Fix T93350: Cycles renders shows black during rendering huge resolutions

The root of the issue is caused by Cycles ignoring OpenGL limitation on
the maximum resolution of textures: Cycles was allocating texture of the
final render resolution. It was exceeding limitation on certain GPUs and
driver.

The idea is simple: use multiple textures for the display, each of which
will fit into OpenGL limitations.

There is some code which allows the display driver to know when to start
the new tile. Also added some code to allow force graphics interop to be
re-created. The latter one ended up not used in the final version of the
patch, but it might be helpful for other drivers implementation.

The tile size is limited to 8K now as it is the safest size for textures
on many GPUs and OpenGL drivers.

Differential Revision: https://developer.blender.org/D13385

1 files changed, 4 insertions, 2 deletions

diff --git a/intern/cycles/session/tile.cpp b/intern/cycles/session/tile.cpp
index 3b8482fa16f..afd1f334120 100644
--- a/intern/cycles/session/tile.cpp
+++ b/intern/cycles/session/tile.cpp
@@ -341,8 +341,10 @@ int TileManager::compute_render_tile_size(const int suggested_tile_size) const
   /* Must be a multiple of IMAGE_TILE_SIZE so that we can write render tiles into the image file
    * aligned on image tile boundaries. We can't set IMAGE_TILE_SIZE equal to the render tile size
    * because too big tile size leads to integer overflow inside OpenEXR. */
-  return (suggested_tile_size <= IMAGE_TILE_SIZE) ? suggested_tile_size :
-                                                    align_up(suggested_tile_size, IMAGE_TILE_SIZE);
+  const int computed_tile_size = (suggested_tile_size <= IMAGE_TILE_SIZE) ?
+                                     suggested_tile_size :
+                                     align_up(suggested_tile_size, IMAGE_TILE_SIZE);
+  return min(computed_tile_size, MAX_TILE_SIZE);
 }
 
 void TileManager::reset_scheduling(const BufferParams &params, int2 tile_size)