/*********************************************************************
SSD1306 I2C Library for Raspberry Pi.
Based on Adafruit SSD1306 Arduino library. Some functions came from Adafruit GFX lib

Modified by Ilia Penev
Tested on Raspberry Pi 2 with 0.96 Yellow/Blue OLED
*********************************************************************/

/*********************************************************************
This is a library for our Monochrome OLEDs based on SSD1306 drivers

  Pick one up today in the adafruit shop!
  ------> http://www.adafruit.com/category/63_98

These displays use SPI to communicate, 4 or 5 pins are required to
interface

Adafruit invests time and resources providing this open source code,
please support Adafruit and open-source hardware by purchasing
products from Adafruit!

Written by Limor Fried/Ladyada  for Adafruit Industries.
BSD license, check license.txt for more information
All text above, and the splash screen below must be included in any redistribution
*********************************************************************/

#include <stdint.h>
#include <string.h>

#include "ssd1306_i2c.h"
#include "oled_fonts.h"
#include "lcd_oled.h"

#define true 1
#define false 0

#define rotation 0

int8_t cursor_y = 0;
int8_t cursor_x = 0;

int16_t i2cd;

#define ssd1306_swap(a, b) { int16_t t = a; a = b; b = t; }

//Section : 10.1.12 Set Display ON/OFF (AEh/AFh) | Page 37
void ssd1306_i2c_set_display_off(i2c_t *i2c_dev)
{
	ssd1306_i2c_send_command(i2c_dev,SSD1306_DISPLAYOFF);
}

//Section : 10.1.12 Set Display ON/OFF (AEh/AFh) | Page 37
void ssd1306_i2c_set_display_on(i2c_t *i2c_dev)
{
	ssd1306_i2c_send_command(i2c_dev,SSD1306_DISPLAYON);
}

// TODO: Find a ferq Calculator
// Section : 10.1.16 Set Display Clock Divide Ratio/ Oscillator Frequency (D5h) | Page : 40
void ssd1306_i2c_set_display_clkDiv_oscFreq(i2c_t *i2c_dev, uint8_t clockDivider, uint8_t oscillatorFreq)
{
	
	uint8_t value = 0;

	if(oscillatorFreq <= 15)
	{
		if(clockDivider <= 16)
		{
			value = (oscillatorFreq << 4) | clockDivider;
		}
	}

	ssd1306_i2c_send_command(i2c_dev,SSD1306_SETDISPLAYCLOCKDIV);	// 0xD5
	ssd1306_i2c_send_command(i2c_dev,value);	// the suggested ratio 0x80
}

// Section : 10.1.11 Set Multiplex Ratio (A8h) | Page : 37 
void ssd1306_i2c_set_multiplex_ratio(i2c_t *i2c_dev, uint8_t ratio)
{
	ssd1306_i2c_send_command(i2c_dev,SSD1306_SETMULTIPLEX);	// 0xA8
	ssd1306_i2c_send_command(i2c_dev,ratio);
}

// Section : 10.1.15 Set Display Offset (D3h) | Page : 37 
void ssd1306_i2c_set_display_offset(i2c_t *i2c_dev, uint8_t offset)
{
	ssd1306_i2c_send_command(i2c_dev,SSD1306_SETDISPLAYOFFSET);	// 0xD3
	ssd1306_i2c_send_command(i2c_dev,offset);	
}
// Section : 10.1.13 Set Page Start Address for Page Addressing Mode (B0h~B7h) | Page : 37
void ssd1306_i2c_set_display_start_line(i2c_t *i2c_dev, uint8_t start)
{
	if(start <= 7)
	{
		ssd1306_i2c_send_command(i2c_dev,SSD1306_SETSTARTLINE | start);
	}
}

// TODO : Some things are not clear What does 0x10 do ? 
// Section : 2.1 Command Table for Charge Bump Setting | Page : 60
void ssd1306_i2c_set_chage_pump(i2c_t *i2c_dev, uint8_t voltageSource)
{
	ssd1306_i2c_send_command(i2c_dev,SSD1306_CHARGEPUMP);	// 0x8D
	if (voltageSource == SSD1306_EXTERNALVCC) {
		ssd1306_i2c_send_command(i2c_dev,0x10);
	} else {
		ssd1306_i2c_send_command(i2c_dev,SSD1306_ENABLE_CHAGE_PUMP);
	}
}

