[Mesa-dev] [PATCH 1/4] egl: Add MESA_get_display infrastructure
Kristian Høgsberg
krh at bitplanet.net
Fri May 28 11:21:21 PDT 2010
2010/5/28 Jakob Bornecrantz <wallbraker at gmail.com>:
> Some thoughs:
>
> Hmm I don't like adding new special entry points but I guess its much
> less magical then what we had before. Anyways thinking about it this
> does makes more sense. Please read the comments below, otherwise I'm
> fine with patch 1-3 of this series.
Great, thanks for looking through the patches.
> Maybe we should not export eglGetDisplayMESA as public symbol from
> libEGL but only return it from eglGetProc so to avoid any missing
> symbols problems. And it would require apps to actually check for it.
This is how we handle all extension entrypoints. We define an
entrypoint in libEGL, make a conditional prototype in eglext.h and
make it available through eglGetProcAddress(). There's certainly an
argument for not providing the entrypoint, but doesn't that apply to
all other extensions as well?
> We should for consistency add a X11 type as well, to let programs use
> one path and to allow people to use X11 on other platforms then unix.
That's what the EGL_NATIVE_DISPLAY_TYPE_MESA type is. It's not
specific to the Unix platform, it's "whatever the native type is on
your platform". So that would be an X11 display pointer on Unix. But
maybe that's bad, maybe we should be explicit about the display types
for the current platforms. That is, we should add a Win32 display
type, an X11 display type etc.
> Also to Issue 1 yes we should try and allocate the tokens out of the
> official pool.
I think so too, just to have unique values that prevent passing in the
wrong kind of tokens.
> For 2 its not a strong opinion but no, since its more
> of a libEGL extension then a Display extension, if that makes any
> sense.
Yeah, I'm leaning towards 'no' too.
Kristian
> Cheers Jakob.
>
>
> 2010/5/28 Kristian Høgsberg <krh at bitplanet.net>:
>> ---
>> docs/MESA_get_display.spec | 109 +++++++++++++++++++++++++++++++++++++++
>> include/EGL/eglext.h | 15 +++++
>> src/egl/drivers/dri2/egl_dri2.c | 23 ++++++---
>> src/egl/drivers/glx/egl_glx.c | 5 ++
>> src/egl/main/eglapi.c | 13 ++++-
>> src/egl/main/egldisplay.c | 8 ++-
>> src/egl/main/egldisplay.h | 4 +-
>> 7 files changed, 165 insertions(+), 12 deletions(-)
>> create mode 100644 docs/MESA_get_display.spec
>>
>> diff --git a/docs/MESA_get_display.spec b/docs/MESA_get_display.spec
>> new file mode 100644
>> index 0000000..979e2b2
>> --- /dev/null
>> +++ b/docs/MESA_get_display.spec
>> @@ -0,0 +1,109 @@
>> +Name
>> +
>> + MESA_get_display
>> +
>> +Name Strings
>> +
>> + EGL_MESA_get_display
>> +
>> +Contact
>> +
>> + Kristian Høgsberg <krh at bitplanet.net>
>> +
>> +Status
>> +
>> + Proposal
>> +
>> +Version
>> +
>> + Version 1, May 27, 2010
>> +
>> +Number
>> +
>> + EGL Extension #not assigned
>> +
>> +Dependencies
>> +
>> + Reguires EGL 1.4 or later. This extension is written against the
>> + wording of the EGL 1.4 specification.
>> +
>> +Overview
>> +
>> + The EGL platform mechanism was designed to support one type of display
>> + per platform. On Unix, the native display type is an X11 Display
>> + pointer, on Windows, the native display type is a handle to a device
>> + context (HDC).
>> +
>> + A platform may provide different types of displays. Under Linux, for
>> + example, one might want to initialize an EGL display from an XCB
>> + connection or a DRM file descriptor. However, there is only one EGL
>> + entry point for initializing the display and it takes an
>> + EGLNativeDisplayType. To support multiple displays on one platform, one
>> + would need multiple EGL libraries.
