_Damage"
#define __DRI_DAMAGE_VERSION 1
struct __DRIdamageExtensionRec {
    __DRIextension base;

    /**
     * Reports areas of the given drawable which have been modified by the
     * driver.
     *
     * \param drawable which the drawing was done to.
     * \param rects rectangles affected, with the drawable origin as the
     *        origin.
     * \param x X offset of the drawable within the screen (used in the
     *        front_buffer case)
     * \param y Y offset of the drawable within the screen.
     * \param front_buffer boolean flag for whether the drawing to the
     *        drawable was actually done directly to the front buffer (instead
     *        of backing storage, for example)
     * \param loaderPrivate the data passed in at createNewDrawable time
     */
    void (*reportDamage)(__DRIdrawable *draw,
                         int x, int y,
                         drm_clip_rect_t *rects, int num_rects,
                         GLboolean front_buffer,
                         void *loaderPrivate);
};

#define __DRI_SWRAST_IMAGE_OP_DRAW      1
#define __DRI_SWRAST_IMAGE_OP_CLEAR     2
#define __DRI_SWRAST_IMAGE_OP_SWAP      3

/**
 * SWRast Loader extension.
 */
#define __DRI_SWRAST_LOADER "DRI_SWRastLoader"
#define __DRI_SWRAST_LOADER_VERSION 3
struct __DRIswrastLoaderExtensionRec {
    __DRIextension base;

    /*
     * Drawable position and size
     */
    void (*getDrawableInfo)(__DRIdrawable *drawable,
                            int *x, int *y, int *width, int *height,
                            void *loaderPrivate);

    /**
     * Put image to drawable
     */
    void (*putImage)(__DRIdrawable *drawable, int op,
                     int x, int y, int width, int height,
                     char *data, void *loaderPrivate);

    /**
     * Get image from readable
     */
    void (*getImage)(__DRIdrawable *readable,
                     int x, int y, int width, int height,
                     char *data, void *loaderPrivate);

    /**
     * Put image to drawable
     *
     * \since 2
     */
    void (*putImage2)(__DRIdrawable *drawable, int op,
                      int x, int y, int width, int height, int stride,
                      char *data, void *loaderPrivate);

   /**
     * Put image to drawable
     *
     * \since 3
     */
   void (*getImage2)(__DRIdrawable *readable,
                     int x, int y, int width, int height, int stride,
                     char *data, void *loaderPrivate);
};

/**
 * Invalidate loader extension.  The presence of this extension
 * indicates to the DRI driver that the loader will call invalidate in
 * the __DRI2_FLUSH extension, whenever the needs to query for new
 * buffers.  This means that the DRI driver can drop the polling in
 * glViewport().
 *
 * The extension doesn't provide any functionality, it's only use to
 * indicate to the driver that it can use the new semantics.  A DRI
 * driver can use this to switch between the different semantics or
 * just refuse to initialize if this extension isn't present.
 */
#define __DRI_USE_INVALIDATE "DRI_UseInvalidate"
#define __DRI_USE_INVALIDATE_VERSION 1

typedef struct __DRIuseInvalidateExtensionRec __DRIuseInvalidateExtension;
struct __DRIuseInvalidateExtensionRec {
   __DRIextension base;
};

/**
 * The remaining extensions describe driver extensions, immediately
 * available interfaces provided by the driver.  To start using the
 * driver, dlsym() for the __DRI_DRIVER_EXTENSIONS symbol and look for
 * the extension you need in the array.
 */
#define __DRI_DRIVER_EXTENSIONS "__driDriverExtensions"

/**
 * This symbol replaces the __DRI_DRIVER_EXTENSIONS symbol, and will be
 * suffixed by "_drivername", allowing multiple drivers to be built into one
 * library, and also giving the driver the chance to return a variable driver
 * extensions struct depending on the driver name being loaded or any other
 * system state.
 *
 * The function prototype is:
 *
 * const __DRIextension **__driDriverGetExtensions_drivername(void);
 */
#define __DRI_DRIVER_GET_EXTENSIONS "__driDriverGetExtensions"

/**
 * Tokens for __DRIconfig attribs.  A number of attributes defined by
 * GLX or EGL standards are not in the table, as they must be provided
 * by the loader.  For example, FBConfig ID or visual ID, drawable type.
 */

#define __DRI_ATTRIB_BUFFER_SIZE                 1
#define __DRI_ATTRIB_LEVEL                       2
#define __DRI_ATTRIB_RED_SIZE                    3
#define __DRI_ATTRIB_GREEN_SIZE                  4
#define __DRI_ATTRIB_BLUE_SIZE                   5
#define __DRI_ATTRIB_LUMINANCE_SIZE              6
#define __DRI_ATTRIB_ALPHA_SIZE                  7
#define __DRI_ATTRIB_ALPHA_MASK_SIZE             8
#define __DRI_ATTRIB_DEPTH_SIZE                  9
#define __DRI_ATTRIB_STENCIL_SIZE               10
#define __DRI_ATTRIB_ACCUM_RED_SIZE             11
#define __DRI_ATTRIB_ACCUM_GREEN_SIZE           12
#define __DRI_ATTRIB_ACCUM_BLUE_SIZE            13
#define __DRI_ATTRIB_ACCUM_ALPHA_SIZE           14
#define __DRI_ATTRIB_SAMPLE_BUFFERS             15
#define __DRI_ATTRIB_SAMPLES                    16
#define __DRI_ATTRIB_RENDER_TYPE                17
#define __DRI_ATTRIB_CONFIG_CAVEAT              18
#define __DRI_ATTRIB_CONFORMANT                 19
#define __DRI_ATTRIB_DOUBLE_BUFFER              20
#define __DRI_ATTRIB_STEREO                     21
#define __DRI_ATTRIB_AUX_BUFFERS                22
#define __DRI_ATTRIB_TRANSPARENT_TYPE           23
#define __DRI_ATTRIB_TRANSPARENT_INDEX_VALUE    24
#define __DRI_ATTRIB_TRANSPARENT_RED_VALUE      25
#define __DRI_ATTRIB_TRANSPARENT_GREEN_VALUE    26
#define __DRI_ATTRIB_TRANSPARENT_BLUE_VALUE     27
#define __DRI_ATTRIB_TRANSPARENT_ALPHA_VALUE    28
#define __DRI_ATTRIB_FLOAT_MODE                 29
#define __DRI_ATTRIB_RED_MASK                   30
#define __DRI_ATTRIB_GREEN_MASK                 31
#define __DRI_ATTRIB_BLUE_MASK                  32
#define __DRI_ATTRIB_ALPHA_MASK                 33
#define __DRI_ATTRIB_MAX_PBUFFER_WIDTH          34
#define __DRI_ATTRIB_MAX_PBUFFER_HEIGHT         35
#define __DRI_ATTRIB_MAX_PBUFFER_PIXELS         36
#define __DRI_ATTRIB_OPTIMAL_PBUFFER_WIDTH      37
#define __DRI_ATTRIB_OPTIMAL_PBUFFER_HEIGHT     38
#define __DRI_ATTRIB_VISUAL_SELECT_GROUP        39
#define __DRI_ATTRIB_SWAP_METHOD                40
#define __DRI_ATTRIB_MAX_SWAP_INTERVAL          41
#define __DRI_ATTRIB_MIN_SWAP_INTERVAL          42
#define __DRI_ATTRIB_BIND_TO_TEXTURE_RGB        43
#define __DRI_ATTRIB_BIND_TO_TEXTURE_RGBA       44
#define __DRI_ATTRIB_BIND_TO_MIPMAP_TEXTURE     45
#define __DRI_ATTRIB_BIND_TO_TEXTURE_TARGETS    46
#define __DRI_ATTRIB_YINVERTED                  47
#define __DRI_ATTRIB_FRAMEBUFFER_SRGB_CAPABLE   48
#define __DRI_ATTRIB_MAX                        (__DRI_ATTRIB_FRAMEBUFFER_SRGB_CAPABLE + 1)

