build_matrix includes weird imaginary numbers

[gm-bug-reporter]

Description

making a matrix like matrix_build(0,0,0,90,0,0,1,1,1)
should make a matrix at position 0, rotated 90 degrees on the "x" axis
in gamemaker that appears like this.

specifically -4.371... so on. Appears incorrect. I think it should be 0
if you take that number and round it. It also becomes 0, depsite not being close to 0.

squaring the number however, doesn't give the result -4.371.... should give either. but gives 1.9106....

show_debug_message on the number also simply displays 0

in short, i think there is some decimal error shenanigans with how matrices are created and handled, that makes these 0's in disguise appear that can cause issues, if you need to use them directly.

Steps To Reproduce

1. Start GameMaker
2. create code in create event of an object. placed in a room

var rotation_mat = matrix_build(0,0,0,90,0,0,1,1,1)
var odd_number = rotation_mat[5]

var rounded = round(odd_number) //becomes 0
var squared = sqr(odd_number) //becomes 1.910605....

3. place breakpoint, on odd_number, and observe the result of the different variables.

Which version of GameMaker are you reporting this issue for?

IDE v2024.11.0.179 Runtime v2024.11.0.227

Which operating system(s) are you seeing the problem on?

Windows 10.0.19045.0

Which platform(s) are you seeing the problem on?

Windows

e86cae4a-7ab0-480a-8fcc-a736a5778e5d

[L-Clouds]

Those are numbers in scientific notation, not imaginary numbers.

They are close to zero. -4.371...E-08 means -4.371*10^-8, which is -0.00000004371

They likely are not exactly 0 due to imperfect numerical precision for better speed and memory use, a very normal and standardized concept in computing.

[stuckie]

Closing as above.