1 | /*****************************************************************************/ |
2 | /* */ |
3 | /* fileio.c */ |
4 | /* */ |
5 | /* File I/O for the sp65 sprite and bitmap utility */ |
6 | /* */ |
7 | /* */ |
8 | /* */ |
9 | /* (C) 1998-2012, Ullrich von Bassewitz */ |
10 | /* Roemerstrasse 52 */ |
11 | /* D-70794 Filderstadt */ |
12 | /* EMail: uz@cc65.org */ |
13 | /* */ |
14 | /* */ |
15 | /* This software is provided 'as-is', without any expressed or implied */ |
16 | /* warranty. In no event will the authors be held liable for any damages */ |
17 | /* arising from the use of this software. */ |
18 | /* */ |
19 | /* Permission is granted to anyone to use this software for any purpose, */ |
20 | /* including commercial applications, and to alter it and redistribute it */ |
21 | /* freely, subject to the following restrictions: */ |
22 | /* */ |
23 | /* 1. The origin of this software must not be misrepresented; you must not */ |
24 | /* claim that you wrote the original software. If you use this software */ |
25 | /* in a product, an acknowledgment in the product documentation would be */ |
26 | /* appreciated but is not required. */ |
27 | /* 2. Altered source versions must be plainly marked as such, and must not */ |
28 | /* be misrepresented as being the original software. */ |
29 | /* 3. This notice may not be removed or altered from any source */ |
30 | /* distribution. */ |
31 | /* */ |
32 | /*****************************************************************************/ |
33 | |
34 | |
35 | |
36 | #include <string.h> |
37 | #include <errno.h> |
38 | |
39 | /* od65 */ |
40 | #include "error.h" |
41 | #include "fileio.h" |
42 | |
43 | |
44 | |
45 | /*****************************************************************************/ |
46 | /* Code */ |
47 | /*****************************************************************************/ |
48 | |
49 | |
50 | |
51 | void FileSetPos (FILE* F, unsigned long Pos) |
52 | /* Seek to the given absolute position, fail on errors */ |
53 | { |
54 | if (fseek (F, Pos, SEEK_SET) != 0) { |
55 | Error ("Cannot seek: %s" , strerror (errno)); |
56 | } |
57 | } |
58 | |
59 | |
60 | |
61 | unsigned long FileGetPos (FILE* F) |
62 | /* Return the current file position, fail on errors */ |
63 | { |
64 | long Pos = ftell (F); |
65 | if (Pos < 0) { |
66 | Error ("Error in ftell: %s" , strerror (errno)); |
67 | } |
68 | return Pos; |
69 | } |
70 | |
71 | |
72 | |
73 | unsigned Read8 (FILE* F) |
74 | /* Read an 8 bit value from the file */ |
75 | { |
76 | int C = getc (F); |
77 | if (C == EOF) { |
78 | Error ("Read error (file corrupt?)" ); |
79 | } |
80 | return C; |
81 | } |
82 | |
83 | |
84 | |
85 | unsigned Read16 (FILE* F) |
86 | /* Read a 16 bit value from the file */ |
87 | { |
88 | unsigned Lo = Read8 (F); |
89 | unsigned Hi = Read8 (F); |
90 | return (Hi << 8) | Lo; |
91 | } |
92 | |
93 | |
94 | |
95 | unsigned long Read24 (FILE* F) |
96 | /* Read a 24 bit value from the file */ |
97 | { |
98 | unsigned long Lo = Read16 (F); |
99 | unsigned long Hi = Read8 (F); |
100 | return (Hi << 16) | Lo; |
101 | } |
102 | |
103 | |
104 | |
105 | unsigned long Read32 (FILE* F) |
106 | /* Read a 32 bit value from the file */ |
107 | { |
108 | unsigned long Lo = Read16 (F); |
109 | unsigned long Hi = Read16 (F); |
110 | return (Hi << 16) | Lo; |
111 | } |
112 | |
113 | |
114 | |
115 | void* ReadData (FILE* F, void* Data, unsigned Size) |
116 | /* Read data from the file */ |
117 | { |
118 | /* Accept zero sized reads */ |
119 | if (Size > 0) { |
120 | if (fread (Data, 1, Size, F) != Size) { |
121 | Error ("Read error (file corrupt?)" ); |
122 | } |
123 | } |
124 | return Data; |
125 | } |
126 | |