/************************************************************************** * * Copyright 2008 VMware, Inc. * Copyright 2009-2010 Chia-I Wu * Copyright 2010-2011 LunarG, Inc. * 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 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 NONINFRINGEMENT. IN NO EVENT SHALL * THE AUTHORS OR COPYRIGHT HOLDERS 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. * **************************************************************************/ #include #include #include #include "eglconfig.h" #include "eglcontext.h" #include "egldisplay.h" #include "eglcurrent.h" #include "eglsurface.h" #include "egllog.h" #include "util/macros.h" /** * Return the API bit (one of EGL_xxx_BIT) of the context. */ static EGLint _eglGetContextAPIBit(_EGLContext *ctx) { EGLint bit = 0; switch (ctx->ClientAPI) { case EGL_OPENGL_ES_API: switch (ctx->ClientMajorVersion) { case 1: bit = EGL_OPENGL_ES_BIT; break; case 2: bit = EGL_OPENGL_ES2_BIT; break; case 3: bit = EGL_OPENGL_ES3_BIT_KHR; break; default: break; } break; case EGL_OPENVG_API: bit = EGL_OPENVG_BIT; break; case EGL_OPENGL_API: bit = EGL_OPENGL_BIT; break; default: break; } return bit; } /** * Parse the list of context attributes and return the proper error code. */ static EGLint _eglParseContextAttribList(_EGLContext *ctx, _EGLDisplay *dpy, const EGLint *attrib_list) { EGLenum api = ctx->ClientAPI; EGLint i, err = EGL_SUCCESS; if (!attrib_list) return EGL_SUCCESS; if (api == EGL_OPENVG_API && attrib_list[0] != EGL_NONE) { _eglLog(_EGL_DEBUG, "bad context attribute 0x%04x", attrib_list[0]); return EGL_BAD_ATTRIBUTE; } for (i = 0; attrib_list[i] != EGL_NONE; i++) { EGLint attr = attrib_list[i++]; EGLint val = attrib_list[i]; switch (attr) { case EGL_CONTEXT_CLIENT_VERSION: /* The EGL 1.4 spec says: * * "attribute EGL_CONTEXT_CLIENT_VERSION is only valid when the * current rendering API is EGL_OPENGL_ES_API" * * The EGL_KHR_create_context spec says: * * "EGL_CONTEXT_MAJOR_VERSION_KHR 0x3098 * (this token is an alias for EGL_CONTEXT_CLIENT_VERSION)" * * "The values for attributes EGL_CONTEXT_MAJOR_VERSION_KHR and * EGL_CONTEXT_MINOR_VERSION_KHR specify the requested client API * version. They are only meaningful for OpenGL and OpenGL ES * contexts, and specifying them for other types of contexts will * generate an error." */ if ((api != EGL_OPENGL_ES_API && (!dpy->Extensions.KHR_create_context || api != EGL_OPENGL_API))) { err = EGL_BAD_ATTRIBUTE; break; } ctx->ClientMajorVersion = val; break; case EGL_CONTEXT_MINOR_VERSION_KHR: /* The EGL_KHR_create_context spec says: * * "The values for attributes EGL_CONTEXT_MAJOR_VERSION_KHR and * EGL_CONTEXT_MINOR_VERSION_KHR specify the requested client API * version. They are only meaningful for OpenGL and OpenGL ES * contexts, and specifying them for other types of contexts will * generate an error." */ if (!dpy->Extensions.KHR_create_context || (api != EGL_OPENGL_ES_API && api != EGL_OPENGL_API)) { err = EGL_BAD_ATTRIBUTE; break; } ctx->ClientMinorVersion = val; break; case EGL_CONTEXT_FLAGS_KHR: if (!dpy->Extensions.KHR_create_context) { err = EGL_BAD_ATTRIBUTE; break; } /* The EGL_KHR_create_context spec says: * * "If the EGL_CONTEXT_OPENGL_DEBUG_BIT_KHR flag bit is set in * EGL_CONTEXT_FLAGS_KHR, then a will be created. * [...] * In some cases a debug context may be identical to a non-debug * context. This bit is supported for OpenGL and OpenGL ES * contexts." */ if ((val & EGL_CONTEXT_OPENGL_DEBUG_BIT_KHR) && (api != EGL_OPENGL_API && api != EGL_OPENGL_ES_API)) { err = EGL_BAD_ATTRIBUTE; break; } /* The EGL_KHR_create_context spec says: * * "If