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 api_bit;
 117
 118       api_bit = _eglGetContextAPIBit(ctx);
 119       if (!(ctx->Config->RenderableType & api_bit)) {
 120          _eglLog(_EGL_DEBUG, "context api is 0x%x while config supports 0x%x",
 121                api_bit, ctx->Config->RenderableType);
 122          err = EGL_BAD_CONFIG;
 123       }
 124    }
 125    if (err != EGL_SUCCESS)
 126       return _eglError(err, "eglCreateContext");
 127
 128    return EGL_TRUE;
 129 }
 130
 131
 132 #ifdef EGL_VERSION_1_2
 133 static EGLint
 134 _eglQueryContextRenderBuffer(_EGLContext *ctx)
 135 {
 136    _EGLSurface *surf = ctx->DrawSurface;
 137    EGLint rb;
 138
 139    if (!surf)
 140       return EGL_NONE;
 141    if (surf->Type == EGL_WINDOW_BIT && ctx->WindowRenderBuffer != EGL_NONE)
 142       rb = ctx->WindowRenderBuffer;
 143    else
 144       rb = surf->RenderBuffer;
 145    return rb;
 146 }
 147 #endif /* EGL_VERSION_1_2 */
 148
 149
 150 EGLBoolean
 151 _eglQueryContext(_EGLDriver *drv, _EGLDisplay *dpy, _EGLContext *c,
 152                  EGLint attribute, EGLint *value)
 153 {
 154    (void) drv;
 155    (void) dpy;
 156
 157    if (!value)
 158       return _eglError(EGL_BAD_PARAMETER, "eglQueryContext");
 159
 160    switch (attribute) {
 161    case EGL_CONFIG_ID:
 162       if (!c->Config)
 163          return _eglError(EGL_BAD_ATTRIBUTE, "eglQueryContext");
 164       *value = c->Config->ConfigID;
 165       break;
 166    case EGL_CONTEXT_CLIENT_VERSION:
 167       *value = c->ClientVersion;
 168       break;
 169 #ifdef EGL_VERSION_1_2
 170    case EGL_CONTEXT_CLIENT_TYPE:
 171       *value = c->ClientAPI;
 172       break;
 173    case EGL_RENDER_BUFFER:
 174       *value = _eglQueryContextRenderBuffer(c);
 175       break;
 176 #endif /* EGL_VERSION_1_2 */
 177    default:
 178       return _eglError(EGL_BAD_ATTRIBUTE, "eglQueryContext");
 179    }
 180
 181    return EGL_TRUE;
 182 }
 183
 184
 185 /**
 186  * Bind the context to the thread and return the previous context.
 187  *
 188  * Note that the context may be NULL.
 189  */
 190 static _EGLContext *
 191 _eglBindContextToThread(_EGLContext *ctx, _EGLThreadInfo *t)
 192 {
 193    EGLint apiIndex;
 194    _EGLContext *oldCtx;
 195
 196    apiIndex = (ctx) ?
 197       _eglConvertApiToIndex(ctx->ClientAPI) : t->CurrentAPIIndex;
 198
 199    oldCtx = t->CurrentContexts[apiIndex];
 200    if (ctx != oldCtx) {
 201       if (oldCtx)
 202          oldCtx->Binding = NULL;
 203       if (ctx)
 204          ctx->Binding = t;
 205
 206       t->CurrentContexts[apiIndex] = ctx;
 207    }
 208
 209    return oldCtx;
 210 }
 211
 212
 213 /**
 214  * Return true if the given context and surfaces can be made current.
