1 files changed, 17 insertions, 7 deletions

diff --git a/source/blender/blenkernel/intern/image_gpu.cc b/source/blender/blenkernel/intern/image_gpu.cc
index 6506b40b603..6893a50638a 100644
--- a/source/blender/blenkernel/intern/image_gpu.cc
+++ b/source/blender/blenkernel/intern/image_gpu.cc
@@ -138,6 +138,8 @@ static GPUTexture *gpu_texture_create_tile_array(Image *ima, ImBuf *main_ibuf)
   int arraywidth = 0, arrayheight = 0;
   ListBase boxes = {nullptr};
 
+  int planes = 0;
+
   LISTBASE_FOREACH (ImageTile *, tile, &ima->tiles) {
     ImageUser iuser;
     BKE_imageuser_default(&iuser);
@@ -164,6 +166,7 @@ static GPUTexture *gpu_texture_create_tile_array(Image *ima, ImBuf *main_ibuf)
 
       BKE_image_release_ibuf(ima, ibuf, nullptr);
       BLI_addtail(&boxes, packtile);
+      planes = max_ii(planes, ibuf->planes);
     }
   }
 
@@ -195,9 +198,15 @@ static GPUTexture *gpu_texture_create_tile_array(Image *ima, ImBuf *main_ibuf)
   }
 
   const bool use_high_bitdepth = (ima->flag & IMA_HIGH_BITDEPTH);
+  const bool use_grayscale = planes <= 8;
   /* Create Texture without content. */
-  GPUTexture *tex = IMB_touch_gpu_texture(
-      ima->id.name + 2, main_ibuf, arraywidth, arrayheight, arraylayers, use_high_bitdepth);
+  GPUTexture *tex = IMB_touch_gpu_texture(ima->id.name + 2,
+                                          main_ibuf,
+                                          arraywidth,
+                                          arrayheight,
+                                          arraylayers,
+                                          use_high_bitdepth,
+                                          use_grayscale);
 
   /* Upload each tile one by one. */
   LISTBASE_FOREACH (ImageTile *, tile, &ima->tiles) {
@@ -223,6 +232,7 @@ static GPUTexture *gpu_texture_create_tile_array(Image *ima, ImBuf *main_ibuf)
                                  tilelayer,
                                  UNPACK2(tilesize),
                                  use_high_bitdepth,
+                                 use_grayscale,
                                  store_premultiplied);
     }
 
@@ -541,7 +551,7 @@ void BKE_image_free_anim_gputextures(Main *bmain)
 void BKE_image_free_old_gputextures(Main *bmain)
 {
   static int lasttime = 0;
-  int ctime = (int)PIL_check_seconds_timer();
+  int ctime = int(PIL_check_seconds_timer());
 
   /*
    * Run garbage collector once for every collecting period of time
@@ -592,8 +602,8 @@ static ImBuf *update_do_scale(uchar *rect,
                               int full_h)
 {
   /* Partial update with scaling. */
-  float xratio = limit_w / (float)full_w;
-  float yratio = limit_h / (float)full_h;
+  float xratio = limit_w / float(full_w);
+  float yratio = limit_h / float(full_h);
 
   int part_w = *w, part_h = *h;
 
@@ -601,8 +611,8 @@ static ImBuf *update_do_scale(uchar *rect,
    * losing 1 pixel due to rounding errors in x,y. */
   *x *= xratio;
   *y *= yratio;
-  *w = (int)ceil(xratio * (*w));
-  *h = (int)ceil(yratio * (*h));
+  *w = int(ceil(xratio * (*w)));
+  *h = int(ceil(yratio * (*h)));
 
   /* ...but take back if we are over the limit! */
   if (*x + *w > limit_w) {