buffer_printf.c

/*
 * buffer_printf.c
 *
 *  Created on: Mar 11, 2014
 *      Author: Michael
 */
#include "buffer.h"
#include "buffer_printf.h"
#include <stdarg.h>

#define ESC 0x1B

void Push_printf(buffer_t * buf, char * str,...) {
    // variable argument list type
    va_list vars;
    // initialize the variable argument list pointer by specifying the
    // input argument immediately preceding the variable list
    va_start(vars, str);
    Push_vprintf(buf, str, vars);
    va_end(vars);
}

void Push_vprintf(buffer_t * buf, char * str, va_list vars) {
    char escape = 0;
    while(*str != 0) {
        if(*str == '%' && !escape) {
            switch(*(str+1)) {
				case 0:
					str++;
					continue;
				case 'c': // char
					// to be implemented by everyone else
					Push(buf, va_arg(vars, char));
					str+=2;
					continue;
                case 'd':
                    // Capo
                	// use va_arg to ge the next variable of length int
					Push_int16(buf,va_arg(vars, int));
					str+=2;
                    continue;
                case 'e':
                case 'f':
                case 'g': // scientific notation of float
                	// Jehandad
                	PushFloat(buf, va_arg(vars, double));
                	str+=2;
                	continue;
                case 's': // string
                	// Cecere / Paterson
                	PushStr(buf, va_arg(vars, char *));
					str+=2;
					continue;
                case 'u':
					// use va_arg to ge the next variable of length int
					Push_uint16(buf,va_arg(vars, unsigned int));
					str+=2;
					continue;
                case 'x': // hex
                	// Jake
                	PushHex(buf,va_arg(vars, int));
                	str+=2;
                	continue;
                default:
                    // if the character following the % was not "special"
                    // then we will print the % and whatever follows it
                    break;
            }
        }
        escape = (*str == '\\') ? 1 : 0;
        Push(buf,*str++);
    }

}

void Push_uint16(buffer_t * buf, uint16_t x) {
    char num[6];
    unsigned int i = 0;
    do {
        num[i] = (x % 10) + '0';
        x /= 10;
        i++;
    } while (x);
    do {
        Push(buf, num[--i]);
    } while (i);
}

void Push_int16(buffer_t * buf, int16_t x) {
	if (x < 0) {
		Push(buf, '-');
		x = -x;
	}
	Push_uint16(buf, x);
}

void Push_int32(buffer_t * buf, int32_t x) {
	if (x < 0) {
		Push(buf, '-');
		x = -x;
	}
	Push_uint32(buf, x);
}

void Push_uint32(buffer_t * buf, uint32_t x) {
	char num[10];
	unsigned int i = 0;
	do {
		num[i] = (x % 10) + '0';
		x /= 10;
		i++;
	} while (x);
	do {
		Push(buf, num[--i]);
	} while (i);
}

void PushStr(buffer_t * buf, char * str){
	do{
		Push(buf, *str);
	} while( *str++ != 0);
}

void PushHex(buffer_t *buf, uint16_t x)
{
	volatile unsigned int y;
    char num[4];
	unsigned int i = 0;
    do {
    	y = x - ((x >> 4) << 4); // x % 16
    	num[i++] = (y >= 10) ? (y + 0x37) : (y + 0x30);
    	x >>= 4; // x / 16
    } while(x);

    do {
        Push(buf, num[--i]);
    } while (i);
}

void PushFloat(buffer_t * buf, float x) {
	int i;
	long l;
	// for now just print 0.000 format
	i = x;
	Push_int16(buf, i);
	l = (x * 1000);
	l = l - i * 1000;
	Push(buf, '.');
	if(l < 100) Push(buf, '0');
	if(l < 10) Push(buf, '0');
	if(l == 0) Push(buf, '0');
	else Push_uint16(buf, l & 0xFFFF);
}