Added documentation chapter "Versioning and compatibility"

Many improvements in documentation and README.
This commit is contained in:
Adam Sawicki 2022-02-26 13:26:20 +01:00
parent 86c124c772
commit 4039e45a19
17 changed files with 150 additions and 104 deletions

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@ -91,18 +91,20 @@ GPU-only resource</h1>
<div class="line"><a class="code hl_struct" href="struct_vma_allocation_create_info.html">VmaAllocationCreateInfo</a> allocCreateInfo = {};</div>
<div class="line">allocCreateInfo.<a class="code hl_variable" href="struct_vma_allocation_create_info.html#accb8b06b1f677d858cb9af20705fa910">usage</a> = <a class="code hl_enumvalue" href="group__group__alloc.html#ggaa5846affa1e9da3800e3e78fae2305cca27cde9026a84d34d525777baa41fce6e">VMA_MEMORY_USAGE_AUTO</a>;</div>
<div class="line">allocCreateInfo.<a class="code hl_variable" href="struct_vma_allocation_create_info.html#add09658ac14fe290ace25470ddd6d41b">flags</a> = <a class="code hl_enumvalue" href="group__group__alloc.html#ggad9889c10c798b040d59c92f257cae597a3fc311d855c2ff53f1090ef5c722b38f">VMA_ALLOCATION_CREATE_DEDICATED_MEMORY_BIT</a>;</div>
<div class="line">allocCreateInfo.<a class="code hl_variable" href="struct_vma_allocation_create_info.html#a983d39e1a2e63649d78a960aa2fdd0f7">priority</a> = 1.0f;</div>
<div class="line"> </div>
<div class="line">VkImage img;</div>
<div class="line"><a class="code hl_struct" href="struct_vma_allocation.html">VmaAllocation</a> alloc;</div>
<div class="line"><a class="code hl_function" href="group__group__alloc.html#ga02a94f25679275851a53e82eacbcfc73">vmaCreateImage</a>(allocator, &amp;imgCreateInfo, &amp;allocCreateInfo, &amp;img, &amp;alloc, <span class="keyword">nullptr</span>);</div>
<div class="ttc" id="agroup__group__alloc_html_ga02a94f25679275851a53e82eacbcfc73"><div class="ttname"><a href="group__group__alloc.html#ga02a94f25679275851a53e82eacbcfc73">vmaCreateImage</a></div><div class="ttdeci">VkResult vmaCreateImage(VmaAllocator allocator, const VkImageCreateInfo *pImageCreateInfo, const VmaAllocationCreateInfo *pAllocationCreateInfo, VkImage *pImage, VmaAllocation *pAllocation, VmaAllocationInfo *pAllocationInfo)</div><div class="ttdoc">Function similar to vmaCreateBuffer().</div></div>
<div class="ttc" id="agroup__group__alloc_html_ggaa5846affa1e9da3800e3e78fae2305cca27cde9026a84d34d525777baa41fce6e"><div class="ttname"><a href="group__group__alloc.html#ggaa5846affa1e9da3800e3e78fae2305cca27cde9026a84d34d525777baa41fce6e">VMA_MEMORY_USAGE_AUTO</a></div><div class="ttdeci">@ VMA_MEMORY_USAGE_AUTO</div><div class="ttdef"><b>Definition:</b> vk_mem_alloc.h:488</div></div>
<div class="ttc" id="agroup__group__alloc_html_ggad9889c10c798b040d59c92f257cae597a3fc311d855c2ff53f1090ef5c722b38f"><div class="ttname"><a href="group__group__alloc.html#ggad9889c10c798b040d59c92f257cae597a3fc311d855c2ff53f1090ef5c722b38f">VMA_ALLOCATION_CREATE_DEDICATED_MEMORY_BIT</a></div><div class="ttdeci">@ VMA_ALLOCATION_CREATE_DEDICATED_MEMORY_BIT</div><div class="ttdoc">Set this flag if the allocation should have its own memory block.</div><div class="ttdef"><b>Definition:</b> vk_mem_alloc.h:524</div></div>
<div class="ttc" id="astruct_vma_allocation_create_info_html"><div class="ttname"><a href="struct_vma_allocation_create_info.html">VmaAllocationCreateInfo</a></div><div class="ttdef"><b>Definition:</b> vk_mem_alloc.h:1211</div></div>