// Section :10.1.3 Set Memory Addressing Mode (20h) | Page : 34
void ssd1306_i2c_set_memory_addressing_mode(i2c_t *i2c_dev, uint8_t mode)
{
	ssd1306_i2c_send_command(i2c_dev,SSD1306_MEMORYMODE);	
	ssd1306_i2c_send_command(i2c_dev,mode);
}

// TODO : Not very clear what this functionality does :S
// Section : 10.1.8 Set Segment Re-map (A0h/A1h)
void ssd1306_i2c_set_segment_remap(i2c_t *i2c_dev, uint8_t enable)
{
	if(enable)
	{	
		ssd1306_i2c_send_command(i2c_dev,SSD1306_SEGREMAP | 0x1);
	}
	else
	{
		ssd1306_i2c_send_command(i2c_dev,SSD1306_SEGREMAP | 0x0);
	}
}
// Section : 10.1.14 Set COM Output Scan Direction (C0h/C8h) | Page 37 
void ssd1306_i2c_set_com_scan_direction(i2c_t *i2c_dev, uint8_t incremental)
{
	if(incremental)
	{
		ssd1306_i2c_send_command(i2c_dev,SSD1306_COMSCANINC);
	}
	else
	{
		ssd1306_i2c_send_command(i2c_dev,SSD1306_COMSCANDEC);
	}
}

// Section : 10.1.18 Set COM Pins Hardware Configuration (DAh) | Page : 40 
void ssd1306_i2c_set_com_pins(i2c_t *i2c_dev, uint8_t alignment)
{
	ssd1306_i2c_send_command(i2c_dev,SSD1306_SETCOMPINS);
	ssd1306_i2c_send_command(i2c_dev,alignment);
}

void ssd1306_i2c_set_contrast(i2c_t *i2c_dev, uint8_t contrast)
{
	ssd1306_i2c_send_command(i2c_dev,SSD1306_SETCONTRAST);	// 0x81
	ssd1306_i2c_send_command(i2c_dev,contrast);	
}

void ssd1306_i2c_set_prechage_period(i2c_t *i2c_dev, uint8_t period)
{
	ssd1306_i2c_send_command(i2c_dev,SSD1306_SETPRECHARGE);	// 0xd9
	ssd1306_i2c_send_command(i2c_dev,period);
}

void ssd1306_i2c_set_com_deselect_level(i2c_t *i2c_dev, uint8_t voltageLevel)
{
	ssd1306_i2c_send_command(i2c_dev,SSD1306_SETVCOMDETECT);	// 0xDB
	ssd1306_i2c_send_command(i2c_dev,voltageLevel);
}

void ssd1306_i2c_set_display_entire_on(i2c_t *i2c_dev, uint8_t resumeOrForce)
{
	if(resumeOrForce == SSD1306_DISPLAYALLON_RESUME)
	{
		ssd1306_i2c_send_command(i2c_dev,SSD1306_DISPLAYALLON_RESUME);	// 0xA4
	}
	else 
	{
		ssd1306_i2c_send_command(i2c_dev,SSD1306_DISPLAYALLON);	// 0xA4
	}

}

void ssd1306_i2c_set_display_invert_pixel(i2c_t *i2c_dev, uint8_t inverted)
{
	if(inverted)
	{
		ssd1306_i2c_send_command(i2c_dev,SSD1306_INVERTDISPLAY);	// 0xA6
	}
	else 
	{
		ssd1306_i2c_send_command(i2c_dev,SSD1306_NORMALDISPLAY);	// 0xA6
	}
}

void ssd1306_i2c_set_scroll(i2c_t *i2c_dev, uint8_t onOff)
{
	if(onOff)
	{
		ssd1306_i2c_send_command(i2c_dev,SSD1306_ACTIVATE_SCROLL);
	}
	else
	{
		ssd1306_i2c_send_command(i2c_dev,SSD1306_DEACTIVATE_SCROLL);
	}
}


void ssd1306_i2c_send_command(i2c_t *i2c_dev,uint8_t c)
{
	// I2C
	uint8_t control = 0x00;	// Co = 0, D/C = 0
	uint8_t i2cDataLenght = 1;	// Co = 0, D/C = 0
	uint16_t address = SSD1306_I2C_ADDRESS;   	// Co = 0, D/C = 0
	i2c_write(i2c_dev, &address, &control, &c, &i2cDataLenght);
}