/* __DRI_ATTRIB_RENDER_TYPE */
#define __DRI_ATTRIB_RGBA_BIT                   0x01    
#define __DRI_ATTRIB_COLOR_INDEX_BIT            0x02
#define __DRI_ATTRIB_LUMINANCE_BIT              0x04
#define __DRI_ATTRIB_FLOAT_BIT                  0x08
#define __DRI_ATTRIB_UNSIGNED_FLOAT_BIT         0x10

/* __DRI_ATTRIB_CONFIG_CAVEAT */
#define __DRI_ATTRIB_SLOW_BIT                   0x01
#define __DRI_ATTRIB_NON_CONFORMANT_CONFIG      0x02

/* __DRI_ATTRIB_TRANSPARENT_TYPE */
#define __DRI_ATTRIB_TRANSPARENT_RGB            0x00
#define __DRI_ATTRIB_TRANSPARENT_INDEX          0x01

/* __DRI_ATTRIB_BIND_TO_TEXTURE_TARGETS  */
#define __DRI_ATTRIB_TEXTURE_1D_BIT             0x01
#define __DRI_ATTRIB_TEXTURE_2D_BIT             0x02
#define __DRI_ATTRIB_TEXTURE_RECTANGLE_BIT      0x04

/* __DRI_ATTRIB_SWAP_METHOD */
/* Note that with the exception of __DRI_ATTRIB_SWAP_NONE, we need to define
 * the same tokens as GLX. This is because old and current X servers will
 * transmit the driconf value grabbed from the AIGLX driver untranslated as
 * the GLX fbconfig value. __DRI_ATTRIB_SWAP_NONE is only used by dri drivers
 * to signal to the dri core that the driconfig is single-buffer.
 */
#define __DRI_ATTRIB_SWAP_NONE                  0x0000
#define __DRI_ATTRIB_SWAP_EXCHANGE              0x8061
#define __DRI_ATTRIB_SWAP_COPY                  0x8062
#define __DRI_ATTRIB_SWAP_UNDEFINED             0x8063

/**
 * This extension defines the core DRI functionality.
 *
 * Version >= 2 indicates that getConfigAttrib with __DRI_ATTRIB_SWAP_METHOD
 * returns a reliable value.
 */
#define __DRI_CORE "DRI_Core"
#define __DRI_CORE_VERSION 2

struct __DRIcoreExtensionRec {
    __DRIextension base;

    __DRIscreen *(*createNewScreen)(int screen, int fd,
                                    unsigned int sarea_handle,
                                    const __DRIextension **extensions,
                                    const __DRIconfig ***driverConfigs,
                                    void *loaderPrivate);

    void (*destroyScreen)(__DRIscreen *screen);

    const __DRIextension **(*getExtensions)(__DRIscreen *screen);

    int (*getConfigAttrib)(const __DRIconfig *config,
                           unsigned int attrib,
                           unsigned int *value);

    int (*indexConfigAttrib)(const __DRIconfig *config, int index,
                             unsigned int *attrib, unsigned int *value);

    __DRIdrawable *(*createNewDrawable)(__DRIscreen *screen,
                                        const __DRIconfig *config,
                                        unsigned int drawable_id,
                                        unsigned int head,
                                        void *loaderPrivate);

    void (*destroyDrawable)(__DRIdrawable *drawable);

    void (*swapBuffers)(__DRIdrawable *drawable);

    __DRIcontext *(*createNewContext)(__DRIscreen *screen,
                                      const __DRIconfig *config,
                                      __DRIcontext *shared,
                                      void *loaderPrivate);

    int (*copyContext)(__DRIcontext *dest,
                       __DRIcontext *src,
                       unsigned long mask);

    void (*destroyContext)(__DRIcontext *context);

    int (*bindContext)(__DRIcontext *ctx,
                       __DRIdrawable *pdraw,
                       __DRIdrawable *pread);

    int (*unbindContext)(__DRIcontext *ctx);
};

/**
 * Stored version of some component (i.e., server-side DRI module, kernel-side
 * DRM, etc.).
 * 
 * \todo
 * There are several data structures that explicitly store a major version,
 * minor version, and patch level.  These structures should be modified to
 * have a \c __DRIversionRec instead.
 */
struct __DRIversionRec {
    int    major;        /**< Major version number. */
    int    minor;        /**< Minor version number. */
    int    patch;        /**< Patch-level. */
};

/**
 * Framebuffer information record.  Used by libGL to communicate information
 * about the framebuffer to the driver's \c __driCreateNewScreen function.
 * 
 * In XFree86, most of this information is derrived from data returned by
 * calling \c XF86DRIGetDeviceInfo.
 *
 * \sa XF86DRIGetDeviceInfo __DRIdisplayRec::createNewScreen
 *     __driUtilCreateNewScreen CallCreateNewScreen
 *
 * \bug This structure could be better named.
 */
struct __DRIframebufferRec {
    unsigned char *base;    /**< Framebuffer base address in the CPU's
                             * address space.  This value is calculated by
                             * calling \c drmMap on the framebuffer handle
                             * returned by \c XF86DRIGetDeviceInfo (or a
                             * similar function).
                             */
    int size;               /**< Framebuffer size, in bytes. */
    int stride;             /**< Number of bytes from one line to the next. */
    int width;              /**< Pixel width of the framebuffer. */
    int height;             /**< Pixel height of the framebuffer. */
    int dev_priv_size;      /**< Size of the driver's dev-priv structure. */
    void *dev_priv;         /**< Pointer to the driver's dev-priv structure. */
};


/**
 * This extension provides alternative screen, drawable and context
 * constructors for legacy DRI functionality.  This is used in
 * conjunction with the core extension.
 */
#define __DRI_LEGACY "DRI_Legacy"
#define __DRI_LEGACY_VERSION 1

struct __DRIlegacyExtensionRec {
    __DRIextension base;

    __DRIscreen *(*createNewScreen)(int screen,
                                    const __DRIversion *ddx_version,
                                    const __DRIversion *dri_version,
                                    const __DRIversion *drm_version,
                                    const __DRIframebuffer *frame_buffer,
                                    void *pSAREA, int fd, 
                                    const __DRIextension **extensions,
                                    const __DRIconfig ***driver_configs,
                                    void *loaderPrivate);

    __DRIdrawable *(*createNewDrawable)(__DRIscreen *screen,
                                        const __DRIconfig *config,
                                        drm_drawable_t hwDrawable,
                                        int renderType, const int *attrs,
                                        void *loaderPrivate);

