Modern Math TryInverse

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TryInverse

Writes the inverse of a matrix into a second one, or returns false if there is none.

Syntax

TryInverse( byref a as Mat4, byref outm as Mat4 ) as boolean

Notes

• FALSE when the matrix is singular, rather than filling the output with infinities -- the determinant is checked first.
• The output is written only on success.
• For a pure rotation, Transpose is the inverse and is far cheaper.

Examples

#import "std/numeric"
using numeric

dim as Mat4 m
for i as int32 = 0 to 15
    m.m( i ) = 0
next
for i as int32 = 0 to 3
    m.m( i * 4 + i ) = 2     '' uniform scale by 2
next

dim as Mat4 inv
print TryInverse( m, inv )   '' true
print inv.m( 0 )             '' 0.5

'' A singular matrix answers FALSE instead of producing infinities
dim as Mat4 s = m
s.m( 0 ) = 0
print TryInverse( s, inv )   '' false

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Library: Math Library
Category: Math Library
Documented under: Members