<div class="ttc" id="astruct_vma_allocation_create_info_html_accb8b06b1f677d858cb9af20705fa910"><div class="ttname"><a href="struct_vma_allocation_create_info.html#accb8b06b1f677d858cb9af20705fa910">VmaAllocationCreateInfo::usage</a></div><div class="ttdeci">VmaMemoryUsage usage</div><div class="ttdoc">Intended usage of memory.</div><div class="ttdef"><b>Definition:</b> vk_mem_alloc.h:1219</div></div>
<div class="ttc" id="astruct_vma_allocation_create_info_html_add09658ac14fe290ace25470ddd6d41b"><div class="ttname"><a href="struct_vma_allocation_create_info.html#add09658ac14fe290ace25470ddd6d41b">VmaAllocationCreateInfo::flags</a></div><div class="ttdeci">VmaAllocationCreateFlags flags</div><div class="ttdoc">Use VmaAllocationCreateFlagBits enum.</div><div class="ttdef"><b>Definition:</b> vk_mem_alloc.h:1213</div></div>
<div class="ttc" id="agroup__group__alloc_html_ggaa5846affa1e9da3800e3e78fae2305cca27cde9026a84d34d525777baa41fce6e"><div class="ttname"><a href="group__group__alloc.html#ggaa5846affa1e9da3800e3e78fae2305cca27cde9026a84d34d525777baa41fce6e">VMA_MEMORY_USAGE_AUTO</a></div><div class="ttdeci">@ VMA_MEMORY_USAGE_AUTO</div><div class="ttdef"><b>Definition:</b> vk_mem_alloc.h:489</div></div>
<div class="ttc" id="agroup__group__alloc_html_ggad9889c10c798b040d59c92f257cae597a3fc311d855c2ff53f1090ef5c722b38f"><div class="ttname"><a href="group__group__alloc.html#ggad9889c10c798b040d59c92f257cae597a3fc311d855c2ff53f1090ef5c722b38f">VMA_ALLOCATION_CREATE_DEDICATED_MEMORY_BIT</a></div><div class="ttdeci">@ VMA_ALLOCATION_CREATE_DEDICATED_MEMORY_BIT</div><div class="ttdoc">Set this flag if the allocation should have its own memory block.</div><div class="ttdef"><b>Definition:</b> vk_mem_alloc.h:525</div></div>
<div class="ttc" id="astruct_vma_allocation_create_info_html"><div class="ttname"><a href="struct_vma_allocation_create_info.html">VmaAllocationCreateInfo</a></div><div class="ttdef"><b>Definition:</b> vk_mem_alloc.h:1212</div></div>
<div class="ttc" id="astruct_vma_allocation_create_info_html_a983d39e1a2e63649d78a960aa2fdd0f7"><div class="ttname"><a href="struct_vma_allocation_create_info.html#a983d39e1a2e63649d78a960aa2fdd0f7">VmaAllocationCreateInfo::priority</a></div><div class="ttdeci">float priority</div><div class="ttdoc">A floating-point value between 0 and 1, indicating the priority of the allocation relative to other m...</div><div class="ttdef"><b>Definition:</b> vk_mem_alloc.h:1258</div></div>
<div class="ttc" id="astruct_vma_allocation_create_info_html_accb8b06b1f677d858cb9af20705fa910"><div class="ttname"><a href="struct_vma_allocation_create_info.html#accb8b06b1f677d858cb9af20705fa910">VmaAllocationCreateInfo::usage</a></div><div class="ttdeci">VmaMemoryUsage usage</div><div class="ttdoc">Intended usage of memory.</div><div class="ttdef"><b>Definition:</b> vk_mem_alloc.h:1220</div></div>
<div class="ttc" id="astruct_vma_allocation_create_info_html_add09658ac14fe290ace25470ddd6d41b"><div class="ttname"><a href="struct_vma_allocation_create_info.html#add09658ac14fe290ace25470ddd6d41b">VmaAllocationCreateInfo::flags</a></div><div class="ttdeci">VmaAllocationCreateFlags flags</div><div class="ttdoc">Use VmaAllocationCreateFlagBits enum.</div><div class="ttdef"><b>Definition:</b> vk_mem_alloc.h:1214</div></div>
<div class="ttc" id="astruct_vma_allocation_html"><div class="ttname"><a href="struct_vma_allocation.html">VmaAllocation</a></div><div class="ttdoc">Represents single memory allocation.</div></div>
