Added VmaDefragmentationInfo::customBreakCallback - a callback pointer of new type PFN_vmaCheckDefragmentationBreak

include/vk_mem_alloc.h

diff --git a/include/vk_mem_alloc.h b/include/vk_mem_alloc.h
index fbe4f13..a61a77d 100644
--- a/include/vk_mem_alloc.h
+++ b/include/vk_mem_alloc.h
@@ -1395,6 +1395,12 @@
     const char* VMA_NULLABLE pName;
 } VmaAllocationInfo;
 
+/** Callback function called during defragmentation to check custom criterion about ending current defragmentation pass.
+
+Should return 'true' if the defragmentation needs to stop current pass.
+*/
+typedef VkBool32 (VKAPI_PTR* PFN_vmaCheckDefragmentationBreak)();
+
 /** \brief Parameters for defragmentation.
 
 To be used with function vmaBeginDefragmentation().
@@ -1418,6 +1424,11 @@
     `0` means no limit.
     */
     uint32_t maxAllocationsPerPass;
+    /** \brief Optional custom callback for stopping pass of defragmentation.
+
+    Have to return 'VK_TRUE' for breaking current defragmentation pass.
+    */
+    PFN_vmaCheckDefragmentationBreak customBreakCallback;
 } VmaDefragmentationInfo;
 
 /// Single move of an allocation to be done for defragmentation.
@@ -11044,6 +11055,7 @@
 
     const VkDeviceSize m_MaxPassBytes;
     const uint32_t m_MaxPassAllocations;
+    const PFN_vmaCheckDefragmentationBreak m_IsBreak;
 
     VmaStlAllocator<VmaDefragmentationMove> m_MoveAllocator;
     VmaVector<VmaDefragmentationMove, VmaStlAllocator<VmaDefragmentationMove>> m_Moves;
@@ -12974,6 +12986,7 @@
     const VmaDefragmentationInfo& info)
     : m_MaxPassBytes(info.maxBytesPerPass == 0 ? VK_WHOLE_SIZE : info.maxBytesPerPass),
     m_MaxPassAllocations(info.maxAllocationsPerPass == 0 ? UINT32_MAX : info.maxAllocationsPerPass),
+    m_IsBreak(info.customBreakCallback),
     m_MoveAllocator(hAllocator->GetAllocationCallbacks()),
     m_Moves(m_MoveAllocator)
 {
@@ -13369,6 +13382,10 @@
 
 VmaDefragmentationContext_T::CounterStatus VmaDefragmentationContext_T::CheckCounters(VkDeviceSize bytes)
 {
+    // Check custom criteria if exists
+    if (m_IsBreak && m_IsBreak())
+        return CounterStatus::End;
+
     // Ignore allocation if will exceed max size for copy
     if (m_PassStats.bytesMoved + bytes > m_MaxPassBytes)
     {