[14] | 1 | #include "alutInternal.h" |
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| 2 | #include <string.h> |
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| 3 | |
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| 4 | struct OutputStream_struct |
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| 5 | { |
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| 6 | char *data; |
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| 7 | char *current; |
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| 8 | size_t maximumLength; |
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| 9 | }; |
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| 10 | |
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| 11 | /**************************************************************************** |
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| 12 | * The functions below know the internal OutputStream representation. |
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| 13 | ****************************************************************************/ |
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| 14 | |
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| 15 | OutputStream * |
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| 16 | _alutOutputStreamConstruct (size_t maximumLength) |
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| 17 | { |
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| 18 | OutputStream *stream = (OutputStream *) _alutMalloc (sizeof (OutputStream)); |
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| 19 | if (stream == NULL) |
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| 20 | { |
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| 21 | return NULL; |
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| 22 | } |
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| 23 | stream->data = _alutMalloc (maximumLength); |
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| 24 | if (stream->data == NULL) |
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| 25 | { |
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| 26 | free (stream); |
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| 27 | return NULL; |
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| 28 | } |
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| 29 | stream->current = stream->data; |
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| 30 | stream->maximumLength = maximumLength; |
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| 31 | return stream; |
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| 32 | } |
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| 33 | |
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| 34 | ALboolean |
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| 35 | _alutOutputStreamDestroy (OutputStream *stream) |
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| 36 | { |
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| 37 | free (stream->data); |
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| 38 | free (stream); |
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| 39 | return AL_TRUE; |
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| 40 | } |
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| 41 | |
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| 42 | void * |
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| 43 | _alutOutputStreamGetData (OutputStream *stream) |
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| 44 | { |
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| 45 | return stream->data; |
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| 46 | } |
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| 47 | |
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| 48 | size_t |
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| 49 | _alutOutputStreamGetLength (OutputStream *stream) |
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| 50 | { |
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| 51 | return stream->current - stream->data; |
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| 52 | } |
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| 53 | |
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| 54 | static ALboolean |
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| 55 | streamWrite (OutputStream *stream, const void *ptr, size_t numBytesToWrite) |
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| 56 | { |
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| 57 | size_t remainingLength = |
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| 58 | stream->maximumLength - _alutOutputStreamGetLength (stream); |
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| 59 | if (remainingLength < numBytesToWrite) |
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| 60 | { |
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| 61 | /* this should never happen within our library */ |
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| 62 | _alutSetError (ALUT_ERROR_IO_ERROR); |
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| 63 | return AL_FALSE; |
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| 64 | } |
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| 65 | memcpy (stream->current, ptr, numBytesToWrite); |
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| 66 | stream->current += numBytesToWrite; |
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| 67 | return AL_TRUE; |
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| 68 | } |
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| 69 | |
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| 70 | /**************************************************************************** |
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| 71 | * The utility functions below do not know the internal OutputStream |
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| 72 | * representation. |
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| 73 | ****************************************************************************/ |
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| 74 | |
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| 75 | ALboolean |
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| 76 | _alutOutputStreamWriteInt16BE (OutputStream *stream, Int16BigEndian value) |
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| 77 | { |
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| 78 | unsigned char buf[2]; |
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| 79 | buf[0] = (unsigned char) (value >> 8); |
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| 80 | buf[1] = (unsigned char) value; |
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| 81 | return streamWrite (stream, buf, 2); |
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| 82 | } |
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| 83 | |
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| 84 | ALboolean |
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| 85 | _alutOutputStreamWriteInt32BE (OutputStream *stream, Int32BigEndian value) |
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| 86 | { |
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| 87 | unsigned char buf[4]; |
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| 88 | buf[0] = (unsigned char) (value >> 24); |
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| 89 | buf[1] = (unsigned char) (value >> 16); |
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| 90 | buf[2] = (unsigned char) (value >> 8); |
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| 91 | buf[3] = (unsigned char) value; |
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| 92 | return streamWrite (stream, buf, 4); |
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| 93 | } |
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