lowenware / dotrix

A 3D engine with ECS and Vulkan renderer for Rust developers
https://dotrix.rs
MIT License
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Helper for writing gpu data #167

Open QuantumEntangledAndy opened 2 years ago

QuantumEntangledAndy commented 2 years ago

Gpu data like uniforms and storage need special rules for alignement of data. It would be nice if we have some sort of convenince methods that would automatically align data and place data.

For example consider a matrix of 3x3. On the gpu the data is arranged as: m11, m12, m13, PAD_BYTE, m21, m22, m23, PAD_BYTE, m31, m32, m33, PAD_BYTE due to how the data is 16byte aligned

Similaraly for vec3 it is also 16byte aliged so that a structure of kind:

Struct Example {
  a: vec3<f32>,
  b: vec3<f32>,
}

Is actually in memory

Struct ExampleOnCpu {
  a: [f32; 3],
  pad_a: f32,
  b: [f32; 3],
  pad_b: f32,
}

Having some way to consistenty serialise this would reduce code complexity and reduce errors caused by missunderstood alignments

Lowentwickler commented 2 years ago

I agree we need some rules. And I like your suggestion with pad_ prefix with name of padded property. You suggest to write down rules somewhere? Or prepare some tool to handle this? Like macro or something?