src/egl/main/eglcontext.c

   1 #include <assert.h>
   2 #include <stdlib.h>
   3 #include <string.h>
   4 #include "eglconfig.h"
   5 #include "eglcontext.h"
   6 #include "egldisplay.h"
   7 #include "eglcurrent.h"
   8 #include "eglsurface.h"
   9 #include "egllog.h"
  10
  11
  12 /**
  13  * Return the API bit (one of EGL_xxx_BIT) of the context.
  14  */
  15 static EGLint
  16 _eglGetContextAPIBit(_EGLContext *ctx)
  17 {
  18    EGLint bit = 0;
  19
  20    switch (ctx->ClientAPI) {
  21    case EGL_OPENGL_ES_API:
  22       switch (ctx->ClientVersion) {
  23       case 1:
  24          bit = EGL_OPENGL_ES_BIT;
  25          break;
  26       case 2:
  27          bit = EGL_OPENGL_ES2_BIT;
  28          break;
  29       default:
  30          break;
  31       }
  32       break;
  33    case EGL_OPENVG_API:
  34       bit = EGL_OPENVG_BIT;
  35       break;
  36    case EGL_OPENGL_API:
  37       bit = EGL_OPENGL_BIT;
  38       break;
  39    default:
  40       break;
  41    }
  42
  43    return bit;
  44 }
  45
  46
  47 /**
  48  * Parse the list of context attributes and return the proper error code.
  49  */
  50 static EGLint
  51 _eglParseContextAttribList(_EGLContext *ctx, const EGLint *attrib_list)
  52 {
  53    EGLenum api = ctx->ClientAPI;
  54    EGLint i, err = EGL_SUCCESS;
  55
  56    if (!attrib_list)
  57       return EGL_SUCCESS;
  58
  59    for (i = 0; attrib_list[i] != EGL_NONE; i++) {
  60       EGLint attr = attrib_list[i++];
  61       EGLint val = attrib_list[i];
  62
  63       switch (attr) {
  64       case EGL_CONTEXT_CLIENT_VERSION:
  65          if (api != EGL_OPENGL_ES_API) {
  66             err = EGL_BAD_ATTRIBUTE;
  67             break;
  68          }
  69          if (val != 1 && val != 2) {
  70             err = EGL_BAD_ATTRIBUTE;
  71             break;
  72          }
  73          ctx->ClientVersion = val;
  74          break;
  75       default:
  76          err = EGL_BAD_ATTRIBUTE;
  77          break;
  78       }
  79
  80       if (err != EGL_SUCCESS) {
  81          _eglLog(_EGL_DEBUG, "bad context attribute 0x%04x", attr);
  82          break;
  83       }
  84    }
  85
  86    return err;
  87 }
  88
  89
  90 /**
  91  * Initialize the given _EGLContext object to defaults and/or the values
  92  * in the attrib_list.
  93  */
  94 EGLBoolean
  95 _eglInitContext(_EGLContext *ctx, _EGLDisplay *dpy, _EGLConfig *conf,
  96                 const EGLint *attrib_list)
  97 {
  98    const EGLenum api = eglQueryAPI();
  99    EGLint err;
 100
 101    if (api == EGL_NONE) {
 102       _eglError(EGL_BAD_MATCH, "eglCreateContext(no client API)");
 103       return EGL_FALSE;
 104    }
 105
 106    memset(ctx, 0, sizeof(_EGLContext));
 107    ctx->Resource.Display = dpy;
 108    ctx->ClientAPI = api;
 109    ctx->Config = conf;
 110    ctx->WindowRenderBuffer = EGL_NONE;
 111
 112    ctx->ClientVersion = 1; /* the default, per EGL spec */
 113
 114    err = _eglParseContextAttribList(ctx, attrib_list);
 115    if (err == EGL_SUCCESS && ctx->Config) {
 116       EGLint renderable_type, api_bit;
 117
 118       renderable_type = GET_CONFIG_ATTRIB(ctx->Config, EGL_RENDERABLE_TYPE);
 119       api_bit = _eglGetContextAPIBit(ctx);
 120       if (!(renderable_type & api_bit)) {
 121          _eglLog(_EGL_DEBUG, "context api is 0x%x while config supports 0x%x",
 122                api_bit, renderable_type);
 123          err = EGL_BAD_CONFIG;
 124       }
 125    }
 126    if (err != EGL_SUCCESS)
 127       return _eglError(err, "eglCreateContext");
 128
 129    return EGL_TRUE;
 130 }
 131
 132
 133 /**
 134  * Just a placeholder/demo function.  Real driver will never use this!
 135  */
 136 _EGLContext *
 137 _eglCreateContext(_EGLDriver *drv, _EGLDisplay *dpy, _EGLConfig *conf,
 138                   _EGLContext *share_list, const EGLint *attrib_list)
 139 {
 140    return NULL;
 141 }
 142
 143
 144 /**
 145  * Default fallback routine - drivers should usually override this.
