FidelityFX FSR3

FfxFsr3UpscalerMessage

typedef void (*FfxFsr3UpscalerMessage )(
    FfxMsgType type,
    const wchar_t *message
    )

Pass a string message.

Used for debug messages.

Parameters:

ffxFsr3UpscalerContextCreate

FFX_API  FfxErrorCode  ffxFsr3UpscalerContextCreate (
    FfxFsr3UpscalerContext * pContext,
    const FfxFsr3UpscalerContextDescription * pContextDescription
)

Create a FidelityFX Super Resolution 3 context from the parameters programmed to the FfxFsr3UpscalerCreateParams structure.

The context structure is the main object used to interact with the FSR3 API, and is responsible for the management of the internal resources used by the FSR3 algorithm. When this API is called, multiple calls will be made via the pointers contained in the callbacks structure. These callbacks will attempt to retreive the device capabilities, and create the internal resources, and pipelines required by FSR3’s frame-to-frame function. Depending on the precise configuration used when creating the FfxFsr3UpscalerContext a different set of resources and pipelines might be requested via the callback functions.

The flags included in the flags field of FfxFsr3UpscalerContext how match the configuration of your application as well as the intended use of FSR3. It is important that these flags are set correctly (as well as a correct programmed FfxFsr3UpscalerDispatchDescription) to ensure correct operation. It is recommended to consult the overview documentation for further details on how FSR3 should be integerated into an application.

When the FfxFsr3UpscalerContext is created, you should use the ffxFsr3UpscalerContextDispatch function each frame where FSR3 upscaling should be applied. See the documentation of ffxFsr3UpscalerContextDispatch for more details.

The FfxFsr3UpscalerContext should be destroyed when use of it is completed, typically when an application is unloaded or FSR3 upscaling is disabled by a user. To destroy the FSR3 context you should call ffxFsr3UpscalerContextDestroy.

Parameters:

Return values:

ffxFsr3UpscalerContextGetGpuMemoryUsage

FFX_API  FfxErrorCode  ffxFsr3UpscalerContextGetGpuMemoryUsage (
    FfxFsr3UpscalerContext * pContext,
    FfxEffectMemoryUsage * pVramUsage
)

Get GPU memory usage of the FidelityFX Super Resolution context.

Parameters:

Return values:

ffxFsr3UpscalerContextDispatch

FFX_API  FfxErrorCode  ffxFsr3UpscalerContextDispatch (
    FfxFsr3UpscalerContext * pContext,
    const FfxFsr3UpscalerDispatchDescription * pDispatchDescription
)

Dispatch the various passes that constitute FidelityFX Super Resolution 3.

FSR3 is a composite effect, meaning that it is compromised of multiple constituent passes (implemented as one or more clears, copies and compute dispatches). The ffxFsr3UpscalerContextDispatch function is the function which (via the use of the functions contained in the callbacks field of the FfxFsr3UpscalerContext structure) utlimately generates the sequence of graphics API calls required each frame.

As with the creation of the FfxFsr3UpscalerContext correctly programming the FfxFsr3UpscalerDispatchDescription is key to ensuring the correct operation of FSR3. It is particularly important to ensure that camera jitter is correctly applied to your application’s projection matrix (or camera origin for raytraced applications). FSR3 provides the ffxFsr3UpscalerGetJitterPhaseCount and ffxFsr3UpscalerGetJitterOffset entry points to help applications correctly compute the camera jitter. Whatever jitter pattern is used by the application it should be correctly programmed to the jitterOffset field of the dispatchDescription structure. For more guidance on camera jitter please consult the documentation for ffxFsr3UpscalerGetJitterOffset as well as the accompanying overview documentation for FSR3.

Parameters:

Return values:

ffxFsr3UpscalerContextGenerateReactiveMask

FFX_API  FfxErrorCode  ffxFsr3UpscalerContextGenerateReactiveMask (
    FfxFsr3UpscalerContext * pContext,
    const FfxFsr3UpscalerGenerateReactiveDescription * pParams
)

A helper function generate a Reactive mask from an opaque only texure and one containing translucent objects.

Parameters:

Return values:

ffxFsr3UpscalerContextDestroy

FFX_API  FfxErrorCode  ffxFsr3UpscalerContextDestroy (FfxFsr3UpscalerContext * pContext)

Destroy the FidelityFX Super Resolution context.

Parameters:

Return values:

ffxFsr3UpscalerGetUpscaleRatioFromQualityMode

FFX_API  float ffxFsr3UpscalerGetUpscaleRatioFromQualityMode (FfxFsr3UpscalerQualityMode  qualityMode)

Get the upscale ratio from the quality mode.

The following table enumerates the mapping of the quality modes to per-dimension scaling ratios.

Passing an invalid qualityMode will return 0.0f.

Parameters:

Returns:

The upscaling the per-dimension upscaling ratio for qualityMode according to the table above.

ffxFsr3UpscalerGetRenderResolutionFromQualityMode

FFX_API  FfxErrorCode  ffxFsr3UpscalerGetRenderResolutionFromQualityMode (
    uint32_t* pRenderWidth,
    uint32_t* pRenderHeight,
    uint32_t displayWidth,
    uint32_t displayHeight,
    FfxFsr3UpscalerQualityMode  qualityMode
)

A helper function to calculate the rendering resolution from a target resolution and desired quality level.