 215  */
 216 static EGLBoolean
 217 _eglCheckMakeCurrent(_EGLContext *ctx, _EGLSurface *draw, _EGLSurface *read)
 218 {
 219    _EGLThreadInfo *t = _eglGetCurrentThread();
 220    _EGLDisplay *dpy;
 221    EGLint conflict_api;
 222    EGLBoolean surfaceless;
 223
 224    if (_eglIsCurrentThreadDummy())
 225       return _eglError(EGL_BAD_ALLOC, "eglMakeCurrent");
 226
 227    /* this is easy */
 228    if (!ctx) {
 229       if (draw || read)
 230          return _eglError(EGL_BAD_MATCH, "eglMakeCurrent");
 231       return EGL_TRUE;
 232    }
 233
 234    dpy = ctx->Resource.Display;
 235    switch (_eglGetContextAPIBit(ctx)) {
 236    case EGL_OPENGL_ES_BIT:
 237       surfaceless = dpy->Extensions.KHR_surfaceless_gles1;
 238       break;
 239    case EGL_OPENGL_ES2_BIT:
 240       surfaceless = dpy->Extensions.KHR_surfaceless_gles2;
 241       break;
 242    case EGL_OPENGL_BIT:
 243       surfaceless = dpy->Extensions.KHR_surfaceless_opengl;
 244       break;
 245    default:
 246       surfaceless = EGL_FALSE;
 247       break;
 248    }
 249
 250    if (!surfaceless && (draw == NULL || read == NULL))
 251       return _eglError(EGL_BAD_MATCH, "eglMakeCurrent");
 252
 253    /* context stealing from another thread is not allowed */
 254    if (ctx->Binding && ctx->Binding != t)
 255       return _eglError(EGL_BAD_ACCESS, "eglMakeCurrent");
 256
 257    /*
 258     * The spec says
 259     *
 260     * "If ctx is current to some other thread, or if either draw or read are
 261     * bound to contexts in another thread, an EGL_BAD_ACCESS error is
 262     * generated."
 263     *
 264     * But it also says
 265     *
 266     * "at most one context may be bound to a particular surface at a given
 267     * time"
 268     *
 269     * The latter is more restrictive so we can check only the latter case.
 270     */
 271    if ((draw && draw->CurrentContext && draw->CurrentContext != ctx) ||
 272        (read && read->CurrentContext && read->CurrentContext != ctx))
 273       return _eglError(EGL_BAD_ACCESS, "eglMakeCurrent");
 274
 275    /* simply require the configs to be equal */
 276    if ((draw && draw->Config != ctx->Config) ||
 277        (read && read->Config != ctx->Config))
 278       return _eglError(EGL_BAD_MATCH, "eglMakeCurrent");
 279
 280    switch (ctx->ClientAPI) {
 281 #ifdef EGL_VERSION_1_4
 282    /* OpenGL and OpenGL ES are conflicting */
 283    case EGL_OPENGL_ES_API:
 284       conflict_api = EGL_OPENGL_API;
 285       break;
 286    case EGL_OPENGL_API:
 287       conflict_api = EGL_OPENGL_ES_API;
 288       break;
 289 #endif
 290    default:
 291       conflict_api = -1;
 292       break;
 293    }
 294
 295    if (conflict_api >= 0 && _eglGetAPIContext(conflict_api))
 296       return _eglError(EGL_BAD_ACCESS, "eglMakeCurrent");
 297
 298    return EGL_TRUE;
 299 }
 300
 301
 302 /**
 303  * Bind the context to the current thread and given surfaces.  Return the
 304  * "orphaned" context and surfaces.  Each argument is both input and output.
 305  */
 306 EGLBoolean
 307 _eglBindContext(_EGLContext **ctx, _EGLSurface **draw, _EGLSurface **read)
 308 {
 309    _EGLThreadInfo *t = _eglGetCurrentThread();
 310    _EGLContext *newCtx = *ctx, *oldCtx;
 311    _EGLSurface *newDraw = *draw, *newRead = *read;
 312
 313    if (!_eglCheckMakeCurrent(newCtx, newDraw, newRead))
 314       return EGL_FALSE;
 315
 316    /* bind the new context */
 317    oldCtx = _eglBindContextToThread(newCtx, t);
 318
 319    /* break old bindings */
 320    if (oldCtx) {
 321       *ctx = oldCtx;
 322       *draw = oldCtx->DrawSurface;
 323       *read = oldCtx->ReadSurface;
 324
 325       if (*draw)
 326          (*draw)->CurrentContext = NULL;
 327       if (*read)
 328          (*read)->CurrentContext = NULL;
 329
 330       oldCtx->DrawSurface = NULL;
 331       oldCtx->ReadSurface = NULL;
 332    }
 333
 334    /* establish new bindings */
 335    if (newCtx) {
 336       if (newDraw)
 337          newDraw->CurrentContext = newCtx;
 338       if (newRead)
 339          newRead->CurrentContext = newCtx;
 340
 341       newCtx->DrawSurface = newDraw;
 342       newCtx->ReadSurface = newRead;
 343    }
 344
 345    /* an old context or surface is not orphaned if it is still bound */
 346    if (*ctx == newCtx)
 347       *ctx = NULL;
 348    if (*draw == newDraw || *draw == newRead)
 349       *draw = NULL;
 350    if (*read == newDraw || *read == newRead)
 351       *read = NULL;
 352
 353    return EGL_TRUE;
 354 }