graphics - Please explain about unmap

Question

I am studying directx12 and I think there is a problem with understanding map and unmap, so I ask a question

hr = constantBufferUploadHeap[i]->Map(0, nullptr, reinterpret_cast<void**>(&cbColorMultiplierGPUAddress[i]));
    constantBufferUploadHeap[i]->Unmap(0, &readRange);
    memcpy(cbColorMultiplierGPUAddress[i], &cbColorMultiplierData, sizeof(cbColorMultiplierData));

If I use map and call unmap right away, can't memcpy be able to work normally? But seeing it work. Please explain about unmap

question from:https://stackoverflow.com/questions/65830388/please-explain-about-unmap

Answer 1

Waitting for answers