src/common/bmpfile.h

/* RCSid $Id: bmpfile.h,v 2.8 2017/09/05 18:41:22 greg Exp $ */
/*
 *  Windows and OS/2 BMP file support
 */

#ifndef _RAD_BMPFILE_H_
#define _RAD_BMPFILE_H_

#include "tiff.h"                       /* needed for int32, etc. */

#ifdef __cplusplus
extern "C" {
#endif

                                        /* compression modes */
#define BI_UNCOMPR              0               /* no compression */
#define BI_RLE8                 1               /* runlength on bytes */
#define BI_RLE4                 2               /* runlength on half-bytes */
#define BI_BITFIELDS            3               /* uncompressed w/ bitfields */

/* A Color table entry */
typedef struct {
        uint8           b, g, r;        /* blue, green, & red bytes */
        uint8           padding;        /* padding to 32-bit boundary */
} RGBquad;

/* Allocated BMP header data */
typedef struct {
        /* the following fields may be altered before the open call */
        int             yIsDown;        /* scanlines proceed downward? */
        int32           hRes;           /* horizontal resolution pixels/meter */
        int32           vRes;           /* vertical resolution pixels/meter */
        int             nColors;        /* total color palette size */
        int             impColors;      /* number of colors actually used */
        int             compr;          /* compression */
        int32           width;          /* bitmap width (pixels) */
        int32           height;         /* bitmap height (pixels) */
        /* the following fields must not be altered after allocation */
        int             bpp;            /* bits per pixel (1,4,8,16,24,32) */
        uint32          infoSiz;        /* info buffer size (bytes) */
        /* but the color table should be filled by writer before open call */
        RGBquad         palette[3];     /* color palette (extends struct) */
} BMPHeader;
                                
                                        /* access to bit field triple */
#define BMPbitField(h)  ((uint32 *)(h)->palette)

                                        /* info buffer access */
#define BMPinfo(h)      ((char *)((h)->palette + (h)->nColors))

                                        /* function return values */
#define BIR_OK                  0               /* all is well */
#define BIR_EOF                 (-1)            /* reached end of file */
#define BIR_TRUNCATED           1               /* unexpected EOF */
#define BIR_UNSUPPORTED         2               /* unsupported encoding */
#define BIR_RLERROR             3               /* RLE error */
#define BIR_SEEKERR             4               /* could not seek */

/* A BMP reader structure */
typedef struct BMPReader {
        /* members in this structure should be considered read-only */
        uint8           *scanline;      /* unpacked scanline data */
        int             yscan;          /* last scanline read */
        BMPHeader       *hdr;           /* pointer to allocated header */
        uint32          fpos;           /* current file position */
                                        /* get character callback */
        int             (*cget)(void *);
                                        /* absolute seek callback (or NULL) */
        int             (*seek)(uint32, void *);
        void            *c_data;        /* client's opaque data */
        uint32          scanpos[1];     /* recorded scanline position(s) */
} BMPReader;

/* A BMP writer structure */
typedef struct {
        /* the scanline data is filled in by caller before each write */
        uint8           *scanline;      /* caller-prepared scanline data */
        /* modify yscan only if seek is defined & data is uncompressed */
        int             yscan;          /* scanline for next write */
        /* the following fields should not be altered directly */
        BMPHeader       *hdr;           /* allocated header */
        uint32          fbmp;           /* beginning of bitmap data */
        uint32          fpos;           /* current file position */
        uint32          flen;           /* last character written */
                                        /* put character callback */
        void            (*cput)(int, void *);
                                        /* absolute seek callback (or NULL) */
        int             (*seek)(uint32, void *);
        void            *c_data;        /* client's opaque data */
} BMPWriter;

                                        /* open BMP stream for reading */
extern BMPReader        *BMPopenReader(int (*cget)(void *),
                                int (*seek)(uint32, void *), void *c_data);

                                        /* determine if image is grayscale */
extern int              BMPisGrayscale(const BMPHeader *hdr);

                                        /* read next BMP scanline */
extern int              BMPreadScanline(BMPReader *br);

                                        /* read a specific scanline */
extern int              BMPseekScanline(int y, BMPReader *br);

                                        /* get ith pixel from last scanline */
extern RGBquad          BMPdecodePixel(int i, const BMPReader *br);

                                        /* free BMP reader resources */
extern void             BMPfreeReader(BMPReader *br);

                                        /* allocate uncompressed RGB header */
extern BMPHeader        *BMPtruecolorHeader(int xr, int yr, int infolen);

                                        /* allocate color-mapped header */
extern BMPHeader        *BMPmappedHeader(int xr, int yr, int infolen, int ncolors);

                                        /* open BMP stream for writing */
extern BMPWriter        *BMPopenWriter(void (*cput)(int, void *),
                                int (*seek)(uint32, void *), void *c_data,
                                        BMPHeader *hdr);
                                
                                        /* write the prepared scanline */
extern int              BMPwriteScanline(BMPWriter *bw);

