Integers: I'm confused

[Words Fail]

I would like something to go up by 0.25. Then I need to check later for 1.00, 1.25, 1.50, 1.75, and 2.00. What do I need to dim?
 

dim speed = a.b

 

The whole page on 4.4 and 8.8 confuses me. I think it should say something like this is an example of a few 4.4.. and this is an example of a few 8.8

[KevKelley]

I think I did something similar in trying to make acceleration in one game where I would do something like

 

if joy0right then b=b+25

 

and then I would do something like 

 

if b=100 then a=a+1:b=0

 

There are probably other ways to do this but it seemed to work for this purpose. 

[bogax]

  the fractional part is still just a byte
  it can reperesent 256 values, 0..255 inclusive
  as a .8 fraction (8 is the number of bits in a byte)
  a byte is the integer number of 256ths (1/256)
  1 = 256 256ths
  .25 = 256 * .25 = 64
  for 0.25 you have two bytes 0 and 64
  ie the fractional byte will equal 64
  this will be relatively neat in your case because youre
  looking for multiples of a power of two
  so eg .25 (a power of 2, 2^-2) is an integer number of 256ths

  if you want to test for 1.5 it will be 1 and .5 * 256 = 128

 

  if a = 1 && b = 128 then [do something]

 

  for non powers of two it gets messier
  0.33 is 84.48 256ths ie .33 * 256 = 84.48 and bB rounds it to 84

 

 

  personally I'd dim it as b.a because the variables are in order
  in memory and the processor is little endian and expects
  a 16 bit quantity to be in order in memory with the least byte first
  but that has nothing to do with what you're doing  

Edited January 30, 2023 by bogax

[KevKelley]

1 hour ago, bogax said:

  personally I'd dim it as b.a because the variables are in order
  in memory and the processor is little endian and expects
  a 16 bit quantity to be in order in memory with the least byte first
  but that has nothing to do with what you're doing  

Out of curiosity, would doing this result in some space saved? Less cycles?

[+Gemintronic]

Never tried the a.b whatever thing as my brain can't handle it.

 

I usually have a main counter that goes up by one each main game loop:

 

main

 counter = counter + 1

 

If I want something to happen every four iterations of the main loop I do this:

 

 if counter&3 = 0 then goto everyforthdothis

 

That takes the counter that goes from 0 - 255 to something like 0 1 2 3 0 1 2 3 0 1 2 3 ..

 

If you wanted something to happen every other iteration of the main loop you can just check the first bit in the counter since it always flips each time:

 

 if counter{0} then goto otherframe