From b7745aaa8b8f84cca70e80ac714c524cdc110877 Mon Sep 17 00:00:00 2001
From: Magnus Norddahl <dpjudas@users.noreply.github.com>
Date: Sat, 23 Nov 2019 02:26:52 +0100
Subject: [PATCH] Make absolutely sure allocated frame memory is always 16-byte
 aligned

---
 src/rendering/swrenderer/r_memory.cpp | 40 +++++++++++++++++++++++++++
 src/rendering/swrenderer/r_memory.h   |  4 +--
 2 files changed, 42 insertions(+), 2 deletions(-)

diff --git a/src/rendering/swrenderer/r_memory.cpp b/src/rendering/swrenderer/r_memory.cpp
index 6e0556edb..dcc56f3bc 100644
--- a/src/rendering/swrenderer/r_memory.cpp
+++ b/src/rendering/swrenderer/r_memory.cpp
@@ -37,6 +37,7 @@
 #include "po_man.h"
 #include "r_data/colormaps.h"
 #include "r_memory.h"
+#include <stdlib.h>
 
 void *RenderMemory::AllocBytes(int size)
 {
@@ -73,3 +74,42 @@ void RenderMemory::Clear()
 		FreeBlocks.push_back(std::move(block));
 	}
 }
+
+static void* aligned_alloc(size_t alignment, size_t size)
+{
+	void* ptr;
+#if defined _MSC_VER
+	ptr = _aligned_malloc(size, alignment);
+	if (!ptr)
+		throw std::bad_alloc();
+#else
+	// posix_memalign required alignment to be a min of sizeof(void *)
+	if (alignment < sizeof(void*))
+		alignment = sizeof(void*);
+
+	if (posix_memalign((void**)&ptr, alignment, size))
+		throw std::bad_alloc();
+#endif
+	return ptr;
+}
+
+static void aligned_free(void* ptr)
+{
+	if (ptr)
+	{
+#if defined _MSC_VER
+		_aligned_free(ptr);
+#else
+		free(ptr);
+#endif
+	}
+}
+
+RenderMemory::MemoryBlock::MemoryBlock() : Data(static_cast<uint8_t*>(aligned_alloc(16, BlockSize))), Position(0)
+{
+}
+
+RenderMemory::MemoryBlock::~MemoryBlock()
+{
+	aligned_free(Data);
+}
diff --git a/src/rendering/swrenderer/r_memory.h b/src/rendering/swrenderer/r_memory.h
index 67ade026e..8007b6cc1 100644
--- a/src/rendering/swrenderer/r_memory.h
+++ b/src/rendering/swrenderer/r_memory.h
@@ -29,8 +29,8 @@ private:
 		
 	struct MemoryBlock
 	{
-		MemoryBlock() : Data(new uint8_t[BlockSize]), Position(0) { }
-		~MemoryBlock() { delete[] Data; }
+		MemoryBlock();
+		~MemoryBlock();
 			
 		MemoryBlock(const MemoryBlock &) = delete;
 		MemoryBlock &operator=(const MemoryBlock &) = delete;