the EGL_CONTEXT_OPENGL_FORWARD_COMPATIBLE_BIT_KHR flag bit * is set in EGL_CONTEXT_FLAGS_KHR, then a * context will be created. Forward-compatible contexts are * defined only for OpenGL versions 3.0 and later. They must not * support functionality marked as by that version of * the API, while a non-forward-compatible context must support * all functionality in that version, deprecated or not. This bit * is supported for OpenGL contexts, and requesting a * forward-compatible context for OpenGL versions less than 3.0 * will generate an error." */ if ((val & EGL_CONTEXT_OPENGL_FORWARD_COMPATIBLE_BIT_KHR) && (api != EGL_OPENGL_API || ctx->ClientMajorVersion < 3)) { err = EGL_BAD_ATTRIBUTE; break; } if ((val & EGL_CONTEXT_OPENGL_ROBUST_ACCESS_BIT_KHR) && api != EGL_OPENGL_API) { /* The EGL_KHR_create_context spec says: * * 10) Which error should be generated if robust buffer access * or reset notifications are requested under OpenGL ES? * * As per Issue 6, this extension does not support creating * robust contexts for OpenGL ES. This is only supported via * the EGL_EXT_create_context_robustness extension. * * Attempting to use this extension to create robust OpenGL * ES context will generate an EGL_BAD_ATTRIBUTE error. This * specific error is generated because this extension does * not define the EGL_CONTEXT_OPENGL_ROBUST_ACCESS_BIT_KHR * and EGL_CONTEXT_OPENGL_RESET_NOTIFICATION_STRATEGY_KHR * bits for OpenGL ES contexts. Thus, use of these bits fall * under condition described by: "If an attribute is * specified that is not meaningful for the client API * type.." in the above specification. * * The spec requires that we emit the error even if the display * supports EGL_EXT_create_context_robustness. To create a robust * GLES context, the *attribute* * EGL_CONTEXT_OPENGL_ROBUST_ACCESS_EXT must be used, not the * *flag* EGL_CONTEXT_OPENGL_ROBUST_ACCESS_BIT_KHR. */ err = EGL_BAD_ATTRIBUTE; break; } ctx->Flags |= val; break; case EGL_CONTEXT_OPENGL_PROFILE_MASK_KHR: if (!dpy->Extensions.KHR_create_context) { err = EGL_BAD_ATTRIBUTE; break; } /* The EGL_KHR_create_context spec says: * * "[EGL_CONTEXT_OPENGL_PROFILE_MASK_KHR] is only meaningful for * OpenGL contexts, and specifying it for other types of * contexts, including OpenGL ES contexts, will generate an * error." */ if (api != EGL_OPENGL_API) { err = EGL_BAD_ATTRIBUTE; break; } ctx->Profile = val; break; case EGL_CONTEXT_OPENGL_RESET_NOTIFICATION_STRATEGY_KHR: /* The EGL_KHR_create_context spec says: * * "[EGL_CONTEXT_OPENGL_RESET_NOTIFICATION_STRATEGY_KHR] is only * meaningful for OpenGL contexts, and specifying it for other * types of contexts, including OpenGL ES contexts, will generate * an error." */ if (!dpy->Extensions.KHR_create_context || api != EGL_OPENGL_API) { err = EGL_BAD_ATTRIBUTE; break; } ctx->ResetNotificationStrategy = val; break; case EGL_CONTEXT_OPENGL_RESET_NOTIFICATION_STRATEGY_EXT: /* The EGL_EXT_create_context_robustness spec says: * * "[EGL_CONTEXT_OPENGL_RESET_NOTIFICATION_STRATEGY_EXT] is only * meaningful for OpenGL ES contexts, and specifying it for other * types of contexts will generate an EGL_BAD_ATTRIBUTE error." */ if (!dpy->Extensions.EXT_create_context_robustness || api != EGL_OPENGL_ES_API) { err = EGL_BAD_ATTRIBUTE; break; } ctx->ResetNotificationStrategy = val; break; case EGL_CONTEXT_OPENGL_ROBUST_ACCESS_EXT: if (!dpy->Extensions.EXT_create_context_robustness) { err = EGL_BAD_ATTRIBUTE; break; } if (val == EGL_TRUE) ctx->Flags |= EGL_CONTEXT_OPENGL_ROBUST_ACCESS_BIT_KHR; break; case EGL_CONTEXT_OPENGL_ROBUST_ACCESS: if (dpy->Version < 15) { err = EGL_BAD_ATTRIBUTE; break; } if (val == EGL_TRUE) ctx->Flags |= EGL_CONTEXT_OPENGL_ROBUST_ACCESS_BIT_KHR; break; case EGL_CONTEXT_OPENGL_DEBUG: if (dpy->Version < 15) { err = EGL_BAD_ATTRIBUTE; break; } if (val == EGL_TRUE) ctx->Flags |= EGL_CONTEXT_OPENGL_DEBUG_BIT_KHR; break; case EGL_CONTEXT_OPENGL_FORWARD_COMPATIBLE: if (dpy->Version < 15) { err = EGL_BAD_ATTRIBUTE; break; } if (val == EGL_TRUE) ctx->Flags |= EGL_CONTEXT_OPENGL_FORWARD_COMPATIBLE_BIT_KHR; break; case EGL_CONTEXT_OPENGL_NO_ERROR_KHR: if (dpy->Version < 14 || !dpy->Extensions.KHR_create_context_no_error) { err = EGL_BAD_ATTRIBUTE; break; } /* The KHR_no_error spec only applies against OpenGL 2.0+ and * OpenGL ES 2.0+ */ if ((api != EGL_OPENGL_API && api != EGL_OPENGL_ES_API) || ctx->ClientMajorVersion < 2) { err = EGL_BAD_ATTRIBUTE; break; } /* Canonicalize value to EGL_TRUE/EGL_FALSE definitions */ ctx->NoError = !!val; break; case EGL_CONTEXT_PRIORITY_LEVEL_IMG: /* The EGL_IMG_context_priority spec says: * * "EGL_CONTEXT_PRIORITY_LEVEL_IMG determines the priority level of * the context to be created. This attribute is a hint, as an * implementation may not support multiple contexts at some * priority levels and system policy may limit access to high * priority contexts to appropriate system privilege level. The * default value for EGL_CONTEXT_PRIORITY_LEVEL_IMG is * EGL_CONTEXT_PRIORITY_MEDIUM_IMG." */ { int bit; switch (val) { case EGL_CONTEXT_PRIORITY_HIGH_IMG: bit = __EGL_CONTEXT_PRIORITY_HIGH_BIT; break; case EGL_CONTEXT_PRIORITY_MEDIUM_IMG: bit = __EGL_CONTEXT_PRIORITY_MEDIUM_BIT; break; case EGL_CONTEXT_PRIORITY_LOW_IMG: bit = __EGL_CONTEXT_PRIORITY_LOW_BIT; break; default: bit = -1; break; } if (bit < 0) { err = EGL_BAD_ATTRIBUTE; break; } /* "This extension allows an EGLContext to be created with a * priority hint. It is possible that an implementation will not * honour the hint, especially if there are constraints on the * number of high priority contexts available in the system, or * system policy limits access to high priority contexts to * appropriate system privilege level. A query is provided to find * the real priority level assigned to the context after creation." * * We currently assume that the driver applies the priority hint * and filters out any it cannot handle during the screen setup, * e.g. dri2_setup_screen(). As such we can mask any change that * the driver would fail, and ctx->ContextPriority matches the * hint applied to the driver/hardware backend. */ if (dpy->Extensions.IMG_context_priority & (1 << bit)) ctx->ContextPriority = val; break; } case EGL_CONTEXT_RELEASE_BEHAVIOR_KHR: if (val == EGL_CONTEXT_RELEASE_BEHAVIOR_NONE_KHR || val == EGL_CONTEXT_RELEASE_BEHAVIOR_FLUSH_KHR) { ctx->ReleaseBehavior = val; } else { err = EGL_BAD_ATTRIBUTE; } break; default: err = EGL_BAD_ATTRIBUTE; break; } if (err != EGL_SUCCESS) { _eglLog(_EGL_DEBUG, "bad context attribute 0x%04x", attr); break; } } if (api == EGL_OPENGL_API) { /* The EGL_KHR_create_context spec says: * * "If the requested OpenGL version is less than 3.2, * EGL_CONTEXT_OPENGL_PROFILE_MASK_KHR is ignored and the * functionality of the context is determined solely by the * requested version." * * Since the value is ignored, only validate the setting if the version * is >= 3.2. */ if (ctx->ClientMajorVersion >= 4 || (ctx->ClientMajorVersion == 3 && ctx->ClientMinorVersion >= 2)) { switch (ctx->Profile) { case EGL_CONTEXT_OPENGL_CORE_PROFILE_BIT_KHR: case EGL_CONTEXT_OPENGL_COMPATIBILITY_PROFILE_BIT_KHR: break; default: /* The EGL_KHR_create_context spec says: * * "* If an OpenGL context is requested, the requested version * is greater than 