/*
* Implement SVGF style denoising as bgfx example. Goal is to explore various
* options and parameters, not produce an optimized, efficient denoiser.
*
* Starts with deferred rendering scene with very basic lighting. Lighting is
* masked out with a noise pattern to provide something to denoise. There are
* two options for the noise pattern. One is a fixed 2x2 dither pattern to
* stand-in for lighting at quarter resolution. The other is the common
* shadertoy random pattern as a stand-in for some fancier lighting without
* enough samples per pixel, like ray tracing.
*
* First a temporal denoising filter is applied. The temporal filter is only
* using normals to reject previous samples. The SVGF paper also describes using
* depth comparison to reject samples but that is not implemented here.
*
* Followed by some number of spatial filters. These are implemented like in the
* SVGF paper. As an alternative to the 5x5 Edge-Avoiding A-Trous filter, can
* select a 3x3 filter instead. The 3x3 filter takes fewer samples and covers a
* smaller area, but takes less time to compute. From a loosely eyeballed
* comparison, N 5x5 passes looks similar to N+1 3x3 passes. The wider spatial
* filters take a fair chunk of time to compute. I wonder if it would be a good
* idea to interleave the input texture before computing, after the first pass
* which skips zero pixels.
*
* I have not implemetened the variance guided part.
*
* There's also an optional TXAA pass to be applied after. I am not happy with
* its implementation yet, so it defaults to off here.
*/
/*
* References:
* Spatiotemporal Variance-Guided Filtering: Real-Time Reconstruction for
* Path-Traced Global Illumination. by Christoph Schied and more.
* - SVGF denoising algorithm
*
* Streaming G-Buffer Compression for Multi-Sample Anti-Aliasing.
* by E. Kerzner and M. Salvi.
* - details about history comparison for temporal denoising filter
*
* Edge-Avoiding À-Trous Wavelet Transform for Fast Global Illumination
* Filtering. by Holger Dammertz and more.
* - details about a-trous algorithm for spatial denoising filter
*/
* Implement SDF font outlines, drop shadows, and image glyphs
* Update 11-fontsdf to showcase the SDF outlines, drop shadows, and image glyphs
Co-authored-by: Josh Jensen <josh@everrush.com>
* Adds UAV support for D3D12, Vulkan and reworked support for OpenGL, D3D11
UAV support is now uniform across compute and draw.
To set a UAV you just use bgfx::setImage() and IMAGE2D in the shader, just like in compute.
Due to these changes shaders will have to be recompiled.
The changes include:
- D3D11 requires patching of the UAV slot number (which is now done by modifying the DXBC instead of using a macro)
- If the DXBC binary includes a debug chunk, that is also patched to match the new slot number
- All the other renderers don't need any kind of patching
- There are some shader annotations to better convert the UAV format used in hlsl to spirv
Possibility of further enhancements:
- bgfx::setViewFrameBuffer() only supports binding to a framebuffer or, using BGFX_INVALID_HANDLE, to bind the default backbuffer. This doesn't allow for the case where there is no need to bind to either one of them, for example when using a fragment shader only to read and write to an UAV.
* Bump shader version, because they need to be recompiled.
Because example 42 was using the shaders from example 07 (callback), which have
input vertex attributes position and color, while the mesh from example 42 has
attributes position and normal, this causes problems on Windows when using
AMD gpus (no bunny mesh would appear on the window).
The glsl function findMSB is overriden, causing an error on Windows and Linux
when running on AMD or Intel gpus. Nvidia, for whatever reason, seems to allow
overriding the function.
When compiling shader cs_gdr_stream_compaction.sc on GCN 1.0 gpus
the following error appears:
Compute link error: HW_UNSUPPORTED.
ERROR: Internal compile error, error code: E_SC_NOTSUPPORTED
Shader not supported by HW
These changes avoid the error.