</div><!-- fragment --><p ><b>Also consider:</b> Consider creating them as dedicated allocations using <a class="el" href="group__group__alloc.html#ggad9889c10c798b040d59c92f257cae597a3fc311d855c2ff53f1090ef5c722b38f" title="Set this flag if the allocation should have its own memory block.">VMA_ALLOCATION_CREATE_DEDICATED_MEMORY_BIT</a>, especially if they are large or if you plan to destroy and recreate them with different sizes e.g. when display resolution changes. Prefer to create such resources first and all other GPU resources (like textures and vertex buffers) later.</p>
</div><!-- fragment --><p ><b>Also consider:</b> Consider creating them as dedicated allocations using <a class="el" href="group__group__alloc.html#ggad9889c10c798b040d59c92f257cae597a3fc311d855c2ff53f1090ef5c722b38f" title="Set this flag if the allocation should have its own memory block.">VMA_ALLOCATION_CREATE_DEDICATED_MEMORY_BIT</a>, especially if they are large or if you plan to destroy and recreate them with different sizes e.g. when display resolution changes. Prefer to create such resources first and all other GPU resources (like textures and vertex buffers) later. When VK_EXT_memory_priority extension is enabled, it is also worth setting high priority to such allocation to decrease chances to be evicted to system memory by the operating system.</p>
<h1><a class="anchor" id="usage_patterns_staging_copy_upload"></a>
Staging copy for upload</h1>
<p ><b>When:</b> A "staging" buffer than you want to map and fill from CPU code, then use as a source od transfer to some GPU resource.</p>
@ -125,10 +127,10 @@ Staging copy for upload</h1>
<div class="line"> </div>
<div class="line">memcpy(allocInfo.<a class="code hl_variable" href="struct_vma_allocation_info.html#a5eeffbe2d2f30f53370ff14aefbadbe2">pMappedData</a>, myData, myDataSize);</div>
<div class="ttc" id="agroup__group__alloc_html_gac72ee55598617e8eecca384e746bab51"><div class="ttname"><a href="group__group__alloc.html#gac72ee55598617e8eecca384e746bab51">vmaCreateBuffer</a></div><div class="ttdeci">VkResult vmaCreateBuffer(VmaAllocator allocator, const VkBufferCreateInfo *pBufferCreateInfo, const VmaAllocationCreateInfo *pAllocationCreateInfo, VkBuffer *pBuffer, VmaAllocation *pAllocation, VmaAllocationInfo *pAllocationInfo)</div></div>
<div class="ttc" id="agroup__group__alloc_html_ggad9889c10c798b040d59c92f257cae597a11da372cc3a82931c5e5d6146cd9dd1f"><div class="ttname"><a href="group__group__alloc.html#ggad9889c10c798b040d59c92f257cae597a11da372cc3a82931c5e5d6146cd9dd1f">VMA_ALLOCATION_CREATE_MAPPED_BIT</a></div><div class="ttdeci">@ VMA_ALLOCATION_CREATE_MAPPED_BIT</div><div class="ttdoc">Set this flag to use a memory that will be persistently mapped and retrieve pointer to it.</div><div class="ttdef"><b>Definition:</b> vk_mem_alloc.h:546</div></div>
<div class="ttc" id="agroup__group__alloc_html_ggad9889c10c798b040d59c92f257cae597a9be224df3bfc1cfa06203aed689a30c5"><div class="ttname"><a href="group__group__alloc.html#ggad9889c10c798b040d59c92f257cae597a9be224df3bfc1cfa06203aed689a30c5">VMA_ALLOCATION_CREATE_HOST_ACCESS_SEQUENTIAL_WRITE_BIT</a></div><div class="ttdeci">@ VMA_ALLOCATION_CREATE_HOST_ACCESS_SEQUENTIAL_WRITE_BIT</div><div class="ttdef"><b>Definition:</b> vk_mem_alloc.h:593</div></div>
<div class="ttc" id="astruct_vma_allocation_info_html"><div class="ttname"><a href="struct_vma_allocation_info.html">VmaAllocationInfo</a></div><div class="ttdoc">Parameters of VmaAllocation objects, that can be retrieved using function vmaGetAllocationInfo().</div><div class="ttdef"><b>Definition:</b> vk_mem_alloc.h:1326</div></div>
