/***************************************************************************
 *   helper functions for demo modes                                       *
 *                                                                         *
 *   Copyright (C) 2011 - 2012 by Olaf Rempel                              *
 *   razzor AT kopf MINUS tisch DOT de                                     *
 *                                                                         *
 *   This program 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; version 2 of the License,               *
 *                                                                         *
 *   This program 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 this program; if not, write to the                         *
 *   Free Software Foundation, Inc.,                                       *
 *   59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.             *
 ***************************************************************************/
#include <stdint.h>
#include <string.h>
#include "rgb16mpm.h"

uint8_t sequence_chase(uint8_t old_value, uint8_t *dir, uint16_t mask)
{
    uint8_t value = old_value;

    do {
        value = (*dir) ? value +1 : value -1;
        value &= 0x0F;

        if (value == 0x00 || value == 0x0F) {
            *dir = (value == 0x00);
        }

    } while (!((1<<value) & mask) || value == old_value);

    return value;
}

uint16_t color_ramp(uint16_t value, uint8_t *color)
{
    uint8_t col1 = (value & 0xFF);
    uint8_t col2 = 0xFF - col1;

    switch (value >> 8) {
        default:
            value = 0x0000;
            /* no break */

        case 0: /* red: on, green: ramp up, blue: off */
            color[0] = 0xFF;
            color[1] = col1;
            color[2] = 0x00;
            break;

        case 1: /* red: ramp down, green: on, blue:off */
            color[0] = col2;
            color[1] = 0xFF;
            color[2] = 0x00;
            break;

        case 2: /* red: off, green: on, blue: ramp up */
            color[0] = 0x00;
            color[1] = 0xFF;
            color[2] = col1;
            break;

        case 3: /* red: off, green: ramp down: blue: on */
            color[0] = 0x00;
            color[1] = col2;
            color[2] = 0xFF;
            break;

        case 4: /* red: ramp up, green: off, blue: on */
            color[0] = col1;
            color[1] = 0x00;
            color[2] = 0xFF;
            break;

        case 5: /* red: on, green: off, blue: ramp down */
            color[0] = 0xFF;
            color[1] = 0x00;
            color[2] = col2;
            break;
    }

    return value;
}

void color_add(uint8_t *color1, uint8_t *color2, uint8_t *output)
{
    uint8_t i;
    for (i = 0; i < 3; i++) {
        uint16_t tmp = color1[i] + color2[i];
        output[i] = (tmp & 0xFF00) ? 0xFF : tmp;
    }
}

void color_sub(uint8_t *color1, uint8_t *color2, uint8_t *output)
{
    uint8_t i;
    for (i = 0; i < 3; i++) {
        uint16_t tmp = color1[i] - color2[i];
        output[i] = (tmp & 0xFF00) ? 0x00 : tmp;
    }
}

void color_div(uint8_t *color, uint8_t div, uint8_t *output)
{
    uint8_t i;
    for (i = 0; i < 3; i++) {
        if (color[i] != 0) {
            output[i] = color[i] / div;
            if (output[i] == 0) {
                output[i] = 0x01;
            }

        } else {
            output[i] = 0x00;
        }
    }
}