nuclear@24: /*
nuclear@24: libdrawtext - a simple library for fast text rendering in OpenGL
nuclear@24: Copyright (C) 2011  John Tsiombikas <nuclear@member.fsf.org>
nuclear@24: 
nuclear@24: This program is free software: you can redistribute it and/or modify
nuclear@24: it under the terms of the GNU Lesser General Public License as published by
nuclear@24: the Free Software Foundation, either version 3 of the License, or
nuclear@24: (at your option) any later version.
nuclear@24: 
nuclear@24: This program is distributed in the hope that it will be useful,
nuclear@24: but WITHOUT ANY WARRANTY; without even the implied warranty of
nuclear@24: MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
nuclear@24: GNU Lesser General Public License for more details.
nuclear@24: 
nuclear@24: You should have received a copy of the GNU Lesser General Public License
nuclear@24: along with this program.  If not, see <http://www.gnu.org/licenses/>.
nuclear@24: */
nuclear@24: #ifndef NO_FREETYPE
nuclear@24: #define USE_FREETYPE
nuclear@24: #endif
nuclear@24: 
nuclear@24: #include <stdio.h>
nuclear@24: #include <stdlib.h>
nuclear@24: #include <string.h>
nuclear@24: #include <math.h>
nuclear@24: #include <limits.h>
nuclear@24: #include <ctype.h>
nuclear@24: #include <float.h>
nuclear@24: #include <errno.h>
nuclear@24: #ifdef USE_FREETYPE
nuclear@24: #include <ft2build.h>
nuclear@24: #include FT_FREETYPE_H
nuclear@24: #endif
nuclear@24: #include "drawtext.h"
nuclear@24: #include "drawtext_impl.h"
nuclear@24: 
nuclear@24: #define FTSZ_TO_PIXELS(x)	((x) / 64)
nuclear@24: #define MAX_IMG_WIDTH		4096
nuclear@24: 
nuclear@24: 
nuclear@24: #ifdef USE_FREETYPE
nuclear@24: static int init_freetype(void);
nuclear@24: static void cleanup(void);
nuclear@24: 
nuclear@24: static void calc_best_size(int total_width, int max_glyph_height, int padding, int pow2, int *imgw, int *imgh);
nuclear@24: static int next_pow2(int x);
nuclear@24: 
nuclear@24: static FT_Library ft;
nuclear@24: 
nuclear@24: 
nuclear@24: static int init_done;
nuclear@24: 
nuclear@24: static int init_freetype(void)
nuclear@24: {
nuclear@24: 	if(!init_done) {
nuclear@24: 		if(FT_Init_FreeType(&ft) != 0) {
nuclear@24: 			return -1;
nuclear@24: 		}
nuclear@24: 		atexit(cleanup);
nuclear@24: 		init_done = 1;
nuclear@24: 	}
nuclear@24: 	return 0;
nuclear@24: }
nuclear@24: 
nuclear@24: static void cleanup(void)
nuclear@24: {
nuclear@24: 	if(init_done) {
nuclear@24: 		FT_Done_FreeType(ft);
nuclear@24: 	}
nuclear@24: }
nuclear@24: 
nuclear@24: struct dtx_font *dtx_open_font(const char *fname, int sz)
nuclear@24: {
nuclear@24: 	struct dtx_font *fnt;
nuclear@24: 
nuclear@24: 	init_freetype();
nuclear@24: 
nuclear@24: 	if(!(fnt = calloc(1, sizeof *fnt))) {
