Single-resource descriptor writes for updateDescriptorSets. bufferWrite covers the whole-buffer case (a uniform or storage buffer bound in its entirety); imageWrite is its samplerless image sibling (a storage image in GENERAL layout, a sampled image in SHADER_READ_ONLY_OPTIMAL, …); combinedImageSamplerWrite binds an image together with a sampler. Bindings needing partial buffer ranges or descriptor arrays are out of scope — assemble those WriteDescriptorSets directly.