Hello everyone, as the title says, I need a clipped line routine (I mean a routine that still draws the line even if it is partly off-screen) that I can call with LINE(X1,Y1,X2,Y2) or that would use X1,Y1,X2 and Y2 as variables (there roles in the routine being obvious).

I saw this one by Darl181 but it is not a routine that I can call with LINE(X1,Y1,X2,Y2), it is a full program that includes line clipping, but only supporting one point and the other one always at the center

Then I saw this and tried to write it myself but failed miserably.
Here is the source in the spoiler if you see where the error is (note that it fails even though it is not optimized, I coded it noob-style to be sure that it would work but still failed )

So, anyone has a solution ?

Why are you using the fixed ** multiplication ? I tought that it was only for 8.8 fixed number  .

Isn't it for multiplication between two signed integers ?
"The signed multiplication is performed using the high byte as the integer part and the low byte as the decimal part returning a number in the same format."

yes it's true. I think there is a tuto on this.

 // still the signed division (with two integer), isn't it ?

see this one : http://ourl.ca/16928
(only for y>64)

But that would be great to have one that supports clipping in all 4 directions.

Done
Code in spoiler.
However, after my recent fail, I decided to code this one like a complete noob, so there are lines that are the same and a lot of basic optimizations to do (and also less basic optimizations but I don't think I'll see them anyway ). Feel free to optimize it

(Also, lol, I just double posted and quoted myself )

What is the cause of the line being cut off at the right side of the screen?

What do you mean ? Do you mean that it gets clipped before reaching the edge of the screen ?
Well that is because I put a wrong number
Same for what happens at the bottom
I put 62 and 94 instead of 63 and 95, but that is not really difficult to change

Nice Hayleia. Clipping is annoying lol -_-

How does that perform speed-wise? I think one easy optimization would be to make If r1<<0
 r4-(r2-r4*r3//(r1-r3))->r2
 0->r1
End
If r1>94
 r2-r4*94//(r1-r3)+r2-(r2-r4*r1//(r1-r3))->r2
 94->r1
Endinto
If r1<<0
 -1->r1
 r4-(r2-r4*r3//(r1-r3))->r2
ElseIf r1>94
 r2-r4*94//(r1-r3)+r2-(r2-r4*r1//(r1-r3))->r2
 94->r1
Endand same for all the other pieces, since a variable can't be less than 0 and greater than 94 at the same time..there'll be a small speed gain there (and a tiny bit saved by manipulating the placement of 0->r1.

Preevaluating dX and dY would also be helpful

I'll look at it some more later, but maybe Runer112 will show up lol