<div class="ttc" id="astruct_vma_allocation_info_html_a5eeffbe2d2f30f53370ff14aefbadbe2"><div class="ttname"><a href="struct_vma_allocation_info.html#a5eeffbe2d2f30f53370ff14aefbadbe2">VmaAllocationInfo::pMappedData</a></div><div class="ttdeci">void * pMappedData</div><div class="ttdoc">Pointer to the beginning of this allocation as mapped data.</div><div class="ttdef"><b>Definition:</b> vk_mem_alloc.h:1368</div></div>
<div class="ttc" id="agroup__group__alloc_html_ggad9889c10c798b040d59c92f257cae597a11da372cc3a82931c5e5d6146cd9dd1f"><div class="ttname"><a href="group__group__alloc.html#ggad9889c10c798b040d59c92f257cae597a11da372cc3a82931c5e5d6146cd9dd1f">VMA_ALLOCATION_CREATE_MAPPED_BIT</a></div><div class="ttdeci">@ VMA_ALLOCATION_CREATE_MAPPED_BIT</div><div class="ttdoc">Set this flag to use a memory that will be persistently mapped and retrieve pointer to it.</div><div class="ttdef"><b>Definition:</b> vk_mem_alloc.h:547</div></div>
<div class="ttc" id="agroup__group__alloc_html_ggad9889c10c798b040d59c92f257cae597a9be224df3bfc1cfa06203aed689a30c5"><div class="ttname"><a href="group__group__alloc.html#ggad9889c10c798b040d59c92f257cae597a9be224df3bfc1cfa06203aed689a30c5">VMA_ALLOCATION_CREATE_HOST_ACCESS_SEQUENTIAL_WRITE_BIT</a></div><div class="ttdeci">@ VMA_ALLOCATION_CREATE_HOST_ACCESS_SEQUENTIAL_WRITE_BIT</div><div class="ttdef"><b>Definition:</b> vk_mem_alloc.h:594</div></div>
<div class="ttc" id="astruct_vma_allocation_info_html"><div class="ttname"><a href="struct_vma_allocation_info.html">VmaAllocationInfo</a></div><div class="ttdoc">Parameters of VmaAllocation objects, that can be retrieved using function vmaGetAllocationInfo().</div><div class="ttdef"><b>Definition:</b> vk_mem_alloc.h:1327</div></div>
<div class="ttc" id="astruct_vma_allocation_info_html_a5eeffbe2d2f30f53370ff14aefbadbe2"><div class="ttname"><a href="struct_vma_allocation_info.html#a5eeffbe2d2f30f53370ff14aefbadbe2">VmaAllocationInfo::pMappedData</a></div><div class="ttdeci">void * pMappedData</div><div class="ttdoc">Pointer to the beginning of this allocation as mapped data.</div><div class="ttdef"><b>Definition:</b> vk_mem_alloc.h:1369</div></div>
</div><!-- fragment --><p ><b>Also consider:</b> You can map the allocation using <a class="el" href="group__group__alloc.html#gad5bd1243512d099706de88168992f069" title="Maps memory represented by given allocation and returns pointer to it.">vmaMapMemory()</a> or you can create it as persistenly mapped using <a class="el" href="group__group__alloc.html#ggad9889c10c798b040d59c92f257cae597a11da372cc3a82931c5e5d6146cd9dd1f" title="Set this flag to use a memory that will be persistently mapped and retrieve pointer to it.">VMA_ALLOCATION_CREATE_MAPPED_BIT</a>, as in the example above.</p>
<h1><a class="anchor" id="usage_patterns_readback"></a>
Readback</h1>
@ -151,7 +153,7 @@ Readback</h1>
<div class="line">...</div>
<div class="line"> </div>
<div class="line">const <span class="keywordtype">float</span>* downloadedData = (<span class="keyword">const</span> <span class="keywordtype">float</span>*)allocInfo.<a class="code hl_variable" href="struct_vma_allocation_info.html#a5eeffbe2d2f30f53370ff14aefbadbe2">pMappedData</a>;</div>
