/*
	RS.com CA(P)TCHA Pre-Processor
	20.04.2008 von Kugelfisch
	BSD-artige Lizenz
*/
#include <stdio.h>
#include <stdlib.h>
#include <jpeglib.h>
#include <math.h>

#define CATCHA_W 456
#define CATCHA_H 71

typedef struct {
	unsigned char image[CATCHA_W][CATCHA_H];
} catcha;


void load_catcha(catcha* cat, char* filename) {
	JSAMPARRAY buffer;	
	struct jpeg_error_mgr jerr;
	struct jpeg_decompress_struct cinfo;
	int x,y;
	
	FILE* f = fopen(filename,"rb");

	cinfo.err = jpeg_std_error(&jerr);
	jpeg_create_decompress(&cinfo);
	jpeg_stdio_src(&cinfo, f);
	jpeg_read_header(&cinfo, TRUE);
	jpeg_start_decompress(&cinfo);
	if(cinfo.output_width != CATCHA_W || cinfo.output_height != CATCHA_H) {
		fprintf(stderr,"Invalid CAPTCHA size!");
		exit(-1);
	}
	buffer = (*cinfo.mem->alloc_sarray)((j_common_ptr) &cinfo, JPOOL_IMAGE, cinfo.output_width * cinfo.output_components, 1);
	while ((y = cinf             e) {
	JSAMPARRAY buffer;	
	struct jpeg_error_mgr jerr;
	struct jpeg_compress_struct cinfo;
	int x,y;
	FILE* f = fope 
	cinfo.image_width = CATCHA_W;
	cinfo.image_height = CATCHA_H;
	cinfo.input_components = 1;
	cinfo.in_color_space = JCS_GRAYSCALE;
	jpeg_set_defaults(&cinfo);
	jpeg_set_quality(&cinfo,100,TRUE);
	
	jpeg_stdio_dest(&cinfo, f);
	jpeg_start_compress(&cinfo, FALSE);
	buffer = (*cinfo.mem->alloc_sarray)((j_common_ptr) &cinfo, JPOOL_IMAGE, CATCHA_W, 1);
	for(y=0; y<CATCHA_H; y++) {
		for(x=0; x<CATCHA_W; x++)
			if(cat->image[x][y] < 200)
				buffer[0][x] = cat->image[x][y];
			else
				buffer[0][x] = 0xFF;
		jpeg_write_scanlines(&cinfo, buffer, 1);
	}

	jpeg_finish_compress(&cinfo);
	fclose(f);

	jpeg_destroy_compress(&cinfo);
	 
#define SINE_PHI_Y   (0)

void catcha_reverse_sine_transform(catcha* cat) {
	int x,y,shift;

	
	// transform in x-direction
	for(y=0; y<CATCHA_H; y++) {
		shift = -(int)round(SINE_MAX_X*sin(SINE_OMEGA_X*y+SINE_PHI_X));
		if(shift > 0) {
			for(x=0; x<CATCHA_W; x++)
				cat->image[x][y] = (x+shift<CATCHA_W)?cat->image[x+shift][y]:0xFF;
		} else {
			for(x=CATCHA_W-1; x>=0; x--)
				cat->image[x][y] = (x+shift>=0)?cat->image[x+shift][y]:0xFF;
		}
	}

	// transform in y-direction
	for(x=0; x<CATCHA_W; x++) {
		shift = -(int)round(SINE_MAX_Y*sin(SINE_OMEGA_Y*x+SINE_PHI_Y));
		if(shift > 0) {
			for(y=0; y<CATCHA_H; y++)
				 

}


int main(int argc, char** argv) {
	catcha cat;
	if(argc < 3)
		return -1;
	load_catcha(&cat,argv[1]);
	catcha_reverse_sine_transform(&cat);
	save_catcha(&cat,argv[2]);
	
	return 0;
}