Ian Romanick | ee6c9fc | 2013-02-15 22:38:23 -0800 | [diff] [blame] | 1 | Name |
| 2 | |
| 3 | MESA_query_renderer |
| 4 | |
| 5 | Name Strings |
| 6 | |
| 7 | GLX_MESA_query_renderer |
| 8 | |
| 9 | Contact |
| 10 | |
| 11 | Ian Romanick <ian.d.romanick@intel.com> |
| 12 | |
| 13 | IP Status |
| 14 | |
| 15 | No known IP claims. |
| 16 | |
| 17 | Status |
| 18 | |
Ian Romanick | f0fdee5 | 2014-02-18 15:24:21 -0800 | [diff] [blame] | 19 | Shipping as of Mesa 10.0 |
Ian Romanick | ee6c9fc | 2013-02-15 22:38:23 -0800 | [diff] [blame] | 20 | |
| 21 | Version |
| 22 | |
Emil Velikov | 68bc1e2 | 2014-02-21 22:52:46 +0000 | [diff] [blame] | 23 | Version 8, 14-February-2014 |
Ian Romanick | ee6c9fc | 2013-02-15 22:38:23 -0800 | [diff] [blame] | 24 | |
| 25 | Number |
| 26 | |
| 27 | TBD. |
| 28 | |
| 29 | Dependencies |
| 30 | |
| 31 | GLX 1.4 is required. |
| 32 | |
| 33 | GLX_ARB_create_context and GLX_ARB_create_context_profile are required. |
| 34 | |
| 35 | This extension interacts with GLX_EXT_create_context_es2_profile and |
| 36 | GLX_EXT_create_context_es_profile. |
| 37 | |
| 38 | Overview |
| 39 | |
| 40 | In many situations, applications want to detect characteristics of a |
| 41 | rendering device before creating a context for that device. Information |
| 42 | gathered at this stage may guide choices the application makes about |
| 43 | color depth, number of samples per-pixel, texture quality, and so on. |
| 44 | In addition, versions of supported APIs and implementation API |
| 45 | preference may also guide start-up decisions made by the application. |
| 46 | For example, one implementation may prefer vertex data be supplied using |
| 47 | methods only available in a compatibility profile, but another |
| 48 | implementation may only support the desired version in a core profile. |
| 49 | |
| 50 | There are also cases where more than one renderer may be available per |
| 51 | display. For example, there is typically a hardware implementation and |
| 52 | a software based implementation. There are cases where an application |
| 53 | may want to pick one over the other. One such situation is when the |
| 54 | software implementation supports more features than the hardware |
| 55 | implementation. Another situation is when a particular version of the |
| 56 | hardware implementation is blacklisted due to known bugs. |
| 57 | |
| 58 | This extension provides a mechanism for the application to query all of |
| 59 | the available renderers for a particular display and screen. In |
| 60 | addition, this extension provides a mechanism for applications to create |
| 61 | contexts with respect to a specific renderer. |
| 62 | |
| 63 | New Procedures and Functions |
| 64 | |
| 65 | Bool glXQueryRendererIntegerMESA(Display *dpy, int screen, |
| 66 | int renderer, int attribute, |
| 67 | unsigned int *value); |
| 68 | Bool glXQueryCurrentRendererIntegerMESA(int attribute, unsigned int *value); |
| 69 | |
| 70 | const char *glXQueryRendererStringMESA(Display *dpy, int screen, |
| 71 | int renderer, int attribute); |
| 72 | |
| 73 | const char *glXQueryCurrentRendererStringMESA(int attribute); |
| 74 | |
| 75 | New Tokens |
| 76 | |
| 77 | Accepted as an <attribute> in glXQueryRendererIntegerMESA and |
