Compression Module

Intrinsic-backed vertex decompression helpers for packed positions, normals, UVs, and colors.

Import

bwsl

import Compression

This module has no module imports.

Usage Examples

Read Packed Vertex Attributes

Use Compression when vertex buffers store compact packed data and the shader needs normalized positions, normals, UVs, or colors.

bwsl

import Compression

attributes {
  positionPacked: uint
  normalPacked: uint
  uvPacked: uint
  colorPacked: uint
}

float3 localPos = Compression::decompressPosition_10_10_10(attributes.positionPacked);
float3 normal = Compression::decompressOctahedral16(attributes.normalPacked);
float2 uv = Compression::decompressUV16_16(attributes.uvPacked);
float4 color = Compression::decompressColor8888(attributes.colorPacked);

output.position = resources.modelViewProjection * float4(localPos, 1.0);
output.normal = normal;
output.uv = uv;
output.color = color;

Keep Bandwidth Down for Dense Meshes

Use decompression helpers when the mesh is bandwidth-bound, such as particles, crowds, impostors, foliage, or mobile/WebGL targets.

bwsl

import Compression

float3 n = Compression::decompressOctahedral16(attributes.normalPacked);
float2 uv = Compression::decompressUV16_16(attributes.uvPacked);

float windMask = sample(resources.windMask, resources.linearSampler, uv).r;
float bend = sin(resources.time + attributes.position.x * 0.15) * windMask;

float3 bentPosition = attributes.position + n * bend * resources.windStrength;
output.position = resources.viewProjection * float4(bentPosition, 1.0);

Constants

None.

Structs

No structs found.

Enums

No enums found.

Functions

decompressPosition_10_10_10

Decode a packed 10-10-10 position

bwsl

decompressPosition_10_10_10 :: (uint packed) -> float3

decompressOctahedral16

Decode a 16-bit octahedral normal from two packed UNorm8 channels

bwsl

decompressOctahedral16 :: (uint packed) -> float3

decompressUV16_16

Decode packed UNorm16 UV coordinates

bwsl

decompressUV16_16 :: (uint packed) -> float2

decompressColor8888

Decode packed UNorm8 color

bwsl

decompressColor8888 :: (uint packed) -> float4

Source

Generated from compiler-reference/modules/Compression.bwsl.