/**
* Bind the context to the current thread and given surfaces. Return the
* previously bound context and the surfaces it bound to. Each argument is
* both input and output.
*/
EGLBoolean
_eglBindContext(_EGLContext **ctx, _EGLSurface **draw, _EGLSurface **read)
{
_EGLThreadInfo *t = _eglGetCurrentThread();
_EGLContext *newCtx = *ctx, *oldCtx;
if (!_eglCheckMakeCurrent(newCtx, *draw, *read))
return EGL_FALSE;
/* bind the new context */
oldCtx = _eglBindContextToThread(newCtx, t);
*ctx = oldCtx;
if (newCtx)
_eglBindContextToSurfaces(newCtx, draw, read);
/* unbind the old context from its binding surfaces */
if (oldCtx) {
/*
* If the new context replaces some old context, the new one should not
* be current before the replacement and it should not be bound to any
* surface.
*/
if (newCtx)
assert(!*draw && !*read);
*draw = oldCtx->DrawSurface;
*read = oldCtx->ReadSurface;
assert(*draw && *read);
_eglBindContextToSurfaces(NULL, draw, read);
}
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;
}