nuclear@24: 		fperror("failed to allocate font structure");
nuclear@24: 		return 0;
nuclear@24: 	}
nuclear@24: 
nuclear@24: 	if(FT_New_Face(ft, fname, 0, (FT_Face*)&fnt->face) != 0) {
nuclear@24: 		fprintf(stderr, "failed to open font file: %s\n", fname);
nuclear@24: 		return 0;
nuclear@24: 	}
nuclear@24: 
nuclear@24: 	/* pre-create the extended ASCII range glyphmap */
nuclear@24: 	if(sz) {
nuclear@24: 		dtx_prepare_range(fnt, sz, 0, 256);
nuclear@24: 	}
nuclear@24: 
nuclear@24: 	return fnt;
nuclear@24: }
nuclear@24: 
nuclear@24: void dtx_close_font(struct dtx_font *fnt)
nuclear@24: {
nuclear@24: 	if(!fnt) return;
nuclear@24: 
nuclear@24: 	FT_Done_Face(fnt->face);
nuclear@24: 
nuclear@24: 	/* destroy the glyphmaps */
nuclear@24: 	while(fnt->gmaps) {
nuclear@24: 		void *tmp = fnt->gmaps;
nuclear@24: 		fnt->gmaps = fnt->gmaps->next;
nuclear@24: 		dtx_free_glyphmap(tmp);
nuclear@24: 	}
nuclear@24: 
nuclear@24: 	free(fnt);
nuclear@24: }
nuclear@24: 
nuclear@24: void dtx_prepare(struct dtx_font *fnt, int sz)
nuclear@24: {
nuclear@24: 	dtx_get_font_glyphmap_range(fnt, sz, 0, 256);
nuclear@24: }
nuclear@24: 
nuclear@24: void dtx_prepare_range(struct dtx_font *fnt, int sz, int cstart, int cend)
nuclear@24: {
nuclear@24: 	dtx_get_font_glyphmap_range(fnt, sz, cstart, cend);
nuclear@24: }
nuclear@24: 
nuclear@24: struct dtx_glyphmap *dtx_get_font_glyphmap(struct dtx_font *fnt, int sz, int code)
nuclear@24: {
nuclear@24: 	struct dtx_glyphmap *gm;
nuclear@24: 
nuclear@24: 	/* check to see if the last we've given out fits the bill */
nuclear@24: 	if(fnt->last_gmap && code >= fnt->last_gmap->cstart && code < fnt->last_gmap->cend && fnt->last_gmap->ptsize == sz) {
nuclear@24: 		return fnt->last_gmap;
nuclear@24: 	}
nuclear@24: 
nuclear@24: 	/* otherwise search for the appropriate glyphmap */
nuclear@24: 	gm = fnt->gmaps;
nuclear@24: 	while(gm) {
nuclear@24: 		if(code >= gm->cstart && code < gm->cend && sz == gm->ptsize) {
nuclear@24: 			fnt->last_gmap = gm;
nuclear@24: 			return gm;
nuclear@24: 		}
nuclear@24: 		gm = gm->next;
nuclear@24: 	}
nuclear@24: 	return 0;
nuclear@24: }
nuclear@24: 
nuclear@24: struct dtx_glyphmap *dtx_get_font_glyphmap_range(struct dtx_font *fnt, int sz, int cstart, int cend)
nuclear@24: {
nuclear@24: 	struct dtx_glyphmap *gm;
nuclear@24: 
nuclear@24: 	/* search the available glyphmaps to see if we've got one that includes
nuclear@24: 	 * the requested range
nuclear@24: 	 */
nuclear@24: 	gm = fnt->gmaps;
nuclear@24: 	while(gm) {
nuclear@24: 		if(gm->cstart <= cstart && gm->cend >= cend && gm->ptsize == sz) {
nuclear@24: 			return gm;
nuclear@24: 		}
nuclear@24: 		gm = gm->next;
nuclear@24: 	}
nuclear@24: 
nuclear@24: 	/* not found, create one and add it to the list */
