#include <stdio.h>
  #include <stdlib.h>
  
  int main(int argc, char *argv[])
  {
  	if(argc != 3)
  	{
  		printf("bmp2rgb565 [BMP_SRC] [RGB565_DEST]\n");
  		return 1;
  	}
  
  	FILE* src = NULL;
  	FILE* dst = NULL;

  	unsigned char buffer[5];
  	int initOffsetBMP;

  
  	src = fopen(argv[1], "r");
  	dst = fopen(argv[2], "w");
  
  	if(src == NULL)
  	{
  		printf("Unable to open the BMP file\n");
  		return 2;
  	}
  
  	if(dst == NULL)
  	{
  		printf("Unable to open the RGB565 file\n");
  		return 3;
  	}
  

  	printf("Reading BMP\n");
  
  	fseek(src, 0x0A, SEEK_SET);
  	buffer[0] = getc(src);
  	buffer[1] = getc(src);
  	buffer[2] = getc(src);
  	buffer[3] = getc(src);
  	printf("Pixel array offset %02x %02x %02x %02x\n", buffer[3], buffer[2], buffer[1], buffer[0]);
  	initOffsetBMP = buffer[0] + (buffer[1] >> 8) + (buffer[2] >> 16) + (buffer[3] >> 24);
  
  	fseek(src, 0x12, SEEK_SET);
  	buffer[0] = getc(src);
  	buffer[1] = getc(src);
  	buffer[2] = getc(src);
  	buffer[3] = getc(src);
  	printf("Width %02x %02x %02x %02x\n", buffer[3], buffer[2], buffer[1], buffer[0]);
  
  	//fseek(src, 0x12, SEEK_SET);
  	buffer[0] = getc(src);
  	buffer[1] = getc(src);
  	buffer[2] = getc(src);
  	buffer[3] = getc(src);
  	printf("Height %02x %02x %02x %02x\n", buffer[3], buffer[2], buffer[1], buffer[0]);
  
  	fseek(src, 0x1C, SEEK_SET);
  	buffer[0] = getc(src);
  	buffer[1] = getc(src);
  	printf("Bits Per Pixel %02x %02x\n", buffer[0], buffer[1]);
  
  	if(buffer[1] != 0 || buffer[0] != 0x18)
  	{
  		printf("Could not read BMP\n");
  		return 1;
  	}
  
  	fseek(src, initOffsetBMP, SEEK_SET);
  
  	printf("Now reading BMP pixels and printing them to the RBG565 file\n");
  	while(1)
  	{
  		buffer[0] = getc(src);
  		buffer[1] = getc(src);
  		buffer[2] = getc(src);
  		if(feof(src))
  			break;
  		printf("Pixel BMP 24 bits R %02X G %02X B %02X ", buffer[2], buffer[1], buffer[0]);
  		buffer[2] = buffer[2] >> 3; //R
  		buffer[1] = buffer[1] >> 2; //G
  		buffer[0] = buffer[0] >> 3; //B
  		printf("-> RGB 565 R %02X G %02X B %02X ", buffer[2], buffer[1], buffer[0]);
  		buffer[3] = ((buffer[0] & 0x1F) << 3) + ((buffer[1] & 0x38) >> 3);
  		buffer[4] = ((buffer[1] & 0x07) << 5) + (buffer[2] & 0x1F);
  		printf("-> RGB 565 M %02X%02X\n", buffer[3], buffer[4]);
  		fprintf(dst, "%c%c", buffer[4], buffer[3]);
  	}
  
  	printf("Done !\n");
  
  	fclose(src);
  	fclose(dst);
  

  	return 0;
  }