>> +
>> + This extensions introduces a new entry point that allows an application
>> + to pass in different types of displays along with an integer to identify
>> + the type of display. This allows one EGL library to support multiple
>> + display types and lets applications clearly identify which one they want
>> + to use.
>> +
>> +IP Status
>> +
>> + Open-source; freely implementable.
>> +
>> +Issues
>> +
>> + 1) Should we use official EGL tokens for the display types or just
>> + sequential numbers? Using tokens helps avoiding clashes, but
>> + we'll need to allocate those.
>> +
>> + 2) We can't detect this as a regular EGL extension as we can't get
>> + the extension string until we have an EGL display. It should be
>> + sufficient to just require applications to use eglGetProcAddress()
>> + to find out whether or not the eglGetDisplayMESA() entry point is
>> + available. Should we advertise the extension in the EGL extension
>> + string anyway? It's not useful once you have an EGL display.
>> +
>> +New Procedures and Functions
>> +
>> + void eglGetDisplayMESA(EGLint type, void *display);
>> +
>> +New Tokens
>> +
>> + None.
>> +
>> +Additions to Chapter 3 of the EGL 1.4 Specification (EGL Functions and Errors)
>> +
>> + Add to section 3.2 Initialization:
>> +
>> + Alternatively, the function
>> +
>> + void eglGetDisplayMESA(EGLint type, void *display);
>> +
>> + may be used to obtain an EGL display for an alternative type of native
>> + display. 'type' identifies the type of native display and 'display'
>> + provides the details of the native display. This extension defines
>> + three types of native display types: EGL_DISPLAY_TYPE_NATIVE_MESA,
>> + EGL_DISPLAY_TYPE_DRM_MESA, and EGL_DISPLAY_TYPE_XCB_MESA.
>> +
>> + When type is EGL_DISPLAY_TYPE_NATIVE_MESA, the value of 'display' will
>> + be interpreted as an EGLNativeDisplayType. In other words, this is
>> + equivalent to calling eglGetDisplay with the value of 'display'.
>> +
>> + When type is EGL_DISPLAY_TYPE_DRM_MESA, the value of 'display' will be
>> + interpreted as an integer file descriptor cast to a void pointer. The
>> + file descriptor will be assumed to refer to a DRM device under Linux
>> + (typically /dev/dri/card0 or such).
>> +
>> + When type is EGL_DISPLAY_TYPE_XCB_MESA, the value of 'display' will
>> + interpreted as an xcb_connection_t pointer as used by the XCB library.
>> + The XCB library is a new client side library for the X11 window system.
>> +
>> + If no display matching type and display is available, EGL_NO_DISPLAY is
>> + returned; no error condition is raised in this case.
