diff options
author | Norbert Preining <norbert@preining.info> | 2019-09-02 13:46:59 +0900 |
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committer | Norbert Preining <norbert@preining.info> | 2019-09-02 13:46:59 +0900 |
commit | e0c6872cf40896c7be36b11dcc744620f10adf1d (patch) | |
tree | 60335e10d2f4354b0674ec22d7b53f0f8abee672 /dviware/umddvi/lib/conv.c |
Initial commit
Diffstat (limited to 'dviware/umddvi/lib/conv.c')
-rw-r--r-- | dviware/umddvi/lib/conv.c | 49 |
1 files changed, 49 insertions, 0 deletions
diff --git a/dviware/umddvi/lib/conv.c b/dviware/umddvi/lib/conv.c new file mode 100644 index 0000000000..91f2088cda --- /dev/null +++ b/dviware/umddvi/lib/conv.c @@ -0,0 +1,49 @@ +/* + * Copyright (c) 1987 University of Maryland Department of Computer Science. + * All rights reserved. Permission to copy for any purpose is hereby granted + * so long as this copyright notice remains intact. + */ + +#ifndef lint +static char rcsid[] = "$Header: conv.c,v 1.3 87/06/16 18:27:39 chris Exp $"; +#endif + +/* + * Conversions. + */ + +#include "types.h" +#include "conv.h" + +double DMagFactor(); + +/* + * Set a conversion (possibly the global conversion). + */ +void +CSetConversion(c, dpi, usermag, num, denom, dvimag) + register struct conversion *c; + int dpi, usermag; + i32 num, denom, dvimag; +{ + double ddpi = dpi; + + c->c_mag = DMagFactor((int) dvimag) * DMagFactor(usermag); + c->c_dpi = ddpi; + + /* + * The conversion facture is figured as follows: there are exactly + * num/denom DVI units per decimicron, and 254000 decimicrons per + * inch, and dpi pixels per inch. Then we have to adjust this by + * the stated magnification. + */ + c->c_fromsp = (num / 254000.0) * (ddpi / denom) * c->c_mag; + + /* + * c->c_tosp is 1/c->c_fromsp, but we will invert the expression + * above in the hopes of some extra accuracy. + * + * IS THIS ANY GOOD? I NEED A NUMERICAL ANALYST! + */ + c->c_tosp = (254000.0 / num) * (denom / ddpi) * (1.0 / c->c_mag); +} |