eden-emu/VulkanMemoryAllocator
14
0
Fork 0
mirror of https://github.com/GPUOpen-LibrariesAndSDKs/VulkanMemoryAllocator.git synced 2025-05-15 01:08:31 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions

Fixes and improvements in documentation

Browse source
This commit is contained in:
Adam Sawicki 2021-07-29 13:12:59 +02:00
parent 9ca6ecd2ae
commit b0fce340b6
15 changed files with 29 additions and 25 deletions
Download patch file Download diff file Expand all files Collapse all files

4
docs/html/memory_mapping.html
View file

@ -72,7 +72,7 @@ $(function() {
<div class="textblock"><p>To "map memory" in Vulkan means to obtain a CPU pointer to <code>VkDeviceMemory</code>, to be able to read from it or write to it in CPU code. Mapping is possible only of memory allocated from a memory type that has <code>VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT</code> flag. Functions <code>vkMapMemory()</code>, <code>vkUnmapMemory()</code> are designed for this purpose. You can use them directly with memory allocated by this library, but it is not recommended because of following issue: Mapping the same <code>VkDeviceMemory</code> block multiple times is illegal - only one mapping at a time is allowed. This includes mapping disjoint regions. Mapping is not reference-counted internally by Vulkan. Because of this, Vulkan Memory Allocator provides following facilities:</p>
<h1><a class="anchor" id="memory_mapping_mapping_functions"></a>
Mapping functions</h1>
<p>The library provides following functions for mapping of a specific <a class="el" href="struct_vma_allocation.html" title="Represents single memory allocation.">VmaAllocation</a>: <a class="el" href="vk__mem__alloc_8h.html#ad5bd1243512d099706de88168992f069" title="Maps memory represented by given allocation and returns pointer to it.">vmaMapMemory()</a>, <a class="el" href="vk__mem__alloc_8h.html#a9bc268595cb33f6ec4d519cfce81ff45" title="Unmaps memory represented by given allocation, mapped previously using vmaMapMemory().">vmaUnmapMemory()</a>. They are safer and more convenient to use than standard Vulkan functions. You can map an allocation multiple times simultaneously - mapping is reference-counted internally. You can also map different allocations simultaneously regardless of whether they use the same <code>VkDeviceMemory</code> block. The way it's implemented is that the library always maps entire memory block, not just region of the allocation. For further details, see description of <a class="el" href="vk__mem__alloc_8h.html#ad5bd1243512d099706de88168992f069" title="Maps memory represented by given allocation and returns pointer to it.">vmaMapMemory()</a> function. Example:</p>
<p>The library provides following functions for mapping of a specific <a class="el" href="struct_vma_allocation.html" title="Represents single memory allocation.">VmaAllocation</a>: <a class="el" href="vk__mem__alloc_8h.html#ad5bd1243512d099706de88168992f069" title="Maps memory represented by given allocation and returns pointer to it.">vmaMapMemory()</a>, <a class="el" href="vk__mem__alloc_8h.html#a9bc268595cb33f6ec4d519cfce81ff45" title="Unmaps memory represented by given allocation, mapped previously using vmaMapMemory().">vmaUnmapMemory()</a>. They are safer and more convenient to use than standard Vulkan functions. You can map an allocation multiple times simultaneously - mapping is reference-counted internally. You can also map different allocations simultaneously regardless of whether they use the same <code>VkDeviceMemory</code> block. The way it is implemented is that the library always maps entire memory block, not just region of the allocation. For further details, see description of <a class="el" href="vk__mem__alloc_8h.html#ad5bd1243512d099706de88168992f069" title="Maps memory represented by given allocation and returns pointer to it.">vmaMapMemory()</a> function. Example:</p>
<div class="fragment"><div class="line"><span class="comment">// Having these objects initialized:</span></div>
<div class="line"> </div>
<div class="line"><span class="keyword">struct </span>ConstantBuffer</div>
@ -188,7 +188,7 @@ Finding out if memory is mappable</h1>
<div class="line"><span class="keywordflow">if</span>(allocInfo.<a class="code" href="struct_vma_allocation_info.html#a5eeffbe2d2f30f53370ff14aefbadbe2">pMappedData</a> != <span class="keyword">nullptr</span>)</div>
<div class="line">{</div>
<div class="line"> <span class="comment">// Allocation ended up in mappable memory.</span></div>
<div class="line"> <span class="comment">// It&#39;s persistently mapped. You can access it directly.</span></div>
<div class="line"> <span class="comment">// It is persistently mapped. You can access it directly.</span></div>
<div class="line"> memcpy(allocInfo.<a class="code" href="struct_vma_allocation_info.html#a5eeffbe2d2f30f53370ff14aefbadbe2">pMappedData</a>, &amp;constantBufferData, <span class="keyword">sizeof</span>(constantBufferData));</div>
<div class="line">}</div>
<div class="line"><span class="keywordflow">else</span></div>