texture_size

The texture_size function returns the integer dimensions of a texture at a specific mip level. Use it when shader code needs texel-sized offsets, pixel-perfect addressing, or bounds-aware texture access.

Live Demo

Signature

bwsl

texture_size :: (texture2D tex, int mip = 0) -> int2 {...}
texture_size :: (texture3D tex, int mip = 0) -> int3 {...}
texture_size :: (textureCube tex, int mip = 0) -> int2 {...}

The mip argument is optional and defaults to 0, so texture_size(resources.albedo) returns the base level's size.

Parameters

Parameter	Type	Description
`tex`	`texture*`	Texture to query
`mip`	`int`	Mip level to query (optional, default `0`)

Return Value

Returns the width, height, and depth for the requested mip level. 2D and cube textures return int2; 3D textures return int3.

Known issue: 3D and array textures

The current compiler returns int2 for every texture type, so a texture3D's depth and a texture2DArray's layer count can't be queried yet. Until this is fixed, read the result into an int2. Tracked in BWSL#204.

Example

bwsl

int2 size = texture_size(resources.albedoTexture, 0);
float2 texel = float2(1.0 / float(size.x), 1.0 / float(size.y));
float4 center = sample(resources.albedoTexture, resources.albedoSampler, input.uv);
float4 right = sample(resources.albedoTexture, resources.albedoSampler, input.uv + float2(texel.x, 0.0));

Mip-Aware

Pass the mip level you intend to read. Higher mip levels are smaller, so their texel size is larger.

Compiled Output

When compiled to GLSL:

glsl

textureSize(tex, mip)

When compiled to HLSL:

hlsl

tex.GetDimensions(...)

When compiled to Metal:

metal

tex.get_width(mip), tex.get_height(mip)

Test texture_size in a live shader