                                        /* free BMP writer resources */
extern void             BMPfreeWriter(BMPWriter *bw);

                                        /* get corresponding error message */
extern const char       *BMPerrorMessage(int ec);

                                        /* stdio callback functions */
extern int              stdio_getc(void *p);
extern void             stdio_putc(int c, void *p);
extern int              stdio_fseek(uint32 pos, void *p);

                                        /* open stdio input stream */
#define BMPopenInputStream(fp)  BMPopenReader(&stdio_getc, NULL, (void *)fp)

                                        /* open input file */
#define BMPopenInputFile(fn)    BMPopenReader(&stdio_getc, &stdio_fseek, \
                                        (void *)fopen(fn, "rb"))

                                        /* close stdio input file or stream */
#define BMPcloseInput(br)       ( fclose((FILE *)(br)->c_data), \
                                        BMPfreeReader(br) )

                                        /* open stdio output stream */
#define BMPopenOutputStream(fp,hdr) \
                        BMPopenWriter(&stdio_putc, NULL, (void *)fp, hdr)

                                        /* open stdio output file */
#define BMPopenOutputFile(fn,hdr) \
                        BMPopenWriter(&stdio_putc, &stdio_fseek, \
                                        (void *)fopen(fn, "wb"), hdr)

                                        /* close stdio output file or stream */
#define BMPcloseOutput(bw)      ( fclose((FILE *)(bw)->c_data), \
                                        BMPfreeWriter(bw) )

