/*
   wacom graphire on serial port only...
*/

#include <m_pd.h>
#include "s_stuff.h"

#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>

#define BUFSIZE 256
#define HEADER_BIT	0x80
#define ZAXIS_SIGN_BIT	0x40
#define ZAXIS_BIT    	0x04
#define ZAXIS_BITS    	0x3f
#define POINTER_BIT     0x20
#define PROXIMITY_BIT   0x40
#define BUTTON_FLAG	0x08
#define BUTTONS_BITS	0x78
#define TILT_SIGN_BIT	0x40
#define TILT_BITS	0x3f

/* defines to discriminate second side button and the eraser */
#define ERASER_PROX	4
#define OTHER_PROX	1

#define Threshold 1000
unsigned char data[7];

typedef struct _wac
{
    t_object t_ob;
    t_outlet *axis_out;
    t_outlet *button_out;
    t_symbol *file;
    int fd;
 	int count;
	int oldbuttons;
	unsigned char data[BUFSIZE];
}t_wac;

t_class *wac_class;

void wac_setup(void);
static void wac_read(t_wac *x,int fd);
static void wac_process(t_wac *x);

static void wac_open(t_wac *x)
{
	if(x->fd>=0) return;
	
	x->fd = open (x->file->s_name, O_RDONLY | O_NONBLOCK);
	if(x->fd<0){
		post("open (%s, O_RDONLY | O_NONBLOCK)",x->file->s_name);
		perror("open");
		return;
	}
	sys_addpollfn(x->fd,(t_fdpollfn)wac_read,(void*)x);
}

static void wac_close(t_wac *x)
{
	if(x->fd<0) return;

	sys_rmpollfn(x->fd);
	close(x->fd);
	x->fd=-1;
}

static void wac_float(t_wac *x,t_floatarg connect)
{
	if(connect!=0) wac_open(x);
	else wac_close(x);
}

static void *wac_new(t_symbol *file)
{  
	t_wac *x = (t_wac *)pd_new(wac_class);
	
	//if(file->s_name)
	if(file!=&s_)
		x->file=file;
	else x->file=gensym("/dev/ttyS0");
	
	post("wac_new file=%s",x->file->s_name);
	x->axis_out = outlet_new(&x->t_ob, &s_list);
	x->button_out = outlet_new(&x->t_ob, &s_list);
	
	x->fd=-1;
	
	return (void *)x;
}

void wac_setup(void)
{
	wac_class = class_new(gensym("wac"),(t_newmethod)wac_new, 
		(t_method)wac_close, sizeof(t_wac), 0, A_DEFSYM, 0);
	class_addfloat(wac_class, wac_float);
	

}


static void wac_read(t_wac *x,int fd)
{
	int len,i=0;
	unsigned char b;  
	unsigned char buffer[BUFSIZE];
  	
	while((len=read(fd,buffer,BUFSIZE))> -1){	

		for(i=0;i<len;i++){
			if(buffer[i]&128) x->count=0;
			x->data[x->count++]=buffer[i];
			if(x->count==7) wac_process(x);
		}		
	}	
}

static void wac_process(t_wac *X)
{
    int			is_stylus = 1, is_button, is_proximity, wheel=0;
    int			x, y, z, buttons, tx = 0, ty = 0;
	unsigned char *data=X->data;
	t_atom ats[3];

	    is_stylus = (data[0] & POINTER_BIT);
		
		if(!is_stylus) return;
		
		x = (((data[0] & 0x3) << 14) +
		 (data[1] << 7) +
		 data[2]);
	    y = (((data[3] & 0x3) << 14) +
		 (data[4] << 7) +
		 data[5]);


	    z = ((data[6] & ZAXIS_BITS) * 2) +
		((data[3] & ZAXIS_BIT) >> 2);

		//z = z*4 + ((data[0] & ZAXIS_BIT) >> 1);

		if (!(data[6] & ZAXIS_SIGN_BIT)) {
		    z += 128;
		}

	    is_proximity = (data[0] & PROXIMITY_BIT);

		buttons = ((data[3] & 0x38) >> 3);
		/*if (is_stylus) {
		    buttons = ((data[3] & 0x30) >> 3) |
			(z >= Threshold ? 1 : 0);
		}
		else {
		    buttons = (data[3] & 0x38) >> 3;

		    wheel = (data[6] & 0x30) >> 4;

		    if (data[6] & 0x40) {
			wheel = -wheel;
		    }
		}*/
		//is_button = (buttons != 0);
		if(buttons!=X->oldbuttons)
		{
			X->oldbuttons=buttons;
			
			SETFLOAT(&ats[0],buttons&1);
			SETFLOAT(&ats[1],(buttons&2)!=0);
			SETFLOAT(&ats[2],(buttons&4)!=0);
			outlet_list(X->button_out,0,3,ats);
		}
		SETFLOAT(&ats[0],x/5103.0);
		SETFLOAT(&ats[1],y/3711.0);
		SETFLOAT(&ats[2],z/256.0);
		outlet_list(X->axis_out,0,3,ats);
}
	/* Format of 7 bytes data packet for Wacom Tablets
	Byte 1
	bit 7  Sync bit always 1
	bit 6  Pointing device detected
	bit 5  Cursor = 0 / Stylus = 1
	bit 4  Reserved
	bit 3  1 if a button on the pointing device has been pressed
	bit 2  Reserved
	bit 1  X15
	bit 0  X14

	Byte 2
	bit 7  Always 0
	bits 6-0 = X13 - X7

	Byte 3
	bit 7  Always 0
	bits 6-0 = X6 - X0

	Byte 4
	bit 7  Always 0
	bit 6  B3
	bit 5  B2
	bit 4  B1
	bit 3  B0
	bit 2  P0
	bit 1  Y15
	bit 0  Y14

	Byte 5
	bit 7  Always 0
	bits 6-0 = Y13 - Y7

	Byte 6
	bit 7  Always 0
	bits 6-0 = Y6 - Y0

	Byte 7
	bit 7 Always 0
	bit 6  Sign of pressure data
	bit 5  P6
	bit 4  P5
	bit 3  P4
	bit 2  P3
	bit 1  P2
	bit 0  P1

	byte 8 and 9 are optional and present only
	in tilt mode.

	Byte 8
	bit 7 Always 0
	bit 6 Sign of tilt X
	bit 5  Xt6
	bit 4  Xt5
	bit 3  Xt4
	bit 2  Xt3
	bit 1  Xt2
	bit 0  Xt1

	Byte 9
	bit 7 Always 0
	bit 6 Sign of tilt Y
	bit 5  Yt6
	bit 4  Yt5
	bit 3  Yt4
	bit 2  Yt3
	bit 1  Yt2
	bit 0  Yt1

	*/