XinJiangBBH_LBE/Plugins/Streamline/Docs/APIChangesAndImprovements.md

Improvements and API changes in SL 1.5 and SL 2.0

NOTE: This document contains the high level breakdown of changes introduced in SL 1.5/2.0 and how they compare to previous SL versions. For more details please read the full programming guide

SL 1.5

RESOURCE STATE TRACKING

• SL no longer tracks resource states, host is responsible for providing correct states when tagging resources.

COMMAND LIST STATE TRACKING

• SL by default disables any command list (CL) tracking, host is responsible for restoring CL state after each slEvaluateFeature call.

DISABLING OF THE INTERPOSER

• SL disables interposer (DXGI/D3D proxies) unless they are explicitly requested by at least one supported plugin

VERIFYING SL DLLs

• SL now includes sl_security.h header as part of the main SDK (no longer needed to download the SL sample SDK)

OS VERSION DETECTION

• Switched to obtaining the correct version from the kernel32.dll product description instead of using various MS APIs which return different/incorrect versions
• Flag PreferenceFlags::eBypassOSVersionCheck in sl::Preferences can be used to opt-out from the OS detection (off by default and highly discouraged to use)

OTA OPT-IN

• Expanded sl::Preferences to include PreferenceFlags::eAllowOTA to automatically opt-in in the OTA program (SL and NGX). This flag is set by default.

DLSS PRESETS

• Host can change DL networks (presets) for the DLSS by modifying sl::DLSSOptions.

SL 2.0

Streamline 2.0 includes all the above mentioned v1.5 changes with the following additions:

FEATURE ID

• No longer provided as enum but rather as constant expression unsigned integers.
• Core feature IDs declared and defined in sl.h while specific feature IDs are now located in their respective header files.

ENUM NAMING

• All enums have been converted to enum class Name::eValue format.

ERROR REPORTING

• All SL functions now return sl::Result (new header sl_result.h)
• Still required to monitor error logging callbacks to catch every single possible error at the right time but this improves handling of the most common errors.
• Introduced helper macro SL_FAILED.
• Helper method added to convert sl::Result to a string.

VERSIONING AND OTA

• New API slGetFeatureVersion returns both SL and NGX (if any) versions.

REQUIREMENTS REPORTING

• Removed slGetFeatureConfiguration which was returning JSON since it is not always convenient for eve
• New API slGetFeatureRequirements is added to provide info about OS, driver, HWS, rendering API, VK extensions and other requirements
• Added getVkPhysicalDeviceVulkan12Features and getVkPhysicalDeviceVulkan13Features helper functions in the new sl_helpers_vk.h header.

CONSTANTS VS SETTINGS

• Generic slSetFeatureConsts and slGetFeatureSettings API have been removed and new API slGetFeatureFunction has been added.
• Each SL feature exports set of functions which are used to perform feature specific task.
• New helper macro SL_FEATURE_FUN_IMPORT and helper functions in the related sl_$feature.h headers.
• Helper functions added to each per-feature header to make importing easy.

IS FEATURE SUPPORTED AND ADAPTER BIT-MASK

• slIsFeatureSupported is modified to use adapter LUID which is easily obtained from DXGIAdapterDesc or VK physical device.
• Engines are already enumerating adapters so this should fit in nicely with the existing code.
• When using VK host can provide VkPhysicalDevice instead of LUID if needed.

ACTUAL FPS

• Removed actualFrameTimeMs and timeBetweenPresentsMs and replaced with an integer value numFramesActuallyPresented.

IMPROVED VIEWPORT SUPPORT FOR DLSS-G

• Host can specify any viewport id when calling slDLSSGSetOptions rather than forcing viewport 0 all the time.

"NOT RENDERING GAME FRAMES" FLAG

• Removed completely since it has become redundant.
• Host is now required to turn DLSS-G on/off using slDLSSGSetOptions

BUFFER COPIES AND TAGGING

• slSetTag API has been expanded to include command list and resource life-cycle information.
• If needed resources are automatically copied internally by SL.
• slEvaluateFeature can be used to tag resources locally (tags only valid for the specific evaluate call, see programming guide for details)

FRAME ID

• New API slGetNewFrameToken is added to allow host to obtain frame handle for the next frame.
• Same handle is then passed around to all SL calls.
• If host wants to fully control frame counting the frame index can be provided as input

MULTIPLE DEVICES

• New API slSetD3DDevice and slSetVulkanInfo can be used to specify which device SL should be using.

OBTAINING NATIVE INTERFACES

• When using 3rd party libraries (including NVAPI) it is not advisable to pass SL proxies as inputs.
• New API slGetNativeInterface added to allow access to native interfaces as needed.

MANUAL HOOKING

• Removed slGetHook* API
• New API slGetNativeInterface in combination with slUpgradeIntercace is now used to significantly simplify manual hooking.