    __DRIcontext *(*createNewContext)(__DRIscreen *screen,
                                      const __DRIconfig *config,
                                      int render_type,
                                      __DRIcontext *shared,
                                      drm_context_t hwContext,
                                      void *loaderPrivate);
};

/**
 * This extension provides alternative screen, drawable and context
 * constructors for swrast DRI functionality.  This is used in
 * conjunction with the core extension.
 */
#define __DRI_SWRAST "DRI_SWRast"
#define __DRI_SWRAST_VERSION 4

struct __DRIswrastExtensionRec {
    __DRIextension base;

    __DRIscreen *(*createNewScreen)(int screen,
                                    const __DRIextension **extensions,
                                    const __DRIconfig ***driver_configs,
                                    void *loaderPrivate);

    __DRIdrawable *(*createNewDrawable)(__DRIscreen *screen,
                                        const __DRIconfig *config,
                                        void *loaderPrivate);

   /* Since version 2 */
   __DRIcontext *(*createNewContextForAPI)(__DRIscreen *screen,
                                           int api,
                                           const __DRIconfig *config,
                                           __DRIcontext *shared,
                                           void *data);

   /**
    * Create a context for a particular API with a set of attributes
    *
    * \since version 3
    *
    * \sa __DRIdri2ExtensionRec::createContextAttribs
    */
   __DRIcontext *(*createContextAttribs)(__DRIscreen *screen,
                                         int api,
                                         const __DRIconfig *config,
                                         __DRIcontext *shared,
                                         unsigned num_attribs,
                                         const uint32_t *attribs,
                                         unsigned *error,
                                         void *loaderPrivate);

   /**
    * createNewScreen() with the driver extensions passed in.
    *
    * \since version 4
    */
   __DRIscreen *(*createNewScreen2)(int screen,
                                    const __DRIextension **loader_extensions,
                                    const __DRIextension **driver_extensions,
                                    const __DRIconfig ***driver_configs,
                                    void *loaderPrivate);

};

/** Common DRI function definitions, shared among DRI2 and Image extensions
 */

typedef __DRIscreen *
(*__DRIcreateNewScreen2Func)(int screen, int fd,
                             const __DRIextension **extensions,
                             const __DRIextension **driver_extensions,
                             const __DRIconfig ***driver_configs,
                             void *loaderPrivate);

typedef __DRIdrawable *
(*__DRIcreateNewDrawableFunc)(__DRIscreen *screen,
                              const __DRIconfig *config,
                              void *loaderPrivate);

typedef __DRIcontext *
(*__DRIcreateContextAttribsFunc)(__DRIscreen *screen,
                                 int api,
                                 const __DRIconfig *config,
                                 __DRIcontext *shared,
                                 unsigned num_attribs,
                                 const uint32_t *attribs,
                                 unsigned *error,
                                 void *loaderPrivate);

typedef unsigned int
(*__DRIgetAPIMaskFunc)(__DRIscreen *screen);

/**
 * DRI2 Loader extension.
 */
#define __DRI_BUFFER_FRONT_LEFT         0
#define __DRI_BUFFER_BACK_LEFT          1
#define __DRI_BUFFER_FRONT_RIGHT        2
#define __DRI_BUFFER_BACK_RIGHT         3
#define __DRI_BUFFER_DEPTH              4
#define __DRI_BUFFER_STENCIL            5
#define __DRI_BUFFER_ACCUM              6
#define __DRI_BUFFER_FAKE_FRONT_LEFT    7
#define __DRI_BUFFER_FAKE_FRONT_RIGHT   8
#define __DRI_BUFFER_DEPTH_STENCIL      9  /**< Only available with DRI2 1.1 */
#define __DRI_BUFFER_HIZ                10

/* Inofficial and for internal use. Increase when adding a new buffer token. */
#define __DRI_BUFFER_COUNT              11

struct __DRIbufferRec {
    unsigned int attachment;
    unsigned int name;
    unsigned int pitch;
    unsigned int cpp;
    unsigned int flags;
};

#define __DRI_DRI2_LOADER "DRI_DRI2Loader"
#define __DRI_DRI2_LOADER_VERSION 4

enum dri_loader_cap {
   /* Whether the loader handles RGBA channel ordering correctly. If not,
    * only BGRA ordering can be exposed.
    */
   DRI_LOADER_CAP_RGBA_ORDERING,
};

struct __DRIdri2LoaderExtensionRec {
    __DRIextension base;

    __DRIbuffer *(*getBuffers)(__DRIdrawable *driDrawable,
                               int *width, int *height,
                               unsigned int *attachments, int count,
                               int *out_count, void *loaderPrivate);

    /**
     * Flush pending front-buffer rendering
     *
     * Any rendering that has been performed to the
     * \c __DRI_BUFFER_FAKE_FRONT_LEFT will be flushed to the
     * \c __DRI_BUFFER_FRONT_LEFT.
     *
     * \param driDrawable    Drawable whose front-buffer is to be flushed
     * \param loaderPrivate  Loader's private data that was previously passed
     *                       into __DRIdri2ExtensionRec::createNewDrawable
     *
     * \since 2
     */
    void (*flushFrontBuffer)(__DRIdrawable *driDrawable, void *loaderPrivate);


    /**
     * Get list of buffers from the server
     *
     * Gets a list of buffer for the specified set of attachments.  Unlike
     * \c ::getBuffers, this function takes a list of attachments paired with
     * opaque \c unsigned \c int value describing the format of the buffer.
     * It is the responsibility of the caller to know what the service that
     * allocates the buffers will expect to receive for the format.
     *
     * \param driDrawable    Drawable whose buffers are being queried.
     * \param width          Output where the width of the buffers is stored.
     * \param height         Output where the height of the buffers is stored.
     * \param attachments    List of pairs of attachment ID and opaque format
     *                       requested for the drawable.
     * \param count          Number of attachment / format pairs stored in
     *                       \c attachments.
     * \param loaderPrivate  Loader's private data that was previously passed
     *                       into __DRIdri2ExtensionRec::createNewDrawable.
     *
     * \since 3
     */
    __DRIbuffer *(*getBuffersWithFormat)(__DRIdrawable *driDrawable,
                                         int *width, int *height,
                                         unsigned int *attachments, int count,
                                         int *out_count, void *loaderPrivate);

    /**
     * Return a loader capability value. If the loader doesn't know the enum,
     * it will return 0.
     *
     * \param loaderPrivate The last parameter of createNewScreen or
     *                      createNewScreen2.
     * \param cap           See the enum.
     *
     * \since 4
     */
    unsigned (*getCapability)(void *loaderPrivate, enum dri_loader_cap cap);
};

/**
 * This extension provides alternative screen, drawable and context
 * constructors for DRI2.
 */
#define __DRI_DRI2 "DRI_DRI2"
#define __DRI_DRI2_VERSION 4

#define __DRI_API_OPENGL        0       /**< OpenGL compatibility profile */
#define __DRI_API_GLES          1       /**< OpenGL ES 1.x */
#define __DRI_API_GLES2         2       /**< OpenGL ES 2.x */
#define __DRI_API_OPENGL_CORE   3       /**< OpenGL 3.2+ core profile */
#define __DRI_API_GLES3         4       /**< OpenGL ES 3.x */