nuclear@24: 	if(!(gm = dtx_create_glyphmap_range(fnt, sz, cstart, cend))) {
nuclear@24: 		return 0;
nuclear@24: 	}
nuclear@24: 	return gm;
nuclear@24: }
nuclear@24: 
nuclear@24: struct dtx_glyphmap *dtx_create_glyphmap_range(struct dtx_font *fnt, int sz, int cstart, int cend)
nuclear@24: {
nuclear@24: 	FT_Face face = fnt->face;
nuclear@24: 	struct dtx_glyphmap *gmap;
nuclear@24: 	int i, j;
nuclear@24: 	int gx, gy;
nuclear@24: 	int padding = 4;
nuclear@24: 	int total_width = padding;
nuclear@24: 	int max_height = 0;
nuclear@24: 
nuclear@24: 	FT_Set_Char_Size(fnt->face, 0, sz * 64, 72, 72);
nuclear@24: 
nuclear@24: 	if(!(gmap = calloc(1, sizeof *gmap))) {
nuclear@24: 		return 0;
nuclear@24: 	}
nuclear@24: 
nuclear@24: 	gmap->ptsize = sz;
nuclear@24: 	gmap->cstart = cstart;
nuclear@24: 	gmap->cend = cend;
nuclear@24: 	gmap->crange = cend - cstart;
nuclear@24: 	gmap->line_advance = FTSZ_TO_PIXELS((float)face->size->metrics.height);
nuclear@24: 
nuclear@24: 	if(!(gmap->glyphs = malloc(gmap->crange * sizeof *gmap->glyphs))) {
nuclear@24: 		free(gmap);
nuclear@24: 		return 0;
nuclear@24: 	}
nuclear@24: 
nuclear@24: 	for(i=0; i<gmap->crange; i++) {
nuclear@24: 		int h;
nuclear@24: 
nuclear@24: 		FT_Load_Char(face, i + cstart, 0);
nuclear@24: 		h = FTSZ_TO_PIXELS(face->glyph->metrics.height);
nuclear@24: 
nuclear@24: 		if(h > max_height) {
nuclear@24: 			max_height = h;
nuclear@24: 		}
nuclear@24: 		total_width += FTSZ_TO_PIXELS(face->glyph->metrics.width) + padding;
nuclear@24: 	}
nuclear@24: 
nuclear@24: 	calc_best_size(total_width, max_height, padding, 1, &gmap->xsz, &gmap->ysz);
nuclear@24: 
nuclear@24: 	if(!(gmap->pixels = malloc(gmap->xsz * gmap->ysz))) {
nuclear@24: 		free(gmap->glyphs);
nuclear@24: 		free(gmap);
nuclear@24: 		return 0;
nuclear@24: 	}
nuclear@24: 	memset(gmap->pixels, 0, gmap->xsz * gmap->ysz);
nuclear@24: 
nuclear@24: 	gx = padding;
nuclear@24: 	gy = padding;
nuclear@24: 
nuclear@24: 	for(i=0; i<gmap->crange; i++) {
nuclear@24: 		float gwidth, gheight;
nuclear@24: 		unsigned char *src, *dst;
nuclear@24: 		FT_GlyphSlot glyph;
nuclear@24: 
nuclear@24: 		FT_Load_Char(face, i + cstart, FT_LOAD_RENDER);
nuclear@24: 		glyph = face->glyph;
nuclear@24: 		gwidth = FTSZ_TO_PIXELS((float)glyph->metrics.width);
nuclear@24: 		gheight = FTSZ_TO_PIXELS((float)glyph->metrics.height);
nuclear@24: 
nuclear@24: 		if(gx > gmap->xsz - gwidth - padding) {
nuclear@24: 			gx = padding;
nuclear@24: 			gy += max_height + padding;
nuclear@24: 		}
nuclear@24: 
nuclear@24: 		src = glyph->bitmap.buffer;
nuclear@24: 		dst = gmap->pixels + gy * gmap->xsz + gx;
nuclear@24: 
nuclear@24: 		for(j=0; j<glyph->bitmap.rows; j++) {
nuclear@24: 			memcpy(dst, src, glyph->bitmap.width);
nuclear@24: 			dst += gmap->xsz;