// startscrollright
// Activate a right handed scroll for rows start through stop
// Hint, the display is 16 rows tall. To scroll the whole display, run:
// ssd1306_scrollright(0x00, 0x0F)
void ssd1306_startscrollright(i2c_t *i2c_dev, uint16_t start, uint16_t stop)
{
	ssd1306_i2c_send_command(i2c_dev,SSD1306_RIGHT_HORIZONTAL_SCROLL);
	ssd1306_i2c_send_command(i2c_dev,0X00);
	ssd1306_i2c_send_command(i2c_dev,start);
	ssd1306_i2c_send_command(i2c_dev,0X00);
	ssd1306_i2c_send_command(i2c_dev,stop);
	ssd1306_i2c_send_command(i2c_dev,0X00);
	ssd1306_i2c_send_command(i2c_dev,0XFF);
	ssd1306_i2c_send_command(i2c_dev,SSD1306_ACTIVATE_SCROLL);
}

// startscrollleft
// Activate a right handed scroll for rows start through stop
// Hint, the display is 16 rows tall. To scroll the whole display, run:
// ssd1306_scrollright(0x00, 0x0F)
void ssd1306_startscrollleft(i2c_t *i2c_dev,uint16_t start, uint16_t stop)
{
	ssd1306_i2c_send_command(i2c_dev,SSD1306_LEFT_HORIZONTAL_SCROLL);
	ssd1306_i2c_send_command(i2c_dev,0X00);
	ssd1306_i2c_send_command(i2c_dev,start);
	ssd1306_i2c_send_command(i2c_dev,0X00);
	ssd1306_i2c_send_command(i2c_dev,stop);
	ssd1306_i2c_send_command(i2c_dev,0X00);
	ssd1306_i2c_send_command(i2c_dev,0XFF);
	ssd1306_i2c_send_command(i2c_dev,SSD1306_ACTIVATE_SCROLL);
}

// startscrolldiagright
// Activate a diagonal scroll for rows start through stop
// Hint, the display is 16 rows tall. To scroll the whole display, run:
// ssd1306_scrollright(0x00, 0x0F)
void ssd1306_startscrolldiagright(i2c_t *i2c_dev, uint16_t start, uint16_t stop)
{
	ssd1306_i2c_send_command(i2c_dev,SSD1306_SET_VERTICAL_SCROLL_AREA);
	ssd1306_i2c_send_command(i2c_dev,0X00);
	ssd1306_i2c_send_command(i2c_dev,SSD1306_LCDHEIGHT);
	ssd1306_i2c_send_command(i2c_dev,SSD1306_VERTICAL_AND_RIGHT_HORIZONTAL_SCROLL);
	ssd1306_i2c_send_command(i2c_dev,0X00);
	ssd1306_i2c_send_command(i2c_dev,start);
	ssd1306_i2c_send_command(i2c_dev,0X00);
	ssd1306_i2c_send_command(i2c_dev,stop);
	ssd1306_i2c_send_command(i2c_dev,0X01);
	ssd1306_i2c_send_command(i2c_dev,SSD1306_ACTIVATE_SCROLL);
}

// startscrolldiagleft
// Activate a diagonal scroll for rows start through stop
// Hint, the display is 16 rows tall. To scroll the whole display, run:
// ssd1306_scrollright(0x00, 0x0F)
void ssd1306_startscrolldiagleft(i2c_t *i2c_dev, uint16_t start, uint16_t stop)
{
	ssd1306_i2c_send_command(i2c_dev,SSD1306_SET_VERTICAL_SCROLL_AREA);
	ssd1306_i2c_send_command(i2c_dev,0X00);
	ssd1306_i2c_send_command(i2c_dev,SSD1306_LCDHEIGHT);
	ssd1306_i2c_send_command(i2c_dev,SSD1306_VERTICAL_AND_LEFT_HORIZONTAL_SCROLL);
	ssd1306_i2c_send_command(i2c_dev,0X00);
	ssd1306_i2c_send_command(i2c_dev,start);
	ssd1306_i2c_send_command(i2c_dev,0X00);
	ssd1306_i2c_send_command(i2c_dev,stop);
	ssd1306_i2c_send_command(i2c_dev,0X01);
	ssd1306_i2c_send_command(i2c_dev,SSD1306_ACTIVATE_SCROLL);
}