 146  */
 147 EGLBoolean
 148 _eglDestroyContext(_EGLDriver *drv, _EGLDisplay *dpy, _EGLContext *ctx)
 149 {
 150    if (!_eglIsContextBound(ctx))
 151       free(ctx);
 152    return EGL_TRUE;
 153 }
 154
 155
 156 #ifdef EGL_VERSION_1_2
 157 static EGLint
 158 _eglQueryContextRenderBuffer(_EGLContext *ctx)
 159 {
 160    _EGLSurface *surf = ctx->DrawSurface;
 161    EGLint rb;
 162
 163    if (!surf)
 164       return EGL_NONE;
 165    if (surf->Type == EGL_WINDOW_BIT && ctx->WindowRenderBuffer != EGL_NONE)
 166       rb = ctx->WindowRenderBuffer;
 167    else
 168       rb = surf->RenderBuffer;
 169    return rb;
 170 }
 171 #endif /* EGL_VERSION_1_2 */
 172
 173
 174 EGLBoolean
 175 _eglQueryContext(_EGLDriver *drv, _EGLDisplay *dpy, _EGLContext *c,
 176                  EGLint attribute, EGLint *value)
 177 {
 178    (void) drv;
 179    (void) dpy;
 180
 181    if (!value)
 182       return _eglError(EGL_BAD_PARAMETER, "eglQueryContext");
 183
 184    switch (attribute) {
 185    case EGL_CONFIG_ID:
 186       *value = GET_CONFIG_ATTRIB(c->Config, EGL_CONFIG_ID);
 187       break;
 188    case EGL_CONTEXT_CLIENT_VERSION:
 189       *value = c->ClientVersion;
 190       break;
 191 #ifdef EGL_VERSION_1_2
 192    case EGL_CONTEXT_CLIENT_TYPE:
 193       *value = c->ClientAPI;
 194       break;
 195    case EGL_RENDER_BUFFER:
 196       *value = _eglQueryContextRenderBuffer(c);
 197       break;
 198 #endif /* EGL_VERSION_1_2 */
 199    default:
 200       return _eglError(EGL_BAD_ATTRIBUTE, "eglQueryContext");
 201    }
 202
 203    return EGL_TRUE;
 204 }
 205
 206
 207 /**
 208  * Bind the context to the thread and return the previous context.
 209  *
 210  * Note that the context may be NULL.
 211  */
 212 static _EGLContext *
 213 _eglBindContextToThread(_EGLContext *ctx, _EGLThreadInfo *t)
 214 {
 215    EGLint apiIndex;
 216    _EGLContext *oldCtx;
 217
 218    apiIndex = (ctx) ?
 219       _eglConvertApiToIndex(ctx->ClientAPI) : t->CurrentAPIIndex;
 220
 221    oldCtx = t->CurrentContexts[apiIndex];
 222    if (ctx != oldCtx) {
 223       if (oldCtx)
 224          oldCtx->Binding = NULL;
 225       if (ctx)
 226          ctx->Binding = t;
 227
 228       t->CurrentContexts[apiIndex] = ctx;
 229    }
 230
 231    return oldCtx;
 232 }
 233
 234
 235 /**
 236  * Return true if the given context and surfaces can be made current.
 237  */
 238 static EGLBoolean
 239 _eglCheckMakeCurrent(_EGLContext *ctx, _EGLSurface *draw, _EGLSurface *read)
 240 {
 241    _EGLThreadInfo *t = _eglGetCurrentThread();
 242    _EGLDisplay *dpy;
 243    EGLint conflict_api;
 244    EGLBoolean surfaceless;
 245
 246    if (_eglIsCurrentThreadDummy())
 247       return _eglError(EGL_BAD_ALLOC, "eglMakeCurrent");
 248
 249    /* this is easy */
 250    if (!ctx) {
 251       if (draw || read)
 252          return _eglError(EGL_BAD_MATCH, "eglMakeCurrent");
 253       return EGL_TRUE;
 254    }
 255
 256    dpy = ctx->Resource.Display;
 257    switch (_eglGetContextAPIBit(ctx)) {
 258    case EGL_OPENGL_ES_BIT:
 259       surfaceless = dpy->Extensions.KHR_surfaceless_gles1;
 260       break;
 261    case EGL_OPENGL_ES2_BIT:
 262       surfaceless = dpy->Extensions.KHR_surfaceless_gles2;
 263       break;
 264    case EGL_OPENGL_BIT:
 265       surfaceless = dpy->Extensions.KHR_surfaceless_opengl;
 266       break;
 267    default:
 268       surfaceless = EGL_FALSE;
 269       break;
 270    }
 271
 272    if (!surfaceless && (draw == NULL || read == NULL))
 273       return _eglError(EGL_BAD_MATCH, "eglMakeCurrent");
 274
 275    /* context stealing from another thread is not allowed */
 276    if (ctx->Binding && ctx->Binding != t)
 277       return _eglError(EGL_BAD_ACCESS, "eglMakeCurrent");
 278
 279    /*
 280     * The spec says
 281     *
 282     * "If ctx is current to some other thread, or if either draw or read are
 283     * bound to contexts in another thread, an EGL_BAD_ACCESS error is
 284     * generated."
