#include <stdio.h>
#include <stdlib.h>
#include <complex.h>
#include <math.h>
#include <stdint.h>
/* this program only works on little-endian CPUs */
/* www.ece.ualberta.ca/~elliott/ee552/studentAppNotes/2003_w/misc/bmp_file_format/bmp_file_format.htm
BMP:
	header	14 bytes
		signature	2 bytes	BM
		filesize	4 bytes	in bytes
		reserved	4 bytes	unused, set to zero
		dataoffset	4 bytes	offset to beginning of pixel data, set to 0x36
	infohdr	40 bytes
		size		4 bytes	size of infoheader, set to 40
		width		4 bytes	width of image, number of columns
		height		4 bytes height in pixels as well, number of lines
		planes		2 bytes	number of planes, idrk, set to 1
		bits per pixel	2 bytes	set to 24
		compression	4 bytes	set to 0, no compression
		imagesize	4 bytes	set to 0, since we use no compression
		xpixelSPERM	4 bytes	pixels per meter. thanks microsoft. set to 1
		ypixelSPERM	4 bytes	pixels per meter. thanks microsoft. set to 1
		colorsused	4 bytes number of actually used colours. set to 16777216 (2**24)
		importantcolors	4 bytes	idrk, thanks microsoft. set to 0, that way all colors are imp
	colortable 4 * numcolors ( = zero ) bytes
	pixeldata width * height * 3 bytes
		triplets of bytes: first byte blue, second byte green, third byte red over and over.
		lines must be padded to the nearest 4-byte boundary, so make your life easier (:
		lines are sent from bottom to top. thanks microsoft.
*/
struct piksel {
	uint8_t r;
	uint8_t g;
	uint8_t b;
};
struct bmpheader {
	char signature[2]	 /* packed ignored for char */;
	uint32_t filesize	 __attribute__((packed));
	uint32_t reserved	 __attribute__((packed));
	uint32_t dataoffset	 __attribute__((packed));
	uint32_t size		 __attribute__((packed));
	uint32_t width		 __attribute__((packed));
	uint32_t height		 __attribute__((packed));
	uint16_t planes		 __attribute__((packed));
	uint16_t bitsperpixel	 __attribute__((packed));
	uint32_t compression	 __attribute__((packed));
	uint32_t imagesize	 __attribute__((packed));
	uint32_t xpixelsperm	 __attribute__((packed));
	uint32_t ypixelsperm	 __attribute__((packed));
	uint32_t colorsused	 __attribute__((packed));
	uint32_t importantcolors __attribute__((packed));
} __attribute__((packed));
void bmpheader_init (struct bmpheader * in) {
	in->signature[0] = 'B';
	in->signature[1] = 'M';
	in->reserved = 0;
	in->dataoffset = 14+40;
	in->size = 40;
	in->planes = 1;
	in->bitsperpixel = 24;
	in->compression = 0;
	in->imagesize = 0;
	in->xpixelsperm = 1;
	in->ypixelsperm = 1;
	in->colorsused = 16777216; /* 2^24 */
	in->importantcolors = 0;
}
int shraniBMP (struct piksel ** in, unsigned int cols, unsigned int lines, FILE * out) {
#define LINELEN (cols*3+((4-cols*3%4) == 4 ? 0 : 4-cols*3%4))		/* returns negative on fail or 1 on success */
	struct bmpheader bh = {
		.filesize = 14+40+LINELEN*lines,
		.width = cols,
		.height = lines
	};
	bmpheader_init(&bh);
	if (!fwrite(&bh, sizeof(bh), 1, out)) {
		fprintf(stderr, "NAPAČA pri pisanju v FILE\n");
		return -1;
	}
	for (unsigned int i = lines-1; 1; i--) {
		for (unsigned int j = 0; j < cols; j++) {
#define PISIBARVO(x)	if (!fwrite(&in[i][j].x, 1, 1, out)) {	\
				fprintf(stderr, "NAPAČA pri pisanju barve\n");	\
				return -2;					\
			}
			PISIBARVO(b)
			PISIBARVO(g)
			PISIBARVO(r)
		}
		if (4 - cols*3%4 != 4) {
			/* fprintf(stderr, "pišem %d bajtov paddinga\n", cols*3%4); */
			char krneki[4] = "\0\0\0";
			if (fwrite(krneki, 1, 4 - cols*3%4, out) != 4 - cols*3%4) {
				fprintf(stderr, "NAPAČA pri pisanju paddinga\n");
				return -3;
			}
		}
		if (i == 0)
			break;
	}
	return 1;
}
long double complex preberi (char * in) {
	long double r = 0;
	long double i = 0;
preberi:
	;
	long double nasl = strtold(in, &in);
	if (in[0] == 'i') { /* pravkar je bil povedan imaginarni del */
		fprintf(stderr, "je bil povedan imaginarni del\n");
		i = nasl;
		in++;
	} else {
		fprintf(stderr, "je bil povedan realni del\n");
		r = nasl;
	}
	if (in[0] == '+' || in[0] == '-') /* imamo še eno */
		goto preberi;
	long double complex out = r + i * I;
	return out;
}
#define P(z) (cpowl(z, 2)+c)
int main (int argc, char ** argv) {
	if (argc != 1+2+3) {
		fprintf(stderr, "uporaba: %s 512 -13.32344-3.0123i 0 0 1\n", argv[0] ? argv[0] : "hekr");
		return 1;
	}
	int offset1 = atoi(argv[3]);
	int offset2 = atoi(argv[4]);
	long double scale = strtold(argv[5], NULL);
	int dim = atoi(argv[1]);
	long double dimf = dim;
	long double complex c = preberi(argv[2]);
	struct piksel ** piksli = calloc(1, dim*sizeof(*piksli));
	for (int i = 0; i < dim; i++)
		piksli[i] = calloc(1, dim*sizeof(*piksli[i]));
	for (int i = 0; i < dim; i++) {
		for (int j = 0; j < dim; j++) {
			int counter;
#define COUNTER (counter)
			COUNTER = 0;
#define PRETVORI(n) (((n)-((dimf)/2))/((dimf)/3.8))
			long double complex z = PRETVORI(i+offset1)*scale + PRETVORI(j+offset2)*scale * I;
			while (creall(z) < 2 && cimagl(z) < 2 && creall(z) > -2 && cimagl(z) > -2 && ++COUNTER < 255)
				z = P(z);
			piksli[i][j].r = COUNTER;
		}
		fprintf(stderr, "\rGeneriranje vrstice %d od %d.", i, dim);
	}
	shraniBMP(piksli, dim, dim, stdout);	/* OH NO, ne gledamo return valuea (rodilnik) */
	fprintf(stderr, "\rGeneriranje slike končano. Izpisano na standardni izhod.\n");
	for (int i = 0; i < dim; i++)
		free(piksli[i]);
	free(piksli);
	return 0;
}