From ee6c9fcbcaf525b13f23537f50e207bff57581d8 Mon Sep 17 00:00:00 2001 From: Ian Romanick Date: Fri, 15 Feb 2013 22:38:23 -0800 Subject: [PATCH] docs: Import extension spec for GLX_MESA_query_renderer MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit The enumerated values are currently allocated from Intel's range. v2: Fix a typo. Update the list of functions to which the new enums can be passed. The "Current" versions were previously missing. Both things noticed by Marek. v3: Fix typo in return type of glXQueryRendererIntegerMESA in the spec body (noticed by Ken). Fix typo in issue #14 referencing itself instead of issue #13 (noticed by Dave). Signed-off-by: Ian Romanick Reviewed-by: Kenneth Graunke Acked-by: Marek Olšák Acked-by: Dave Airlie --- docs/specs/MESA_query_renderer.spec | 405 ++++++++++++++++++++++++++++++++++++ 1 file changed, 405 insertions(+) create mode 100644 docs/specs/MESA_query_renderer.spec diff --git a/docs/specs/MESA_query_renderer.spec b/docs/specs/MESA_query_renderer.spec new file mode 100644 index 0000000..bf09756 --- /dev/null +++ b/docs/specs/MESA_query_renderer.spec @@ -0,0 +1,405 @@ +Name + + MESA_query_renderer + +Name Strings + + GLX_MESA_query_renderer + +Contact + + Ian Romanick + +IP Status + + No known IP claims. + +Status + + Incomplete. DO NOT SHIP. + +Version + + Version 6, 7-November-2013 + +Number + + TBD. + +Dependencies + + GLX 1.4 is required. + + GLX_ARB_create_context and GLX_ARB_create_context_profile are required. + + This extension interacts with GLX_EXT_create_context_es2_profile and + GLX_EXT_create_context_es_profile. + +Overview + + In many situations, applications want to detect characteristics of a + rendering device before creating a context for that device. Information + gathered at this stage may guide choices the application makes about + color depth, number of samples per-pixel, texture quality, and so on. + In addition, versions of supported APIs and implementation API + preference may also guide start-up decisions made by the application. + For example, one implementation may prefer vertex data be supplied using + methods only available in a compatibility profile, but another + implementation may only support the desired version in a core profile. + + There are also cases where more than one renderer may be available per + display. For example, there is typically a hardware implementation and + a software based implementation. There are cases where an application + may want to pick one over the other. One such situation is when the + software implementation supports more features than the hardware + implementation. Another situation is when a particular version of the + hardware implementation is blacklisted due to known bugs. + + This extension provides a mechanism for the application to query all of + the available renderers for a particular display and screen. In + addition, this extension provides a mechanism for applications to create + contexts with respect to a specific renderer. + +New Procedures and Functions + + Bool glXQueryRendererIntegerMESA(Display *dpy, int screen, + int renderer, int attribute, + unsigned int *value); + Bool glXQueryCurrentRendererIntegerMESA(int attribute, unsigned int *value); + + const char *glXQueryRendererStringMESA(Display *dpy, int screen, + int renderer, int attribute); + + const char *glXQueryCurrentRendererStringMESA(int attribute); + +New Tokens + + Accepted as an in glXQueryRendererIntegerMESA and + glXQueryCurrentRendererIntegerMESA: + + GLX_RENDERER_VENDOR_ID_MESA 0x8183 + GLX_RENDERER_DEVICE_ID_MESA 0x8184 + GLX_RENDERER_VERSION_MESA 0x8185 + GLX_RENDERER_ACCELERATED_MESA 0x8186 + GLX_RENDERER_VIDEO_MEMORY_MESA 0x8187 + GLX_RENDERER_UNIFIED_MEMORY_ARCHITECTURE_MESA 0x8188 + GLX_RENDERER_PREFERRED_PROFILE_MESA 0x8189 + GLX_RENDERER_OPENGL_CORE_PROFILE_VERSION_MESA 0x818A + GLX_RENDERER_OPENGL_COMPATIBILITY_PROFILE_VERSION_MESA 0x818B + GLX_RENDERER_OPENGL_ES_PROFILE_VERSION_MESA 0x818C + GLX_RENDERER_OPENGL_ES2_PROFILE_VERSION_MESA 0x818D + + Accepted as an in glXQueryRendererStringMESA and + glXQueryCurrentRendererStringMESA: + + GLX_RENDERER_VENDOR_ID_MESA + GLX_RENDERER_DEVICE_ID_MESA + + Accepted as an attribute name in <*attrib_list> in + glXCreateContextAttribsARB: + + GLX_RENDERER_ID_MESA 0x818E + +Additions to the OpenGL / WGL Specifications + + None. This specification is written for GLX. + +Additions to the GLX 1.4 Specification + + [Add the following to Section X.Y.Z of the GLX Specification] + + To obtain information about the available renderers for a particular + display and screen, + + Bool glXQueryRendererIntegerMESA(Display *dpy, int screen, int renderer, + int attribute, unsigned int *value); + + can be used. The value for will be returned in one or more + integers specified by . The values, data sizes, and descriptions + of each renderer attribute are listed in the table below. + + GLX renderer attribute number description + of values + ---------------------- --------- ----------- + GLX_RENDERER_VENDOR_ID_MESA 1 PCI ID of the device vendor + GLX_RENDERER_DEVICE_ID_MESA 1 PCI ID of the device + GLX_RENDERER_VERSION_MESA 3 Major, minor, and patch level of + the renderer implementation + GLX_RENDERER_ACCELERATED_MESA 1 Boolean indicating whether or + not the renderer is hardware + accelerated + GLX_RENDERER_VIDEO_MEMORY_MESA 1 Number of megabytes of video + memory available to the renderer + GLX_RENDERER_UNIFIED_MEMORY_ARCHITECTURE_MESA + 1 Boolean indicating whether or + not the renderer uses a unified + memory architecture or has + separate "on-card" and GART + memory. + GLX_RENDERER_PREFERRED_PROFILE_MESA + 1 Bitmask of the preferred context + profile for this renderer. This + value is suitable to be supplied + with the + GLX_CONTEXT_PROFILE_MASK_ARB + attribute to + glXCreateContextAttribsARB + GLX_RENDERER_OPENGL_CORE_PROFILE_VERSION_MESA + 2 Maximum core profile major and + minor version supported by the + renderer + GLX_RENDERER_OPENGL_COMPATIBILITY_PROFILE_VERSION_MESA + 2 Maximum compatibility profile + major and minor version + supported by the renderer + GLX_RENDERER_OPENGL_ES_PROFILE_VERSION_MESA + 2 Maximum OpenGL ES 1.x + major and minor version + supported by the renderer + GLX_RENDERER_OPENGL_ES2_PROFILE_VERSION_MESA + 2 Maximum OpenGL ES 2.x or 3.x + major and minor version + supported by the renderer + + In the table, boolean attributes will have either the value 0 or 1. + + GLX_RENDERER_OPENGL_CORE_PROFILE_VERSION_MESA, + GLX_RENDERER_OPENGL_COMPATIBILITY_PROFILE_VERSION_MESA, + GLX_RENDERER_OPENGL_ES_PROFILE_VERSION_MESA, and + GLX_RENDERER_OPENGL_ES2_PROFILE_VERSION_MESA each return <0, 0> in + *value if no version of that profile is supported. + + GLX_RENDERER_VENDOR_ID_MESA and GLX_RENDERER_DEVICE_ID_MESA may return + 0xFFFFFFFF if the device does not have a PCI ID (because it is not a PCI + device) or if the PCI ID is not available. In this case the application + should rely on the string query instead. + + If is not a recognized value, False is returned, but no GLX + error is generated. Otherwise, True is returned. + + String versions of some attributes may also be queried using + + const char *glXQueryRendererStringMESA(Display *dpy, int screen, + int renderer, int attribute); + + The value for will be returned in one or more + integers specified by . The values, data sizes, and descriptions + of each renderer attribute are listed in the table below. + + GLX renderer attribute description + ---------------------- ----------- + GLX_RENDERER_VENDOR_ID_MESA Name of the renderer provider. This may + differ from the vendor name of the + underlying hardware. + GLX_RENDERER_DEVICE_ID_MESA Name of the renderer. This may differ from + the name of the underlying hardware (e.g., + for a software renderer). + + If is not a recognized value, NULL is returned, but no GLX + error is generated. + + The string returned for GLX_RENDERER_VENDOR_ID_MESA will have the same + format as the string that would be returned by glGetString of GL_VENDOR. + It may, however, have a different value. + + The string returned for GLX_RENDERER_DEVICE_ID_MESA will have the same + format as the string that would be returned by glGetString of GL_RENDERER. + It may, however, have