// mesh_3a.c

#include <stdio.h>
#include <stdlib.h>

#define X_SIZE	32
#define Y_SIZE	32
#define HIGH	255

typedef unsigned char u_char;

void save_image_data(char* f_name);
void normalize(void);
void disp_img(u_char img[][X_SIZE]);
void cut_img(int n);
void load_image_data(char* f_name);

u_char	image[Y_SIZE][X_SIZE * 10];
u_char	img_a[Y_SIZE][X_SIZE];
u_char	img_b[Y_SIZE][X_SIZE];

int main()
{
	char	f_name[256];
	int	i;

	load_image_data("number2.pgm");
	for (i = 0; i < 10; i++) {
		cut_img(i);
		printf("\nimg_a:%d\n", i);
		disp_img(img_a);

		normalize();
		printf("\nimg_b:%d\n", i);
		disp_img(img_b);

		sprintf_s(f_name, _countof(f_name), "num%d.pgm", i);
		save_image_data(f_name);
	}

	return 0;
}

void save_image_data(char* f_name)
{
	FILE*	fp;
	errno_t	err;
	int	ix, iy;

	err = fopen_s(&fp, f_name, "wb");
	if (err) {
		fprintf(stderr, "fopen_s\n");
		return;
	}

	fputs("P5\n", fp);
	fputs("# Created by Image Processing\n", fp);
	fprintf(fp, "%d %d\n", X_SIZE, Y_SIZE);
	fprintf(fp, "%d\n", HIGH);

	for (iy = 0; iy < Y_SIZE; iy++) {
		for (ix = 0; ix < X_SIZE; ix++) {
			fputc(img_b[iy][ix], fp);
		}
	}

	fclose(fp);
}

void normalize(void)
{
	int	xs = X_SIZE;
	int	xe = -1;
	int	ys = Y_SIZE;
	int	ye = -1;
	int	ix, iy;
	int	iw, ih;
	int	ax, ay;
	int	max;

	// Y走査
	for (iy = 0; iy < Y_SIZE; iy++) {
		for (ix = 0; ix < X_SIZE; ix++) {
			if (img_a[iy][ix]) continue;
			if (iy < ys) ys = iy;
			if (ye < iy) ye = iy;
		}
	}
	// X走査
	for (ix = 0; ix < X_SIZE; ix++) {
		for (iy = 0; iy < Y_SIZE; iy++) {
			if (img_a[iy][ix]) continue;
			if (ix < xs) xs = ix;
			if (xe < ix) xe = ix;
		}
	}
	iw = xe - xs + 1;
	ih = ye - ys + 1;
	printf("xs=%d xe=%d ys=%d ye=%d, w=%d h=%d\n", xs, xe, ys, ye, iw, ih);

	if (iw < ih) {
		max = ih;
		xs += (iw - max) / 2;
	} else {
		max = iw;
		ys += (ih - max) / 2;
	}
	for (iy = 0; iy < Y_SIZE; iy++) {
		for (ix = 0; ix < X_SIZE; ix++) {
			ax = xs + ix * max / X_SIZE;
			ay = ys + iy * max / Y_SIZE;
			if (ax < 0 || X_SIZE <= ax || ay < 0 || Y_SIZE <= ay) {
				img_b[iy][ix] = 0xff;
			} else {
				img_b[iy][ix] = img_a[ay][ax];
			}
		}
	}
}

void disp_img(u_char img[][X_SIZE])
{
	int	ix, iy;

	for (iy = 0; iy < Y_SIZE; iy++) {
		for (ix = 0; ix < X_SIZE; ix++) {
			printf("%02x", img[iy][ix]);
		}
		printf("\n");
	}
}

void cut_img(int n)
{
	int	ix, iy;

	for (iy = 0; iy < Y_SIZE; iy++) {
		for (ix = 0; ix < X_SIZE; ix++) {
			img_a[iy][ix] = image[iy][X_SIZE * n + ix];
		}
	}
}

void load_image_data(char* f_name)
{
	FILE*	fp;
	char	buf[640];
	errno_t	err;
	int	x_size, y_size;
	int	max_gray;
	int	ix, iy;

	err = fopen_s(&fp, f_name, "rb");
	if (err) {
		fprintf(stderr, "fopen_s\n");
		return;
	}

	// P5
	fgets(buf, sizeof buf, fp);
	if (buf[0] != 'P' || buf[1] != '5') {
		fprintf(stderr, "not P5\n");
		return;
	}

	// x y
	x_size = y_size = 0;
	while (x_size == 0) {
		fgets(buf, sizeof buf, fp);
		if (buf[0] == '#') continue;
		sscanf_s(buf, "%d%d", &x_size, &y_size);
	}

	// max
	max_gray = 0;
	while (max_gray == 0) {
		fgets(buf, sizeof buf, fp);
		if (buf[0] == '#') continue;
		sscanf_s(buf, "%d", &max_gray);
	}

	for (iy = 0; iy < y_size; iy++) {
		for (ix = 0; ix < x_size; ix++) {
			image[iy][ix] = fgetc(fp);
		}
	}

	fclose(fp);
}

/*
img_a:9
ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff
ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff
ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff
ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff
ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff
ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff
ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff
ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff
ffffffffff0000000000ffffffffffffffffffffffffffffffffffffffffffff
ffffff0000ffffffffff00ffffffffffffffffffffffffffffffffffffffffff
ffff0000ffffffffffffff00ffffffffffffffffffffffffffffffffffffffff
ffff00ffffffffffffffffff00ffffffffffffffffffffffffffffffffffffff
ff0000ffffffffffffffffff00ffffffffffffffffffffffffffffffffffffff
ff0000ffffffffffffffffff0000ffffffffffffffffffffffffffffffffffff
ff0000ffffffffffffffffff0000ffffffffffffffffffffffffffffffffffff
ff0000ffffffffffffffffff0000ffffffffffffffffffffffffffffffffffff
ffff0000ffffffffffffff000000ffffffffffffffffffffffffffffffffffff
ffffff0000ffffffffff00ff0000ffffffffffffffffffffffffffffffffffff
ffffffff000000000000ffff0000ffffffffffffffffffffffffffffffffffff
ffffffffffffffffffffffff0000ffffffffffffffffffffffffffffffffffff
ffffffffffffffffffffffff0000ffffffffffffffffffffffffffffffffffff
ffffffffffffffffffffffff00ffffffffffffffffffffffffffffffffffffff
ffff000000ffffffffffff0000ffffffffffffffffffffffffffffffffffffff
ffff000000ffffffffffff00ffffffffffffffffffffffffffffffffffffffff
ffff0000ffffffffffff0000ffffffffffffffffffffffffffffffffffffffff
ffffff00ffffffffff0000ffffffffffffffffffffffffffffffffffffffffff
ffffffff0000000000ffffffffffffffffffffffffffffffffffffffffffffff
ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff
ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff
ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff
ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff
ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff
xs=1 xe=13 ys=8 ye=26, w=13 h=19

img_b:9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*/