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Updated CHANGELOG.md. Recompiled binaries and Doxygen documentation.

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Adam Sawicki 2018-08-27 11:05:24 +02:00
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@ -101,19 +101,20 @@ Linear allocation algorithm</h1>
<img src="../gfx/Linear_allocator_2_algo_linear.png" alt="Linear allocation algorithm"/>
</div>
<p>With this one flag, you can create a custom pool that can be used in many ways: free-at-once, stack, double stack, and ring buffer. See below for details.</p>
<p>Pools with linear algorithm must have only one memory block - <a class="el" href="struct_vma_pool_create_info.html#ae41142f2834fcdc82baa4883c187b75c" title="Maximum number of blocks that can be allocated in this pool. Optional. ">VmaPoolCreateInfo::maxBlockCount</a> must be 1.</p>
<h2><a class="anchor" id="linear_algorithm_free_at_once"></a>
Free-at-once</h2>
<p>In a pool that uses linear algorithm, you still need to free all the allocations individually, e.g. by using <a class="el" href="vk__mem__alloc_8h.html#a11f0fbc034fa81a4efedd73d61ce7568" title="Frees memory previously allocated using vmaAllocateMemory(), vmaAllocateMemoryForBuffer(), or vmaAllocateMemoryForImage(). ">vmaFreeMemory()</a> or <a class="el" href="vk__mem__alloc_8h.html#a0d9f4e4ba5bf9aab1f1c746387753d77" title="Destroys Vulkan buffer and frees allocated memory. ">vmaDestroyBuffer()</a>. You can free them in any order. New allocations are always made after last one - free space in the middle is not reused. However, when you release all the allocation and the pool becomes empty, allocation starts from the beginning again. This way you can use linear algorithm to speed up creation of allocations that you are going to release all at once.</p>
<div class="image">
<img src="../gfx/Linear_allocator_3_free_at_once.png" alt="Free-at-once"/>
</div>
<p>This mode is also available for pools created with <a class="el" href="struct_vma_pool_create_info.html#ae41142f2834fcdc82baa4883c187b75c" title="Maximum number of blocks that can be allocated in this pool. Optional. ">VmaPoolCreateInfo::maxBlockCount</a> value that allows multiple memory blocks.</p>
<h2><a class="anchor" id="linear_algorithm_stack"></a>
Stack</h2>
<p>When you free an allocation that was created last, its space can be reused. Thanks to this, if you always release allocations in the order opposite to their creation (LIFO - Last In First Out), you can achieve behavior of a stack.</p>
<div class="image">
<img src="../gfx/Linear_allocator_4_stack.png" alt="Stack"/>
</div>
<p>This mode is also available for pools created with <a class="el" href="struct_vma_pool_create_info.html#ae41142f2834fcdc82baa4883c187b75c" title="Maximum number of blocks that can be allocated in this pool. Optional. ">VmaPoolCreateInfo::maxBlockCount</a> value that allows multiple memory blocks.</p>
<h2><a class="anchor" id="linear_algorithm_double_stack"></a>
Double stack</h2>
<p>The space reserved by a custom pool with linear algorithm may be used by two stacks:</p>
@ -122,10 +123,11 @@ Double stack</h2>
<li>Second, "upper" one, growing down from the end towards lower offsets.</li>
</ul>
<p>To make allocation from upper stack, add flag <a class="el" href="vk__mem__alloc_8h.html#ad9889c10c798b040d59c92f257cae597a42ba3a2d2c7117953210b7c3ef8da0df">VMA_ALLOCATION_CREATE_UPPER_ADDRESS_BIT</a> to <a class="el" href="struct_vma_allocation_create_info.html#add09658ac14fe290ace25470ddd6d41b" title="Use VmaAllocationCreateFlagBits enum. ">VmaAllocationCreateInfo::flags</a>.</p>
<p>When the two stacks' ends meet so there is not enough space between them for a new allocation, such allocation fails with usual <code>VK_ERROR_OUT_OF_DEVICE_MEMORY</code> error.</p>
<div class="image">
<img src="../gfx/Linear_allocator_7_double_stack.png" alt="Double stack"/>
</div>
<p>Double stack is available only in pools with one memory block - <a class="el" href="struct_vma_pool_create_info.html#ae41142f2834fcdc82baa4883c187b75c" title="Maximum number of blocks that can be allocated in this pool. Optional. ">VmaPoolCreateInfo::maxBlockCount</a> must be 1. Otherwise behavior is undefined.</p>
<p>When the two stacks' ends meet so there is not enough space between them for a new allocation, such allocation fails with usual <code>VK_ERROR_OUT_OF_DEVICE_MEMORY</code> error.</p>
<h2><a class="anchor" id="linear_algorithm_ring_buffer"></a>
Ring buffer</h2>
<p>When you free some allocations from the beginning and there is not enough free space for a new one at the end of a pool, allocator's "cursor" wraps around to the beginning and starts allocation there. Thanks to this, if you always release allocations in the same order as you created them (FIFO - First In First Out), you can achieve behavior of a ring buffer / queue.</p>
@ -136,7 +138,8 @@ Ring buffer</h2>
<div class="image">
<img src="../gfx/Linear_allocator_6_ring_buffer_lost.png" alt="Ring buffer with lost allocations"/>
</div>
</div></div><!-- contents -->
<p>Ring buffer is available only in pools with one memory block - <a class="el" href="struct_vma_pool_create_info.html#ae41142f2834fcdc82baa4883c187b75c" title="Maximum number of blocks that can be allocated in this pool. Optional. ">VmaPoolCreateInfo::maxBlockCount</a> must be 1. Otherwise behavior is undefined. </p>
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