/*
  BDF simple reader and printer (ASCII Support only)
  include stdio.h stddef.h stdlib.h string.h
  Should define SBDF_IMPLEMENTATION in only one .c file
*/

typedef struct SBDF_Font SBDF_Font;

SBDF_Font*   SBDF_FontLoad(const char *);
void         SBDF_FontDestroy(SBDF_Font *);
#ifdef SBDF_USESDL
void         SBDF_SDLPrint(const SDL_Renderer *, const SBDF_Font *, const char *, int, int);
#endif

#ifdef SBDF_IMPLEMENTATION
struct SBDF_Glyph {
	int dx, dy;
	int bx, by, bw, bh;
	size_t s;
};

struct SBDF_Font {
	struct SBDF_Glyph g[256];
	unsigned char *data;
};

struct SBDF_Font*
SBDF_FontInit(size_t sz) {
	struct SBDF_Font *res;
	int i;
	res = malloc(sizeof(*res));
	if (res == NULL) return NULL;

	res->data = malloc(sz);
	if (res->data == NULL) {
		free(res);
		return NULL;
	}
	for (i = 0; i < 256; i++)
		res->g[i].s = -1;
	return res;
}

void
SBDF_FontDestroy(struct SBDF_Font *f) {
	if (f == NULL) return;
	free(f->data);
	free(f);
}

#define SBDF_NULL    0x00000
#define SBDF_PROPS   0x00010
#define SBDF_CHARS   0x00100
#define SBDF_GLYPH   0x01100

struct SBDF_Font*
SBDF_FontLoad(const char *path) {
	FILE *f;
	int cnt, rd, tp;
	struct SBDF_Glyph g;
	size_t sz;
	char line[2049];
	char word[2049];
	char *v;
	unsigned char val;
	int state;
	struct SBDF_Font *res;
	res = NULL;
	f = fopen(path, "r");
	if (f == NULL) goto SBDF_FontLoad_defer;

	state = SBDF_NULL;
	rd = cnt = sz = 0;
	while (fgets(line, 2049, f)) {
		if ((state&SBDF_CHARS) == 0) {
			sscanf(line, "%s", word);
			if (state == SBDF_PROPS) {
				if (strcmp(word, "ENDPROPERTIES") == 0)
					state = SBDF_NULL;
			} else {
				if (strcmp(word, "STARTPROPERTIES") == 0)
					state = SBDF_PROPS;
				else if (strcmp(word, "CHARS") == 0)
					state = SBDF_CHARS;
			}
			continue;
		} else {
			sscanf(line, "%s", word);
			if (cnt) {
				--cnt;
				continue;
			}
			if (strcmp(word, "ENCODING") == 0) {
				sscanf(line, "%*s %d", &tp);
				rd = (tp > -1 && tp < 256);
				continue;
			}
			if (strcmp(word, "DWIDTH") == 0) {
				sscanf(line, "%*s %d %d", &g.dx, &g.dy);
				continue;
			}
			if (strcmp(word, "BBX") == 0) {
				sscanf(line, "%*s %d %d %d %d", &g.bw, &g.bh, &g.bx, &g.by);
				if (rd) {
					sz += (g.bw+7) / 8 * g.bh;
				}
				continue;
			}
			if (strcmp(word, "BITMAP") == 0) {
				cnt = g.bh;
				continue;
			}
		}
	}

	fclose(f);
	res = SBDF_FontInit(sz);
	if (res == NULL) goto SBDF_FontLoad_defer;
	f = fopen(path, "r");
	if (f == NULL) goto SBDF_FontLoad_defer;

	state = SBDF_NULL;
	rd = cnt = sz = 0;
	while (fgets(line, 2049, f)) {
		if ((state&SBDF_CHARS) == 0) {
			sscanf(line, "%s", word);
			if (state == SBDF_PROPS) {
				if (strcmp(word, "ENDPROPERTIES") == 0)
					state = SBDF_NULL;
			} else {
				if (strcmp(word, "STARTPROPERTIES") == 0)
					state = SBDF_PROPS;
				else if (strcmp(word, "CHARS") == 0)
					state = SBDF_CHARS;
			}
			continue;
		} else {
			sscanf(line, "%s", word);
			if (cnt) {
				--cnt;
				if (rd) {
					v = word;
					while (v[0] != '\0') {
						if (v[0] <= '9')
							val = (unsigned char)16*(v[0] - '0');
						else
							val = (unsigned char)16*(v[0] - 'A' + 10);
						if (v[1] <= '9')
							val += (unsigned char)(v[1] - '0');
						else
							val += (unsigned char)(v[1] - 'A' + 10);
						res->data[sz] = val;
						sz++;
						v += 2;
					}
				}
				continue;
			}
			if (strcmp(word, "ENCODING") == 0) {
				sscanf(line, "%*s %d", &tp);
				rd = (tp > -1 && tp < 256);
				continue;
			}
			if (strcmp(word, "DWIDTH") == 0) {
				sscanf(line, "%*s %d %d", &g.dx, &g.dy);
				continue;
			}
			if (strcmp(word, "BBX") == 0) {
				sscanf(line, "%*s %d %d %d %d", &g.bw, &g.bh, &g.bx, &g.by);
				continue;
			}
			if (strcmp(word, "BITMAP") == 0) {
				cnt = g.bh;
				if (rd) {
					g.s = sz;
					res->g[tp] = g;
				}
				continue;
			}
		}
	}
	return res;
SBDF_FontLoad_defer:
	if (f != NULL)
		fclose(f);
	SBDF_FontDestroy(res);
	return NULL;
}

#ifdef SBDF_USESDL
void
SBDF_SDLPrint(const SDL_Renderer *r, const struct SBDF_Font *f, const char *text, int x, int y) {
	char *u;
	unsigned char *v;
	int i, j;
	u = text;
	while (*u != '\0') {
		v = &f->data[f->g[*u].s];
		x += f->g[*u].bx;
		y += f->g[*u].by;
		for (i = 0; i < f->g[*u].bh; i++) {
			for (j = 0; j < f->g[*u].bw; j++) {
				if (v[j/8]>>(7-(j%8))&1)
					SDL_RenderDrawPoint(r, x+j, y+i);
			}
			v += (j + 7) / 8;
		}
		x += f->g[*u].dx - f->g[*u].bx;
		y += f->g[*u].dy - f->g[*u].by;
		u++;
	}
}
#endif
#endif