a different value. + + + [Add to section section 3.3.7 "Rendering Contexts"] + + The attribute name GLX_RENDERER_ID_MESA specified the index of the render + against which the context should be created. The default value of + GLX_RENDER_ID_MESA is 0. + + + [Add to list of errors for glXCreateContextAttribsARB in section section + 3.3.7 "Rendering Contexts"] + + * If the value of GLX_RENDERER_ID_MESA specifies a non-existent + renderer, BadMatch is generated. + +Dependencies on GLX_EXT_create_context_es_profile and +GLX_EXT_create_context_es2_profile + + If neither extension is supported, remove all mention of + GLX_RENDERER_OPENGL_ES2_PROFILE_VERSION_MESA from the spec. + + If GLX_EXT_create_context_es_profile is not supported, remove all mention of + GLX_RENDERER_OPENGL_ES_PROFILE_VERSION_MESA from the spec. + +Issues + + 1) How should the difference between on-card and GART memory be exposed? + + UNRESOLVED. + + 2) How should memory limitations of unified memory architecture (UMA) + systems be exposed? + + UNRESOLVED. Some hardware has different per-process and global + limits for memory that can be accessed within a single draw call. + + 3) How should the renderer's API preference be advertised? + + UNRESOLVED. The common case for desktop renderers is to prefer + either core or compatibility. However, some renderers may actually + prefer an ES context. This leaves the application in a tough spot + if it can only support core or compatibility and the renderer says it + wants ES. + + 4) Should OpenGL ES 2.0 and OpenGL ES 3.0 be treated separately? + + RESOLVED. No. OpenGL ES 3.0 is backwards compatible with OpenGL ES + 2.0. Applications can detect OpenGL ES 3.0 support by querying + GLX_RENDERER_OPENGL_ES2_PROFILE_VERSION_MESA. + + 5) How can applications tell the difference between different hardware + renderers for the same device? For example, whether the renderer is the + open-source driver or the closed-source driver. + + RESOLVED. Assuming this extension is ever implemented outside Mesa, + applications can query GLX_RENDERER_VENDOR_ID_MESA from + glXQueryRendererStringMESA. This will almost certainly return + different strings for open-source and closed-source drivers. + + 6) What is the value of GLX_RENDERER_UNIFIED_MEMORY_ARCHITECTURE_MESA for + software renderers? + + UNRESOLVED. Video (display) memory and texture memory is not unified + for software implementations, so it seems reasonable for this to be + False. + + 7) How does an application determine the number of available renderers? + + UNRESOLVED. + + 8) What happens if a fbconfig is used to create context on a renderer + that cannot support it? For example, if a multisampled config is used + with a software renderer that does not support multisampling. + + RESOLVED. The language for glXCreateContextAttribsARB already covers + this case. Context creation will fail, and BadMatch is generated. + + 9) In addition to being able to query the supported versions, should + applications also be able to query the supported extensions? + + RESOLVED. No. Desktop OpenGL core profiles and OpenGL ES 3.0 have + moved away from the monolithic string returned by glGetString of + GL_EXTENSIONS. Providing the newer indexed query would require adding + a lot of extra infrastructure, and it would probably provide little + benefit to applications. + + 10) What combination of values for GLX_RENDERER_PREFERRED_PROFILE_MESA, + GLX_RENDERER_OPENGL_COMPATIBILITY_PROFILE_VERSION_MESA, and + GLX_RENDERER_OPENGL_CORE_PROFILE_VERSION_MESA should be returned + for a renderer that only supports OpenGL 3.1 without the + GL_ARB_compatibility extension? + + RESOLVED. The renderer will return GLX_CONTEXT_CORE_PROFILE_BIT_ARB + for GLX_RENDERER_PREFERRED_PROFILE_MESA. + + Further, the renderer will return <3,0> for + GLX_RENDERER_OPENGL_COMPATIBILITY_PROFILE_VERSION_MESA because OpenGL + 3.1 without GL_ARB_compatibility is not backwards compatible with + previous versions of OpenGL. The render will return <3,1> for + GLX_RENDERER_OPENGL_CORE_PROFILE_VERSION_MESA indicating that support + for OpenGL 3.1 is