[MIRROR] Extends the metric prefixes. (#1343)

* Extends the metric prefixes. (#81739)

## About The Pull Request
Extends the metric prefixes some things will display. Adds the quecto,
ronto, yocto, zepto. atto, exa, zetta, yotta, ronna and quetta prefixes.
## Why It's Good For The Game
Makes it easier to read the numbers when someone manages to break atmos
or whatever.
## Changelog
:cl:
qol: Extended the metric prefixes.
/:cl:

* Extends the metric prefixes.

---------

Co-authored-by: Pickle-Coding <[email protected]>

code/__HELPERS/maths.dm

@@ -131,23 +131,23 @@
  * Returns: [SI_COEFFICIENT = si unit coefficient, SI_UNIT = prefixed si unit.]
  */
 /proc/siunit_isolated(value, unit, maxdecimals=1)
-	var/static/list/prefixes = list("f","p","n","μ","m","","k","M","G","T","P")
+	var/static/list/prefixes = list("q","r","y","z","a","f","p","n","μ","m","","k","M","G","T","P","E","Z","Y","R","Q")
 
 	// We don't have prefixes beyond this point
 	// and this also captures value = 0 which you can't compute the logarithm for
 	// and also byond numbers are floats and doesn't have much precision beyond this point anyway
-	if(abs(value) <= 1e-18)
+	if(abs(value) < 1e-30)
 		. = list(SI_COEFFICIENT = 0, SI_UNIT = " [unit]")
 		return
 
-	var/exponent = clamp(log(10, abs(value)), -15, 15) // Calculate the exponent and clamp it so we don't go outside the prefix list bounds
+	var/exponent = clamp(log(10, abs(value)), -30, 30) // Calculate the exponent and clamp it so we don't go outside the prefix list bounds
 	var/divider = 10 ** (round(exponent / 3) * 3) // Rounds the exponent to nearest SI unit and power it back to the full form
 	var/coefficient = round(value / divider, 10 ** -maxdecimals) // Calculate the coefficient and round it to desired decimals
-	var/prefix_index = round(exponent / 3) + 6 // Calculate the index in the prefixes list for this exponent
+	var/prefix_index = round(exponent / 3) + 11 // Calculate the index in the prefixes list for this exponent
 
 	// An edge case which happens if we round 999.9 to 0 decimals for example, which gets rounded to 1000
 	// In that case, we manually swap up to the next prefix if there is one available
-	if(coefficient >= 1000 && prefix_index < 11)
+	if(coefficient >= 1000 && prefix_index < 21)
 		coefficient /= 1e3
 		prefix_index++
 

code/modules/unit_tests/siunit.dm

@@ -12,4 +12,4 @@
 	TEST_ASSERT_EQUAL(siunit_pressure(999.9e3), "999.9 MPa" , "")
 	TEST_ASSERT_EQUAL(siunit_pressure(999.9e3, 0), "1 GPa", "")
 	TEST_ASSERT_EQUAL(siunit_pressure(1e6), "1 GPa", "")
-	TEST_ASSERT_EQUAL(siunit_pressure(3e17), "300000 PPa", "")
+	TEST_ASSERT_EQUAL(siunit_pressure(3e32), "300000 QPa", "")