#define __DRI_CTX_ATTRIB_MAJOR_VERSION          0
#define __DRI_CTX_ATTRIB_MINOR_VERSION          1
#define __DRI_CTX_ATTRIB_FLAGS                  2

/**
 * \requires __DRI2_ROBUSTNESS.
 */
#define __DRI_CTX_ATTRIB_RESET_STRATEGY         3

#define __DRI_CTX_FLAG_DEBUG                    0x00000001
#define __DRI_CTX_FLAG_FORWARD_COMPATIBLE       0x00000002

/**
 * \requires __DRI2_ROBUSTNESS.
 */
#define __DRI_CTX_FLAG_ROBUST_BUFFER_ACCESS     0x00000004

/**
 * \requires __DRI2_NO_ERROR.
 *
 */
#define __DRI_CTX_FLAG_NO_ERROR                 0x00000008

/**
 * \name Context reset strategies.
 */
/*@{*/
#define __DRI_CTX_RESET_NO_NOTIFICATION         0
#define __DRI_CTX_RESET_LOSE_CONTEXT            1
/*@}*/

#define __DRI_CTX_ATTRIB_PRIORITY               4

#define __DRI_CTX_PRIORITY_LOW                  0
#define __DRI_CTX_PRIORITY_MEDIUM               1
#define __DRI_CTX_PRIORITY_HIGH                 2

/**
 * \name Context release behaviors.
 */
/*@{*/
#define __DRI_CTX_ATTRIB_RELEASE_BEHAVIOR       5

#define __DRI_CTX_RELEASE_BEHAVIOR_NONE         0
#define __DRI_CTX_RELEASE_BEHAVIOR_FLUSH        1
/*@}*/

/**
 * \name Reasons that __DRIdri2Extension::createContextAttribs might fail
 */
/*@{*/
/** Success! */
#define __DRI_CTX_ERROR_SUCCESS                 0

/** Memory allocation failure */
#define __DRI_CTX_ERROR_NO_MEMORY               1

/** Client requested an API (e.g., OpenGL ES 2.0) that the driver can't do. */
#define __DRI_CTX_ERROR_BAD_API                 2

/** Client requested an API version that the driver can't do. */
#define __DRI_CTX_ERROR_BAD_VERSION             3

/** Client requested a flag or combination of flags the driver can't do. */
#define __DRI_CTX_ERROR_BAD_FLAG                4

/** Client requested an attribute the driver doesn't understand. */
#define __DRI_CTX_ERROR_UNKNOWN_ATTRIBUTE       5

/** Client requested a flag the driver doesn't understand. */
#define __DRI_CTX_ERROR_UNKNOWN_FLAG            6
/*@}*/

struct __DRIdri2ExtensionRec {
    __DRIextension base;

    __DRIscreen *(*createNewScreen)(int screen, int fd,
                                    const __DRIextension **extensions,
                                    const __DRIconfig ***driver_configs,
                                    void *loaderPrivate);

   __DRIcreateNewDrawableFunc   createNewDrawable;
   __DRIcontext *(*createNewContext)(__DRIscreen *screen,
                                     const __DRIconfig *config,
                                     __DRIcontext *shared,
                                     void *loaderPrivate);

   /* Since version 2 */
   __DRIgetAPIMaskFunc          getAPIMask;

   __DRIcontext *(*createNewContextForAPI)(__DRIscreen *screen,
                                           int api,
                                           const __DRIconfig *config,
                                           __DRIcontext *shared,
                                           void *data);

   __DRIbuffer *(*allocateBuffer)(__DRIscreen *screen,
                                  unsigned int attachment,
                                  unsigned int format,
                                  int width,
                                  int height);
   void (*releaseBuffer)(__DRIscreen *screen,
                         __DRIbuffer *buffer);

   /**
    * Create a context for a particular API with a set of attributes
    *
    * \since version 3
    *
    * \sa __DRIswrastExtensionRec::createContextAttribs
    */
   __DRIcreateContextAttribsFunc        createContextAttribs;

   /**
    * createNewScreen with the driver's extension list passed in.
    *
    * \since version 4
    */
   __DRIcreateNewScreen2Func            createNewScreen2;
};


/**
 * This extension provides functionality to enable various EGLImage
 * extensions.
 */
#define __DRI_IMAGE "DRI_IMAGE"
#define __DRI_IMAGE_VERSION 17

/**
 * These formats correspond to the similarly named MESA_FORMAT_*
 * tokens, except in the native endian of the CPU.  For example, on
 * little endian __DRI_IMAGE_FORMAT_XRGB8888 corresponds to
 * MESA_FORMAT_XRGB8888, but MESA_FORMAT_XRGB8888_REV on big endian.
 *
 * __DRI_IMAGE_FORMAT_NONE is for images that aren't directly usable
 * by the driver (YUV planar formats) but serve as a base image for
 * creating sub-images for the different planes within the image.
 *
 * R8, GR88 and NONE should not be used with createImageFromName or
 * createImage, and are returned by query from sub images created with
 * createImageFromNames (NONE, see above) and fromPlane (R8 & GR88).
 */
#define __DRI_IMAGE_FORMAT_RGB565       0x1001
#define __DRI_IMAGE_FORMAT_XRGB8888     0x1002
#define __DRI_IMAGE_FORMAT_ARGB8888     0x1003
#define __DRI_IMAGE_FORMAT_ABGR8888     0x1004
#define __DRI_IMAGE_FORMAT_XBGR8888     0x1005
#define __DRI_IMAGE_FORMAT_R8           0x1006 /* Since version 5 */
#define __DRI_IMAGE_FORMAT_GR88         0x1007
#define __DRI_IMAGE_FORMAT_NONE         0x1008
#define __DRI_IMAGE_FORMAT_XRGB2101010  0x1009
#define __DRI_IMAGE_FORMAT_ARGB2101010  0x100a
#define __DRI_IMAGE_FORMAT_SARGB8       0x100b
#define __DRI_IMAGE_FORMAT_ARGB1555     0x100c
#define __DRI_IMAGE_FORMAT_R16          0x100d
#define __DRI_IMAGE_FORMAT_GR1616       0x100e

#define __DRI_IMAGE_USE_SHARE           0x0001
#define __DRI_IMAGE_USE_SCANOUT         0x0002
#define __DRI_IMAGE_USE_CURSOR          0x0004 /* Deprecated */
#define __DRI_IMAGE_USE_LINEAR          0x0008
/* The buffer will only be read by an external process after SwapBuffers,
 * in contrary to gbm buffers, front buffers and fake front buffers, which
 * could be read after a flush."
 */
#define __DRI_IMAGE_USE_BACKBUFFER      0x0010


#define __DRI_IMAGE_TRANSFER_READ            0x1
#define __DRI_IMAGE_TRANSFER_WRITE           0x2
#define __DRI_IMAGE_TRANSFER_READ_WRITE      \
        (__DRI_IMAGE_TRANSFER_READ | __DRI_IMAGE_TRANSFER_WRITE)