>> +
>> +Revision History
>> +
>> + May 27, 2010
>> + Initial draft (Kristian Høgsberg)
>> +
>> diff --git a/include/EGL/eglext.h b/include/EGL/eglext.h
>> index e9f5a49..664fe55 100644
>> --- a/include/EGL/eglext.h
>> +++ b/include/EGL/eglext.h
>> @@ -246,6 +246,21 @@ typedef EGLBoolean (EGLAPIENTRYP PFNEGLSWAPBUFFERSREGIONNOK) (EGLDisplay dpy, EG
>> #endif /* EGL_NOK_texture_from_pixmap */
>>
>>
>> +#ifndef EGL_MESA_get_display
>> +#define EGL_MESA_get_display 1
>> +
>> +#define EGL_DISPLAY_TYPE_NATIVE_MESA 0
>> +#define EGL_DISPLAY_TYPE_DRM_MESA 1
>> +#define EGL_DISPLAY_TYPE_XCB_MESA 2
>> +
>> +#ifdef EGL_EGLEXT_PROTOTYPES
>> +EGLAPI EGLDisplay EGLAPIENTRY eglGetDisplayMESA(EGLint type, void *display);
>> +#endif
>> +
>> +typedef EGLDisplay (EGLAPIENTRYP PFNEGLGETDISPLAYMESA) (EGLint type, void *display);
>> +#endif
>> +
>> +
>> #ifdef __cplusplus
>> }
>> #endif
>> diff --git a/src/egl/drivers/dri2/egl_dri2.c b/src/egl/drivers/dri2/egl_dri2.c
>> index eb9a651..4ca6f80 100644
>> --- a/src/egl/drivers/dri2/egl_dri2.c
>> +++ b/src/egl/drivers/dri2/egl_dri2.c
>> @@ -645,14 +645,23 @@ dri2_initialize(_EGLDriver *drv, _EGLDisplay *disp,
>> return _eglError(EGL_BAD_ALLOC, "eglInitialize");
>>
>> disp->DriverData = (void *) dri2_dpy;
>> - if (disp->NativeDisplay == NULL) {
>> - dri2_dpy->conn = xcb_connect(0, 0);
>> - if (!dri2_dpy->conn) {
>> - _eglLog(_EGL_WARNING, "DRI2: xcb_connect failed");
>> - goto cleanup_dpy;
>> + switch (disp->DisplayType) {
>> + case EGL_DISPLAY_TYPE_NATIVE_MESA:
>> + if (disp->NativeDisplay == NULL) {
>> + dri2_dpy->conn = xcb_connect(0, 0);
>> + if (!dri2_dpy->conn) {
>> + _eglLog(_EGL_WARNING, "DRI2: xcb_connect failed");
>> + goto cleanup_dpy;
>> + }
>> + } else {
>> + dri2_dpy->conn = XGetXCBConnection(disp->NativeDisplay);
>> }
>> - } else {
>> - dri2_dpy->conn = XGetXCBConnection(disp->NativeDisplay);
>> + break;
>> +
>> + default:
>> + _eglLog(_EGL_WARNING,
>> + "DRI2: unknown display type: %d", disp->DisplayType);
>> + goto cleanup_dpy;
>> }
>>
>> if (dri2_dpy->conn == NULL)
>> diff --git a/src/egl/drivers/glx/egl_glx.c b/src/egl/drivers/glx/egl_glx.c
>> index e08ef5f..cd54c77 100644
>> --- a/src/egl/drivers/glx/egl_glx.c
>> +++ b/src/egl/drivers/glx/egl_glx.c
>> @@ -502,6 +502,11 @@ GLX_eglInitialize(_EGLDriver *drv, _EGLDisplay *disp,
>> if (!GLX_dpy)
>> return _eglError(EGL_BAD_ALLOC, "eglInitialize");
>>
>> + if (disp->DisplayType != EGL_DISPLAY_TYPE_NATIVE_MESA) {
>> + _eglLog(_EGL_WARNING, "GLX: Unsupported display type");
>> + return EGL_FALSE;
>> + }
>> +
>> GLX_dpy->dpy = (Display *) disp->NativeDisplay;
>> if (!GLX_dpy->dpy) {
>> GLX_dpy->dpy = XOpenDisplay(NULL);
>> diff --git a/src/egl/main/eglapi.c b/src/egl/main/eglapi.c
>> index 1a533e0..d158714 100644
>> --- a/src/egl/main/eglapi.c
>> +++ b/src/egl/main/eglapi.c
>> @@ -248,7 +248,8 @@ _eglUnlockDisplay(_EGLDisplay *dpy)
>> EGLDisplay EGLAPIENTRY
