#!/usr/bin/python

import string
import os
import time

########## play functions:

def open_port(device_arg):
	global port
	port=open(device_arg,'w')

def pitch_bend(channel, bend):
	global port
	low_byte = (bend & 127)
	high_byte = (bend >> 7)
	port.write("%c%c%c" % (0xE0+channel,low_byte,high_byte))
	port.flush()

def pb(channel, bend):
	global port
#	bend = int((bend - 8192.0)/128)
	port.write("%c%c%c" % (0xE0+channel,0x00, (bend % 128)))
	port.flush()

def note_on(channel,note,volume):
	global port
	port.write("%c%c%c" % (0x90+channel, note, volume))
	port.flush()
	
def note_off(channel,note):
	global port
	port.write("%c%c%c" % (0x80+channel, note, 0))
	port.flush()

def all_notes_off():
	global port
	for channel in range(16):
		port.write("%c%c%c" % (0xB0+channel, 123, 0))
		port.flush()

def close_port():
	global port
	port.close()

############## standard midi file functions:

def read_var_length(fp):
	output = 0
	inbyte = ord(fp.read(1))
	output = inbyte & 0x7f
	while inbyte & 0x80 == 0x80:
		inbyte = ord(fp.read(1))
		output = (output << 7 ) + (inbyte & 0x7f)
	return output

def write_var_length(var):
	from sys import stdout
	from string import join
	#### result goes into an array
	result_array = []
	#### we have at least one value, right? :
	result_array.append(var & 0x7f)
	var >>= 7 ### shift right
	#### if 'var' still has any value greater than 0,
	#### 'and' it with 0x7f and then 'or' with 0x80,
	#### then put it out to result. Then we shift right
	#### for the next iteration:
	while var > 0x0:
		result_array.append((var & 0x7f) | 0x80)
		var >>= 7
	result_array.reverse()
	####for item in result_array:
	####	print hex(item)
	hex_string_array=[]
	for n in result_array:
		hex_string_array.append(chr(n))
	return join(hex_string_array,'')

############## range functions:

def bounce(index, max):
	if index < 0 or index > max:
		return max-(index%max)
	else:
		return index

def see_saw(index, max):
	return bounce(index%max*2,max)


########### mf2t functions

def midi_text_open(file,midi_file_type,num_channels, resolution):
	global text_file
	text_file=open(file, 'w')
	text_file.write("MFile %i %i %i\nMTrk\n" %
					(midi_file_type,num_channels, resolution))

def midi_text_close():
	global text_file
	text_file.close()

def midi_text_new_channel():
	global text_file
	text_file.write("TrkEnd\nMTrk\n")

def midi_text_final_trkend():
	global text_file
	text_file.write("TrkEnd\n")

def midi_text_pitch_bend(time, channel, bend):
	global text_file
	text_file.write("%i Pb ch=%i v=%i\n" % (time, channel+1, bend))

def midi_text_note_on(time, channel, note, volume):
	global text_file
	text_file.write("%i On ch=%i n=%i v=%i\n" % (time, channel+1, note, volume))

def midi_text_note_off(time, channel, note):
	global text_file
	text_file.write("%i Off ch=%i n=%i v=0\n" % (time, channel+1, note))

def midi_text_tempo(time, tempo):
	global text_file
	tempo = int((60.0/tempo)*1000000)
	text_file.write("%i Tempo %i\n" % (time,tempo))

def midi_text_program_change(time, channel, program):
	global text_file
	text_file.write("%i PrCh ch=%i p=%i\n" % (time,channel+1,program))

def midi_text_controller(time, channel, parameter, value):
	global text_file
	text_file.write("%i Par ch=%i c=%i v=%i\n" % (time, channel+1, parameter, value))