/**
 * Four CC formats that matches with WL_DRM_FORMAT_* from wayland_drm.h,
 * GBM_FORMAT_* from gbm.h, and DRM_FORMAT_* from drm_fourcc.h. Used with
 * createImageFromNames.
 *
 * \since 5
 */

#define __DRI_IMAGE_FOURCC_R8           0x20203852
#define __DRI_IMAGE_FOURCC_GR88         0x38385247
#define __DRI_IMAGE_FOURCC_ARGB1555     0x35315241
#define __DRI_IMAGE_FOURCC_R16          0x20363152
#define __DRI_IMAGE_FOURCC_GR1616       0x32335247
#define __DRI_IMAGE_FOURCC_RGB565       0x36314752
#define __DRI_IMAGE_FOURCC_ARGB8888     0x34325241
#define __DRI_IMAGE_FOURCC_XRGB8888     0x34325258
#define __DRI_IMAGE_FOURCC_ABGR8888     0x34324241
#define __DRI_IMAGE_FOURCC_XBGR8888     0x34324258
#define __DRI_IMAGE_FOURCC_SARGB8888    0x83324258
#define __DRI_IMAGE_FOURCC_YUV410       0x39565559
#define __DRI_IMAGE_FOURCC_YUV411       0x31315559
#define __DRI_IMAGE_FOURCC_YUV420       0x32315559
#define __DRI_IMAGE_FOURCC_YUV422       0x36315559
#define __DRI_IMAGE_FOURCC_YUV444       0x34325559
#define __DRI_IMAGE_FOURCC_NV12         0x3231564e
#define __DRI_IMAGE_FOURCC_NV16         0x3631564e
#define __DRI_IMAGE_FOURCC_YUYV         0x56595559
#define __DRI_IMAGE_FOURCC_UYVY         0x59565955

#define __DRI_IMAGE_FOURCC_YVU410       0x39555659
#define __DRI_IMAGE_FOURCC_YVU411       0x31315659
#define __DRI_IMAGE_FOURCC_YVU420       0x32315659
#define __DRI_IMAGE_FOURCC_YVU422       0x36315659
#define __DRI_IMAGE_FOURCC_YVU444       0x34325659

/**
 * Queryable on images created by createImageFromNames.
 *
 * RGB and RGBA are may be usable directly as images but its still
 * recommended to call fromPlanar with plane == 0.
 *
 * Y_U_V, Y_UV,Y_XUXV and Y_UXVX all requires call to fromPlanar to create
 * usable sub-images, sampling from images return raw YUV data and
 * color conversion needs to be done in the shader.
 *
 * \since 5
 */

#define __DRI_IMAGE_COMPONENTS_RGB      0x3001
#define __DRI_IMAGE_COMPONENTS_RGBA     0x3002
#define __DRI_IMAGE_COMPONENTS_Y_U_V    0x3003
#define __DRI_IMAGE_COMPONENTS_Y_UV     0x3004
#define __DRI_IMAGE_COMPONENTS_Y_XUXV   0x3005
#define __DRI_IMAGE_COMPONENTS_Y_UXVX   0x3008
#define __DRI_IMAGE_COMPONENTS_R        0x3006
#define __DRI_IMAGE_COMPONENTS_RG       0x3007


/**
 * queryImage attributes
 */

#define __DRI_IMAGE_ATTRIB_STRIDE       0x2000
#define __DRI_IMAGE_ATTRIB_HANDLE       0x2001
#define __DRI_IMAGE_ATTRIB_NAME         0x2002
#define __DRI_IMAGE_ATTRIB_FORMAT       0x2003 /* available in versions 3+ */
#define __DRI_IMAGE_ATTRIB_WIDTH        0x2004 /* available in versions 4+ */
#define __DRI_IMAGE_ATTRIB_HEIGHT       0x2005
#define __DRI_IMAGE_ATTRIB_COMPONENTS   0x2006 /* available in versions 5+ */
#define __DRI_IMAGE_ATTRIB_FD           0x2007 /* available in versions
                                                * 7+. Each query will return a
                                                * new fd. */
#define __DRI_IMAGE_ATTRIB_FOURCC       0x2008 /* available in versions 11 */
#define __DRI_IMAGE_ATTRIB_NUM_PLANES   0x2009 /* available in versions 11 */

#define __DRI_IMAGE_ATTRIB_OFFSET 0x200A /* available in versions 13 */
#define __DRI_IMAGE_ATTRIB_MODIFIER_LOWER 0x200B /* available in versions 14 */
#define __DRI_IMAGE_ATTRIB_MODIFIER_UPPER 0x200C /* available in versions 14 */

enum __DRIYUVColorSpace {
   __DRI_YUV_COLOR_SPACE_UNDEFINED = 0,
   __DRI_YUV_COLOR_SPACE_ITU_REC601 = 0x327F,
   __DRI_YUV_COLOR_SPACE_ITU_REC709 = 0x3280,
   __DRI_YUV_COLOR_SPACE_ITU_REC2020 = 0x3281
};

enum __DRISampleRange {
   __DRI_YUV_RANGE_UNDEFINED = 0,
   __DRI_YUV_FULL_RANGE = 0x3282,
   __DRI_YUV_NARROW_RANGE = 0x3283
};

enum __DRIChromaSiting {
   __DRI_YUV_CHROMA_SITING_UNDEFINED = 0,
   __DRI_YUV_CHROMA_SITING_0 = 0x3284,
   __DRI_YUV_CHROMA_SITING_0_5 = 0x3285
};

/**
 * \name Reasons that __DRIimageExtensionRec::createImageFromTexture or
 * __DRIimageExtensionRec::createImageFromDmaBufs might fail
 */
/*@{*/
/** Success! */
#define __DRI_IMAGE_ERROR_SUCCESS       0

/** Memory allocation failure */
#define __DRI_IMAGE_ERROR_BAD_ALLOC     1

/** Client requested an invalid attribute */
#define __DRI_IMAGE_ERROR_BAD_MATCH     2

/** Client requested an invalid texture object */
#define __DRI_IMAGE_ERROR_BAD_PARAMETER 3

/** Client requested an invalid pitch and/or offset */
#define __DRI_IMAGE_ERROR_BAD_ACCESS    4
/*@}*/

/**
 * \name Capabilities that might be returned by __DRIimageExtensionRec::getCapabilities
 */
/*@{*/
#define __DRI_IMAGE_CAP_GLOBAL_NAMES 1
/*@}*/

/**
 * blitImage flags
 */

#define __BLIT_FLAG_FLUSH               0x0001
#define __BLIT_FLAG_FINISH              0x0002

/**
 * queryDmaBufFormatModifierAttribs attributes
 */

/* Available in version 16 */
#define __DRI_IMAGE_FORMAT_MODIFIER_ATTRIB_PLANE_COUNT   0x0001

typedef struct __DRIimageRec          __DRIimage;
typedef struct __DRIimageExtensionRec __DRIimageExtension;
struct __DRIimageExtensionRec {
    __DRIextension base;

    __DRIimage *(*createImageFromName)(__DRIscreen *screen,
                                       int width, int height, int format,
                                       int name, int pitch,
                                       void *loaderPrivate);

