/*
 * cube.c
 *
 * Copyright 2011 Thomas Buck <xythobuz@me.com>
 * Copyright 2011 Max Nuding <max.nuding@gmail.com>
 * Copyright 2011 Felix Bäder <baeder.felix@gmail.com>
 *
 * This file is part of LED-Cube.
 *
 * LED-Cube is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * LED-Cube is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with LED-Cube.  If not, see <http://www.gnu.org/licenses/>.
 */
#include <avr/io.h>
#include <avr/interrupt.h>
#include <stdlib.h>

#include "cube.h"

#ifndef F_CPU
#define F_CPU 16000000L
#endif

volatile uint8_t _isrCounter = 0;
volatile uint8_t **imgBuffer = NULL; // imgBuffer[8][8]
volatile uint8_t imgFlag = 0;

// Wir zählen 21 mal bis 3968
ISR(TIMER1_COMPA_vect) {
	if (_isrCounter < 20) {
		_isrCounter++;
	} else {
		_isrCounter = 0;
		isrCall();
	}
}

inline void setFet(uint8_t data) {
	data &= ~((1 << 1) | 1);
	PORTD = data;
	data &= ~(3);
	data = data << 3;
	PORTB |= data;
}


inline void selectLatch(uint8_t latchNr) {
	PORTC = 0;
	if (latchNr < 8) {
		PORTC = 1 << latchNr;
	}
}

inline void setLatch(uint8_t latchNr, uint8_t data) {
	setFet(0); // All LEDs off
	selectLatch(latchNr); // Activate current latch
	PORTA = data; // Put latch data
	delay_ns(LATCHDELAY); // Wait for latch
	selectLatch(8); // Deactivate all latches
	setFet(1 << latchNr); // Activate current plane
}

inline void isrCall(void) {
	static uint8_t layer = 0;
	uint8_t latchCtr = 0;
	
	for (; latchCtr < 8; latchCtr++) {
		setLatch(latchCtr, imgBuffer[layer][latchCtr]); // Put out all the data
	}
	
	// Select next layer
	if (layer < 7) {
		layer++;
	} else {
		layer = 0;
	}
}

inline void delay_ns(int16_t ns) {
	// minimum 63 nanoseconds (= 1 tick)
	for (ns > 0; ns -= 63)
		asm volatile("nop"::);
}