nuclear@24: 			src += glyph->bitmap.pitch;
nuclear@24: 		}
nuclear@24: 
nuclear@24: 		gmap->glyphs[i].code = i;
nuclear@24: 		gmap->glyphs[i].x = gx - 1;
nuclear@24: 		gmap->glyphs[i].y = gy - 1;
nuclear@24: 		gmap->glyphs[i].width = gwidth + 2;
nuclear@24: 		gmap->glyphs[i].height = gheight + 2;
nuclear@24: 		gmap->glyphs[i].orig_x = -FTSZ_TO_PIXELS((float)glyph->metrics.horiBearingX) + 1;
nuclear@24: 		gmap->glyphs[i].orig_y = FTSZ_TO_PIXELS((float)glyph->metrics.height - glyph->metrics.horiBearingY) + 1;
nuclear@24: 		gmap->glyphs[i].advance = FTSZ_TO_PIXELS((float)glyph->metrics.horiAdvance);
nuclear@24: 		/* also precalc normalized */
nuclear@24: 		gmap->glyphs[i].nx = (float)gmap->glyphs[i].x / (float)gmap->xsz;
nuclear@24: 		gmap->glyphs[i].ny = (float)gmap->glyphs[i].y / (float)gmap->ysz;
nuclear@24: 		gmap->glyphs[i].nwidth = (float)gmap->glyphs[i].width / (float)gmap->xsz;
nuclear@24: 		gmap->glyphs[i].nheight = (float)gmap->glyphs[i].height / (float)gmap->ysz;
nuclear@24: 
nuclear@24: 		gx += gwidth + padding;
nuclear@24: 	}
nuclear@24: 
nuclear@24: 	/* add it to the glyphmaps list of the font */
nuclear@24: 	gmap->next = fnt->gmaps;
nuclear@24: 	fnt->gmaps = gmap;
nuclear@24: 
nuclear@24: 	return gmap;
nuclear@24: }
nuclear@24: #endif	/* USE_FREETYPE */
nuclear@24: 
nuclear@24: void dtx_free_glyphmap(struct dtx_glyphmap *gmap)
nuclear@24: {
nuclear@24: 	if(gmap) {
nuclear@24: 		free(gmap->pixels);
nuclear@24: 		free(gmap->glyphs);
nuclear@24: 		free(gmap);
nuclear@24: 	}
nuclear@24: }
nuclear@24: 
nuclear@24: unsigned char *dtx_get_glyphmap_pixels(struct dtx_glyphmap *gmap)
nuclear@24: {
nuclear@24: 	return gmap->pixels;
nuclear@24: }
nuclear@24: 
nuclear@24: int dtx_get_glyphmap_width(struct dtx_glyphmap *gmap)
nuclear@24: {
nuclear@24: 	return gmap->xsz;
nuclear@24: }
nuclear@24: 
nuclear@24: int dtx_get_glyphmap_height(struct dtx_glyphmap *gmap)
nuclear@24: {
nuclear@24: 	return gmap->ysz;
nuclear@24: }
nuclear@24: 
nuclear@24: struct dtx_glyphmap *dtx_load_glyphmap(const char *fname)
nuclear@24: {
nuclear@24: 	FILE *fp;
nuclear@24: 	struct dtx_glyphmap *gmap;
nuclear@24: 
nuclear@24: 	if(!(fp = fopen(fname, "r"))) {
nuclear@24: 		return 0;
nuclear@24: 	}
nuclear@24: 	gmap = dtx_load_glyphmap_stream(fp);
nuclear@24: 	fclose(fp);
nuclear@24: 	return gmap;
nuclear@24: }
nuclear@24: 
nuclear@24: struct dtx_glyphmap *dtx_load_glyphmap_stream(FILE *fp)
nuclear@24: {
nuclear@24: 	char buf[512];
nuclear@24: 	int hdr_lines = 0;
nuclear@24: 	struct dtx_glyphmap *gmap;
nuclear@24: 	struct glyph *glyphs = 0;
nuclear@24: 	int min_code = INT_MAX;
nuclear@24: 	int max_code = INT_MIN;
nuclear@24: 	int i, max_pixval, num_pixels;
nuclear@24: 
nuclear@24: 	if(!(gmap = calloc(1, sizeof *gmap))) {
