From dd4d741aedc190f4a565499118109b2aab17e5d2 Mon Sep 17 00:00:00 2001
From: dweiller <4678790+dweiller@users.noreplay.github.com>
Date: Mon, 13 Jun 2022 00:54:59 +1000
Subject: [PATCH] ecs: use std.mem.alignForward to calculate padding

---
 ecs/src/entities.zig | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/ecs/src/entities.zig b/ecs/src/entities.zig
index 757323f2..db9b55fe 100644
--- a/ecs/src/entities.zig
+++ b/ecs/src/entities.zig
@@ -154,8 +154,9 @@ pub const ArchetypeStorage = struct {
 
         var offset: usize = 0;
         for (storage.columns) |*column| {
-            const align_mod = @ptrToInt(&new_block[offset]) % column.alignment;
-            const padding = if (align_mod == 0) 0 else column.alignment - align_mod;
+            const addr = @ptrToInt(&new_block[offset]);
+            const aligned_addr = std.mem.alignForward(addr, column.alignment);
+            const padding = aligned_addr - addr;
             offset += padding;
             if (storage.capacity > 0) {
                 const slice = storage.block[column.offset .. column.offset + storage.capacity * column.size];