    /* Deprecated since version 17; see createImageFromRenderbuffer2 */
    __DRIimage *(*createImageFromRenderbuffer)(__DRIcontext *context,
                                               int renderbuffer,
                                               void *loaderPrivate);

    void (*destroyImage)(__DRIimage *image);

    __DRIimage *(*createImage)(__DRIscreen *screen,
                               int width, int height, int format,
                               unsigned int use,
                               void *loaderPrivate);

   GLboolean (*queryImage)(__DRIimage *image, int attrib, int *value);

   /**
    * The new __DRIimage will share the content with the old one, see dup(2).
    */
   __DRIimage *(*dupImage)(__DRIimage *image, void *loaderPrivate);

   /**
    * Validate that a __DRIimage can be used a certain way.
    *
    * \since 2
    */
   GLboolean (*validateUsage)(__DRIimage *image, unsigned int use);

   /**
    * Unlike createImageFromName __DRI_IMAGE_FORMAT is not but instead
    * __DRI_IMAGE_FOURCC and strides are in bytes not pixels. Stride is
    * also per block and not per pixel (for non-RGB, see gallium blocks).
    *
    * \since 5
    */
   __DRIimage *(*createImageFromNames)(__DRIscreen *screen,
                                       int width, int height, int fourcc,
                                       int *names, int num_names,
                                       int *strides, int *offsets,
                                       void *loaderPrivate);

   /**
    * Create an image out of a sub-region of a parent image.  This
    * entry point lets us create individual __DRIimages for different
    * planes in a planar buffer (typically yuv), for example.  While a
    * sub-image shares the underlying buffer object with the parent
    * image and other sibling sub-images, the life times of parent and
    * sub-images are not dependent.  Destroying the parent or a
    * sub-image doesn't affect other images.  The underlying buffer
    * object is free when no __DRIimage remains that references it.
    *
    * Sub-images may overlap, but rendering to overlapping sub-images
    * is undefined.
    *
    * \since 5
    */
    __DRIimage *(*fromPlanar)(__DRIimage *image, int plane,
                              void *loaderPrivate);

    /**
     * Create image from texture.
     *
     * \since 6
     */
   __DRIimage *(*createImageFromTexture)(__DRIcontext *context,
                                         int target,
                                         unsigned texture,
                                         int depth,
                                         int level,
                                         unsigned *error,
                                         void *loaderPrivate);
   /**
    * Like createImageFromNames, but takes a prime fd instead.
    *
    * \since 7
    */
   __DRIimage *(*createImageFromFds)(__DRIscreen *screen,
                                     int width, int height, int fourcc,
                                     int *fds, int num_fds,
                                     int *strides, int *offsets,
                                     void *loaderPrivate);

   /**
    * Like createImageFromFds, but takes additional attributes.
    *
    * For EGL_EXT_image_dma_buf_import.
    *
    * \since 8
    */
   __DRIimage *(*createImageFromDmaBufs)(__DRIscreen *screen,
                                         int width, int height, int fourcc,
                                         int *fds, int num_fds,
                                         int *strides, int *offsets,
                                         enum __DRIYUVColorSpace color_space,
                                         enum __DRISampleRange sample_range,
                                         enum __DRIChromaSiting horiz_siting,
                                         enum __DRIChromaSiting vert_siting,
                                         unsigned *error,
                                         void *loaderPrivate);

   /**
    * Blit a part of a __DRIimage to another and flushes
    *
    * flush_flag:
    *    0:                  no flush
    *    __BLIT_FLAG_FLUSH:  flush after the blit operation
    *    __BLIT_FLAG_FINISH: flush and wait the blit finished
    *
    * \since 9
    */
   void (*blitImage)(__DRIcontext *context, __DRIimage *dst, __DRIimage *src,
                     int dstx0, int dsty0, int dstwidth, int dstheight,
                     int srcx0, int srcy0, int srcwidth, int srcheight,
                     int flush_flag);

   /**
    * Query for general capabilities of the driver that concern
    * buffer sharing and image importing.
    *
    * \since 10
    */
   int (*getCapabilities)(__DRIscreen *screen);

   /**
    * Returns a map of the specified region of a __DRIimage for the specified usage.
    *
    * flags may include __DRI_IMAGE_TRANSFER_READ, which will populate the
    * mapping with the current buffer content. If __DRI_IMAGE_TRANSFER_READ
    * is not included in the flags, the buffer content at map time is
    * undefined. Users wanting to modify the mapping must include
    * __DRI_IMAGE_TRANSFER_WRITE; if __DRI_IMAGE_TRANSFER_WRITE is not
    * included, behaviour when writing the mapping is undefined.
    *
    * Returns the byte stride in *stride, and an opaque pointer to data
    * tracking the mapping in **data, which must be passed to unmapImage().
    *
    * \since 12
    */
   void *(*mapImage)(__DRIcontext *context, __DRIimage *image,
                     int x0, int y0, int width, int height,
                     unsigned int flags, int *stride, void **data);

   /**
    * Unmap a previously mapped __DRIimage
    *
    * \since 12
    */
   void (*unmapImage)(__DRIcontext *context, __DRIimage *image, void *data);


   /**
    * Creates an image with implementation's favorite modifiers.
    *
    * This acts like createImage except there is a list of modifiers passed in
    * which the implementation may selectively use to create the DRIimage. The
    * result should be the implementation selects one modifier (perhaps it would
    * hold on to a few and later pick).
    *
    * The created image should be destroyed with destroyImage().
    *
    * Returns the new DRIimage. The chosen modifier can be obtained later on
    * and passed back to things like the kernel's AddFB2 interface.
    *
    * \sa __DRIimageRec::createImage
    *
    * \since 14
    */
   __DRIimage *(*createImageWithModifiers)(__DRIscreen *screen,
                                           int width, int height, int format,
                                           const uint64_t *modifiers,
                                           const unsigned int modifier_count,
                                           void *loaderPrivate);

   /*
    * Like createImageFromDmaBufs, but takes also format modifiers.
    *
    * For EGL_EXT_image_dma_buf_import_modifiers.
    *
    * \since 15
    */
   __DRIimage *(*createImageFromDmaBufs2)(__DRIscreen *screen,
                                          int width, int height, int fourcc,
                                          uint64_t modifier,
                                          int *fds, int num_fds,
                                          int *strides, int *offsets,
                                          enum __DRIYUVColorSpace color_space,
                                          enum __DRISampleRange sample_range,
                                          enum __DRIChromaSiting horiz_siting,
                                          enum __DRIChromaSiting vert_siting,
                                          unsigned *error,
                                          void *loaderPrivate);

   /*
    * dmabuf format query to support EGL_EXT_image_dma_buf_import_modifiers.
    *
    * \param max      Maximum number of formats that can be accomodated into
    *                 \param formats. If zero, no formats are returned -
    *                 instead, the driver returns the total number of
    *                 supported dmabuf formats in \param count.
    * \param formats  Buffer to fill formats into.
    * \param count    Count of formats returned, or, total number of
    *                 supported formats in case \param max is zero.
    *
    * Returns true on success.
    *
    * \since 15
    */
   GLboolean (*queryDmaBufFormats)(__DRIscreen *screen, int max,
                                   int *formats, int *count);

