140 lines
4.6 KiB
Plaintext
140 lines
4.6 KiB
Plaintext
// Copyright (c) 2016-2017 Khronos Group. This work is licensed under a
|
|
// Creative Commons Attribution 4.0 International License; see
|
|
// http://creativecommons.org/licenses/by/4.0/
|
|
|
|
include::meta/VK_KHR_maintenance2.txt[]
|
|
|
|
*Last Modified Date*::
|
|
2017-04-28
|
|
*Contributors*::
|
|
- Michael Worcester, Imagination Technologies
|
|
- Stuart Smith, Imagination Technologies
|
|
- Jeff Bolz, NVIDIA
|
|
- Daniel Koch, NVIDIA
|
|
- Jan-Harald Fredriksen, ARM
|
|
- Daniel Rakos, AMD
|
|
- Neil Henning, Codeplay
|
|
- Piers Daniell, NVIDIA
|
|
|
|
+VK_KHR_maintenance2+ adds a collection of minor features that were
|
|
intentionally left out or overlooked from the original Vulkan 1.0 release.
|
|
|
|
The new features are as follows:
|
|
|
|
* Allow the application to specify which aspect of an input attachment
|
|
might be read for a given subpass.
|
|
* Allow implementations to express the clipping behavior of points.
|
|
* Allow creating images with usage flags that may not be supported for the
|
|
base image's format, but are supported for image views of the image that
|
|
have a different but compatible format.
|
|
* Allow creating uncompressed image views of compressed images.
|
|
* Allow the application to select between an upper-left and lower-left
|
|
origin for the tessellation domain space.
|
|
* Adds two new image layouts for depth stencil images to allow either the
|
|
depth or stencil aspect to be read-only while the other aspect is
|
|
writable.
|
|
|
|
=== Input Attachment Specification
|
|
|
|
Input attachment specification allows an application to specify which aspect
|
|
of a multi-aspect image (e.g. a combined depth stencil format) will be
|
|
accessed via a code:subpassLoad operation.
|
|
|
|
On some implementations there may: be a performance penalty if the
|
|
implementation does not know (at flink:vkCreateRenderPass time) which
|
|
aspect(s) of multi-aspect images can: be be accessed as input attachments.
|
|
|
|
|
|
|
|
=== New Object Types
|
|
|
|
None.
|
|
|
|
=== New Enum Constants
|
|
|
|
* Extending elink:VkStructureType:
|
|
** ename:VK_STRUCTURE_TYPE_RENDER_PASS_INPUT_ATTACHMENT_ASPECT_CREATE_INFO_KHR
|
|
** ename:VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_POINT_CLIPPING_PROPERTIES_KHR
|
|
** ename:VK_STRUCTURE_TYPE_IMAGE_VIEW_USAGE_CREATE_INFO_KHR
|
|
** ename:VK_STRUCTURE_TYPE_PIPELINE_TESSELLATION_DOMAIN_ORIGIN_STATE_CREATE_INFO_KHR
|
|
|
|
* Extending elink:VkImageCreateFlagBits:
|
|
** ename:VK_IMAGE_CREATE_BLOCK_TEXEL_VIEW_COMPATIBLE_BIT_KHR
|
|
** ename:VK_IMAGE_CREATE_EXTENDED_USAGE_BIT_KHR
|
|
|
|
* Extending elink:VkImageLayout
|
|
** ename:VK_IMAGE_LAYOUT_DEPTH_READ_ONLY_STENCIL_ATTACHMENT_OPTIMAL_KHR
|
|
** ename:VK_IMAGE_LAYOUT_DEPTH_ATTACHMENT_STENCIL_READ_ONLY_OPTIMAL_KHR
|
|
|
|
* ename:VK_POINT_CLIPPING_BEHAVIOR_ALL_CLIP_PLANES_KHR
|
|
* ename:VK_POINT_CLIPPING_BEHAVIOR_USER_CLIP_PLANES_ONLY_KHR
|
|
|
|
=== New Enums
|
|
|
|
* slink:VkPointClippingBehaviorKHR
|
|
* slink:VkTessellationDomainOriginKHR
|
|
|
|
=== New Structures
|
|
|
|
* slink:VkPhysicalDevicePointClippingPropertiesKHR
|
|
* slink:VkRenderPassInputAttachmentAspectCreateInfoKHR
|
|
* slink:VkInputAttachmentAspectReferenceKHR
|
|
* slink:VkImageViewUsageCreateInfoKHR
|
|
* slink:VkPipelineTessellationDomainOriginStateCreateInfoKHR
|
|
|
|
=== New Functions
|
|
|
|
None.
|
|
|
|
=== Input Attachment Specification Example
|
|
|
|
Consider the case where a render pass has two subpasses and two attachments.
|
|
|
|
Attachment 0 has the format ename:VK_FORMAT_D24_UNORM_S8_UINT, attachment 1
|
|
has some color format.
|
|
|
|
Subpass 0 writes to attachment 0, subpass 1 reads only the depth information
|
|
from attachment 0 (using inputAttachmentRead) and writes to attachment 1.
|
|
|
|
[source,c++]
|
|
----------------------------------------
|
|
VkInputAttachmentAspectReferenceKHR references[] = {
|
|
{
|
|
.subpass = 1,
|
|
.inputAttachment = 0,
|
|
.aspectMask = VK_IMAGE_ASPECT_DEPTH_BIT
|
|
}
|
|
};
|
|
|
|
VkRenderPassInputAttachmentAspectCreateInfoKHR specifyAspects = {
|
|
.sType = VK_STRUCTURE_TYPE_RENDER_PASS_INPUT_ATTACHMENT_ASPECT_CREATE_INFO_KHR,
|
|
.pNext = NULL,
|
|
.aspectReferenceCount = 1,
|
|
.pAspectReferences = references
|
|
};
|
|
|
|
|
|
VkRenderPassCreateInfo createInfo = {
|
|
...
|
|
.pNext = &specifyAspects,
|
|
...
|
|
}
|
|
|
|
vkCreateRenderPass(...);
|
|
----------------------------------------
|
|
|
|
=== Issues
|
|
|
|
1) What is the default tessellation domain origin?
|
|
|
|
*RESOLVED*: Vulkan 1.0 originally inadvertently documented a lower-left
|
|
origin, but the conformance tests and all implementations implemented an
|
|
upper-left origin.
|
|
This extension adds a control to select between lower-left (for
|
|
compatibility with OpenGL) and upper-left, and we retroactively fix
|
|
unextended Vulkan to have a default of an upper-left origin.
|
|
|
|
=== Version History
|
|
|
|
* Revision 1, 2017-04-28
|