mirror of
https://github.com/ncblakely/GiantsTools
synced 2024-11-24 15:15:37 +01:00
96 lines
2.8 KiB
HLSL
96 lines
2.8 KiB
HLSL
//
|
|
// Copyright (c) Microsoft. All rights reserved.
|
|
// This code is licensed under the MIT License (MIT).
|
|
// THIS CODE IS PROVIDED *AS IS* WITHOUT WARRANTY OF
|
|
// ANY KIND, EITHER EXPRESS OR IMPLIED, INCLUDING ANY
|
|
// IMPLIED WARRANTIES OF FITNESS FOR A PARTICULAR
|
|
// PURPOSE, MERCHANTABILITY, OR NON-INFRINGEMENT.
|
|
//
|
|
// Developed by Minigraph
|
|
//
|
|
// Author: James Stanard
|
|
//
|
|
|
|
#ifndef __PIXEL_PACKING_VELOCITY_HLSLI__
|
|
#define __PIXEL_PACKING_VELOCITY_HLSLI__
|
|
|
|
#if 1
|
|
// This is a custom packing that devotes 10 bits each to X and Y velocity but 12 bits to Z velocity. Floats
|
|
// are used instead of SNORM to increase precision around small deltas, which are the majority of deltas.
|
|
// With TAA and Motion Blur, velocities are clamped, giving little reason to express them precisely in terms
|
|
// of the size of the screen.
|
|
#define packed_velocity_t uint
|
|
|
|
// Designed to compress (-256.0, +256.0) with a signed 6e3 float
|
|
uint PackXY( float x )
|
|
{
|
|
uint signbit = asuint(x) >> 31;
|
|
x = clamp(abs(x / 32768.0), 0, asfloat(0x3BFFE000));
|
|
return (f32tof16(x) + 8) >> 4 | signbit << 9;
|
|
}
|
|
|
|
float UnpackXY( uint x )
|
|
{
|
|
return f16tof32((x & 0x1FF) << 4 | (x >> 9) << 15) * 32768.0;
|
|
}
|
|
|
|
// Designed to compress (-1.0, 1.0) with a signed 8e3 float
|
|
uint PackZ( float x )
|
|
{
|
|
uint signbit = asuint(x) >> 31;
|
|
x = clamp(abs(x / 128.0), 0, asfloat(0x3BFFE000));
|
|
return (f32tof16(x) + 2) >> 2 | signbit << 11;
|
|
}
|
|
|
|
float UnpackZ( uint x )
|
|
{
|
|
return f16tof32((x & 0x7FF) << 2 | (x >> 11) << 15) * 128.0;
|
|
}
|
|
|
|
// Pack the velocity to write to R10G10B10A2_UNORM
|
|
packed_velocity_t PackVelocity( float3 Velocity )
|
|
{
|
|
return PackXY(Velocity.x) | PackXY(Velocity.y) << 10 | PackZ(Velocity.z) << 20;
|
|
}
|
|
|
|
// Unpack the velocity from R10G10B10A2_UNORM
|
|
float3 UnpackVelocity( packed_velocity_t Velocity )
|
|
{
|
|
return float3(UnpackXY(Velocity & 0x3FF), UnpackXY((Velocity >> 10) & 0x3FF), UnpackZ(Velocity >> 20));
|
|
}
|
|
|
|
#elif 1
|
|
#define packed_velocity_t float4
|
|
|
|
// Pack the velocity to write to R10G10B10A2_UNORM
|
|
packed_velocity_t PackVelocity( float3 Velocity )
|
|
{
|
|
// Stretch dx,dy from [-64, 63.875] to [-512, 511] to [-0.5, 0.5) to [0, 1)
|
|
// Velocity.xy = (0,0) must be representable.
|
|
return float4(Velocity * float3(8, 8, 4096) / 1024.0 + 512 / 1023.0, 0);
|
|
}
|
|
|
|
// Unpack the velocity from R10G10B10A2_UNORM
|
|
float3 UnpackVelocity( packed_velocity_t Velocity )
|
|
{
|
|
return (Velocity.xyz - 512.0 / 1023.0) * float3(1024, 1024, 2) / 8.0;
|
|
}
|
|
#else
|
|
#define packed_velocity_t float4
|
|
|
|
// Pack the velocity to write to R16G16B16A16_FLOAT
|
|
packed_velocity_t PackVelocity( float3 Velocity )
|
|
{
|
|
return float4(Velocity * float3(16, 16, 32*1024), 0);
|
|
}
|
|
|
|
// Unpack the velocity from R10G10B10A2_UNORM
|
|
float3 UnpackVelocity( packed_velocity_t Velocity )
|
|
{
|
|
return Velocity.xyz / float3(16, 16, 32*1024);
|
|
}
|
|
|
|
#endif
|
|
|
|
#endif // __PIXEL_PACKING_HLSLI__
|