Aside from using incorrect values this could crash the renderer if used in the very first rendering frame because the software renderer always operates on a copy.
Vulkan hardware buffer for software canvas may have some padding
Software renderers should be aware of buffer's pitch in order to copy pixels properly
https://forum.zdoom.org/viewtopic.php?t=64562
These can cause highly dangerous recursions and execute play code deep inside the renderer and since the hardware renderer does not have these, there is very little point for the software renderer to retain them.