>> eglGetDisplay(EGLNativeDisplayType nativeDisplay)
>> {
>> - _EGLDisplay *dpy = _eglFindDisplay(nativeDisplay);
>> + _EGLDisplay *dpy =
>> + _eglFindDisplay(EGL_DISPLAY_TYPE_NATIVE_MESA, (void *) nativeDisplay);
>> return _eglGetDisplayHandle(dpy);
>> }
>>
>> @@ -811,6 +812,13 @@ eglGetError(void)
>> return e;
>> }
>>
>> +EGLDisplay EGLAPIENTRY
>> +eglGetDisplayMESA(EGLint type, void *display)
>> +{
>> + _EGLDisplay *dpy = _eglFindDisplay(type, display);
>> +
>> + return _eglGetDisplayHandle(dpy);
>> +}
>>
>> __eglMustCastToProperFunctionPointerType EGLAPIENTRY
>> eglGetProcAddress(const char *procname)
>> @@ -841,6 +849,9 @@ eglGetProcAddress(const char *procname)
>> #ifdef EGL_NOK_swap_region
>> { "eglSwapBuffersRegionNOK", (_EGLProc) eglSwapBuffersRegionNOK },
>> #endif
>> +#ifdef EGL_MESA_get_display
>> + { "eglGetDisplayMESA", (_EGLProc) eglGetDisplayMESA },
>> +#endif
>> { NULL, NULL }
>> };
>> EGLint i;
>> diff --git a/src/egl/main/egldisplay.c b/src/egl/main/egldisplay.c
>> index 5dc5fd9..bd2113b 100644
>> --- a/src/egl/main/egldisplay.c
>> +++ b/src/egl/main/egldisplay.c
>> @@ -49,7 +49,7 @@ _eglFiniDisplay(void)
>> * new one.
>> */
>> _EGLDisplay *
>> -_eglFindDisplay(EGLNativeDisplayType nativeDisplay)
>> +_eglFindDisplay(EGLint type, void *nativeDisplay)
>> {
>> _EGLDisplay *dpy;
>>
>> @@ -58,7 +58,7 @@ _eglFindDisplay(EGLNativeDisplayType nativeDisplay)
>> /* search the display list first */
>> dpy = _eglGlobal.DisplayList;
>> while (dpy) {
>> - if (dpy->NativeDisplay == nativeDisplay)
>> + if (dpy->DisplayType == type && dpy->VoidDisplay == nativeDisplay)
>> break;
>> dpy = dpy->Next;
>> }
>> @@ -68,7 +68,9 @@ _eglFindDisplay(EGLNativeDisplayType nativeDisplay)
>> dpy = (_EGLDisplay *) calloc(1, sizeof(_EGLDisplay));
>> if (dpy) {
>> _eglInitMutex(&dpy->Mutex);
>> - dpy->NativeDisplay = nativeDisplay;
>> + dpy->NativeDisplay = (EGLNativeDisplayType) nativeDisplay;
>> + dpy->VoidDisplay = nativeDisplay;
>> + dpy->DisplayType = type;
>>
>> /* add to the display list */
>> dpy->Next = _eglGlobal.DisplayList;
>> diff --git a/src/egl/main/egldisplay.h b/src/egl/main/egldisplay.h
>> index 42e305f..fdf2686 100644
>> --- a/src/egl/main/egldisplay.h
>> +++ b/src/egl/main/egldisplay.h
>> @@ -61,6 +61,8 @@ struct _egl_display
>> _EGLMutex Mutex;
>>
>> EGLNativeDisplayType NativeDisplay;
>> + EGLint DisplayType;
>> + void *VoidDisplay;
>>
>> EGLBoolean Initialized; /**< True if the display is initialized */
>> _EGLDriver *Driver;
>> @@ -92,7 +94,7 @@ _eglFiniDisplay(void);
>>
>>
>> extern _EGLDisplay *
>> -_eglFindDisplay(EGLNativeDisplayType displayName);
>> +_eglFindDisplay(EGLint type, void *display);
>>
>>
>> PUBLIC void
>> --
>> 1.7.0.1
>>
>>
>> _______________________________________________
>> mesa-dev mailing list
>> mesa-dev at lists.freedesktop.org
>> http://lists.freedesktop.org/mailman/listinfo/mesa-dev
>>
>>
>
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