Additional resources on alignment

[AlecGoncharow]

I noticed you have a page on alignment and just wanted to drop a few links about aligned offset in uniform buffers as I have run into this in my own project.

A great resource for GLSL, which appears to be tackling similar topics is the Uniform block layout section on the Advanced GLSL page on Learn OpenGL.
This includes this example:

layout (std140) uniform ExampleBlock
{
                     // base alignment  // aligned offset
    float value;     // 4               // 0 
    vec3 vector;     // 16              // 16  (offset must be multiple of 16 so 4->16)
    mat4 matrix;     // 16              // 32  (column 0)
                     // 16              // 48  (column 1)
                     // 16              // 64  (column 2)
                     // 16              // 80  (column 3)
    float values[3]; // 16              // 96  (values[0])
                     // 16              // 112 (values[1])
                     // 16              // 128 (values[2])
    bool boolean;    // 4               // 144
    int integer;     // 4               // 148
}; 

Which I found particularly helpful. One additional thing to note is that mat4 (and likely mat3 but I haven't tested it) is also required to be on a multiple of 16 aligned offset.

Another particularly sharp edge is that the mat3 type in GLSL also assumes each column has the same alignment as a vec4 type, not sure if this is true in WGSL as well.

FWIW it seems this is such an annoying thing to deal with that some recommend not using vec3's at all, I am not sold on this idea, but I believe it is worth acknowledging.

[sotrh]

Hmm interesting. Float arrays really get padded like that? You'd think they'd just have padding on the end.