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, 6 insertions, 0 deletions

diff --git a/intern/cycles/session/tile.h b/intern/cycles/session/tile.h
index eace148eb0a..7c8f7570d3e 100644
--- a/intern/cycles/session/tile.h
+++ b/intern/cycles/session/tile.h
@@ -122,6 +122,12 @@ class TileManager {
   /* Tile size in the image file. */
   static const int IMAGE_TILE_SIZE = 128;
 
+  /* Maximum supported tile size.
+   * Needs to be safe from allocation on a GPU point of view: the display driver needs to be able
+   * to allocate texture with the side size of this value.
+   * Use conservative value which is safe for most of OpenGL drivers and GPUs. */
+  static const int MAX_TILE_SIZE = 8192;
+
  protected:
   /* Get tile configuration for its index.
    * The tile index must be within [0, state_.tile_state_). */