Having a dificult time with Directx11 dynamic texture Map/Unmap

Question

I have been trying to upload a dynamic texture with Map/Unmap but no luck so far.

Here's the code im working with

D3D11_MAPPED_SUBRESOURCE subResource = {};
ImmediateContext->Map(dx11Texture, 0, D3D11_MAP_WRITE_DISCARD, 0, &subResource);

Memory::copy(subResource.pData, (const void*)desc.DataSet[0], texture->get_width() * texture->get_height() * GraphicsFormatUtils::get_format_size(texture->get_format()));
subResource.RowPitch = texture->get_width() * GraphicsFormatUtils::get_format_size(texture->get_format());
subResource.DepthPitch = 0;

ImmediateContext->Unmap(dx11Texture, 0);

I have created the texture with immutable state and supplying the data upfront, that worked out well but when i try to create it with a dynamic flag and upload the same data my texture shows a noisy visual.

This is the texture with immutable creation flags and updating the data upfront on the texture creation phase.

Immutable texture

This is the texture with dynamic creation flags and updating the data after the texture creation phase with Map/Unmap mehtods.

Dynamic texture

Any input would be appreciated.

Answer 1

When using map, the subResource rowPitch that is returned by the map function is the one that is expected for you to perform the copy (you can notice that you never send it back to the deviceContext, so it's read only).

It is generally a power of 2, for memory alignment purposes.

When you provide initial data in an (immutable or other) texture, this copy operation is hidden from you, but still happens behind the scene, so in that case, you need to perform the pitch test yourself.

The process of copying a dynamic texture is as follow :

int myDataRowPitch =; //width * format size (if you don't pad)
D3D11_MAPPED_SUBRESOURCE subResource = {};
ImmediateContext->Map(dx11Texture, 0, D3D11_MAP_WRITE_DISCARD, 0, &subResource);

if (myDataRowPitch == subResource.RowPitch)
{
     //you can do a standard mem copy here
}
else
{
    // here you need to copy line per line
}

ImmediateContext->Unmap(dx11Texture, 0);