vo: move DR helper code to a separate source file

So it can be reused by vo_libmpv.c, which needs to use it in a slightly
different way.

1 files changed, 20 insertions, 0 deletions

diff --git a/video/out/dr_helper.h b/video/out/dr_helper.h
new file mode 100644
index 0000000000..cf37c570e2
--- /dev/null
+++ b/video/out/dr_helper.h
@@ -0,0 +1,20 @@
+#pragma once
+
+// This is a helper for implementing thread-safety for DR callbacks. These need
+// to allocate GPU buffers on the GPU thread (e.g. OpenGL with its forced TLS),
+// and the buffers also need to be freed on the GPU thread.
+struct dr_helper;
+
+struct mp_image;
+struct mp_dispatch_queue;
+
+// This MUST be called on the "target" thread (it will call pthread_self()).
+// dr_helper_get_image() calls will use the dispatch queue to run get_image on
+// the target thread too.
+struct dr_helper *dr_helper_create(struct mp_dispatch_queue *dispatch,
+            struct mp_image *(*get_image)(void *ctx, int imgfmt, int w, int h,
+                                          int stride_align),
+            void *get_image_ctx);
+
+struct mp_image *dr_helper_get_image(struct dr_helper *dr, int imgfmt,
+                                     int w, int h, int stride_align);