Vk: ability to allocate Buffer directly during construction.

Again mirrors what's done in Image.

src/Magnum/Vk/Buffer.cpp

@@ -27,6 +27,7 @@
 
 #include "Magnum/Vk/Assert.h"
 #include "Magnum/Vk/Device.h"
+#include "Magnum/Vk/DeviceProperties.h"
 #include "Magnum/Vk/Handle.h"
 #include "Magnum/Vk/Implementation/DeviceState.h"
 
@@ -61,6 +62,14 @@ Buffer::Buffer(Device& device, const BufferCreateInfo& info, NoAllocateT): _devi
     MAGNUM_VK_INTERNAL_ASSERT_SUCCESS(device->CreateBuffer(device, info, nullptr, &_handle));
 }
 
+Buffer::Buffer(Device& device, const BufferCreateInfo& info, const MemoryFlags memoryFlags): Buffer{device, info, NoAllocate} {
+    const MemoryRequirements requirements = memoryRequirements();
+    bindDedicatedMemory(Memory{device, MemoryAllocateInfo{
+        requirements.size(),
+        device.properties().pickMemory(memoryFlags, requirements.memories())
+    }});
+}
+
 Buffer::Buffer(NoCreateT): _device{}, _handle{}, _dedicatedMemory{NoCreate} {}
 
 Buffer::Buffer(Buffer&& other) noexcept: _device{other._device}, _handle{other._handle}, _flags{other._flags}, _dedicatedMemory{std::move(other._dedicatedMemory)} {

src/Magnum/Vk/Buffer.h

@@ -182,10 +182,26 @@ class MAGNUM_VK_EXPORT Buffer {
          * @param device    Vulkan device to create the buffer on
          * @param info      Buffer creation info
          *
-         * @see @fn_vk_keyword{CreateBuffer}
+         * @see @ref Buffer(Device&, const BufferCreateInfo&, MemoryFlags),
+         *      @fn_vk_keyword{CreateBuffer}
          */
         explicit Buffer(Device& device, const BufferCreateInfo& info, NoAllocateT);
 
+        /**
+         * @brief Construct a buffer
+         * @param device        Vulkan device to create the buffer on
+         * @param info          Buffer creation info
+         * @param memoryFlags   Memory allocation flags
+         *
+         * Compared to @ref Buffer(Device&, const BufferCreateInfo&, NoAllocateT)
+         * allocates a memory satisfying @p memoryFlags as well.
+         *
+         * @attention At this point, a dedicated allocation is used,
+         *      subsequently accessible through @ref dedicatedMemory(). This
+         *      behavior may change in the future.
+         */
+        explicit Buffer(Device& device, const BufferCreateInfo& info, MemoryFlags memoryFlags);
+
         /**
          * @brief Construct without creating the buffer
          *

src/Magnum/Vk/Test/BufferVkTest.cpp

@@ -46,6 +46,8 @@ struct BufferVkTest: VulkanTester {
 
     void bindMemory();
     void bindDedicatedMemory();
+
+    void directAllocation();
 };
 
 BufferVkTest::BufferVkTest() {
@@ -57,7 +59,9 @@ BufferVkTest::BufferVkTest() {
               &BufferVkTest::memoryRequirements,
 
               &BufferVkTest::bindMemory,
-              &BufferVkTest::bindDedicatedMemory});
+              &BufferVkTest::bindDedicatedMemory,
+
+              &BufferVkTest::directAllocation});
 }
 
 void BufferVkTest::construct() {
@@ -72,13 +76,9 @@ void BufferVkTest::construct() {
 }
 
 void BufferVkTest::constructMove() {
-    Buffer a{device(), BufferCreateInfo{BufferUsage::StorageBuffer, 1024}, NoAllocate};
-    VkBuffer handle = a.handle();
-
     /* Verify that also the dedicated memory gets moved */
-    MemoryRequirements requirements = a.memoryRequirements();
+    Buffer a{device(), BufferCreateInfo{BufferUsage::StorageBuffer, 1024}, Vk::MemoryFlag::DeviceLocal};
-    a.bindDedicatedMemory(Vk::Memory{device(), Vk::MemoryAllocateInfo{requirements.size(),
+    VkBuffer handle = a.handle();
-        device().properties().pickMemory(Vk::MemoryFlag::DeviceLocal, requirements.memories())}});
     VkDeviceMemory memoryHandle = a.dedicatedMemory().handle();
 
     Buffer b = std::move(a);
@@ -159,6 +159,16 @@ void BufferVkTest::bindDedicatedMemory() {
     CORRADE_COMPARE(buffer.dedicatedMemory().handle(), handle);
 }
 
+void BufferVkTest::directAllocation() {
+    Buffer buffer{device(),
+        BufferCreateInfo{BufferUsage::StorageBuffer, 16384},
+        Vk::MemoryFlag::DeviceLocal};
+
+    /* Not sure what else to test here */
+    CORRADE_VERIFY(buffer.hasDedicatedMemory());
+    CORRADE_VERIFY(buffer.dedicatedMemory().handle());
+}
+
 }}}}
 
 CORRADE_TEST_MAIN(Magnum::Vk::Test::BufferVkTest)