From 8f633d17ec05d888e919eeea2b76c3284ce607c6 Mon Sep 17 00:00:00 2001
From: Gary Talent <gary@drinkingtea.net>
Date: Tue, 28 May 2024 20:44:26 -0500
Subject: [PATCH] [ox/preloader] Fix alignment issue

---
 .../deps/ox/src/ox/preloader/preloader.hpp      | 17 +++++++++++++----
 1 file changed, 13 insertions(+), 4 deletions(-)

diff --git a/deps/nostalgia/deps/ox/src/ox/preloader/preloader.hpp b/deps/nostalgia/deps/ox/src/ox/preloader/preloader.hpp
index 8f675ba..fd428bb 100644
--- a/deps/nostalgia/deps/ox/src/ox/preloader/preloader.hpp
+++ b/deps/nostalgia/deps/ox/src/ox/preloader/preloader.hpp
@@ -94,7 +94,7 @@ class Preloader: public ModelHandlerBase<Preloader<PlatSpec>, OpType::Reflect> {
 		}
 
 		template<typename U, bool force>
-		constexpr ox::Error field(CRStringView, const ox::UnionView<U, force> val) noexcept;
+		constexpr ox::Error field(CRStringView, ox::UnionView<U, force> val) noexcept;
 
 		template<typename T>
 		constexpr ox::Error field(CRStringView, const T *val) noexcept;
@@ -135,6 +135,9 @@ class Preloader: public ModelHandlerBase<Preloader<PlatSpec>, OpType::Reflect> {
 		constexpr ox::Error fieldArray(CRStringView name, ox::ModelValueArray const*val) noexcept;
 
 		constexpr bool unionCheckAndIt() noexcept;
+
+		[[nodiscard]]
+		constexpr size_t calcPadding(size_t align) const noexcept;
 };
 
 template<typename PlatSpec>
@@ -265,7 +268,7 @@ template<typename PlatSpec>
 constexpr ox::Result<std::size_t> Preloader<PlatSpec>::startAlloc(size_t sz, size_t align) noexcept {
 	m_allocStack.emplace_back(static_cast<typename PlatSpec::PtrType>(m_writer.tellp()));
 	oxReturnError(m_writer.seekp(0, ox::ios_base::end));
-	const auto padding = m_writer.tellp() % align;
+	auto const padding = calcPadding(align);
 	oxRequireM(a, ox::allocate(m_writer, sz + padding));
 	a += padding;
 	oxReturnError(m_writer.seekp(a));
@@ -278,7 +281,7 @@ constexpr ox::Result<std::size_t> Preloader<PlatSpec>::startAlloc(
 		std::size_t sz, size_t align, std::size_t restore) noexcept {
 	m_allocStack.emplace_back(restore, ox::ios_base::beg);
 	oxReturnError(m_writer.seekp(0, ox::ios_base::end));
-	const auto padding = m_writer.tellp() % align;
+	auto const padding = calcPadding(align);
 	oxRequireM(a, ox::allocate(m_writer, sz + padding));
 	a += padding;
 	oxReturnError(m_writer.seekp(a));
@@ -358,7 +361,7 @@ constexpr ox::Error Preloader<PlatSpec>::fieldVector(
 		const auto sz = sizeOf<PlatSpec>(&(*val)[0]) * val->size();
 		const auto align = alignOf<PlatSpec>((*val)[0]);
 		oxReturnError(m_writer.seekp(0, ox::ios_base::end));
-		const auto padding = m_writer.tellp() % align;
+		auto const padding = calcPadding(align);
 		oxRequireM(p, ox::allocate(m_writer, sz + padding));
 		p += padding;
 		oxReturnError(m_writer.seekp(p));
@@ -394,6 +397,12 @@ constexpr bool Preloader<PlatSpec>::unionCheckAndIt() noexcept {
 	return u.checkAndIterate();
 }
 
+template<typename PlatSpec>
+constexpr size_t Preloader<PlatSpec>::calcPadding(size_t align) const noexcept {
+	auto const excess = m_writer.tellp() % align;
+	return (align * (excess != 0)) - excess;
+}
+
 template<typename PlatSpec, typename T>
 constexpr ox::Error preload(Preloader<PlatSpec> *pl, ox::CommonPtrWith<T> auto *obj) noexcept {
 	oxReturnError(model(pl->interface(), obj));