This function applies the scaling factor returned by ffxFsr3UpscalerGetUpscaleRatioFromQualityMode to each dimension.

Parameters:

Return values:

ffxFsr3UpscalerGetJitterPhaseCount

FFX_API  int32_t ffxFsr3UpscalerGetJitterPhaseCount (
    int32_t renderWidth,
    int32_t displayWidth
)

A helper function to calculate the jitter phase count from display resolution.

For more detailed information about the application of camera jitter to your application’s rendering please refer to the ffxFsr3UpscalerGetJitterOffset function.

The table below shows the jitter phase count which this function would return for each of the quality presets.

Parameters:

Returns:

The jitter phase count for the scaling factor between renderWidth and displayWidth.

ffxFsr3UpscalerGetJitterOffset

FFX_API  FfxErrorCode  ffxFsr3UpscalerGetJitterOffset (
    float* pOutX,
    float* pOutY,
    int32_t index,
    int32_t phaseCount
)

A helper function to calculate the subpixel jitter offset.

FSR3 relies on the application to apply sub-pixel jittering while rendering. This is typically included in the projection matrix of the camera. To make the application of camera jitter simple, the FSR3 API provides a small set of utility function which computes the sub-pixel jitter offset for a particular frame within a sequence of separate jitter offsets. To begin, the index within the jitter phase must be computed. To calculate the sequence’s length, you can call the ffxFsr3UpscalerGetJitterPhaseCount function. The index should be a value which is incremented each frame modulo the length of the sequence computed by ffxFsr3UpscalerGetJitterPhaseCount. The index within the jitter phase is passed to ffxFsr3UpscalerGetJitterOffset via the index parameter.

This function uses a Halton(2,3) sequence to compute the jitter offset. The ultimate index used for the sequence is index % phaseCount.

It is important to understand that the values returned from the ffxFsr3UpscalerGetJitterOffset function are in unit pixel space, and in order to composite this correctly into a projection matrix we must convert them into projection offsets. This is done as per the pseudo code listing which is shown below.

const int32_t jitterPhaseCount = ffxFsr3UpscalerGetJitterPhaseCount(renderWidth, displayWidth);

float jitterX = 0;
float jitterY = 0;
ffxFsr3UpscalerGetJitterOffset(&jitterX, &jitterY, index, jitterPhaseCount);

const float jitterX = 2.0f * jitterX / (float)renderWidth;
const float jitterY = -2.0f * jitterY / (float)renderHeight;
const Matrix4 jitterTranslationMatrix = translateMatrix(Matrix3::identity, Vector3(jitterX, jitterY, 0));
const Matrix4 jitteredProjectionMatrix = jitterTranslationMatrix * projectionMatrix;

Jitter should be applied to all rendering. This includes opaque, alpha transparent, and raytraced objects. For rasterized objects, the sub-pixel jittering values calculated by the iffxFsr3UpscalerGetJitterOffset function can be applied to the camera projection matrix which is ultimately used to perform transformations during vertex shading. For raytraced rendering, the sub-pixel jitter should be applied to the ray’s origin, often the camera’s position.

Whether you elect to use the ffxFsr3UpscalerGetJitterOffset function or your own sequence generator, you must program the jitterOffset field of the FfxFsr3UpscalerDispatchParameters structure in order to inform FSR3 of the jitter offset that has been applied in order to render each frame.

If not using the recommended ffxFsr3UpscalerGetJitterOffset function, care should be taken that your jitter sequence never generates a null vector; that is value of 0 in both the X and Y dimensions.

Parameters:

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ffxFsr3UpscalerResourceIsNull

FFX_API  bool ffxFsr3UpscalerResourceIsNull (FfxResource  resource)

A helper function to check if a resource is FFX_FSR3UPSCALER_RESOURCE_IDENTIFIER_NULL.

Parameters:

Returns:

true The resource was not FFX_FSR3UPSCALER_RESOURCE_IDENTIFIER_NULL.

false The resource was FFX_FSR3UPSCALER_RESOURCE_IDENTIFIER_NULL.

ffxFsr3UpscalerGetEffectVersion

FFX_API  FfxVersionNumber  ffxFsr3UpscalerGetEffectVersion ()

Queries the effect version number.

Returns:

The SDK version the effect was built with.

FFX_FSR3UPSCALER_CONTEXT_COUNT

#define FFX_FSR3UPSCALER_CONTEXT_COUNT 1

FidelityFX Super Resolution 3 context count.

Defines the number of internal effect contexts required by FSR3

FFX_FSR3UPSCALER_CONTEXT_SIZE

#define FFX_FSR3UPSCALER_CONTEXT_SIZE (FFX_SDK_DEFAULT_CONTEXT_SIZE)

The size of the context specified in 32bit values.

FFX_FSR3UPSCALER_VERSION_MAJOR

#define FFX_FSR3UPSCALER_VERSION_MAJOR (3)

FidelityFX Super Resolution 3 major version.

FFX_FSR3UPSCALER_VERSION_MINOR

#define FFX_FSR3UPSCALER_VERSION_MINOR (1)

FidelityFX Super Resolution 3 minor version.

FFX_FSR3UPSCALER_VERSION_PATCH

#define FFX_FSR3UPSCALER_VERSION_PATCH (0)

FidelityFX Super Resolution 3 patch version.