<div class="ttc" id="agroup__group__alloc_html_ggad9889c10c798b040d59c92f257cae597add61238d98e20917b9a06c617763f492"><div class="ttname"><a href="group__group__alloc.html#ggad9889c10c798b040d59c92f257cae597add61238d98e20917b9a06c617763f492">VMA_ALLOCATION_CREATE_HOST_ACCESS_RANDOM_BIT</a></div><div class="ttdeci">@ VMA_ALLOCATION_CREATE_HOST_ACCESS_RANDOM_BIT</div><div class="ttdef"><b>Definition:</b> vk_mem_alloc.h:605</div></div>
<div class="ttc" id="agroup__group__alloc_html_ggad9889c10c798b040d59c92f257cae597add61238d98e20917b9a06c617763f492"><div class="ttname"><a href="group__group__alloc.html#ggad9889c10c798b040d59c92f257cae597add61238d98e20917b9a06c617763f492">VMA_ALLOCATION_CREATE_HOST_ACCESS_RANDOM_BIT</a></div><div class="ttdeci">@ VMA_ALLOCATION_CREATE_HOST_ACCESS_RANDOM_BIT</div><div class="ttdef"><b>Definition:</b> vk_mem_alloc.h:606</div></div>
</div><!-- fragment --><h1><a class="anchor" id="usage_patterns_advanced_data_uploading"></a>
Advanced data uploading</h1>
<p >For resources that you frequently write on CPU via mapped pointer and freqnently read on GPU e.g. as a uniform buffer (also called "dynamic"), multiple options are possible:</p>
@ -213,6 +215,7 @@ Advanced data uploading</h1>
<div class="line"> </div>
<div class="line"> <span class="comment">// [Executed in runtime]:</span></div>
<div class="line"> memcpy(stagingAllocInfo.<a class="code hl_variable" href="struct_vma_allocation_info.html#a5eeffbe2d2f30f53370ff14aefbadbe2">pMappedData</a>, myData, myDataSize);</div>
<div class="line"> <span class="comment">//vkCmdPipelineBarrier: VK_ACCESS_HOST_WRITE_BIT --&gt; VK_ACCESS_TRANSFER_READ_BIT</span></div>
<div class="line"> VkBufferCopy bufCopy = {</div>
<div class="line"> 0, <span class="comment">// srcOffset</span></div>
<div class="line"> 0, <span class="comment">// dstOffset,</span></div>
@ -220,7 +223,7 @@ Advanced data uploading</h1>
<div class="line"> vkCmdCopyBuffer(cmdBuf, stagingBuf, buf, 1, &amp;bufCopy);</div>
<div class="line">}</div>
<div class="ttc" id="agroup__group__alloc_html_ga571e87dd38e552249b56b1b0b982fad1"><div class="ttname"><a href="group__group__alloc.html#ga571e87dd38e552249b56b1b0b982fad1">vmaGetAllocationMemoryProperties</a></div><div class="ttdeci">void vmaGetAllocationMemoryProperties(VmaAllocator allocator, VmaAllocation allocation, VkMemoryPropertyFlags *pFlags)</div><div class="ttdoc">Given an allocation, returns Property Flags of its memory type.</div></div>
<div class="ttc" id="agroup__group__alloc_html_ggad9889c10c798b040d59c92f257cae597a11337f96eacf34c1016c339eac165cad"><div class="ttname"><a href="group__group__alloc.html#ggad9889c10c798b040d59c92f257cae597a11337f96eacf34c1016c339eac165cad">VMA_ALLOCATION_CREATE_HOST_ACCESS_ALLOW_TRANSFER_INSTEAD_BIT</a></div><div class="ttdeci">@ VMA_ALLOCATION_CREATE_HOST_ACCESS_ALLOW_TRANSFER_INSTEAD_BIT</div><div class="ttdef"><b>Definition:</b> vk_mem_alloc.h:617</div></div>
<div class="ttc" id="agroup__group__alloc_html_ggad9889c10c798b040d59c92f257cae597a11337f96eacf34c1016c339eac165cad"><div class="ttname"><a href="group__group__alloc.html#ggad9889c10c798b040d59c92f257cae597a11337f96eacf34c1016c339eac165cad">VMA_ALLOCATION_CREATE_HOST_ACCESS_ALLOW_TRANSFER_INSTEAD_BIT</a></div><div class="ttdeci">@ VMA_ALLOCATION_CREATE_HOST_ACCESS_ALLOW_TRANSFER_INSTEAD_BIT</div><div class="ttdef"><b>Definition:</b> vk_mem_alloc.h:618</div></div>
</div><!-- fragment --><h1><a class="anchor" id="usage_patterns_other_use_cases"></a>
Other use cases</h1>
<p >Here are some other, less obvious use cases and their recommended settings:</p>