3.2, and the value for attribute * EGL_CONTEXT_OPENGL_PROFILE_MASK_KHR has no bits set; has * any bits set other than EGL_CONTEXT_OPENGL_CORE_PROFILE_BIT_KHR * and EGL_CONTEXT_OPENGL_COMPATIBILITY_PROFILE_BIT_KHR; has * more than one of these bits set; or if the implementation does * not support the requested profile, then an EGL_BAD_MATCH error * is generated." */ err = EGL_BAD_MATCH; break; } } /* The EGL_KHR_create_context spec says: * * "* If an OpenGL context is requested and the values for * attributes EGL_CONTEXT_MAJOR_VERSION_KHR and * EGL_CONTEXT_MINOR_VERSION_KHR, when considered together with * the value for attribute * EGL_CONTEXT_FORWARD_COMPATIBLE_BIT_KHR, specify an OpenGL * version and feature set that are not defined, than an * EGL_BAD_MATCH error is generated. * * ... Thus, examples of invalid combinations of attributes * include: * * - Major version < 1 or > 4 * - Major version == 1 and minor version < 0 or > 5 * - Major version == 2 and minor version < 0 or > 1 * - Major version == 3 and minor version < 0 or > 2 * - Major version == 4 and minor version < 0 or > 2 * - Forward-compatible flag set and major version < 3" */ if (ctx->ClientMajorVersion < 1 || ctx->ClientMinorVersion < 0) err = EGL_BAD_MATCH; switch (ctx->ClientMajorVersion) { case 1: if (ctx->ClientMinorVersion > 5 || (ctx->Flags & EGL_CONTEXT_OPENGL_FORWARD_COMPATIBLE_BIT_KHR) != 0) err = EGL_BAD_MATCH; break; case 2: if (ctx->ClientMinorVersion > 1 || (ctx->Flags & EGL_CONTEXT_OPENGL_FORWARD_COMPATIBLE_BIT_KHR) != 0) err = EGL_BAD_MATCH; break; case 3: /* Note: The text above is incorrect. There *is* an OpenGL 3.3! */ if (ctx->ClientMinorVersion > 3) err = EGL_BAD_MATCH; break; case 4: default: /* Don't put additional version checks here. We don't know that * there won't be versions > 4.2. */ break; } } else if (api == EGL_OPENGL_ES_API) { /* The EGL_KHR_create_context spec says: * * "* If an OpenGL ES context is requested and the values for * attributes EGL_CONTEXT_MAJOR_VERSION_KHR and * EGL_CONTEXT_MINOR_VERSION_KHR specify an OpenGL ES version that * is not defined, than an EGL_BAD_MATCH error is generated. * * ... Examples of invalid combinations of attributes include: * * - Major version < 1 or > 2 * - Major version == 1 and minor version < 0 or > 1 * - Major version == 2 and minor version != 0 */ if (ctx->ClientMajorVersion < 1 || ctx->ClientMinorVersion < 0) err = EGL_BAD_MATCH; switch (ctx->ClientMajorVersion) { case 1: if (ctx->ClientMinorVersion > 1) err = EGL_BAD_MATCH; break; case 2: if (ctx->ClientMinorVersion > 0) err = EGL_BAD_MATCH; break; case 3: /* Don't put additional version checks here. We don't know that * there won't be versions > 3.0. */ break; default: err = EGL_BAD_MATCH; break; } } switch (ctx->ResetNotificationStrategy) { case EGL_NO_RESET_NOTIFICATION_KHR: case EGL_LOSE_CONTEXT_ON_RESET_KHR: break; default: err = EGL_BAD_ATTRIBUTE; break; } /* The EGL_KHR_create_context_no_error spec says: * * "BAD_MATCH is generated if the EGL_CONTEXT_OPENGL_NO_ERROR_KHR is TRUE at * the same time as a debug or robustness context is specified." */ if (ctx->NoError && (ctx->Flags & EGL_CONTEXT_OPENGL_DEBUG_BIT_KHR || ctx->Flags & EGL_CONTEXT_OPENGL_ROBUST_ACCESS_BIT_KHR)) { err = EGL_BAD_MATCH; } if ((ctx->Flags & ~(EGL_CONTEXT_OPENGL_DEBUG_BIT_KHR | EGL_CONTEXT_OPENGL_FORWARD_COMPATIBLE_BIT_KHR | EGL_CONTEXT_OPENGL_ROBUST_ACCESS_BIT_KHR)) != 0) { err = EGL_BAD_ATTRIBUTE; } return err; } /** * Initialize the given _EGLContext object to defaults and/or the values * in the attrib_list. * * According to EGL 1.5 Section 3.7: * * "EGL_OPENGL_API and EGL_OPENGL_ES_API are