// AForge Image Processing Library
//
// Copyright © Andrew Kirillov, 2005-2007
// andrew.kirillov@gmail.com
//
// Rotate image using bilinear interpolation
//
// This algorithm was taken from the AForge.NET sourcecodes
// and adopted for the FreeImage library
//
// Copyright (C) 2007-2008:
// monday2000  monday2000@yandex.ru

#include "FreeImage.h"
#include "Utilities.h"

#define PI	((double)3.14159265358979323846264338327950288419716939937510)

////////////////////////////////////////////////////////////////////////////////

// Calculates rotated image size.
// param - Source image data.
// 
// returns New image size.
// 
void CalculateRotatedSize(FIBITMAP* dib, double angle, unsigned& new_width, unsigned& new_height)
{
	// angle's sine and cosine
	double angleRad = -angle * PI / 180;
	double angleCos = cos(angleRad);
	double angleSin = sin(angleRad);
	
	unsigned width = FreeImage_GetWidth(dib);
	
	unsigned height = FreeImage_GetHeight(dib);	
	
	// calculate half size
	double halfWidth = (double) width / 2;
	double halfHeight = (double) height / 2;
	
	// rotate corners
	double cx1 = halfWidth * angleCos;
	double cy1 = halfWidth * angleSin;
	
	double cx2 = halfWidth * angleCos - halfHeight * angleSin;
	double cy2 = halfWidth * angleSin + halfHeight * angleCos;
	
	double cx3 = -halfHeight * angleSin;
	double cy3 = halfHeight * angleCos;
	
	double cx4 = 0;
	double cy4 = 0;
	
	// recalculate image size
	halfWidth   = MAX( MAX( cx1, cx2 ), MAX( cx3, cx4 ) ) - MIN( MIN( cx1, cx2 ), MIN( cx3, cx4 ) );
	halfHeight  = MAX( MAX( cy1, cy2 ), MAX( cy3, cy4 ) ) - MIN( MIN( cy1, cy2 ), MIN( cy3, cy4 ) );
	
	new_width = (int) ( halfWidth * 2 + 0.5 );
	
	new_height = (int) ( halfHeight * 2 + 0.5 );	
}

////////////////////////////////////////////////////////////////////////////////

FIBITMAP* ProcessFilter(FIBITMAP* src_dib, double angle)
{
	// get source image size
	unsigned width = FreeImage_GetWidth(src_dib);
	
	unsigned height = FreeImage_GetHeight(src_dib);
	
	unsigned src_pitch = FreeImage_GetPitch(src_dib);
	
	unsigned bpp = FreeImage_GetBPP(src_dib);
	
	unsigned btpp = bpp/8;
	
	unsigned new_width, new_height;
	
	CalculateRotatedSize(src_dib, angle, new_width, new_height);
	
	
	FIBITMAP* dst_dib = FreeImage_Allocate(new_width, new_height, bpp);
	
	if(bpp == 8)
	{
		if(FreeImage_GetColorType(src_dib) == FIC_MINISWHITE) {
			// build an inverted greyscale palette
			RGBQUAD *dst_pal = FreeImage_GetPalette(dst_dib);
			for(int i = 0; i < 256; i++) {
				dst_pal[i].rgbRed = dst_pal[i].rgbGreen =
					dst_pal[i].rgbBlue = (BYTE)(255 - i);
			}
		} else {
			// build a greyscale palette
			RGBQUAD *dst_pal = FreeImage_GetPalette(dst_dib);
			for(int i = 0; i < 256; i++) {
				dst_pal[i].rgbRed = dst_pal[i].rgbGreen =
					dst_pal[i].rgbBlue = (BYTE)i;
			}
		}
	}
	
	unsigned dst_pitch = FreeImage_GetPitch(dst_dib);
	
	BYTE* src_bits = (BYTE*)FreeImage_GetBits(src_dib); // The image raster
	
	BYTE* dst_bits = (BYTE*)FreeImage_GetBits(dst_dib); // The image raster
	
	BYTE* lined;
	
	unsigned d;	
	
	double  halfWidth   = (double) width / 2;
	double  halfHeight  = (double) height / 2;
	
	// get destination image size
	double  halfNewWidth    = (double) new_width / 2;
	double  halfNewHeight   = (double) new_height / 2;
	
	// angle's sine and cosine
	double angleRad = -angle * PI / 180;
	double angleCos = cos( angleRad );
	double angleSin = sin( angleRad );
	
	// fill values
	BYTE fill = 0xFF; // white
	
	// destination pixel's coordinate relative to image center
	double cx, cy;
	// coordinates of source points
	double  ox, oy, dx1, dy1, dx2, dy2;
	int     ox1, oy1, ox2, oy2;
	// width and height decreased by 1
	int ymax = height - 1;
	int xmax = width - 1;
	
    // temporary pointers
    BYTE* p1, *p2;
	
	cy = -halfNewHeight;
	
	for ( int y = 0; y < new_height; y++ )
	{
		cx = -halfNewWidth;
		
		lined = dst_bits + y * dst_pitch;
		
		for ( int x = 0; x < new_width; x++ )
		{
			// coordinates of source point
			ox =  angleCos * cx + angleSin * cy + halfWidth;
			oy = -angleSin * cx + angleCos * cy + halfHeight;
			
			// top-left coordinate
			ox1 = (int) ox;
			oy1 = (int) oy;
			
