binaryEditor/binaryEditor.c

#include "binaryEditor.h"

char *input;
unsigned int inByteOffset = 0;
unsigned short inBitOffset = 0;

char *output;
unsigned int outByteOffset = 0;
unsigned short outBitOffset = 0;

void setBuffer(Buffer buffer, void *data){
    switch (buffer){
        case BUF_IN:
            input = (char *) data;
            inByteOffset = 0;
            inBitOffset = 0;
            break;
        case BUF_OUT:
            output = (char *) data;
            outByteOffset = 0;
            outBitOffset = 0;
            break;
    }
}

void seekBuffer(Buffer buffer, unsigned int position){
    switch (buffer){
        case BUF_IN:
            inByteOffset = position - (position % 8);
            inBitOffset = position % 8;
            break;
        case BUF_OUT:
            outByteOffset = position - (position % 8);
            outBitOffset = position % 8;
            break;
    }
}

unsigned int getBufferOffset(Buffer buffer){
    switch (buffer){
        case BUF_IN:
            return (inByteOffset * 8) + inBitOffset;
        case BUF_OUT:
            return (outByteOffset * 8) + outBitOffset;
        default:
            return 0;
    }
}

char readBit(){
    char result = (input[inByteOffset] & (((char) 1) << ( 7 - inBitOffset))) >> (7 - inBitOffset);
    inBitOffset++;
    if (inBitOffset >= 8){
        inByteOffset++;
        inBitOffset = 0;
    }
    return result;
}

char readByte(){
    char result = 0;
    for (int i = 0; i < 8; i++){
        unsigned short bit = readBit();
        result += bit << (7 - i);
    }
    return result;
}

void writeBit(unsigned char bit){
    output[outByteOffset] += bit << (7 - outBitOffset);
    outBitOffset++;
    if (outBitOffset >= 8){
        outByteOffset++;
        outBitOffset = 0;
    }
}

void writeByte(unsigned char byte){
    for (int i = 7; i >= 0; i--){
        writeBit((byte & (1 << i)) >> i);
    }
}