Release Notes 1.66.0

Changelog

Version 1.66.0

Released 02 May 2025

API	Removed developer option for using deprecated `em` behavior
API	Changed layout of constant buffer data for pixel shaders
API Unreal Engine	Added support for the incremental garbage collection in Unreal Engine 5. Projects leveraging Unreal Engine 4.27 will have the plugin files modified during project generation
Feature Unreal Engine	Added support for incremental garbage collection for Unreal Engine 5
Enhancement	Added Compositor and Surface Partitioning support for DirectX 12 in the Player application
Enhancement	Added an example blur filtering of a texture using a compute shader
Enhancement	Added a log message notifying that `StylePropertyMap` is not supported for SVG elements
Enhancement	Added DirectX 12 support to the default samples solution
Enhancement	Fixed unclosed profiling markers when using the default profiling backend on PC platforms
Enhancement Unreal Engine	Simplify view initialization when using UMG widgets
Enhancement Unreal Engine	Ensure virtual keyboard will not use the view or the `InputProxy` after `InputBlur` to prevent possible crashes
Fix	Fixed a layout regression with incorrect handling of undefined dimensions
Fix	Fixed crashes when `data-bind-for` iterator value is used in a single expression with other models
Fix	Fixed crashes with null pointer parents during style solving when using the `IInputProxy` API
Fix	Fixed hover and active pseudo-classes inside slotted and host brackets
Fix	Fixed stale styling when adding an element that creates a complex selector match
Fix	Fixed caret positioning in `input` and `textarea` elements when setting the value from JavaScript
Fix Unity	Fixed accumulation of C# implementations of public interfaces until the library is unloaded
Fix	Fixed localization sample for Nintendo Switch
Fix Unity	Fixed input issues in the `MadRabbits` sample
Fix	Fixed a resource leak of in the DirectX 11 backend
Fix	Fixed performance regression in text rendering
Fix	Fixed SVG border image rendering regression when SVG has no width and height
Fix	Fixed SVG mask size when using relative units
Fix	Fixed the calculation of `em` and `rem` units for inline SVG root element
Fix	Fixed updating of inline SVG styles when the root font style changes
Fix Unreal Engine	Updated Player starting scripts to list the available options
Fix Unreal Engine	Fix possible unpainted frames when using UMG widgets and destroying the scene
Fix Unreal Engine	Fix backdrop-filter on Mobile devices when `MobileHDR` is enabled
Fix Unreal Engine	Fix assert when using shared render target textures and UMG on Sony platforms
Fix Unreal Engine	Add missing lock in `FCohTextureCollector::FindTexture`
Fix Unreal Engine	Invalidate the IME Manager after deactivating and unregistering the Text Input Method Context, resolving a crash
Fix Unreal Engine	Fixed issues with `EnsureMeshData` when running with OpenGL
Fix Unreal Engine	Fixed selection issues when entering text with virtual keyboard
Fix Unreal Engine	Fixed deleting the last character of the input field when using virtual keyboard
Fix Unreal Engine	Fixed possible crash in `FCohRenoirBackend::ReadTexture`

Migration guide

Pixel Shader Changes

Changes to the `Data_PS` constant buffer data layout

With the new release, our Pixel Shader (PS) Constant Buffer Data_PS has had its data layout altered to accommodate more flexible per command data storage. All custom shaders accessing elements from the CB will have to be modified to use the correct elements.

Previous Layout	Current Layout
Per Batch Data float4 (optional, if `shouldClip` is true) AA clipping data float4s Custom per batch data	Per Batch Data float4 (optional, if `shouldClip` is true) AA clipping data float4 `shouldClip` `additionalFlags` Color matrix offset (-1 if there is no color matrix or one is not needed) Padding float4s Custom per batch data
Per Command Data float4 `inColor` / Custom per command data float4 `userData` `additionalFlags` `shouldClip` `sharedCBOffset`	Per Command Data float4 `sharedCBOffset` `userData[3]` float4s `inColor` / Custom per command data

Previous constant buffer offsets usage example:

  int vs, ps, shaderType;
  decode(input.VaryingData, vs, ps, shaderType);
  // ps will point to the color that should be used for this pixel
  // ps + 1 will point to a float4 that contains other per command data
  float4 inColor = Data_PS[ps];
  float4 perCommandData = Data_PS[++ps];
  // perCommandData.w is the index of data used by several batched commands. The format
  // of this shared data is custom for every command type.
  int sharedCBOffset = int(perCommandData.w);

Current constant buffer offsets usage example:

  int vs, ps, shaderType;
  decode(input.VaryingData, vs, ps, shaderType);
  // ps will point to a float4 that contains the shared CB offset and some per command user data
  // ps + 1 will point to the color that should be used for this pixel
  float4 perCommandData = Data_PS[ps];
  float4 inColor = Data_PS[++ps];
  // perCommandData.x is the index of data used by several batched commands. The format
  // of this shared data is custom for every command type.
  int sharedCBOffset = int(perCommandData.x);

Below is a table, mapping the Pixel Shader CB elements' previous and new location inside the Data_PS CB along with their usage:

Before	Now	Usage
`Data_PS[ps]`	`Data_PS[ps + 1]`	`inColor` / Other custom per command data
`Data_PS[ps + 1].x`	`Data_PS[ps].y`	`userData`
`Data_PS[ps + 1].y`	`Data_PS[sharedCBOffset + SHARED_PS_DATA_OFFSET].y`	`additionalFlags`
`Data_PS[ps + 1].z`	`Data_PS[sharedCBOffset + SHARED_PS_DATA_OFFSET].x`	`shouldClip`
`Data_PS[ps + 1].w`	`Data_PS[ps].x`	`sharedCBOffset`
`Data_PS[sharedCBOffset]`	`Data_PS[sharedCBOffset]`	Custom per batch data
`Data_PS[sharedCBOffset + SHARED_PS_DATA_OFFSET]`	`Data_PS[sharedCBOffset + SHARED_PS_AA_CLIPPING_DATA_OFFSET]`	AA clipping data (optional, if `shouldClip` is true)
	`Data_PS[ps].z`	`userData` (unused for now)
	`Data_PS[ps].w`	`userData` (unused for now)
	`Data_PS[sharedCBOffset + SHARED_PS_DATA_OFFSET].z`	Color matrix offset (-1 if none or not needed)
	`Data_PS[sharedCBOffset + SHARED_PS_DATA_OFFSET].w`	Padding (unused for now)

The SHARED_PS_DATA_OFFSET, which was used to calculate the offset of the AA Clipping data, will now be used to find the initial per batch data(containing the shouldClip, additional flags and the color matrix offset), while a new offset called SHARED_PS_AA_CLIPPING_DATA_OFFSET will be used for the original purpose.

Before:

#define SHARED_PS_DATA_OFFSET -1

Now:

#define SHARED_PS_DATA_OFFSET -1
#define SHARED_PS_AA_CLIPPING_DATA_OFFSET -2