| 78 | glXQueryCurrentRendererIntegerMESA: |
| 79 | |
| 80 | GLX_RENDERER_VENDOR_ID_MESA 0x8183 |
| 81 | GLX_RENDERER_DEVICE_ID_MESA 0x8184 |
| 82 | GLX_RENDERER_VERSION_MESA 0x8185 |
| 83 | GLX_RENDERER_ACCELERATED_MESA 0x8186 |
| 84 | GLX_RENDERER_VIDEO_MEMORY_MESA 0x8187 |
| 85 | GLX_RENDERER_UNIFIED_MEMORY_ARCHITECTURE_MESA 0x8188 |
| 86 | GLX_RENDERER_PREFERRED_PROFILE_MESA 0x8189 |
| 87 | GLX_RENDERER_OPENGL_CORE_PROFILE_VERSION_MESA 0x818A |
| 88 | GLX_RENDERER_OPENGL_COMPATIBILITY_PROFILE_VERSION_MESA 0x818B |
| 89 | GLX_RENDERER_OPENGL_ES_PROFILE_VERSION_MESA 0x818C |
| 90 | GLX_RENDERER_OPENGL_ES2_PROFILE_VERSION_MESA 0x818D |
| 91 | |
| 92 | Accepted as an <attribute> in glXQueryRendererStringMESA and |
| 93 | glXQueryCurrentRendererStringMESA: |
| 94 | |
| 95 | GLX_RENDERER_VENDOR_ID_MESA |
| 96 | GLX_RENDERER_DEVICE_ID_MESA |
| 97 | |
| 98 | Accepted as an attribute name in <*attrib_list> in |
| 99 | glXCreateContextAttribsARB: |
| 100 | |
| 101 | GLX_RENDERER_ID_MESA 0x818E |
| 102 | |
| 103 | Additions to the OpenGL / WGL Specifications |
| 104 | |
| 105 | None. This specification is written for GLX. |
| 106 | |
| 107 | Additions to the GLX 1.4 Specification |
| 108 | |
| 109 | [Add the following to Section X.Y.Z of the GLX Specification] |
| 110 | |
| 111 | To obtain information about the available renderers for a particular |
| 112 | display and screen, |
| 113 | |
| 114 | Bool glXQueryRendererIntegerMESA(Display *dpy, int screen, int renderer, |
| 115 | int attribute, unsigned int *value); |
| 116 | |
| 117 | can be used. The value for <attribute> will be returned in one or more |
| 118 | integers specified by <value>. The values, data sizes, and descriptions |
| 119 | of each renderer attribute are listed in the table below. |
| 120 | |
| 121 | GLX renderer attribute number description |
| 122 | of values |
| 123 | ---------------------- --------- ----------- |
| 124 | GLX_RENDERER_VENDOR_ID_MESA 1 PCI ID of the device vendor |
| 125 | GLX_RENDERER_DEVICE_ID_MESA 1 PCI ID of the device |
| 126 | GLX_RENDERER_VERSION_MESA 3 Major, minor, and patch level of |
| 127 | the renderer implementation |
| 128 | GLX_RENDERER_ACCELERATED_MESA 1 Boolean indicating whether or |
| 129 | not the renderer is hardware |
| 130 | accelerated |
| 131 | GLX_RENDERER_VIDEO_MEMORY_MESA 1 Number of megabytes of video |
| 132 | memory available to the renderer |
| 133 | GLX_RENDERER_UNIFIED_MEMORY_ARCHITECTURE_MESA |
| 134 | 1 Boolean indicating whether or |
| 135 | not the renderer uses a unified |
| 136 | memory architecture or has |
| 137 | separate "on-card" and GART |
| 138 | memory. |
| 139 | GLX_RENDERER_PREFERRED_PROFILE_MESA |
| 140 | 1 Bitmask of the preferred context |
| 141 | profile for this renderer. This |
| 142 | value is suitable to be supplied |
| 143 | with the |
| 144 | GLX_CONTEXT_PROFILE_MASK_ARB |
| 145 | attribute to |
| 146 | glXCreateContextAttribsARB |
| 147 | GLX_RENDERER_OPENGL_CORE_PROFILE_VERSION_MESA |
| 148 | 2 Maximum core profile major and |
| 149 | minor version supported by the |
| 150 | renderer |
| 151 | GLX_RENDERER_OPENGL_COMPATIBILITY_PROFILE_VERSION_MESA |
| 152 | 2 Maximum compatibility profile |
| 153 | major and minor version |
| 154 | supported by the renderer |
