From 9667c34e7e2a4f79bfca8ec360a1bd51ccbfd244 Mon Sep 17 00:00:00 2001
From: Alexey Zatelepin <alex.zatelepin@gmail.com>
Date: Thu, 2 Jul 2020 21:17:27 +0300
Subject: [PATCH] Fix read mapping size (size is number of bytes, not number of
 items)

---
 piet-gpu-hal/src/vulkan.rs | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/piet-gpu-hal/src/vulkan.rs b/piet-gpu-hal/src/vulkan.rs
index 2fac015..909823c 100644
--- a/piet-gpu-hal/src/vulkan.rs
+++ b/piet-gpu-hal/src/vulkan.rs
@@ -744,18 +744,18 @@ impl crate::Device for VkDevice {
         result: &mut Vec<T>,
     ) -> Result<(), Error> {
         let device = &self.device.device;
-        let size = buffer.size as usize / std::mem::size_of::<T>();
         let buf = device.map_memory(
             buffer.buffer_memory,
             0,
-            size as u64,
+            buffer.size,
             vk::MemoryMapFlags::empty(),
         )?;
-        if size > result.len() {
-            result.reserve(size - result.len());
+        let len = buffer.size as usize / std::mem::size_of::<T>();
+        if len > result.len() {
+            result.reserve(len - result.len());
         }
-        std::ptr::copy_nonoverlapping(buf as *const T, result.as_mut_ptr(), size);
-        result.set_len(size);
+        std::ptr::copy_nonoverlapping(buf as *const T, result.as_mut_ptr(), len);
+        result.set_len(len);
         device.unmap_memory(buffer.buffer_memory);
         Ok(())
     }