nuclear@24: 		fperror("failed to allocate glyphmap");
nuclear@24: 		return 0;
nuclear@24: 	}
nuclear@24: 
nuclear@24: 	while(hdr_lines < 3) {
nuclear@24: 		char *line = buf;
nuclear@24: 		if(!fgets(buf, sizeof buf, fp)) {
nuclear@24: 			fperror("unexpected end of file");
nuclear@24: 			goto err;
nuclear@24: 		}
nuclear@24: 
nuclear@24: 		while(isspace(*line)) {
nuclear@24: 			line++;
nuclear@24: 		}
nuclear@24: 
nuclear@24: 		if(line[0] == '#') {
nuclear@24: 			struct glyph *g;
nuclear@24: 			int c;
nuclear@24: 			float x, y, xsz, ysz, res;
nuclear@24: 
nuclear@24: 			res = sscanf(line + 1, "%d: %fx%f+%f+%f\n", &c, &xsz, &ysz, &x, &y);
nuclear@24: 			if(res != 5) {
nuclear@24: 				fprintf(stderr, "%s: invalid glyph info line\n", __func__);
nuclear@24: 				goto err;
nuclear@24: 			}
nuclear@24: 
nuclear@24: 			if(!(g = malloc(sizeof *g))) {
nuclear@24: 				fperror("failed to allocate glyph");
nuclear@24: 				goto err;
nuclear@24: 			}
nuclear@24: 			g->code = c;
nuclear@24: 			g->x = x;
nuclear@24: 			g->y = y;
nuclear@24: 			g->width = xsz;
nuclear@24: 			g->height = ysz;
nuclear@24: 			g->next = glyphs;
nuclear@24: 			glyphs = g;
nuclear@24: 
nuclear@24: 			if(c < min_code) {
nuclear@24: 				min_code = c;
nuclear@24: 			}
nuclear@24: 			if(c > max_code) {
nuclear@24: 				max_code = c;
nuclear@24: 			}
nuclear@24: 		} else {
nuclear@24: 			switch(hdr_lines) {
nuclear@24: 			case 0:
nuclear@24: 				if(0[line] != 'P' || 1[line] != '6') {
nuclear@24: 					fprintf(stderr, "%s: invalid file format (magic)\n", __func__);
nuclear@24: 					goto err;
nuclear@24: 				}
nuclear@24: 				break;
nuclear@24: 
nuclear@24: 			case 1:
nuclear@24: 				if(sscanf(line, "%d %d", &gmap->xsz, &gmap->ysz) != 2) {
nuclear@24: 					fprintf(stderr, "%s: invalid file format (dim)\n", __func__);
nuclear@24: 					goto err;
nuclear@24: 				}
nuclear@24: 				break;
nuclear@24: 
nuclear@24: 			case 2:
nuclear@24: 				{
nuclear@24: 					char *endp;
nuclear@24: 					max_pixval = strtol(line, &endp, 10);
nuclear@24: 					if(endp == line) {
nuclear@24: 						fprintf(stderr, "%s: invalid file format (maxval)\n", __func__);
nuclear@24: 						goto err;
nuclear@24: 					}
nuclear@24: 				}
nuclear@24: 				break;
nuclear@24: 
nuclear@24: 			default:
nuclear@24: 				break;	/* can't happen */
nuclear@24: 			}
nuclear@24: 			hdr_lines++;
nuclear@24: 		}
nuclear@24: 	}
nuclear@24: 
nuclear@24: 	num_pixels = gmap->xsz * gmap->ysz;
nuclear@24: 	if(!(gmap->pixels = malloc(num_pixels))) {
nuclear@24: 		fperror("failed to allocate pixels");
nuclear@24: 		goto err;
nuclear@24: 	}
nuclear@24: 
nuclear@24: 	for(i=0; i<num_pixels; i++) {
nuclear@24: 		long c = fgetc(fp);
nuclear@24: 		if(c == -1) {
nuclear@24: 			fprintf(stderr, "unexpected end of file while reading pixels\n");
