LineArt: Correct clamping of out of bound isect index

Handles rare cases where line doesn't intersect the triangle correctly.

1 files changed, 6 insertions, 2 deletions

diff --git a/source/blender/gpencil_modifiers/intern/lineart/lineart_cpu.c b/source/blender/gpencil_modifiers/intern/lineart/lineart_cpu.c
index 9241d256db0..9e1476d928e 100644
--- a/source/blender/gpencil_modifiers/intern/lineart/lineart_cpu.c
+++ b/source/blender/gpencil_modifiers/intern/lineart/lineart_cpu.c
@@ -2585,8 +2585,12 @@ static bool lineart_triangle_edge_image_space_occlusion(SpinLock *UNUSED(spl),
         INTERSECT_JUST_GREATER(is, order, is[LCross], RCross);
       }
       else {
-        INTERSECT_JUST_GREATER(is, order, is[LCross], LCross);
-        INTERSECT_JUST_GREATER(is, order, is[LCross], RCross);
+        if (LCross >= 0) {
+          INTERSECT_JUST_GREATER(is, order, is[LCross], LCross);
+          if (LCross >= 0) {
+            INTERSECT_JUST_GREATER(is, order, is[LCross], RCross);
+          }
+        }
       }
     }
   }