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/* RCSid $Id: resolu.h,v 2.14 2019/07/19 17:37:56 greg Exp $ */ |
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/* |
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* Definitions for resolution line in image file. |
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* |
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* Include after <stdio.h> |
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* |
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* True image orientation is defined by an xy coordinate system |
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* whose origin is at the lower left corner of the image, with |
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* x increasing to the right and y increasing in the upward direction. |
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* This true orientation is independent of how the pixels are actually |
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* ordered in the file, which is indicated by the resolution line. |
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* This line is of the form "{+-}{XY} xyres {+-}{YX} yxres\n". |
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* A typical line for a 1024x600 image might be "-Y 600 +X 1024\n", |
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* indicating that the scanlines are in English text order (PIXSTANDARD). |
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*/ |
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#ifndef _RAD_RESOLU_H_ |
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#define _RAD_RESOLU_H_ |
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|
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#ifdef __cplusplus |
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extern "C" { |
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#endif |
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|
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/* flags for scanline ordering */ |
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#define XDECR 1 |
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#define YDECR 2 |
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#define YMAJOR 4 |
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|
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/* standard scanline ordering */ |
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#define PIXSTANDARD (YMAJOR|YDECR) |
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#define PIXSTDFMT "-Y %d +X %d\n" |
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|
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/* structure for image dimensions */ |
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typedef struct { |
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int rt; /* orientation (from flags above) */ |
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int xr, yr; /* x and y resolution */ |
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} RESOLU; |
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|
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/* macros to get scanline length and number */ |
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#define scanlen(rs) ((rs)->rt & YMAJOR ? (rs)->xr : (rs)->yr) |
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#define numscans(rs) ((rs)->rt & YMAJOR ? (rs)->yr : (rs)->xr) |
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|
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/* resolution string buffer and its size */ |
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#define RESOLU_BUFLEN 32 |
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extern char resolu_buf[RESOLU_BUFLEN]; |
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|
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/* macros for reading/writing resolution struct */ |
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#define fputsresolu(rs,fp) fputs(resolu2str(resolu_buf,rs),fp) |
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#define fgetsresolu(rs,fp) str2resolu(rs, \ |
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fgets(resolu_buf,RESOLU_BUFLEN,fp)) |
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|
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/* reading/writing of standard ordering */ |
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#define fprtresolu(sl,ns,fp) fprintf(fp,PIXSTDFMT,ns,sl) |
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#define fscnresolu(sl,ns,fp) (fgetresolu(sl,ns,fp)==PIXSTANDARD) |
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|
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/* defined in resolu.c */ |
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extern void fputresolu(int ord, int sl, int ns, FILE *fp); |
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extern int fgetresolu(int *sl, int *ns, FILE *fp); |
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extern char * resolu2str(char *buf, RESOLU *rp); |
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extern int str2resolu(RESOLU *rp, char *buf); |
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|
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#ifdef __cplusplus |
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} |
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#endif |
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#endif /* _RAD_RESOLU_H_ */ |
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