I have a question. Suppose I want to make all of player0's lines be %11111111. Also, I want to change the height of player0. I've read the guide from RT and it mentions player0pointerhi and lo, but it doesn't specify what they actually do nor how to use them. I don't even know if that would be helpful.
It's been a long time since I've used them. I'd agree there's not much clear documentation or examples on playerxpointerhi/low stuff.
Basically, you can't strech or shrink a sprite. You can change the height of a sprite so that it doesn't show some of the sprites graphic data. You can also use playerxpointerhi/low to change what section of sprite data is currently on-screen. So, for example, you can design the sprite graphics data like a totem pole of shapes. By altering the "slice" of drawn sprite data displayed you can effectively have different monsters. You can't mix and match parts though. It has to start at a certain point in the sprite data and end somewhere below.
You usually end up using a variable to store the current ending point of the sprite:
dim p0lo = h
p0lo = player0pointerlo
Then, at some point in the game you switch ending positions in the sprite to make it look like a different enemy:
player0pointerlo = (p0lo +(rand&3))