| 155 | GLX_RENDERER_OPENGL_ES_PROFILE_VERSION_MESA |
| 156 | 2 Maximum OpenGL ES 1.x |
| 157 | major and minor version |
| 158 | supported by the renderer |
| 159 | GLX_RENDERER_OPENGL_ES2_PROFILE_VERSION_MESA |
| 160 | 2 Maximum OpenGL ES 2.x or 3.x |
| 161 | major and minor version |
| 162 | supported by the renderer |
| 163 | |
| 164 | In the table, boolean attributes will have either the value 0 or 1. |
| 165 | |
| 166 | GLX_RENDERER_OPENGL_CORE_PROFILE_VERSION_MESA, |
| 167 | GLX_RENDERER_OPENGL_COMPATIBILITY_PROFILE_VERSION_MESA, |
| 168 | GLX_RENDERER_OPENGL_ES_PROFILE_VERSION_MESA, and |
| 169 | GLX_RENDERER_OPENGL_ES2_PROFILE_VERSION_MESA each return <0, 0> in |
| 170 | *value if no version of that profile is supported. |
| 171 | |
| 172 | GLX_RENDERER_VENDOR_ID_MESA and GLX_RENDERER_DEVICE_ID_MESA may return |
| 173 | 0xFFFFFFFF if the device does not have a PCI ID (because it is not a PCI |
| 174 | device) or if the PCI ID is not available. In this case the application |
| 175 | should rely on the string query instead. |
| 176 | |
| 177 | If <attribute> is not a recognized value, False is returned, but no GLX |
| 178 | error is generated. Otherwise, True is returned. |
| 179 | |
| 180 | String versions of some attributes may also be queried using |
| 181 | |
| 182 | const char *glXQueryRendererStringMESA(Display *dpy, int screen, |
| 183 | int renderer, int attribute); |
| 184 | |
| 185 | The value for <attribute> will be returned in one or more |
| 186 | integers specified by <value>. The values, data sizes, and descriptions |
| 187 | of each renderer attribute are listed in the table below. |
| 188 | |
| 189 | GLX renderer attribute description |
| 190 | ---------------------- ----------- |
| 191 | GLX_RENDERER_VENDOR_ID_MESA Name of the renderer provider. This may |
| 192 | differ from the vendor name of the |
| 193 | underlying hardware. |
| 194 | GLX_RENDERER_DEVICE_ID_MESA Name of the renderer. This may differ from |
| 195 | the name of the underlying hardware (e.g., |
| 196 | for a software renderer). |
| 197 | |
| 198 | If <attribute> is not a recognized value, NULL is returned, but no GLX |
| 199 | error is generated. |
| 200 | |
| 201 | The string returned for GLX_RENDERER_VENDOR_ID_MESA will have the same |
| 202 | format as the string that would be returned by glGetString of GL_VENDOR. |
| 203 | It may, however, have a different value. |
| 204 | |
| 205 | The string returned for GLX_RENDERER_DEVICE_ID_MESA will have the same |
| 206 | format as the string that would be returned by glGetString of GL_RENDERER. |
| 207 | It may, however, have a different value. |
| 208 | |
| 209 | |
| 210 | [Add to section section 3.3.7 "Rendering Contexts"] |
| 211 | |
| 212 | The attribute name GLX_RENDERER_ID_MESA specified the index of the render |
| 213 | against which the context should be created. The default value of |
Emil Velikov | 68bc1e2 | 2014-02-21 22:52:46 +0000 | [diff] [blame] | 214 | GLX_RENDERER_ID_MESA is 0. |
Ian Romanick | ee6c9fc | 2013-02-15 22:38:23 -0800 | [diff] [blame] | 215 | |
| 216 | |
| 217 | [Add to list of errors for glXCreateContextAttribsARB in section section |
| 218 | 3.3.7 "Rendering Contexts"] |
| 219 | |
| 220 | * If the value of GLX_RENDERER_ID_MESA specifies a non-existent |
