From ba28bdafd3b74676bc8bbc53952658e6bcfbadb4 Mon Sep 17 00:00:00 2001
From: Squareys <squareys@googlemail.com>
Date: Fri, 22 Jul 2016 13:55:33 +0200
Subject: [PATCH] Vk: Improve PhysicalDevice::getMemoryType(...) and doc++

Signed-off-by: Squareys <squareys@googlemail.com>
---
 src/Magnum/Vk/PhysicalDevice.cpp | 17 ++++++++++-------
 src/Magnum/Vk/PhysicalDevice.h   | 23 ++++++++++++++++++++++-
 2 files changed, 32 insertions(+), 8 deletions(-)

diff --git a/src/Magnum/Vk/PhysicalDevice.cpp b/src/Magnum/Vk/PhysicalDevice.cpp
index 8fce6acfd..ee139373c 100644
--- a/src/Magnum/Vk/PhysicalDevice.cpp
+++ b/src/Magnum/Vk/PhysicalDevice.cpp
@@ -82,18 +82,21 @@ UnsignedInt PhysicalDevice::getQueueFamilyIndex(QueueFamily family) {
     CORRADE_ASSERT(false, "The device does not support the given queue family.", -1);  // TODO
 }
 
-UnsignedInt PhysicalDevice::getMemoryType(UnsignedInt typeBits, VkFlags properties) {
+UnsignedInt PhysicalDevice::getMemoryType(UnsignedInt supportedTypeBits, MemoryProperties properties) {
     if(_deviceMemoryProperties.memoryHeapCount == 0 && _deviceMemoryProperties.memoryTypeCount == 0) {
+        /* first query for physical device memory properties */
         vkGetPhysicalDeviceMemoryProperties(_physicalDevice, &_deviceMemoryProperties);
     }
 
-    for (uint32_t i = 0; i < 32; i++) {
-        if((typeBits & 1) != 0) {
-            if((_deviceMemoryProperties.memoryTypes[i].propertyFlags & properties) == properties) {
-                return i;
-            }
+    const UnsignedInt p = UnsignedInt(properties);
+    for (UnsignedInt i = 0; i < 32; ++i) {
+        /* check whether the memory type at index i is supported */
+        const UnsignedInt memoryTypeSupported = (supportedTypeBits >> i) & 1;
+        if(memoryTypeSupported != 0 &&
+                (_deviceMemoryProperties.memoryTypes[i].propertyFlags & p) == p) {
+            /* memory type and properties match */
+            return i;
         }
-        typeBits >>= 1;
     }
 
     CORRADE_ASSERT(false, "Physical devices does not support memory with given properties.", -1);  // TODO
diff --git a/src/Magnum/Vk/PhysicalDevice.h b/src/Magnum/Vk/PhysicalDevice.h
index a9cb8911b..a1907a8eb 100644
--- a/src/Magnum/Vk/PhysicalDevice.h
+++ b/src/Magnum/Vk/PhysicalDevice.h
@@ -33,11 +33,24 @@
 #include "Magnum/Magnum.h"
 #include "Magnum/Vk/visibility.h"
 
+#include <Corrade/Containers/EnumSet.h>
+
 #include "vulkan.h"
 
 
 namespace Magnum { namespace Vk {
 
+enum class MemoryProperty: UnsignedInt {
+    DeviceLocal = VK_MEMORY_PROPERTY_DEVICE_LOCAL_BIT,
+    HostVisible = VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT,
+    Coherent = VK_MEMORY_PROPERTY_HOST_COHERENT_BIT,
+    HostCached = VK_MEMORY_PROPERTY_HOST_CACHED_BIT,
+    LazilyAllocated = VK_MEMORY_PROPERTY_LAZILY_ALLOCATED_BIT,
+};
+
+typedef Corrade::Containers::EnumSet<MemoryProperty> MemoryProperties;
+CORRADE_ENUMSET_OPERATORS(MemoryProperties)
+
 enum class QueueFamily: UnsignedInt {
     Graphics = VK_QUEUE_GRAPHICS_BIT,
     Compute = VK_QUEUE_COMPUTE_BIT,
@@ -106,7 +119,15 @@ class MAGNUM_VK_EXPORT PhysicalDevice {
             return deviceProperties;
         }
 
-        UnsignedInt getMemoryType(UnsignedInt typeBits, VkFlags properties);
+        /**
+         * @brief Get the index of the memory type with properties
+         * @param supportedTypeBits A bit set with a bit for every memory type index. A
+         *                  bit at index i should be set if the memory type at index i
+         *                  is supported by the resource for which to get the memory type.
+         * @param properties Properties required by the memory type
+         * @return Index of the memory type for this device
+         */
+        UnsignedInt getMemoryType(UnsignedInt supportedTypeBits, MemoryProperties properties);
 
     private:
         VkPhysicalDevice _physicalDevice;