From a9ac482647678fc77d17fd57b4255b2d376e25cd Mon Sep 17 00:00:00 2001
From: Andrew de los Reyes <adlr@rivosinc.com>
Date: Sun, 20 Apr 2025 09:44:39 -0700
Subject: [PATCH] Free up cells memory on resize

---
 src/renderer/OpenGL.zig | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/src/renderer/OpenGL.zig b/src/renderer/OpenGL.zig
index 255097655..364cb9fba 100644
--- a/src/renderer/OpenGL.zig
+++ b/src/renderer/OpenGL.zig
@@ -1784,6 +1784,15 @@ pub fn rebuildCells(
         }
     }
 
+    // Free up memory, generally in case where surface has shrunk.
+    // If more than half of the capacity is unused, remove all unused capacity.
+    if (self.cells.items.len * 2 < self.cells.capacity) {
+        self.cells.shrinkAndFree(self.alloc, self.cells.items.len);
+    }
+    if (self.cells_bg.items.len * 2 < self.cells_bg.capacity) {
+        self.cells_bg.shrinkAndFree(self.alloc, self.cells_bg.items.len);
+    }
+
     // Some debug mode safety checks
     if (std.debug.runtime_safety) {
         for (self.cells_bg.items) |cell| assert(cell.mode == .bg);