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Improvements in documentation formatting.

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This commit is contained in:
Adam Sawicki 2017-10-17 12:07:39 +02:00
parent c005a84e37
commit 07a7deb09d
8 changed files with 276 additions and 388 deletions
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41
docs/html/lost_allocations.html
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@ -77,46 +77,7 @@ $(function() {
<p><b>How do you inform the library when new frame starts?</b></p>
<p>You need to call function <a class="el" href="vk__mem__alloc_8h.html#ade56bf8dc9f5a5eaddf5f119ed525236" title="Sets index of the current frame. ">vmaSetCurrentFrameIndex()</a>.</p>
<p>Example code:</p>
<pre class="fragment">struct MyBuffer
{
VkBuffer m_Buf = nullptr;
VmaAllocation m_Alloc = nullptr;
.// Called when the buffer is really needed in the current frame.
void EnsureBuffer();
};
void MyBuffer::EnsureBuffer()
{
.// Buffer has been created.
if(m_Buf != VK_NULL_HANDLE)
{
.// Check if its allocation is not lost + mark it as used in current frame.
VmaAllocationInfo allocInfo;
vmaGetAllocationInfo(allocator, m_Alloc, &amp;allocInfo);
if(allocInfo.deviceMemory != VK_NULL_HANDLE)
{
.// It's all OK - safe to use m_Buf.
return;
}
}
.// Buffer not yet exists or lost - destroy and recreate it.
vmaDestroyBuffer(allocator, m_Buf, m_Alloc);
VkBufferCreateInfo bufCreateInfo = { VK_STRUCTURE_TYPE_BUFFER_CREATE_INFO };
bufCreateInfo.size = 1024;
bufCreateInfo.usage = VK_BUFFER_USAGE_UNIFORM_BUFFER_BIT | VK_BUFFER_USAGE_TRANSFER_DST_BIT;
VmaAllocationCreateInfo allocCreateInfo = {};
allocCreateInfo.usage = VMA_MEMORY_USAGE_GPU_ONLY;
allocCreateInfo.flags = VMA_ALLOCATION_CREATE_CAN_BECOME_LOST_BIT |
VMA_ALLOCATION_CREATE_CAN_MAKE_OTHER_LOST_BIT;
vmaCreateBuffer(allocator, &amp;bufCreateInfo, &amp;allocCreateInfo, &amp;m_Buf, &amp;m_Alloc, nullptr);
}
</pre><p>When using lost allocations, you may see some Vulkan validation layer warnings about overlapping regions of memory bound to different kinds of buffers and images. This is still valid as long as you implement proper handling of lost allocations (like in the example above) and don't use them.</p>
<div class="fragment"><div class="line"><span class="keyword">struct </span>MyBuffer</div><div class="line">{</div><div class="line"> VkBuffer m_Buf = <span class="keyword">nullptr</span>;</div><div class="line"> VmaAllocation m_Alloc = <span class="keyword">nullptr</span>;</div><div class="line"></div><div class="line"> <span class="comment">// Called when the buffer is really needed in the current frame.</span></div><div class="line"> <span class="keywordtype">void</span> EnsureBuffer();</div><div class="line">};</div><div class="line"></div><div class="line"><span class="keywordtype">void</span> MyBuffer::EnsureBuffer()</div><div class="line">{</div><div class="line"> <span class="comment">// Buffer has been created.</span></div><div class="line"> <span class="keywordflow">if</span>(m_Buf != VK_NULL_HANDLE)</div><div class="line"> {</div><div class="line"> <span class="comment">// Check if its allocation is not lost + mark it as used in current frame.</span></div><div class="line"> <a class="code" href="struct_vma_allocation_info.html">VmaAllocationInfo</a> allocInfo;</div><div class="line"> <a class="code" href="vk__mem__alloc_8h.html#a86dd08aba8633bfa4ad0df2e76481d8b">vmaGetAllocationInfo</a>(allocator, m_Alloc, &amp;allocInfo);</div><div class="line"> <span class="keywordflow">if</span>(allocInfo.<a class="code" href="struct_vma_allocation_info.html#ae0bfb7dfdf79a76ffefc9a94677a2f67">deviceMemory</a> != VK_NULL_HANDLE)</div><div class="line"> {</div><div class="line"> <span class="comment">// It&#39;s all OK - safe to use m_Buf.</span></div><div class="line"> <span class="keywordflow">return</span>;</div><div class="line"> }</div><div class="line"> }</div><div class="line"></div><div class="line"> <span class="comment">// Buffer not yet exists or lost - destroy and recreate it.</span></div><div class="line"></div><div class="line"> <a class="code" href="vk__mem__alloc_8h.html#a0d9f4e4ba5bf9aab1f1c746387753d77">vmaDestroyBuffer</a>(allocator, m_Buf, m_Alloc);</div><div class="line"></div><div class="line"> VkBufferCreateInfo bufCreateInfo = { VK_STRUCTURE_TYPE_BUFFER_CREATE_INFO };</div><div class="line"> bufCreateInfo.size = 1024;</div><div class="line"> bufCreateInfo.usage = VK_BUFFER_USAGE_UNIFORM_BUFFER_BIT | VK_BUFFER_USAGE_TRANSFER_DST_BIT;</div><div class="line"></div><div class="line"> <a class="code" href="struct_vma_allocation_create_info.html">VmaAllocationCreateInfo</a> allocCreateInfo = {};</div><div class="line"> allocCreateInfo.<a class="code" href="struct_vma_allocation_create_info.html#accb8b06b1f677d858cb9af20705fa910">usage</a> = <a class="code" href="vk__mem__alloc_8h.html#aa5846affa1e9da3800e3e78fae2305ccac6b5dc1432d88647aa4cd456246eadf7">VMA_MEMORY_USAGE_GPU_ONLY</a>;</div><div class="line"> allocCreateInfo.<a class="code" href="struct_vma_allocation_create_info.html#add09658ac14fe290ace25470ddd6d41b">flags</a> = <a class="code" href="vk__mem__alloc_8h.html#ad9889c10c798b040d59c92f257cae597a5f436af6c8fe8540573a6d22627a6fd2">VMA_ALLOCATION_CREATE_CAN_BECOME_LOST_BIT</a> |</div><div class="line"> <a class="code" href="vk__mem__alloc_8h.html#ad9889c10c798b040d59c92f257cae597a68686d0ce9beb0d4d1b9f2b8b1389a7e">VMA_ALLOCATION_CREATE_CAN_MAKE_OTHER_LOST_BIT</a>;</div><div class="line"></div><div class="line"> <a class="code" href="vk__mem__alloc_8h.html#ac72ee55598617e8eecca384e746bab51">vmaCreateBuffer</a>(allocator, &amp;bufCreateInfo, &amp;allocCreateInfo, &amp;m_Buf, &amp;m_Alloc, <span class="keyword">nullptr</span>);</div><div class="line">}</div></div><!-- fragment --><p>When using lost allocations, you may see some Vulkan validation layer warnings about overlapping regions of memory bound to different kinds of buffers and images. This is still valid as long as you implement proper handling of lost allocations (like in the example above) and don't use them.</p>
<p>The library uses following algorithm for allocation, in order:</p>
<ol type="1">
<li>Try to find free range of memory in existing blocks.</li>