 285     *
 286     * But it also says
 287     *
 288     * "at most one context may be bound to a particular surface at a given
 289     * time"
 290     *
 291     * The latter is more restrictive so we can check only the latter case.
 292     */
 293    if ((draw && draw->CurrentContext && draw->CurrentContext != ctx) ||
 294        (read && read->CurrentContext && read->CurrentContext != ctx))
 295       return _eglError(EGL_BAD_ACCESS, "eglMakeCurrent");
 296
 297    /* simply require the configs to be equal */
 298    if ((draw && draw->Config != ctx->Config) ||
 299        (read && read->Config != ctx->Config))
 300       return _eglError(EGL_BAD_MATCH, "eglMakeCurrent");
 301
 302    switch (ctx->ClientAPI) {
 303 #ifdef EGL_VERSION_1_4
 304    /* OpenGL and OpenGL ES are conflicting */
 305    case EGL_OPENGL_ES_API:
 306       conflict_api = EGL_OPENGL_API;
 307       break;
 308    case EGL_OPENGL_API:
 309       conflict_api = EGL_OPENGL_ES_API;
 310       break;
 311 #endif
 312    default:
 313       conflict_api = -1;
 314       break;
 315    }
 316
 317    if (conflict_api >= 0 && _eglGetAPIContext(conflict_api))
 318       return _eglError(EGL_BAD_ACCESS, "eglMakeCurrent");
 319
 320    return EGL_TRUE;
 321 }
 322
 323
 324 /**
 325  * Bind the context to the current thread and given surfaces.  Return the
 326  * "orphaned" context and surfaces.  Each argument is both input and output.
 327  */
 328 EGLBoolean
 329 _eglBindContext(_EGLContext **ctx, _EGLSurface **draw, _EGLSurface **read)
 330 {
 331    _EGLThreadInfo *t = _eglGetCurrentThread();
 332    _EGLContext *newCtx = *ctx, *oldCtx;
 333    _EGLSurface *newDraw = *draw, *newRead = *read;
 334
 335    if (!_eglCheckMakeCurrent(newCtx, newDraw, newRead))
 336       return EGL_FALSE;
 337
 338    /* bind the new context */
 339    oldCtx = _eglBindContextToThread(newCtx, t);
 340
 341    /* break old bindings */
 342    if (oldCtx) {
 343       *ctx = oldCtx;
 344       *draw = oldCtx->DrawSurface;
 345       *read = oldCtx->ReadSurface;
 346
 347       if (*draw)
 348          (*draw)->CurrentContext = NULL;
 349       if (*read)
 350          (*read)->CurrentContext = NULL;
 351
 352       oldCtx->DrawSurface = NULL;
 353       oldCtx->ReadSurface = NULL;
 354    }
 355
 356    /* establish new bindings */
 357    if (newCtx) {
 358       if (newDraw)
 359          newDraw->CurrentContext = newCtx;
 360       if (newRead)
 361          newRead->CurrentContext = newCtx;
 362
 363       newCtx->DrawSurface = newDraw;
 364       newCtx->ReadSurface = newRead;
 365    }
 366
 367    /* an old context or surface is not orphaned if it is still bound */
 368    if (*ctx == newCtx)
 369       *ctx = NULL;
 370    if (*draw == newDraw || *draw == newRead)
 371       *draw = NULL;
 372    if (*read == newDraw || *read == newRead)
 373       *read = NULL;
 374
 375    return EGL_TRUE;
 376 }
 377
 378
 379 /**
 380  * Just a placeholder/demo function.  Drivers should override this.
 381  */
 382 EGLBoolean
 383 _eglMakeCurrent(_EGLDriver *drv, _EGLDisplay *dpy, _EGLSurface *draw,
 384                 _EGLSurface *read, _EGLContext *ctx)
 385 {
 386    return EGL_FALSE;
 387 }
 388
 389
 390 /**
 391  * This is defined by the EGL_MESA_copy_context extension.
 392  */
 393 EGLBoolean
 394 _eglCopyContextMESA(_EGLDriver *drv, EGLDisplay dpy, EGLContext source,
 395                     EGLContext dest, EGLint mask)
 396 {
 397    /* This function will always have to be overridden/implemented in the
 398     * device driver.  If the driver is based on Mesa, use _mesa_copy_context().
 399     */
 400    return EGL_FALSE;
 401 }