   /*
    * dmabuf format modifier query for a given format to support
    * EGL_EXT_image_dma_buf_import_modifiers.
    *
    * \param fourcc    The format to query modifiers for. If this format
    *                  is not supported by the driver, return false.
    * \param max       Maximum number of modifiers that can be accomodated in
    *                  \param modifiers. If zero, no modifiers are returned -
    *                  instead, the driver returns the total number of
    *                  modifiers for \param format in \param count.
    * \param modifiers Buffer to fill modifiers into.
    * \param count     Count of the modifiers returned, or, total number of
    *                  supported modifiers for \param fourcc in case
    *                  \param max is zero.
    *
    * Returns true upon success.
    *
    * \since 15
    */
   GLboolean (*queryDmaBufModifiers)(__DRIscreen *screen, int fourcc,
                                     int max, uint64_t *modifiers,
                                     unsigned int *external_only,
                                     int *count);

   /**
    * dmabuf format modifier attribute query for a given format and modifier.
    *
    * \param fourcc    The format to query. If this format is not supported by
    *                  the driver, return false.
    * \param modifier  The modifier to query. If this format+modifier is not
    *                  supported by the driver, return false.
    * \param attrib    The __DRI_IMAGE_FORMAT_MODIFIER_ATTRIB to query.
    * \param value     A pointer to where to store the result of the query.
    *
    * Returns true upon success.
    *
    * \since 16
    */
   GLboolean (*queryDmaBufFormatModifierAttribs)(__DRIscreen *screen,
                                                 uint32_t fourcc, uint64_t modifier,
                                                 int attrib, uint64_t *value);

   /**
    * Create a DRI image from the given renderbuffer.
    *
    * \param context       the current DRI context
    * \param renderbuffer  the GL name of the renderbuffer
    * \param loaderPrivate for callbacks into the loader related to the image
    * \param error         will be set to one of __DRI_IMAGE_ERROR_xxx
    * \return the newly created image on success, or NULL otherwise
    *
    * \since 17
    */
    __DRIimage *(*createImageFromRenderbuffer2)(__DRIcontext *context,
                                                int renderbuffer,
                                                void *loaderPrivate,
                                                unsigned *error);
};


/**
 * This extension must be implemented by the loader and passed to the
 * driver at screen creation time.  The EGLImage entry points in the
 * various client APIs take opaque EGLImage handles and use this
 * extension to map them to a __DRIimage.  At version 1, this
 * extensions allows mapping EGLImage pointers to __DRIimage pointers,
 * but future versions could support other EGLImage-like, opaque types
 * with new lookup functions.
 */
#define __DRI_IMAGE_LOOKUP "DRI_IMAGE_LOOKUP"
#define __DRI_IMAGE_LOOKUP_VERSION 1

typedef struct __DRIimageLookupExtensionRec __DRIimageLookupExtension;
struct __DRIimageLookupExtensionRec {
    __DRIextension base;

    __DRIimage *(*lookupEGLImage)(__DRIscreen *screen, void *image,
                                  void *loaderPrivate);
};

/**
 * This extension allows for common DRI2 options
 */
#define __DRI2_CONFIG_QUERY "DRI_CONFIG_QUERY"
#define __DRI2_CONFIG_QUERY_VERSION 1

typedef struct __DRI2configQueryExtensionRec __DRI2configQueryExtension;
struct __DRI2configQueryExtensionRec {
   __DRIextension base;

   int (*configQueryb)(__DRIscreen *screen, const char *var, unsigned char *val);
   int (*configQueryi)(__DRIscreen *screen, const char *var, int *val);
   int (*configQueryf)(__DRIscreen *screen, const char *var, float *val);
};

/**
 * Robust context driver extension.
 *
 * Existence of this extension means the driver can accept the
 * \c __DRI_CTX_FLAG_ROBUST_BUFFER_ACCESS flag and the
 * \c __DRI_CTX_ATTRIB_RESET_STRATEGY attribute in
 * \c __DRIdri2ExtensionRec::createContextAttribs.
 */
#define __DRI2_ROBUSTNESS "DRI_Robustness"
#define __DRI2_ROBUSTNESS_VERSION 1

typedef struct __DRIrobustnessExtensionRec __DRIrobustnessExtension;
struct __DRIrobustnessExtensionRec {
   __DRIextension base;
};

/**
 * No-error context driver extension.
 *
 * Existence of this extension means the driver can accept the
 * __DRI_CTX_FLAG_NO_ERROR flag.
 */
#define __DRI2_NO_ERROR "DRI_NoError"
#define __DRI2_NO_ERROR_VERSION 1

typedef struct __DRInoErrorExtensionRec {
   __DRIextension base;
} __DRInoErrorExtension;

/*
 * Flush control driver extension.
 *
 * Existence of this extension means the driver can accept the
 * \c __DRI_CTX_ATTRIB_RELEASE_BEHAVIOR attribute in
 * \c __DRIdri2ExtensionRec::createContextAttribs.
 */
#define __DRI2_FLUSH_CONTROL "DRI_FlushControl"
#define __DRI2_FLUSH_CONTROL_VERSION 1

typedef struct __DRI2flushControlExtensionRec __DRI2flushControlExtension;
struct __DRI2flushControlExtensionRec {
   __DRIextension base;
};

/**
 * DRI config options extension.
 *
 * This extension provides the XML string containing driver options for use by
 * the loader in supporting the driconf application.
 *
 * v2:
 * - Add the getXml getter function which allows the driver more flexibility in
 *   how the XML is provided.
 * - Deprecate the direct xml pointer. It is only provided as a fallback for
 *   older versions of libGL and must not be used by clients that are aware of
 *   the newer version. Future driver versions may set it to NULL.
 */
#define __DRI_CONFIG_OPTIONS "DRI_ConfigOptions"
#define __DRI_CONFIG_OPTIONS_VERSION 2

typedef struct __DRIconfigOptionsExtensionRec {
   __DRIextension base;
   const char *xml; /**< deprecated since v2, use getXml instead */

   /**
    * Get an XML string that describes available driver options for use by a
    * config application.
    *
    * The returned string must be heap-allocated. The caller is responsible for
    * freeing it.
    */
   char *(*getXml)(const char *driver_name);
} __DRIconfigOptionsExtension;

/**
 * This extension provides a driver vtable to a set of common driver helper
 * functions (driCoreExtension, driDRI2Extension) within the driver
 * implementation, as opposed to having to pass them through a global
 * variable.
 *
 * It is not intended to be public API to the actual loader, and the vtable
 * layout may change at any time.
 */
#define __DRI_DRIVER_VTABLE "DRI_DriverVtable"
#define __DRI_DRIVER_VTABLE_VERSION 1

typedef struct __DRIDriverVtableExtensionRec {
    __DRIextension base;
    const struct __DriverAPIRec *vtable;
} __DRIDriverVtableExtension;

/**
 * Query renderer driver extension
 *
 * This allows the window system layer (either EGL or GLX) to query aspects of
 * hardware and driver support without creating a context.
 */
#define __DRI2_RENDERER_QUERY "DRI_RENDERER_QUERY"
#define __DRI2_RENDERER_QUERY_VERSION 1

