44 lines
1.0 KiB
C
44 lines
1.0 KiB
C
/*
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* This file is part of the UCB release of Plan 9. It is subject to the license
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* terms in the LICENSE file found in the top-level directory of this
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* distribution and at http://akaros.cs.berkeley.edu/files/Plan9License. No
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* part of the UCB release of Plan 9, including this file, may be copied,
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* modified, propagated, or distributed except according to the terms contained
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* in the LICENSE file.
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*/
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#include <u.h>
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#include <lib9.h>
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#include <draw.h>
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static
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int
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unitsperline(Rectangle r, int d, int bitsperunit)
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{
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uint32_t l, t;
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if(d <= 0 || d > 32) /* being called wrong. d is image depth. */
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abort();
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if(r.min.x >= 0){
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l = (r.max.x*d+bitsperunit-1)/bitsperunit;
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l -= (r.min.x*d)/bitsperunit;
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}else{ /* make positive before divide */
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t = (-r.min.x*d+bitsperunit-1)/bitsperunit;
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l = t+(r.max.x*d+bitsperunit-1)/bitsperunit;
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}
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return l;
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}
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int
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wordsperline(Rectangle r, int d)
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{
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return unitsperline(r, d, 8*sizeof(uint32_t));
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}
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int
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bytesperline(Rectangle r, int d)
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{
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return unitsperline(r, d, 8);
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}
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