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Diffstat (limited to 'glew/auto/EGL-Registry/extensions/EXT/EGL_EXT_platform_x11.txt')
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diff --git a/glew/auto/EGL-Registry/extensions/EXT/EGL_EXT_platform_x11.txt b/glew/auto/EGL-Registry/extensions/EXT/EGL_EXT_platform_x11.txt new file mode 100644 index 0000000..19bfc35 --- /dev/null +++ b/glew/auto/EGL-Registry/extensions/EXT/EGL_EXT_platform_x11.txt @@ -0,0 +1,414 @@ +Name + + EXT_platform_x11 + +Name Strings + + EGL_EXT_platform_x11 + +Contributors + + Chad Versace <chad.versace@intel.com> + James Jones <jajones@nvidia.com> + +Contacts + + Chad Versace <chad.versace@intel.com> + +Status + + Complete + +Version + + Version 13, 2014-03-10 + +Number + + EGL Extension #59 + +Extension Type + + EGL client extension + +Dependencies + + Requires EGL_EXT_client_extensions to query its existence without + a display. + + Requires EGL_EXT_platform_base. + + This extension is written against the wording of version 7 of the + EGL_EXT_platform_base specification. + +Overview + + This extension defines how to create EGL resources from native X11 + resources using the functions defined by EGL_EXT_platform_base. + + This extension defines only how to create EGL resources from Xlib + resources. It does not define how to do so from xcb resources. All X11 + types discussed here are defined by the header `Xlib.h`. + +New Types + + None + +New Procedures and Functions + + None + +New Tokens + + Accepted as the <platform> argument of eglGetPlatformDisplayEXT: + + EGL_PLATFORM_X11_EXT 0x31D5 + + Accepted as an attribute name in the <attrib_list> argument of + eglGetPlatformDisplayEXT: + + EGL_PLATFORM_X11_SCREEN_EXT 0x31D6 + +Additions to the EGL Specification + + None. + +New Behavior + + To determine if the EGL implementation supports this extension, clients + should query the EGL_EXTENSIONS string of EGL_NO_DISPLAY. + + On the X11 platform, an EGLDisplay refers to a specific X11 screen rather + than an X11 display connection. This is the case because separate X11 + screens, even when belonging to the same X11 display connection, may + reside on different GPUs and/or be driven by different drivers. Therefore, + different X11 screens may have different EGL capabilities. + + To obtain an EGLDisplay backed by an X11 screen, call + eglGetPlatformDisplayEXT with <platform> set to EGL_PLATFORM_X11_EXT. The + <native_display> parameter specifies the X11 display connection to use, and + must point to a valid X11 `Display` or be NULL. If <native_display> is + EGL_DEFAULT_DISPLAY, then EGL will create [1] a connection to the default + X11 display. The environment variable DISPLAY determines the default X11 + display as described in the manual page for XOpenDisplay(3). The value of + attribute EGL_PLATFORM_X11_SCREEN_EXT specifies the X11 screen to use. If + the attribute is omitted from <attrib_list>, then the display connection's + default screen is used. Otherwise, the attribute's value must be a valid + screen on the display connection. If the attribute's value is not a valid + screen, then an EGL_BAD_ATTRIBUTE error is generated. + + [fn1] The method by which EGL creates a connection to the default X11 + display is an internal implementation detail. The implementation may use + XOpenDisplay, xcb_connect, or any other method. + + To obtain an on-screen rendering surface from an X11 Window, call + eglCreatePlatformWindowSurfaceEXT with a <dpy> that belongs to X11 and + a <native_window> that points to an X11 Window. + + To obtain an offscreen rendering surface from an X11 Pixmap, call + eglCreatePlatformPixmapSurfaceEXT with a <dpy> that belongs to X11 and + a <native_pixmap> that points to an X11 Pixmap. + +Issues + + 1. Should this extension permit EGL_DEFAULT_DISPLAY as input to + eglGetPlatformDisplayEXT()? + + RESOLVED. Yes. When given EGL_DEFAULT_DISPLAY, eglGetPlatformDisplayEXT + returns an EGLDisplay backed by the default X11 display. + + 2. When given EGL_DEFAULT_DISPLAY, does eglGetPlatformDisplayEXT reuse an + existing X11 display connection or create a new one? + + RESOLVED. eglGetPlatformDisplayEXT creates a new connection because the + alternative is infeasible. EGL cannot reliably detect if the client + process already has a X11 display connection. + + +Example Code + + // This example program creates two EGL surfaces: one from an X11 Window + // and the other from an X11 Pixmap. + // + // If the macro USE_EGL_EXT_PLATFORM_X11 is defined, then the program + // creates the surfaces using the methods defined in this specification. + // Otherwise, it uses the methods defined by the EGL 1.4 specification. + // + // Compile with `cc -std=c99 example.c -lX11 -lEGL`. + + #include <stdlib.h> + #include <string.h> + + #include <EGL/egl.h> + #include <X11/Xlib.h> + + struct my_display { + Display *x11; + EGLDisplay egl; + }; + + struct my_config { + struct my_display dpy; + XVisualInfo *x11; + Colormap colormap; + EGLConfig egl; + }; + + struct my_window { + struct my_config config; + Window x11; + EGLSurface egl; + }; + + struct my_pixmap { + struct my_config config; + Pixmap x11; + EGLSurface egl; + }; + + static void + check_extensions(void) + { + #ifdef USE_EGL_EXT_PLATFORM_X11 + const char *client_extensions = eglQueryString(EGL_NO_DISPLAY, EGL_EXTENSIONS); + + if (!client_extensions) { + // EGL_EXT_client_extensions is unsupported. + abort(); + } + if (!strstr(client_extensions, "EGL_EXT_platform_x11")) { + abort(); + } + #endif + } + + static struct my_display + get_display(void) + { + struct my_display dpy; + + dpy.x11 = XOpenDisplay(NULL); + if (!dpy.x11) { + abort(); + } + + #ifdef USE_EGL_EXT_PLATFORM_X11 + dpy.egl = eglGetPlatformDisplayEXT(EGL_PLATFORM_X11_EXT, dpy.x11, + NULL); + #else + dpy.egl = eglGetDisplay(dpy.x11); + #endif + + if (dpy.egl == EGL_NO_DISPLAY) { + abort(); + } + + EGLint major, minor; + if (!eglInitialize(dpy.egl, &major, &minor)) { + abort(); + } + + return dpy; + } + + static struct my_config + get_config(struct my_display dpy) + { + struct my_config config = { + .dpy = dpy, + }; + + EGLint egl_config_attribs[] = { + EGL_BUFFER_SIZE, 32, + EGL_RED_SIZE, 8, + EGL_GREEN_SIZE, 8, + EGL_BLUE_SIZE, 8, + EGL_ALPHA_SIZE, 8, + + EGL_DEPTH_SIZE, EGL_DONT_CARE, + EGL_STENCIL_SIZE, EGL_DONT_CARE, + + EGL_RENDERABLE_TYPE, EGL_OPENGL_ES2_BIT, + EGL_SURFACE_TYPE, EGL_WINDOW_BIT | EGL_PIXMAP_BIT, + EGL_NONE, + }; + + EGLint num_configs; + if (!eglChooseConfig(dpy.egl, + egl_config_attribs, + &config.egl, 1, + &num_configs)) { + abort(); + } + if (num_configs == 0) { + abort(); + } + + XVisualInfo x11_visual_info_template; + if (!eglGetConfigAttrib(dpy.egl, + config.egl, + EGL_NATIVE_VISUAL_ID, + (EGLint*) &x11_visual_info_template.visualid)) { + abort(); + } + + int num_visuals; + config.x11 = XGetVisualInfo(dpy.x11, + VisualIDMask, + &x11_visual_info_template, + &num_visuals); + if (!config.x11) { + abort(); + } + + config.colormap = XCreateColormap(dpy.x11, + RootWindow(dpy.x11, 0), + config.x11->visual, + AllocNone); + if (config.colormap == None) { + abort(); + } + + return config; + } + + static struct my_window + get_window(struct my_config config) + { + XSetWindowAttributes attr; + unsigned long mask; + + struct my_window window = { + .config = config, + }; + + attr.colormap = config.colormap; + mask = CWColormap; + + window.x11 = XCreateWindow(config.dpy.x11, + DefaultRootWindow(config.dpy.x11), // parent + 0, 0, // x, y + 256, 256, // width, height + 0, // border_width + config.x11->depth, + InputOutput, // class + config.x11->visual, + mask, // valuemask + &attr); // attributes + if (!window.x11) { + abort(); + } + + #ifdef USE_EGL_EXT_PLATFORM_X11 + window.egl = eglCreatePlatformWindowSurfaceEXT(config.dpy.egl, + config.egl, + &window.x11, + NULL); + #else + window.egl = eglCreateWindowSurface(config.dpy.egl, + config.egl, + window.x11, + NULL); + #endif + + if (window.egl == EGL_NO_SURFACE) { + abort(); + } + + return window; + } + + static struct my_pixmap + get_pixmap(struct my_config config) + { + struct my_pixmap pixmap = { + .config = config, + }; + + pixmap.x11 = XCreatePixmap(config.dpy.x11, + DefaultRootWindow(config.dpy.x11), + 256, 256, // width, height + config.x11->depth); + if (!pixmap.x11) { + abort(); + } + + #ifdef USE_EGL_EXT_PLATFORM_X11 + pixmap.egl = eglCreatePlatformPixmapSurfaceEXT(config.dpy.egl, + config.egl, + &pixmap.x11, + NULL); + #else + pixmap.egl = eglCreatePixmapSurface(config.dpy.egl, + config.egl, + pixmap.x11, + NULL); + #endif + + if (pixmap.egl == EGL_NO_SURFACE) { + abort(); + } + + return pixmap; + } + + int + main(void) + { + check_extensions(); + + struct my_display dpy = get_display(); + struct my_config config = get_config(dpy); + struct my_window window = get_window(config); + struct my_pixmap pixmap = get_pixmap(config); + + return 0; + } + +Revision History + + Version 13, 2014-03-10 (Chad Versace) + - Update text to reflect resolution of issue #1. State that + <native_display> may be EGL_DEFAULT_DISPLAY. + - Explain in more detail how EGL connects to the default X11 display. + - Add and resolve issue #2. + + Version 12, 2014-02-11 (Chad Versace) + - Fix 2nd argument to XCreatePixmap in example code. + + Version 11, 2013-07-10 (Jon Leech) + - Fix enumerant values and assign extension number for publication + (Bug 10240). + + Version 10, 2013-07-03 (Chad Versace) + - Add "Extension Type" section, required by EGL_EXT_client_extensions v9. + + Version 9, 2013-06-11 (Chad Versace) + - Replace reference to version 5 of EGL_EXT_platform_base to version 7. + - Add James Jones as contributor. + + Version 8, 2013-06-07 (Chad Versace) + - Assign enum values to new tokens. + + Version 7, 2013-06-07 (Chad Versace) + - Explicitly require EGL_EXT_client_extensions in the Dependencies + section. + + Version 6, 2013-06-07 (Chad Versace) + - Add attribute EGL_PLATFORM_X11_SCREEN_EXT. + + Version 5, 2013-06-07 (Chad Versace) + - Rephrase against version 7 of EGL_EXT_platform_base. + + Version 4, 2013-06-07 (Chad Versace) + - Fix compilation of example code. + + Version 3, 2013-04-26 (Chad Versace) + - Add missing EXT suffix to new token. + + Version 2, 2013-04-22 (Chad Versace) + - Discuss EGL_DEFAULT_DISPLAY. + - Fix minor typographical and grammatical errors. + + Version 1, 2013.03.24 (Chad Versace) + - First draft |