Cleanup: Remove volatile from RenderResult and related APIs

Volatile fields were introduced to the RenderResult struct years ago[1].

However, volatile is most likely not doing what it was intended to do
in this instance, and is problematic when moving files to c++ (see
discussion from D13962). There are complex rules around what happens to
these fields but none of them guarantee what the above commit alluded to.

This patch drops the volatile and cleans up the APIs surrounding it.

[1] rB7930c40051ef1b1a26140629cf1299aa89eed859

Passing on all platforms:
https://builder.blender.org/admin/#/builders/18/builds/338

Differential Revision: https://developer.blender.org/D14298

1 files changed, 1 insertions, 25 deletions

diff --git a/source/blender/blenkernel/intern/image.cc b/source/blender/blenkernel/intern/image.cc
index 4a1cbdba42a..88888831e1c 100644
--- a/source/blender/blenkernel/intern/image.cc
+++ b/source/blender/blenkernel/intern/image.cc
@@ -5105,31 +5105,7 @@ static ImBuf *image_get_render_result(Image *ima, ImageUser *iuser, void **r_loc
     RE_AcquireResultImage(re, &rres, actview);
   }
   else if ((slot = BKE_image_get_renderslot(ima, ima->render_slot))->render) {
-    /* Unfortunately each field needs to be set individually because RenderResult
-     * contains volatile fields and using memcpy would invoke undefined behavior with c++. */
-    rres.next = slot->render->next;
-    rres.prev = slot->render->prev;
-    rres.rectx = slot->render->rectx;
-    rres.recty = slot->render->recty;
-    rres.sample_nr = slot->render->sample_nr;
-    rres.rect32 = slot->render->rect32;
-    rres.rectf = slot->render->rectf;
-    rres.rectz = slot->render->rectz;
-    rres.tilerect = slot->render->tilerect;
-    rres.xof = slot->render->xof;
-    rres.yof = slot->render->yof;
-    rres.layers = slot->render->layers;
-    rres.views = slot->render->views;
-    rres.renrect.xmin = slot->render->renrect.xmin;
-    rres.renrect.xmax = slot->render->renrect.xmax;
-    rres.renrect.ymin = slot->render->renrect.ymin;
-    rres.renrect.ymax = slot->render->renrect.ymax;
-    rres.renlay = slot->render->renlay;
-    rres.framenr = slot->render->framenr;
-    rres.text = slot->render->text;
-    rres.error = slot->render->error;
-    rres.stamp_data = slot->render->stamp_data;
-    rres.passes_allocated = slot->render->passes_allocated;
+    rres = *(slot->render);
     rres.have_combined = ((RenderView *)rres.views.first)->rectf != nullptr;
   }