#ifdef __cplusplus
}
#endif
#endif  /* ! _RAD_BMPFILE_H_ */
Revision:	2.9
Committed:	Mon Feb 8 18:43:21 2021 UTC (4 years, 8 months ago) by greg
Content type:	text/plain
Branch:	MAIN
CVS Tags:	rad5R4, rad6R0, HEAD
Changes since 2.8:	+2 -2 lines
Log Message:	docs: corrected comment
#	User	Rev	Content
1	greg	2.9	/* RCSid $Id: bmpfile.h,v 2.8 2017/09/05 18:41:22 greg Exp $ */
2	greg	2.1	/*
3			* Windows and OS/2 BMP file support
4			*/
5
6			#ifndef _RAD_BMPFILE_H_
7			#define _RAD_BMPFILE_H_
8
9	greg	2.6	#include "tiff.h" /* needed for int32, etc. */
10	greg	2.1
11			#ifdef __cplusplus
12			extern "C" {
13			#endif
14
15			/* compression modes */
16			#define BI_UNCOMPR 0 /* no compression */
17			#define BI_RLE8 1 /* runlength on bytes */
18			#define BI_RLE4 2 /* runlength on half-bytes */
19			#define BI_BITFIELDS 3 /* uncompressed w/ bitfields */
20
21			/* A Color table entry */
22			typedef struct {
23			uint8 b, g, r; /* blue, green, & red bytes */
24			uint8 padding; /* padding to 32-bit boundary */
25			} RGBquad;
26
27			/* Allocated BMP header data */
28			typedef struct {
29	greg	2.3	/* the following fields may be altered before the open call */
30	greg	2.1	int yIsDown; /* scanlines proceed downward? */
31			int32 hRes; /* horizontal resolution pixels/meter */
32			int32 vRes; /* vertical resolution pixels/meter */
33			int nColors; /* total color palette size */
34	greg	2.8	int impColors; /* number of colors actually used */
35	greg	2.3	int compr; /* compression */
36	greg	2.1	int32 width; /* bitmap width (pixels) */
37			int32 height; /* bitmap height (pixels) */
38	greg	2.3	/* the following fields must not be altered after allocation */
39	greg	2.9	int bpp; /* bits per pixel (1,4,8,16,24,32) */
40	greg	2.1	uint32 infoSiz; /* info buffer size (bytes) */
41	greg	2.3	/* but the color table should be filled by writer before open call */
42	greg	2.8	RGBquad palette[3]; /* color palette (extends struct) */
43	greg	2.1	} BMPHeader;
44	greg	2.2
45			/* access to bit field triple */
46	greg	2.8	#define BMPbitField(h) ((uint32 *)(h)->palette)
47	greg	2.1
48			/* info buffer access */
49	greg	2.8	#define BMPinfo(h) ((char *)((h)->palette + (h)->nColors))
50	greg	2.1
51			/* function return values */
52			#define BIR_OK 0 /* all is well */
53			#define BIR_EOF (-1) /* reached end of file */
54			#define BIR_TRUNCATED 1 /* unexpected EOF */
55			#define BIR_UNSUPPORTED 2 /* unsupported encoding */
56	greg	2.2	#define BIR_RLERROR 3 /* RLE error */
57			#define BIR_SEEKERR 4 /* could not seek */
58	greg	2.1
59			/* A BMP reader structure */
60			typedef struct BMPReader {
61			/* members in this structure should be considered read-only */
62	greg	2.8	uint8 scanline; / unpacked scanline data */
63	greg	2.1	int yscan; /* last scanline read */
64	greg	2.8	BMPHeader hdr; / pointer to allocated header */
65	greg	2.1	uint32 fpos; /* current file position */
66			/* get character callback */
67			int (cget)(void );
68			/* absolute seek callback (or NULL) */
69			int (seek)(uint32, void );
70			void c_data; / client's opaque data */
71	greg	2.8	uint32 scanpos[1]; /* recorded scanline position(s) */
72	greg	2.1	} BMPReader;
73
74			/* A BMP writer structure */
75			typedef struct {
76			/* the scanline data is filled in by caller before each write */
77	greg	2.8	uint8 scanline; / caller-prepared scanline data */
78	greg	2.3	/* modify yscan only if seek is defined & data is uncompressed */
79	greg	2.1	int yscan; /* scanline for next write */
80	greg	2.3	/* the following fields should not be altered directly */
81	greg	2.8	BMPHeader hdr; / allocated header */
82	greg	2.1	uint32 fbmp; /* beginning of bitmap data */
83			uint32 fpos; /* current file position */
84			uint32 flen; /* last character written */
85			/* put character callback */
86			void (cput)(int, void );
87			/* absolute seek callback (or NULL) */
88			int (seek)(uint32, void );
89			void c_data; / client's opaque data */
90			} BMPWriter;
91
92			/* open BMP stream for reading */
93	greg	2.8	extern BMPReader BMPopenReader(int (cget)(void *),
94	greg	2.1	int (seek)(uint32, void ), void *c_data);
95
96			/* determine if image is grayscale */
97	greg	2.7	extern int BMPisGrayscale(const BMPHeader *hdr);
98	greg	2.1
99			/* read next BMP scanline */
100	greg	2.7	extern int BMPreadScanline(BMPReader *br);
101	greg	2.1
102			/* read a specific scanline */
103	greg	2.7	extern int BMPseekScanline(int y, BMPReader *br);
104	greg	2.1
105			/* get ith pixel from last scanline */
106	greg	2.7	extern RGBquad BMPdecodePixel(int i, const BMPReader *br);
107	greg	2.1
108			/* free BMP reader resources */
109	greg	2.7	extern void BMPfreeReader(BMPReader *br);
110	greg	2.1
111			/* allocate uncompressed RGB header */
112	greg	2.8	extern BMPHeader *BMPtruecolorHeader(int xr, int yr, int infolen);
113	greg	2.1
114			/* allocate color-mapped header */
115	greg	2.8	extern BMPHeader *BMPmappedHeader(int xr, int yr, int infolen, int ncolors);
116	greg	2.1
117			/* open BMP stream for writing */
118	greg	2.7	extern BMPWriter BMPopenWriter(void (cput)(int, void *),
119	greg	2.1	int (seek)(uint32, void ), void *c_data,
120			BMPHeader *hdr);
121
122			/* write the prepared scanline */
123	greg	2.7	extern int BMPwriteScanline(BMPWriter *bw);
124	greg	2.1
125			/* free BMP writer resources */
126	greg	2.7	extern void BMPfreeWriter(BMPWriter *bw);
127	greg	2.1
128			/* get corresponding error message */
129	greg	2.8	extern const char *BMPerrorMessage(int ec);
130	greg	2.1
131			/* stdio callback functions */
132	greg	2.7	extern int stdio_getc(void *p);
133			extern void stdio_putc(int c, void *p);
134			extern int stdio_fseek(uint32 pos, void *p);
135	greg	2.1
136			/* open stdio input stream */
137	greg	2.8	#define BMPopenInputStream(fp) BMPopenReader(&stdio_getc, NULL, (void *)fp)
138	greg	2.1
139			/* open input file */
140	greg	2.8	#define BMPopenInputFile(fn) BMPopenReader(&stdio_getc, &stdio_fseek, \
141	greg	2.5	(void *)fopen(fn, "rb"))
142	greg	2.1
143			/* close stdio input file or stream */
144	greg	2.8	#define BMPcloseInput(br) ( fclose((FILE *)(br)->c_data), \
145	greg	2.1	BMPfreeReader(br) )
146
147			/* open stdio output stream */
148			#define BMPopenOutputStream(fp,hdr) \
149			BMPopenWriter(&stdio_putc, NULL, (void *)fp, hdr)
150
151			/* open stdio output file */
152			#define BMPopenOutputFile(fn,hdr) \
153			BMPopenWriter(&stdio_putc, &stdio_fseek, \
154	greg	2.5	(void *)fopen(fn, "wb"), hdr)
155	greg	2.1
156			/* close stdio output file or stream */
157	greg	2.8	#define BMPcloseOutput(bw) ( fclose((FILE *)(bw)->c_data), \
158	greg	2.1	BMPfreeWriter(bw) )
159
160			#ifdef __cplusplus
161			}
162			#endif
163			#endif /* ! _RAD_BMPFILE_H_ */