@Neospector(View Post) "c" key is not stuck, my problem is , when i draw line, the display mode changes, even if I change to Fire mode, after draw a line of anything, the display mode cycles.
eventually, I know why display mode changes automatically. if I run the powder toy with some translation software, the translation software will send "Ctrl + C" to the operating system after I holding down the mouse button and drag for some distance in order to capture the word I selected. so the display mode changes.