| 221 | renderer, BadMatch is generated. |
| 222 | |
| 223 | Dependencies on GLX_EXT_create_context_es_profile and |
| 224 | GLX_EXT_create_context_es2_profile |
| 225 | |
| 226 | If neither extension is supported, remove all mention of |
| 227 | GLX_RENDERER_OPENGL_ES2_PROFILE_VERSION_MESA from the spec. |
| 228 | |
| 229 | If GLX_EXT_create_context_es_profile is not supported, remove all mention of |
| 230 | GLX_RENDERER_OPENGL_ES_PROFILE_VERSION_MESA from the spec. |
| 231 | |
| 232 | Issues |
| 233 | |
| 234 | 1) How should the difference between on-card and GART memory be exposed? |
| 235 | |
| 236 | UNRESOLVED. |
| 237 | |
| 238 | 2) How should memory limitations of unified memory architecture (UMA) |
| 239 | systems be exposed? |
| 240 | |
| 241 | UNRESOLVED. Some hardware has different per-process and global |
| 242 | limits for memory that can be accessed within a single draw call. |
| 243 | |
| 244 | 3) How should the renderer's API preference be advertised? |
| 245 | |
| 246 | UNRESOLVED. The common case for desktop renderers is to prefer |
| 247 | either core or compatibility. However, some renderers may actually |
| 248 | prefer an ES context. This leaves the application in a tough spot |
| 249 | if it can only support core or compatibility and the renderer says it |
| 250 | wants ES. |
| 251 | |
| 252 | 4) Should OpenGL ES 2.0 and OpenGL ES 3.0 be treated separately? |
| 253 | |
| 254 | RESOLVED. No. OpenGL ES 3.0 is backwards compatible with OpenGL ES |
| 255 | 2.0. Applications can detect OpenGL ES 3.0 support by querying |
| 256 | GLX_RENDERER_OPENGL_ES2_PROFILE_VERSION_MESA. |
| 257 | |
| 258 | 5) How can applications tell the difference between different hardware |
| 259 | renderers for the same device? For example, whether the renderer is the |
| 260 | open-source driver or the closed-source driver. |
| 261 | |
| 262 | RESOLVED. Assuming this extension is ever implemented outside Mesa, |
| 263 | applications can query GLX_RENDERER_VENDOR_ID_MESA from |
| 264 | glXQueryRendererStringMESA. This will almost certainly return |
| 265 | different strings for open-source and closed-source drivers. |
| 266 | |
| 267 | 6) What is the value of GLX_RENDERER_UNIFIED_MEMORY_ARCHITECTURE_MESA for |
| 268 | software renderers? |
| 269 | |
| 270 | UNRESOLVED. Video (display) memory and texture memory is not unified |
| 271 | for software implementations, so it seems reasonable for this to be |
| 272 | False. |
| 273 | |
| 274 | 7) How does an application determine the number of available renderers? |
| 275 | |
| 276 | UNRESOLVED. |
| 277 | |
| 278 | 8) What happens if a fbconfig is used to create context on a renderer |
| 279 | that cannot support it? For example, if a multisampled config is used |
| 280 | with a software renderer that does not support multisampling. |
| 281 | |
| 282 | RESOLVED. The language for glXCreateContextAttribsARB already covers |
| 283 | this case. Context creation will fail, and BadMatch is generated. |
| 284 | |
| 285 | 9) In addition to being able to query the supported versions, should |
| 286 | applications also be able to query the supported extensions? |
| 287 | |
| 288 | RESOLVED. No. Desktop OpenGL core profiles and OpenGL ES 3.0 have |
