eglglessink: eagl: initialize context and buffers on main thread

iOS expects the EAGL context and buffers to be initialized from the main
thread. Use the dispatcher to make sure it uses the main thread.

1 files changed, 56 insertions, 37 deletions

diff --git a/ext/eglgles/gstegladaptation_eagl.m b/ext/eglgles/gstegladaptation_eagl.m
index 867071436..f78644780 100644
--- a/ext/eglgles/gstegladaptation_eagl.m
+++ b/ext/eglgles/gstegladaptation_eagl.m
@@ -104,21 +104,33 @@ gst_egl_adaptation_destroy_native_window (GstEglAdaptationContext * ctx, gpointe
 gboolean
 gst_egl_adaptation_create_egl_context (GstEglAdaptationContext * ctx)
 {
-  EAGLContext *context;
-  context = [[EAGLContext alloc] initWithAPI:kEAGLRenderingAPIOpenGLES2];
-  if (context == nil) {
-    GST_ERROR_OBJECT (ctx->element, "Failed to create EAGL GLES2 context");
-    return FALSE;
-  }
+  __block EAGLContext *context;
+
+  dispatch_sync(dispatch_get_main_queue(), ^{
+    EAGLContext *cur_ctx = [EAGLContext currentContext];
+    if (cur_ctx) {
+      context = cur_ctx;
+    } else {
+      context = [[EAGLContext alloc] initWithAPI:kEAGLRenderingAPIOpenGLES2];
+      if (context == nil) {
+        GST_ERROR_OBJECT (ctx->element, "Failed to create EAGL GLES2 context");
+      }
+    }
+  });
+
   ctx->eaglctx->eagl_context = context;
+  if (context == nil)
+      return FALSE;
 
-  return TRUE;
+  /* EAGL needs the context to be set here to allow surface creation */
+  return gst_egl_adaptation_make_current (ctx, TRUE);
 }
 
 gboolean
 gst_egl_adaptation_make_current (GstEglAdaptationContext * ctx,
     gboolean bind)
 {
+  __block EAGLContext *ctx_to_set = nil;
   if (bind && ctx->eaglctx->eagl_context) {
     EAGLContext *cur_ctx = [EAGLContext currentContext];
 
@@ -135,6 +147,11 @@ gst_egl_adaptation_make_current (GstEglAdaptationContext * ctx,
       GST_ERROR_OBJECT (ctx->element, "Couldn't bind context");
       return FALSE;
     }
+    ctx_to_set = ctx->eaglctx->eagl_context;
+    dispatch_sync(dispatch_get_main_queue(), ^{
+      [EAGLContext setCurrentContext: ctx_to_set];
+    });
+
   } else {
     GST_DEBUG_OBJECT (ctx->element, "Detaching context from thread %p",
         g_thread_self ());
@@ -151,36 +168,39 @@ gst_egl_adaptation_make_current (GstEglAdaptationContext * ctx,
 gboolean
 gst_egl_adaptation_create_surface (GstEglAdaptationContext * ctx)
 {
-  GLuint framebuffer;
-  GLuint colorRenderbuffer;
-  GLint width;
-  GLint height;
-  GLuint depthRenderbuffer;
-  GLenum status;
-  CAEAGLLayer *eaglLayer = (CAEAGLLayer *)[ctx->eaglctx->window layer];
-
-  /* Allocate framebuffer */
-  glGenFramebuffers(1, &framebuffer);
-  glBindFramebuffer(GL_FRAMEBUFFER, framebuffer);
+  __block GLuint framebuffer;
+  __block GLuint colorRenderbuffer;
+  __block GLint width;
+  __block GLint height;
+  __block GLuint depthRenderbuffer;
+  __block GLenum status;
+  __block CAEAGLLayer *eaglLayer = (CAEAGLLayer *)[ctx->eaglctx->window layer];
+
+  dispatch_sync(dispatch_get_main_queue(), ^{
+    /* Allocate framebuffer */
+    glGenFramebuffers(1, &framebuffer);
+    glBindFramebuffer(GL_FRAMEBUFFER, framebuffer);
  
-  /* Allocate color render buffer */
-  glGenRenderbuffers(1, &colorRenderbuffer);
-  glBindRenderbuffer(GL_RENDERBUFFER, colorRenderbuffer);
-  [ctx->eaglctx->eagl_context renderbufferStorage:GL_RENDERBUFFER fromDrawable:eaglLayer];
-  glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0,
-      GL_RENDERBUFFER, colorRenderbuffer);
-
-  /* Get renderbuffer width/height */
-  glGetRenderbufferParameteriv(GL_RENDERBUFFER, GL_RENDERBUFFER_WIDTH, &width);
-  glGetRenderbufferParameteriv(GL_RENDERBUFFER, GL_RENDERBUFFER_HEIGHT, &height);
-
-  /* allocate depth render buffer */
-  glGenRenderbuffers(1, &depthRenderbuffer);
-  glBindRenderbuffer(GL_RENDERBUFFER, depthRenderbuffer);
-  glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH_COMPONENT16, width, height);
-  glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT,
-  GL_RENDERBUFFER, depthRenderbuffer);
+    /* Allocate color render buffer */
+    glGenRenderbuffers(1, &colorRenderbuffer);
+    glBindRenderbuffer(GL_RENDERBUFFER, colorRenderbuffer);
+    [ctx->eaglctx->eagl_context renderbufferStorage:GL_RENDERBUFFER fromDrawable:eaglLayer];
+    glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0,
+        GL_RENDERBUFFER, colorRenderbuffer);
+
+    /* Get renderbuffer width/height */
+    glGetRenderbufferParameteriv(GL_RENDERBUFFER, GL_RENDERBUFFER_WIDTH, &width);
+    glGetRenderbufferParameteriv(GL_RENDERBUFFER, GL_RENDERBUFFER_HEIGHT, &height);
+
+    /* allocate depth render buffer */
+    glGenRenderbuffers(1, &depthRenderbuffer);
+    glBindRenderbuffer(GL_RENDERBUFFER, depthRenderbuffer);
+    glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH_COMPONENT16, width, height);
+    glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT,
+                              GL_RENDERBUFFER, depthRenderbuffer);
+  });
 
+  glBindFramebuffer(GL_FRAMEBUFFER, framebuffer);
   /* check creation status */
   status = glCheckFramebufferStatus(GL_FRAMEBUFFER);
   if(status != GL_FRAMEBUFFER_COMPLETE) {
@@ -190,6 +210,7 @@ gst_egl_adaptation_create_surface (GstEglAdaptationContext * ctx)
 
   ctx->eaglctx->framebuffer = framebuffer;
   ctx->eaglctx->color_renderbuffer = colorRenderbuffer;
+  glBindRenderbuffer(GL_RENDERBUFFER, ctx->eaglctx->color_renderbuffer);
 
   return TRUE;
 }
@@ -291,9 +312,7 @@ gst_egl_adaptation_destroy_context (GstEglAdaptationContext * ctx)
 gboolean
 gst_egl_adaptation_swap_buffers (GstEglAdaptationContext * ctx)
 {
-  glBindRenderbuffer(GL_RENDERBUFFER, ctx->eaglctx->color_renderbuffer);
   [ctx->eaglctx->eagl_context presentRenderbuffer:GL_RENDERBUFFER];
-
   return TRUE;
 }