nuclear@24: 			goto err;
nuclear@24: 		}
nuclear@24: 		gmap->pixels[i] = 255 * c / max_pixval;
nuclear@24: 		fseek(fp, 2, SEEK_CUR);
nuclear@24: 	}
nuclear@24: 
nuclear@24: 	gmap->cstart = min_code;
nuclear@24: 	gmap->cend = max_code + 1;
nuclear@24: 	gmap->crange = gmap->cend - gmap->cstart;
nuclear@24: 
nuclear@24: 	if(!(gmap->glyphs = calloc(gmap->crange, sizeof *gmap->glyphs))) {
nuclear@24: 		fperror("failed to allocate glyph info");
nuclear@24: 		goto err;
nuclear@24: 	}
nuclear@24: 
nuclear@24: 	while(glyphs) {
nuclear@24: 		struct glyph *g = glyphs;
nuclear@24: 		glyphs = glyphs->next;
nuclear@24: 
nuclear@24: 		gmap->glyphs[g->code - gmap->cstart] = *g;
nuclear@24: 		free(g);
nuclear@24: 	}
nuclear@24: 	return gmap;
nuclear@24: 
nuclear@24: err:
nuclear@24: 	dtx_free_glyphmap(gmap);
nuclear@24: 	while(glyphs) {
nuclear@24: 		void *tmp = glyphs;
nuclear@24: 		glyphs = glyphs->next;
nuclear@24: 		free(tmp);
nuclear@24: 	}
nuclear@24: 	return 0;
nuclear@24: }
nuclear@24: 
nuclear@24: int dtx_save_glyphmap(const char *fname, const struct dtx_glyphmap *gmap)
nuclear@24: {
nuclear@24: 	FILE *fp;
nuclear@24: 	int res;
nuclear@24: 
nuclear@24: 	if(!(fp = fopen(fname, "wb"))) {
nuclear@24: 		fprintf(stderr, "%s: failed to open file: %s: %s\n", __func__, fname, strerror(errno));
nuclear@24: 		return -1;
nuclear@24: 	}
nuclear@24: 	res = dtx_save_glyphmap_stream(fp, gmap);
nuclear@24: 	fclose(fp);
nuclear@24: 	return res;
nuclear@24: }
nuclear@24: 
nuclear@24: int dtx_save_glyphmap_stream(FILE *fp, const struct dtx_glyphmap *gmap)
nuclear@24: {
nuclear@24: 	int i, num_pixels;
nuclear@24: 	struct glyph *g = gmap->glyphs;
nuclear@24: 
nuclear@24: 	fprintf(fp, "P6\n%d %d\n", gmap->xsz, gmap->ysz);
nuclear@24: 	for(i=0; i<gmap->crange; i++) {
nuclear@24: 		fprintf(fp, "# %d: %fx%f+%f+%f\n", g->code, g->width, g->height, g->x, g->y);
nuclear@24: 		g++;
nuclear@24: 	}
nuclear@24: 	fprintf(fp, "255\n");
nuclear@24: 
nuclear@24: 	num_pixels = gmap->xsz * gmap->ysz;
nuclear@24: 	for(i=0; i<num_pixels; i++) {
nuclear@24: 		int c = gmap->pixels[i];
nuclear@24: 		fputc(c, fp);
nuclear@24: 		fputc(c, fp);
nuclear@24: 		fputc(c, fp);
nuclear@24: 	}
nuclear@24: 	return 0;
nuclear@24: }
nuclear@24: 
nuclear@24: 
nuclear@24: void dtx_use_font(struct dtx_font *fnt, int sz)
nuclear@24: {
nuclear@24: 	dtx_gl_init();
nuclear@24: 
nuclear@24: 	dtx_font = fnt;
nuclear@24: 	dtx_font_sz = sz;
nuclear@24: }
nuclear@24: 
nuclear@29: float dtx_line_height(void)
nuclear@29: {
nuclear@29: 	struct dtx_glyphmap *gmap = dtx_get_font_glyphmap(dtx_font, dtx_font_sz, '\n');
nuclear@29: 
nuclear@29: 	return gmap->line_advance;
nuclear@29: }
nuclear@29: 
nuclear@24: void dtx_glyph_box(int code, struct dtx_box *box)