			// validate source pixel's coordinates
			if ( ( ox1 < 0 ) || ( oy1 < 0 ) || ( ox1 >= width ) || ( oy1 >= height ) )
			{
				// fill destination image with filler
				for (d=0; d<btpp; d++)
					
					lined[x * btpp + d] = fill;				
			}
			else
			{
				// bottom-right coordinate
				ox2 = ( ox1 == xmax ) ? ox1 : ox1 + 1;
				oy2 = ( oy1 == ymax ) ? oy1 : oy1 + 1;
				
				if ( ( dx1 = ox - (double) ox1 ) < 0 )
					dx1 = 0;
				dx2 = 1.0 - dx1;
				
				if ( ( dy1 = oy - (double) oy1 ) < 0 )
					dy1 = 0;
				dy2 = 1.0 - dy1;
				
				p1 = src_bits + oy1 * src_pitch;
				p2 = src_bits + oy2 * src_pitch;
				
				// interpolate using 4 points
				
				for (d = 0; d<btpp; d++)
					
					lined[x * btpp + d] = (BYTE) (
					dy2 * ( dx2 * p1[ox1 * btpp + d] + dx1 * p1[ox2 * btpp + d] ) +
					dy1 * ( dx2 * p2[ox1 * btpp + d] + dx1 * p2[ox2 * btpp + d] ) );
			}
			cx++;
		}
		cy++;
	}
	
	// Copying the DPI...
	
	FreeImage_SetDotsPerMeterX(dst_dib, FreeImage_GetDotsPerMeterX(src_dib));
	
	FreeImage_SetDotsPerMeterY(dst_dib, FreeImage_GetDotsPerMeterY(src_dib));
	
	return dst_dib;
}

////////////////////////////////////////////////////////////////////////////////
/**
FreeImage error handler
@param fif Format / Plugin responsible for the error 
@param message Error message
*/
void FreeImageErrorHandler(FREE_IMAGE_FORMAT fif, const char *message) {
	printf("\n*** "); 
	printf("%s Format\n", FreeImage_GetFormatFromFIF(fif));
	printf(message);
	printf(" ***\n");
}

////////////////////////////////////////////////////////////////////////////////

/** Generic image loader

  @param lpszPathName Pointer to the full file name
  @param flag Optional load flag constant
  @return Returns the loaded dib if successful, returns NULL otherwise
*/

FIBITMAP* GenericLoader(const char* lpszPathName, int flag)
{	
	FREE_IMAGE_FORMAT fif = FIF_UNKNOWN;
	// check the file signature and deduce its format
	// (the second argument is currently not used by FreeImage)
	
	fif = FreeImage_GetFileType(lpszPathName, 0);
	
	FIBITMAP* dib;
	
	if(fif == FIF_UNKNOWN)
	{
		// no signature ?
		// try to guess the file format from the file extension
		fif = FreeImage_GetFIFFromFilename(lpszPathName);
	}
	
	// check that the plugin has reading capabilities ...
	if((fif != FIF_UNKNOWN) && FreeImage_FIFSupportsReading(fif))
	{
		// ok, let's load the file
		dib = FreeImage_Load(fif, lpszPathName, flag);
		
		// unless a bad file format, we are done !
		if (!dib)
		{
			printf("%s%s%s\n","File \"", lpszPathName, "\" not found.");
			return NULL;
		}
	}	
	
	return dib;
}

////////////////////////////////////////////////////////////////////////////////

int main(int argc, char *argv[]) {
	
	// call this ONLY when linking with FreeImage as a static library
#ifdef FREEIMAGE_LIB
	FreeImage_Initialise();
#endif // FREEIMAGE_LIB
	
	// initialize your own FreeImage error handler
	
	FreeImage_SetOutputMessage(FreeImageErrorHandler);
	
	if(argc != 3) {
		printf("Usage : rot_bil <input_file> <angle (double degrees)>\n");
		return 0;
	}
	
	FIBITMAP *dib = GenericLoader(argv[1], 0);
	
	double angle = atof(argv[2]);	
	
	if (dib)
	{		
		// bitmap is successfully loaded!
		
		if (FreeImage_GetImageType(dib) == FIT_BITMAP)
		{
			if (FreeImage_GetBPP(dib) == 8 || FreeImage_GetBPP(dib) == 24)
			{
				FIBITMAP* dst_dib = ProcessFilter(dib, angle);
				
				if (dst_dib)
				{					
					// save the filtered bitmap
					const char *output_filename = "filtered.tif";
					
					// first, check the output format from the file name or file extension
					FREE_IMAGE_FORMAT out_fif = FreeImage_GetFIFFromFilename(output_filename);
					
					if(out_fif != FIF_UNKNOWN)
					{
						// then save the file
						FreeImage_Save(out_fif, dst_dib, output_filename, 0);
					}
					
					// free the loaded FIBITMAP
					FreeImage_Unload(dst_dib);					
				}
			}
			
			else
				
				printf("%s\n", "Unsupported color mode.");
		}
		
		else // non-FIT_BITMAP images are not supported.
			
			printf("%s\n", "Unsupported color mode.");
		
		FreeImage_Unload(dib);
	}	 
	
	// call this ONLY when linking with FreeImage as a static library
#ifdef FREEIMAGE_LIB
	FreeImage_DeInitialise();
#endif // FREEIMAGE_LIB
	
	return 0;