| 289 | moved away from the monolithic string returned by glGetString of |
| 290 | GL_EXTENSIONS. Providing the newer indexed query would require adding |
| 291 | a lot of extra infrastructure, and it would probably provide little |
| 292 | benefit to applications. |
| 293 | |
| 294 | 10) What combination of values for GLX_RENDERER_PREFERRED_PROFILE_MESA, |
| 295 | GLX_RENDERER_OPENGL_COMPATIBILITY_PROFILE_VERSION_MESA, and |
| 296 | GLX_RENDERER_OPENGL_CORE_PROFILE_VERSION_MESA should be returned |
| 297 | for a renderer that only supports OpenGL 3.1 without the |
| 298 | GL_ARB_compatibility extension? |
| 299 | |
| 300 | RESOLVED. The renderer will return GLX_CONTEXT_CORE_PROFILE_BIT_ARB |
| 301 | for GLX_RENDERER_PREFERRED_PROFILE_MESA. |
| 302 | |
| 303 | Further, the renderer will return <3,0> for |
| 304 | GLX_RENDERER_OPENGL_COMPATIBILITY_PROFILE_VERSION_MESA because OpenGL |
| 305 | 3.1 without GL_ARB_compatibility is not backwards compatible with |
| 306 | previous versions of OpenGL. The render will return <3,1> for |
| 307 | GLX_RENDERER_OPENGL_CORE_PROFILE_VERSION_MESA indicating that support |
| 308 | for OpenGL 3.1 is available. |
| 309 | |
| 310 | Even though there is no OpenGL 3.1 core profile, the values |
| 311 | returned for GLX_RENDERER_PREFERRED_PROFILE_MESA and |
| 312 | GLX_RENDERER_OPENGL_CORE_PROFILE_VERSION_MESA can be supplied |
| 313 | with the GLX_CONTEXT_PROFILE_MASK_ARB and |
| 314 | GLX_CONTEXT_{MAJOR,MINOR}_VERSION_ARB attributes of |
| 315 | glXCreateContextAttribsARB without error. If the requested |
| 316 | OpenGL version is less than 3.2, the |
| 317 | GLX_CONTEXT_PROFILE_MASK_ARB attribute is ignored by |
| 318 | glXCreateContextAttribsARB. |
| 319 | |
| 320 | 11) How can application learn about multi-GPU (e.g., SLI, CrossFireX, |
| 321 | etc.) configurations? |
| 322 | |
| 323 | UNRESOLVED. Based on ISV feedback, this is important information to |
| 324 | provide to the application. Given the variety of possible hardware |
| 325 | configurations (e.g., Hybrid CrossFireX) and different rendering |
| 326 | modes (e.g., split-frame rendering vs. alternate-frame rendering), |
| 327 | it's not clear how this information can be communicated. |
| 328 | |
| 329 | It is likely that this will be left to a layered extension. |
| 330 | |
| 331 | 12) Should capability queries similar to those in |
| 332 | GL_ARB_internalformat_query or GL_ARB_internalformat_query2 be added? |
| 333 | |
| 334 | RESOLVED. No. With the possible exception of the texture size |
| 335 | queries, it seems unlikely that applications would ever use this |
| 336 | information before creating a context. |
| 337 | |
| 338 | 13) Existing GL extensions (e.g., GL_ATI_meminfo and |
| 339 | GL_NVX_gpu_memory_info) allow easy queries after context creation. With |
| 340 | this extension it is a bit of a pain for a portable application to query |
| 341 | the information after context creation. |
| 342 | |
| 343 | RESOLVED. Add versions of the queries that implicitly take the |
| 344 | display, screen, and renderer from the currently bound context. |
| 345 | |
| 346 | 14) Why not make the queries from issue #13 GL functions (instead of GLX)? |
| 347 | |
| 348 | RESOLVED. It is fairly compelling for the post-creation queries to |