nuclear@24: {
nuclear@24: 	int cidx;
nuclear@24: 	struct dtx_glyphmap *gmap;
nuclear@24: 	gmap = dtx_get_font_glyphmap(dtx_font, dtx_font_sz, code);
nuclear@24: 
nuclear@24: 	cidx = code - gmap->cstart;
nuclear@24: 
nuclear@24: 	box->x = gmap->glyphs[cidx].orig_x;
nuclear@24: 	box->y = gmap->glyphs[cidx].orig_y;
nuclear@24: 	box->width = gmap->glyphs[cidx].width;
nuclear@24: 	box->height = gmap->glyphs[cidx].height;
nuclear@24: }
nuclear@24: 
nuclear@24: float dtx_glyph_width(int code)
nuclear@24: {
nuclear@24: 	struct dtx_box box;
nuclear@24: 	dtx_glyph_box(code, &box);
nuclear@24: 	return box.width;
nuclear@24: }
nuclear@24: 
nuclear@24: float dtx_glyph_height(int code)
nuclear@24: {
nuclear@24: 	struct dtx_box box;
nuclear@24: 	dtx_glyph_box(code, &box);
nuclear@24: 	return box.height;
nuclear@24: }
nuclear@24: 
nuclear@24: void dtx_string_box(const char *str, struct dtx_box *box)
nuclear@24: {
nuclear@24: 	int code;
nuclear@24: 	float pos_x = 0.0f, pos_y = 0.0f;
nuclear@24: 	struct glyph *g = 0;
nuclear@24: 	float x0, y0, x1, y1;
nuclear@24: 
nuclear@24: 	x0 = y0 = FLT_MAX;
nuclear@24: 	x1 = y1 = -FLT_MAX;
nuclear@24: 
nuclear@24: 	while(*str) {
nuclear@24: 		float px, py;
nuclear@24: 		struct dtx_glyphmap *gmap;
nuclear@24: 
nuclear@24: 		code = dtx_utf8_char_code(str);
nuclear@24: 		str = dtx_utf8_next_char((char*)str);
nuclear@24: 
nuclear@24: 		px = pos_x;
nuclear@24: 		py = pos_y;
nuclear@24: 
nuclear@24: 		if((gmap = dtx_proc_char(code, &pos_x, &pos_y))) {
nuclear@24: 			g = gmap->glyphs + code - gmap->cstart;
nuclear@24: 
nuclear@24: 			if(px + g->orig_x < x0) {
nuclear@24: 				x0 = px + g->orig_x;
nuclear@24: 			}
nuclear@24: 			if(py - g->orig_y < y0) {
nuclear@24: 				y0 = py - g->orig_y;
nuclear@24: 			}
nuclear@24: 			if(px + g->orig_x + g->width > x1) {
nuclear@24: 				x1 = px + g->orig_x + g->width;
nuclear@24: 			}
nuclear@24: 			if(py - g->orig_y + g->height > y1) {
nuclear@24: 				y1 = py - g->orig_y + g->height;
nuclear@24: 			}
nuclear@24: 		}
nuclear@24: 	}
nuclear@24: 
nuclear@24: 	box->x = x0;
nuclear@24: 	box->y = y0;
nuclear@24: 	box->width = x1 - x0;
nuclear@24: 	box->height = y1 - y0;
nuclear@24: }
nuclear@24: 
nuclear@24: float dtx_string_width(const char *str)
nuclear@24: {
nuclear@24: 	struct dtx_box box;
nuclear@24: 
nuclear@24: 	dtx_string_box(str, &box);
nuclear@24: 	return box.width;
nuclear@24: }
nuclear@24: 
nuclear@24: float dtx_string_height(const char *str)
nuclear@24: {
nuclear@24: 	struct dtx_box box;
nuclear@24: 
nuclear@24: 	dtx_string_box(str, &box);
nuclear@24: 	return box.height;
nuclear@24: }
nuclear@24: 
nuclear@24: float dtx_char_pos(const char *str, int n)
nuclear@24: {
nuclear@24: 	int i;
nuclear@24: 	float pos = 0.0;
