Mercurial > hg > dmlib
view dmbstr.c @ 510:43ea59887c69
Start work on making C64 formats encoding possible by changing DMDecodeOps
to DMEncDecOps and adding fields and op enums for custom encode functions, renaming,
etc. Split generic op sanity checking into a separate function in
preparation for its use in generic encoding function.
author | Matti Hamalainen <ccr@tnsp.org> |
---|---|
date | Mon, 19 Nov 2012 15:06:01 +0200 |
parents | a7ab6bf5b012 |
children | 136d4ddc7438 |
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/* * DMLib * -- Simple bitstream I/O functions * Programmed and designed by Matti 'ccr' Hamalainen * (C) Copyright 2012 Tecnic Software productions (TNSP) */ #include "dmbstr.h" int dmInitBitStream(DMBitStream *ctx, FILE *fp) { if (ctx == NULL || fp == NULL) return DMERR_NULLPTR; ctx->fp = fp; ctx->buf = 0; ctx->bytecnt = 0; ctx->bitcnt = 8; return DMERR_OK; } BOOL dmPutBits(DMBitStream *ctx, const int val, const int n) { int i; unsigned int mask = 1 << (n - 1); for (i = 0; i < n; i++) { ctx->buf <<= 1; if (val & mask) ctx->buf |= 1; mask >>= 1; ctx->bitcnt--; if (ctx->bitcnt == 0) { if (fputc((ctx->buf & 0xff), ctx->fp) == EOF) return FALSE; ctx->bitcnt = 8; ctx->bytecnt++; } } return TRUE; } int dmFlushBitStream(DMBitStream *ctx) { if (ctx == NULL) return DMERR_NULLPTR; if (ctx->bitcnt != 8) dmPutBits(ctx, 0, ctx->bitcnt); return 0; }