1al_check_inverse(3)        Library Functions Manual        al_check_inverse(3)
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NAME

6       al_check_inverse
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SYNOPSIS

9              #include <allegro5/allegro.h>
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11              int al_check_inverse(const ALLEGRO_TRANSFORM *trans, float tol)
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DESCRIPTION

14       Checks  if  the transformation has an inverse using the supplied toler‐
15       ance.  Tolerance should be a small value between 0 and  1,  with  0.001
16       being sufficient for most applications.  Note that this check is super‐
17       fluous most of the time if you never touched the transformation  matrix
18       values yourself.  The only thing that would cause the transformation to
19       not have an inverse is if you applied a 0 (or very small) scale to  the
20       transformation.   As  long  as  the  scale  is comfortably above 0, the
21       transformation will be invertible.
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23       Parameters:
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25       · trans - Transformation to check
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27       · tol - Tolerance
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29       Returns: 1 if the transformation is invertible, 0 otherwise
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SEE ALSO

32       al_invert_transform(3)
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36Allegro reference manual                                   al_check_inverse(3)
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