available. + + Even though there is no OpenGL 3.1 core profile, the values + returned for GLX_RENDERER_PREFERRED_PROFILE_MESA and + GLX_RENDERER_OPENGL_CORE_PROFILE_VERSION_MESA can be supplied + with the GLX_CONTEXT_PROFILE_MASK_ARB and + GLX_CONTEXT_{MAJOR,MINOR}_VERSION_ARB attributes of + glXCreateContextAttribsARB without error. If the requested + OpenGL version is less than 3.2, the + GLX_CONTEXT_PROFILE_MASK_ARB attribute is ignored by + glXCreateContextAttribsARB. + + 11) How can application learn about multi-GPU (e.g., SLI, CrossFireX, + etc.) configurations? + + UNRESOLVED. Based on ISV feedback, this is important information to + provide to the application. Given the variety of possible hardware + configurations (e.g., Hybrid CrossFireX) and different rendering + modes (e.g., split-frame rendering vs. alternate-frame rendering), + it's not clear how this information can be communicated. + + It is likely that this will be left to a layered extension. + + 12) Should capability queries similar to those in + GL_ARB_internalformat_query or GL_ARB_internalformat_query2 be added? + + RESOLVED. No. With the possible exception of the texture size + queries, it seems unlikely that applications would ever use this + information before creating a context. + + 13) Existing GL extensions (e.g., GL_ATI_meminfo and + GL_NVX_gpu_memory_info) allow easy queries after context creation. With + this extension it is a bit of a pain for a portable application to query + the information after context creation. + + RESOLVED. Add versions of the queries that implicitly take the + display, screen, and renderer from the currently bound context. + + 14) Why not make the queries from issue #13 GL functions (instead of GLX)? + + RESOLVED. It is fairly compelling for the post-creation queries to + just use glGetInteger and glGetString. However, the GL enums and + the GLX enums would have different names and would almost certainly + have different values. It seems like this would cause more problems + than it would solve. + + 15) Should the string queries be required to return the same values as + glGetString(GL_VENDOR) and glGetString(GL_RENDERER)? + + UNRESOLVED. This may be useful for applications that already do + device detection based on these strings. + + 16) What type should the value parameter of glXQueryRendererIntegerMESA + and glXQueryCurrentRendererIntegerMESA be? + + UNRESOLVED. Other similar GLX query functions just use int or + unsigned int, so that's what this extension uses for now. However, + an expeclitly sized value, such as uint32_t or uint64_t, seems + preferable. + + 17) What about SoCs and other systems that don't have PCI? + + RESOLVED. The GLX_RENDERER_VENDOR_ID_MESA and + GLX_RENDERER_DEVICE_ID_MESA integer queries may return 0xFFFFFFFF if a + PCI ID either does not exist or is not available. Implementations + should make every attempt to return as much information as is + possible. For example, if the implementation is running on a non-PCI + SoC with a Qualcomm GPU, GLX_RENDERER_VENDOR_ID_MESA should return + 0x168C, but GLX_RENDERER_DEVICE_ID_MESA will return 0x0000. + +Revision History + + Version 1, 2012/08/27 - Initial version + + Version 2, 2012/09/04 - Specify behavior of implementations that + do not support certain profiles. + Change wording of issue #8 to be more + clear. + Make some wording changes to issue #10 to + clarify the resolution a bit. + + Version 3, 2012/09/23 - Add issue #11 regarding multi-GPU systems. + + Version 4, 2013/02/01 - Add issue #12 regarding texture / renderbuffer + format queries. + + Version 5, 2013/02/14 - Add issues #13 and #14 regarding simpler queires + after the context is created and made current. + Add issue #15 regarding the string query. + Add issue #16 regarding the value type returned + by the Integer functions. + + Version 6, 2013/10/25 - Fix a typo. Update the list of functions to + which the new enums can be passed. The "Current" + versions were previously missing. + + Version 7, 2013/11/07 - Fix a couple more typos. Add issue #17 regarding + the PCI queries on systems that don't have PCI. -- 2.7.4