interchangeable for all * purposes except eglCreateContext." * * And since we only support GL and GLES, this is the only place where the * bound API matters at all. We look up the current API from the current * thread, and stash that in the context we're initializing. Our caller is * responsible for determining whether that's an API it supports. */ EGLBoolean _eglInitContext(_EGLContext *ctx, _EGLDisplay *dpy, _EGLConfig *conf, const EGLint *attrib_list) { const EGLenum api = eglQueryAPI(); EGLint err; if (api == EGL_NONE) return _eglError(EGL_BAD_MATCH, "eglCreateContext(no client API)"); _eglInitResource(&ctx->Resource, sizeof(*ctx), dpy); ctx->ClientAPI = api; ctx->Config = conf; ctx->Profile = EGL_CONTEXT_OPENGL_CORE_PROFILE_BIT_KHR; ctx->ClientMajorVersion = 1; /* the default, per EGL spec */ ctx->ClientMinorVersion = 0; ctx->Flags = 0; ctx->ResetNotificationStrategy = EGL_NO_RESET_NOTIFICATION_KHR; ctx->ContextPriority = EGL_CONTEXT_PRIORITY_MEDIUM_IMG; ctx->ReleaseBehavior = EGL_CONTEXT_RELEASE_BEHAVIOR_FLUSH_KHR; err = _eglParseContextAttribList(ctx, dpy, attrib_list); if (err == EGL_SUCCESS && ctx->Config) { EGLint api_bit; api_bit = _eglGetContextAPIBit(ctx); if (!(ctx->Config->RenderableType & api_bit)) { _eglLog(_EGL_DEBUG, "context api is 0x%x while config supports 0x%x", api_bit, ctx->Config->RenderableType); err = EGL_BAD_CONFIG; } } if (err != EGL_SUCCESS) return _eglError(err, "eglCreateContext"); return EGL_TRUE; } static EGLint _eglQueryContextRenderBuffer(_EGLContext *ctx) { _EGLSurface *surf = ctx->DrawSurface; /* From the EGL 1.5 spec: * * - If the context is not bound to a surface, then EGL_NONE will be * returned. */ if (!surf) return EGL_NONE; switch (surf->Type) { default: unreachable("bad EGLSurface type"); case EGL_PIXMAP_BIT: /* - If the context is bound to a pixmap surface, then EGL_SINGLE_BUFFER * will be returned. */ return EGL_SINGLE_BUFFER; case EGL_PBUFFER_BIT: /* - If the context is bound to a pbuffer surface, then EGL_BACK_BUFFER * will be returned. */ return EGL_BACK_BUFFER; case EGL_WINDOW_BIT: /* - If the context is bound to a window surface, then either * EGL_BACK_BUFFER or EGL_SINGLE_BUFFER may be returned. The value * returned depends on both the buffer requested by the setting of the * EGL_RENDER_BUFFER property of the surface [...], and on the client * API (not all client APIs support single-buffer Rendering to window * surfaces). Some client APIs allow control of whether rendering goes * to the front or back buffer. This client API-specific choice is not * reflected in the returned value, which only describes the buffer * that will be rendered to by default if not overridden by the client * API. */ return surf->ActiveRenderBuffer; } } EGLBoolean _eglQueryContext(_EGLDriver *drv, _EGLDisplay *dpy, _EGLContext *c, EGLint attribute, EGLint *value) { (void) drv; (void) dpy; if (!value) return _eglError(EGL_BAD_PARAMETER, "eglQueryContext"); switch (attribute) { case EGL_CONFIG_ID: /* * From EGL_KHR_no_config_context: * * "Querying EGL_CONFIG_ID returns the ID of the EGLConfig with * respect to which the context was created, or zero if created * without respect to an EGLConfig." */ *value = c->Config ? c->Config->ConfigID : 0; break; case EGL_CONTEXT_CLIENT_VERSION: *value = c->ClientMajorVersion; break; case EGL_CONTEXT_CLIENT_TYPE: *value = c->ClientAPI; break; case EGL_RENDER_BUFFER: *value = _eglQueryContextRenderBuffer(c); break; case EGL_CONTEXT_PRIORITY_LEVEL_IMG: *value = c->ContextPriority; break; default: return _eglError(EGL_BAD_ATTRIBUTE, "eglQueryContext"); } return EGL_TRUE; } /** * Bind the context to the thread