1  include::meta/VK_AMD_negative_viewport_height.txt[]
 2  
 3  *Last Modified Date*::
 4      2016-09-02
 5  *IP Status*::
 6      No known IP claims.
 7  *Contributors*::
 8    - Matthaeus G. Chajdas, AMD
 9    - Graham Sellers, AMD
10    - Baldur Karlsson
11  
12  This extension allows an application to specify a negative viewport height.
13  The result is that the viewport transformation will flip along the y-axis.
14  
15    * Allow negative height to be specified in the
16      slink:VkViewport::pname:height field to perform y-inversion of the
17      clip-space to framebuffer-space transform.
18      This allows apps to avoid having to use `gl_Position.y = -gl_Position.y`
19      in shaders also targeting other APIs.
20  
21  === Obsoletion by VK_KHR_maintenance1 and Vulkan 1.1
22  
23  Functionality in this extension is included in `VK_KHR_maintenance1` and
24  subsequently Vulkan 1.1.
25  Due to some slight behavioral differences, this extension must: not be
26  enabled alongside `VK_KHR_maintenance1`, or in an instance created with
27  version 1.1 or later requested in slink:VkApplicationInfo::pname:apiVersion.
28  
29  === Version History
30  
31   * Revision 1, 2016-09-02 (Matthaeus Chajdas)
32     - Initial draft