| 349 | just use glGetInteger and glGetString. However, the GL enums and |
| 350 | the GLX enums would have different names and would almost certainly |
| 351 | have different values. It seems like this would cause more problems |
| 352 | than it would solve. |
| 353 | |
| 354 | 15) Should the string queries be required to return the same values as |
| 355 | glGetString(GL_VENDOR) and glGetString(GL_RENDERER)? |
| 356 | |
| 357 | UNRESOLVED. This may be useful for applications that already do |
| 358 | device detection based on these strings. |
| 359 | |
| 360 | 16) What type should the value parameter of glXQueryRendererIntegerMESA |
| 361 | and glXQueryCurrentRendererIntegerMESA be? |
| 362 | |
| 363 | UNRESOLVED. Other similar GLX query functions just use int or |
| 364 | unsigned int, so that's what this extension uses for now. However, |
| 365 | an expeclitly sized value, such as uint32_t or uint64_t, seems |
| 366 | preferable. |
| 367 | |
| 368 | 17) What about SoCs and other systems that don't have PCI? |
| 369 | |
| 370 | RESOLVED. The GLX_RENDERER_VENDOR_ID_MESA and |
| 371 | GLX_RENDERER_DEVICE_ID_MESA integer queries may return 0xFFFFFFFF if a |
| 372 | PCI ID either does not exist or is not available. Implementations |
| 373 | should make every attempt to return as much information as is |
| 374 | possible. For example, if the implementation is running on a non-PCI |
| 375 | SoC with a Qualcomm GPU, GLX_RENDERER_VENDOR_ID_MESA should return |
Emil Velikov | 68bc1e2 | 2014-02-21 22:52:46 +0000 | [diff] [blame] | 376 | 0x5143, but GLX_RENDERER_DEVICE_ID_MESA will return 0xFFFFFFFF. |
Ian Romanick | ee6c9fc | 2013-02-15 22:38:23 -0800 | [diff] [blame] | 377 | |
| 378 | Revision History |
| 379 | |
| 380 | Version 1, 2012/08/27 - Initial version |
| 381 | |
| 382 | Version 2, 2012/09/04 - Specify behavior of implementations that |
| 383 | do not support certain profiles. |
| 384 | Change wording of issue #8 to be more |
| 385 | clear. |
| 386 | Make some wording changes to issue #10 to |
| 387 | clarify the resolution a bit. |
| 388 | |
| 389 | Version 3, 2012/09/23 - Add issue #11 regarding multi-GPU systems. |
| 390 | |
| 391 | Version 4, 2013/02/01 - Add issue #12 regarding texture / renderbuffer |
| 392 | format queries. |
| 393 | |
| 394 | Version 5, 2013/02/14 - Add issues #13 and #14 regarding simpler queires |
| 395 | after the context is created and made current. |
| 396 | Add issue #15 regarding the string query. |
| 397 | Add issue #16 regarding the value type returned |
| 398 | by the Integer functions. |
| 399 | |
| 400 | Version 6, 2013/10/25 - Fix a typo. Update the list of functions to |
| 401 | which the new enums can be passed. The "Current" |
| 402 | versions were previously missing. |
| 403 | |
| 404 | Version 7, 2013/11/07 - Fix a couple more typos. Add issue #17 regarding |
| 405 | the PCI queries on systems that don't have PCI. |
Emil Velikov | 68bc1e2 | 2014-02-21 22:52:46 +0000 | [diff] [blame] | 406 | |
| 407 | Version 8, 2014/02/14 - Fix a couple typos. GLX_RENDER_ID_MESA should |
| 408 | read GLX_RENDERER_ID_MESA. The VENDOR/DEVICE_ID |
| 409 | example given in issue #17 should be 0x5143 and |
| 410 | 0xFFFFFFFF respectively. |