and return the previous context. * * Note that the context may be NULL. */ _EGLContext * _eglBindContextToThread(_EGLContext *ctx, _EGLThreadInfo *t) { _EGLContext *oldCtx; oldCtx = t->CurrentContext; if (ctx != oldCtx) { if (oldCtx) oldCtx->Binding = NULL; if (ctx) ctx->Binding = t; t->CurrentContext = ctx; } return oldCtx; } /** * Return true if the given context and surfaces can be made current. */ static EGLBoolean _eglCheckMakeCurrent(_EGLContext *ctx, _EGLSurface *draw, _EGLSurface *read) { _EGLThreadInfo *t = _eglGetCurrentThread(); _EGLDisplay *dpy; if (_eglIsCurrentThreadDummy()) return _eglError(EGL_BAD_ALLOC, "eglMakeCurrent"); /* this is easy */ if (!ctx) { if (draw || read) return _eglError(EGL_BAD_MATCH, "eglMakeCurrent"); return EGL_TRUE; } dpy = ctx->Resource.Display; if (!dpy->Extensions.KHR_surfaceless_context && (draw == NULL || read == NULL)) return _eglError(EGL_BAD_MATCH, "eglMakeCurrent"); /* * The spec says * * "If ctx is current to some other thread, or if either draw or read are * bound to contexts in another thread, an EGL_BAD_ACCESS error is * generated." * * and * * "at most one context may be bound to a particular surface at a given * time" */ if (ctx->Binding && ctx->Binding != t) return _eglError(EGL_BAD_ACCESS, "eglMakeCurrent"); if (draw && draw->CurrentContext && draw->CurrentContext != ctx) { if (draw->CurrentContext->Binding != t) return _eglError(EGL_BAD_ACCESS, "eglMakeCurrent"); } if (read && read->CurrentContext && read->CurrentContext != ctx) { if (read->CurrentContext->Binding != t) return _eglError(EGL_BAD_ACCESS, "eglMakeCurrent"); } /* If the context has a config then it must match that of the two * surfaces */ if (ctx->Config) { if ((draw && draw->Config != ctx->Config) || (read && read->Config != ctx->Config)) return _eglError(EGL_BAD_MATCH, "eglMakeCurrent"); } else { /* Otherwise we must be using the EGL_KHR_no_config_context * extension */ assert(dpy->Extensions.KHR_no_config_context); /* The extension doesn't permit binding draw and read buffers with * differing contexts */ if (draw && read && draw->Config != read->Config) return _eglError(EGL_BAD_MATCH, "eglMakeCurrent"); } return EGL_TRUE; } /** * Bind the context to the current thread and given surfaces. Return the * previous bound context and surfaces. The caller should unreference the * returned context and surfaces. * * Making a second call with the resources returned by the first call * unsurprisingly undoes the first call, except for the resouce reference * counts. */ EGLBoolean _eglBindContext(_EGLContext *ctx, _EGLSurface *draw, _EGLSurface *read, _EGLContext **old_ctx, _EGLSurface **old_draw, _EGLSurface **old_read) { _EGLThreadInfo *t = _eglGetCurrentThread(); _EGLContext *prev_ctx; _EGLSurface *prev_draw, *prev_read; if (!_eglCheckMakeCurrent(ctx, draw, read)) return EGL_FALSE; /* increment refcounts before binding */ _eglGetContext(ctx); _eglGetSurface(draw); _eglGetSurface(read); /* bind the new context */ prev_ctx = _eglBindContextToThread(ctx, t); /* break previous bindings */ if (prev_ctx) { prev_draw = prev_ctx->DrawSurface; prev_read = prev_ctx->ReadSurface; if (prev_draw) prev_draw->CurrentContext = NULL; if (prev_read) prev_read->CurrentContext = NULL; prev_ctx->DrawSurface = NULL; prev_ctx->ReadSurface = NULL; } else { prev_draw = prev_read = NULL; } /* establish new bindings */ if (ctx) { if (draw) draw->CurrentContext = ctx; if (read) read->CurrentContext = ctx; ctx->DrawSurface = draw; ctx->ReadSurface = read; } assert(old_ctx && old_draw && old_read); *old_ctx = prev_ctx; *old_draw = prev_draw; *old_read = prev_read; return EGL_TRUE; }