I get the impression that it kinda is like Minecraft: you have a 0,0 position and a scale factor. On a 1440p 100% scale display the bottom right corner would be

I get the impression that it kinda is like Minecraft: you have a 0,0 position and a scale factor. On a 1440p 100% scale display the bottom right corner would be position 2560,1440. When you zoom the position becomes 2560* scale factor by 1440 * scale factor. Then, during rendering, all size values just hit that scale factor.