#define __DRI2_RENDERER_VENDOR_ID                             0x0000
#define __DRI2_RENDERER_DEVICE_ID                             0x0001
#define __DRI2_RENDERER_VERSION                               0x0002
#define __DRI2_RENDERER_ACCELERATED                           0x0003
#define __DRI2_RENDERER_VIDEO_MEMORY                          0x0004
#define __DRI2_RENDERER_UNIFIED_MEMORY_ARCHITECTURE           0x0005
#define __DRI2_RENDERER_PREFERRED_PROFILE                     0x0006
#define __DRI2_RENDERER_OPENGL_CORE_PROFILE_VERSION           0x0007
#define __DRI2_RENDERER_OPENGL_COMPATIBILITY_PROFILE_VERSION  0x0008
#define __DRI2_RENDERER_OPENGL_ES_PROFILE_VERSION             0x0009
#define __DRI2_RENDERER_OPENGL_ES2_PROFILE_VERSION            0x000a
#define __DRI2_RENDERER_HAS_TEXTURE_3D                        0x000b
/* Whether there is an sRGB format support for every supported 32-bit UNORM
 * color format.
 */
#define __DRI2_RENDERER_HAS_FRAMEBUFFER_SRGB                  0x000c

/* Bitmaks of supported/available context priorities - must match
 * __EGL_CONTEXT_PRIORITY_LOW_BIT et al
 */
#define __DRI2_RENDERER_HAS_CONTEXT_PRIORITY                  0x000d
#define   __DRI2_RENDERER_HAS_CONTEXT_PRIORITY_LOW            (1 << 0)
#define   __DRI2_RENDERER_HAS_CONTEXT_PRIORITY_MEDIUM         (1 << 1)
#define   __DRI2_RENDERER_HAS_CONTEXT_PRIORITY_HIGH           (1 << 2)

typedef struct __DRI2rendererQueryExtensionRec __DRI2rendererQueryExtension;
struct __DRI2rendererQueryExtensionRec {
   __DRIextension base;

   int (*queryInteger)(__DRIscreen *screen, int attribute, unsigned int *val);
   int (*queryString)(__DRIscreen *screen, int attribute, const char **val);
};

/**
 * Image Loader extension. Drivers use this to allocate color buffers
 */

enum __DRIimageBufferMask {
   __DRI_IMAGE_BUFFER_BACK = (1 << 0),
   __DRI_IMAGE_BUFFER_FRONT = (1 << 1)
};

struct __DRIimageList {
   uint32_t image_mask;
   __DRIimage *back;
   __DRIimage *front;
};

#define __DRI_IMAGE_LOADER "DRI_IMAGE_LOADER"
#define __DRI_IMAGE_LOADER_VERSION 3

struct __DRIimageLoaderExtensionRec {
    __DRIextension base;

   /**
    * Allocate color buffers.
    *
    * \param driDrawable
    * \param width              Width of allocated buffers
    * \param height             Height of allocated buffers
    * \param format             one of __DRI_IMAGE_FORMAT_*
    * \param stamp              Address of variable to be updated when
    *                           getBuffers must be called again
    * \param loaderPrivate      The loaderPrivate for driDrawable
    * \param buffer_mask        Set of buffers to allocate
    * \param buffers            Returned buffers
    */
   int (*getBuffers)(__DRIdrawable *driDrawable,
                     unsigned int format,
                     uint32_t *stamp,
                     void *loaderPrivate,
                     uint32_t buffer_mask,
                     struct __DRIimageList *buffers);

    /**
     * Flush pending front-buffer rendering
     *
     * Any rendering that has been performed to the
     * fake front will be flushed to the front
     *
     * \param driDrawable    Drawable whose front-buffer is to be flushed
     * \param loaderPrivate  Loader's private data that was previously passed
     *                       into __DRIdri2ExtensionRec::createNewDrawable
     */
    void (*flushFrontBuffer)(__DRIdrawable *driDrawable, void *loaderPrivate);

    /**
     * Return a loader capability value. If the loader doesn't know the enum,
     * it will return 0.
     *
     * \since 2
     */
    unsigned (*getCapability)(void *loaderPrivate, enum dri_loader_cap cap);

    /**
     * Flush swap buffers
     *
     * Make sure any outstanding swap buffers have been submitted to the
     * device.
     *
     * \param driDrawable    Drawable whose swaps need to be flushed
     * \param loaderPrivate  Loader's private data that was previously passed
     *                       into __DRIdri2ExtensionRec::createNewDrawable
     *
     * \since 3
     */
    void (*flushSwapBuffers)(__DRIdrawable *driDrawable, void *loaderPrivate);
};

/**
 * DRI extension.
 */

#define __DRI_IMAGE_DRIVER           "DRI_IMAGE_DRIVER"
#define __DRI_IMAGE_DRIVER_VERSION   1

struct __DRIimageDriverExtensionRec {
   __DRIextension               base;

   /* Common DRI functions, shared with DRI2 */
   __DRIcreateNewScreen2Func            createNewScreen2;
   __DRIcreateNewDrawableFunc           createNewDrawable;
   __DRIcreateContextAttribsFunc        createContextAttribs;
   __DRIgetAPIMaskFunc                  getAPIMask;
};

/**
 * Background callable loader extension.
 *
 * Loaders expose this extension to indicate to drivers that they are capable
 * of handling callbacks from the driver's background drawing threads.
 */
#define __DRI_BACKGROUND_CALLABLE "DRI_BackgroundCallable"
#define __DRI_BACKGROUND_CALLABLE_VERSION 1

typedef struct __DRIbackgroundCallableExtensionRec __DRIbackgroundCallableExtension;
struct __DRIbackgroundCallableExtensionRec {
   __DRIextension base;

   /**
    * Indicate that this thread is being used by the driver as a background
    * drawing thread which may make callbacks to the loader.
    *
    * \param loaderPrivate is the value that was passed to to the driver when
    * the context was created.  This can be used by the loader to identify
    * which context any callbacks are associated with.
    *
    * If this function is called more than once from any given thread, each
    * subsequent call overrides the loaderPrivate data that was passed in the
    * previous call.  The driver can take advantage of this to re-use a
    * background thread to perform drawing on behalf of multiple contexts.
    *
    * It is permissible for the driver to call this function from a
    * non-background thread (i.e. a thread that has already been bound to a
    * context using __DRIcoreExtensionRec::bindContext()); when this happens,
    * the \c loaderPrivate pointer must be equal to the pointer that was
    * passed to the driver when the currently bound context was created.
    *
    * This call should execute quickly enough that the driver can call it with
    * impunity whenever a background thread starts performing drawing
    * operations (e.g. it should just set a thread-local variable).
    */
   void (*setBackgroundContext)(void *loaderPrivate);

   /**
    * Indicate that it is multithread safe to use glthread.  For GLX/EGL
    * platforms using Xlib, that involves calling XInitThreads, before
    * opening an X display.
    *
    * Note: only supported if extension version is at least 2.
    *
    * \param loaderPrivate is the value that was passed to to the driver when
    * the context was created.  This can be used by the loader to identify
    * which context any callbacks are associated with.
    */
   GLboolean (*isThreadSafe)(void *loaderPrivate);
};

#endif