nuclear@24: 	struct dtx_glyphmap *gmap;
nuclear@24: 
nuclear@24: 	for(i=0; i<n; i++) {
nuclear@24: 		int code = dtx_utf8_char_code(str);
nuclear@24: 		str = dtx_utf8_next_char((char*)str);
nuclear@24: 
nuclear@24: 		gmap = dtx_get_font_glyphmap(dtx_font, dtx_font_sz, code);
nuclear@24: 		pos += gmap->glyphs[i].advance;
nuclear@24: 	}
nuclear@24: 	return pos;
nuclear@24: }
nuclear@24: 
nuclear@24: int dtx_char_at_pt(const char *str, float pt)
nuclear@24: {
nuclear@24: 	int i;
nuclear@24: 	float prev_pos = 0.0f, pos = 0.0f;
nuclear@24: 	struct dtx_glyphmap *gmap;
nuclear@24: 
nuclear@24: 	for(i=0; *str; i++) {
nuclear@24: 		int code = dtx_utf8_char_code(str);
nuclear@24: 		str = dtx_utf8_next_char((char*)str);
nuclear@24: 
nuclear@24: 		gmap = dtx_get_font_glyphmap(dtx_font, dtx_font_sz, code);
nuclear@24: 		pos += gmap->glyphs[i].advance;
nuclear@24: 
nuclear@24: 		if(fabs(pt - prev_pos) < fabs(pt - pos)) {
nuclear@24: 			break;
nuclear@24: 		}
nuclear@24: 		prev_pos = pos;
nuclear@24: 	}
nuclear@24: 	return i;
nuclear@24: }
nuclear@24: 
nuclear@24: struct dtx_glyphmap *dtx_proc_char(int code, float *xpos, float *ypos)
nuclear@24: {
nuclear@24: 	struct dtx_glyphmap *gmap;
nuclear@24: 	gmap = dtx_get_font_glyphmap(dtx_font, dtx_font_sz, code);
nuclear@24: 
nuclear@24: 	switch(code) {
nuclear@24: 	case '\n':
nuclear@24: 		*xpos = 0.0;
nuclear@24: 		if(gmap) {
nuclear@24: 			*ypos -= gmap->line_advance;
nuclear@24: 		}
nuclear@24: 		return 0;
nuclear@24: 
nuclear@24: 	case '\t':
nuclear@24: 		if(gmap) {
nuclear@24: 			*xpos = (fmod(*xpos, 4.0) + 4.0) * gmap->glyphs[0].advance;
nuclear@24: 		}
nuclear@24: 		return 0;
nuclear@24: 
nuclear@24: 	case '\r':
nuclear@24: 		*xpos = 0.0;
nuclear@24: 		return 0;
nuclear@24: 
nuclear@24: 	default:
nuclear@24: 		break;
nuclear@24: 	}
nuclear@24: 
nuclear@24: 	if(gmap) {
nuclear@24: 		*xpos += gmap->glyphs[code - gmap->cstart].advance;
nuclear@24: 	}
nuclear@24: 	return gmap;
nuclear@24: }
nuclear@24: 
nuclear@24: static void calc_best_size(int total_width, int max_glyph_height, int padding, int pow2, int *imgw, int *imgh)
nuclear@24: {
nuclear@24: 	int xsz, ysz, num_rows;
nuclear@24: 	float aspect;
nuclear@24: 
nuclear@24: 	for(xsz=2; xsz<=MAX_IMG_WIDTH; xsz *= 2) {
nuclear@24: 		num_rows = total_width / xsz + 1;
nuclear@24: 
nuclear@24: 		/* take into account the one extra padding for each row after the first */
nuclear@24: 		num_rows = (total_width + padding * (num_rows - 1)) / xsz + 1;
nuclear@24: 
nuclear@24: 		ysz = num_rows * (max_glyph_height + padding) + padding;
nuclear@24: 		if(pow2) {
nuclear@24: 			ysz = next_pow2(ysz);
nuclear@24: 		}
nuclear@24: 		aspect = (float)xsz / (float)ysz;
nuclear@24: 
nuclear@24: 		if(aspect >= 1.0) {
nuclear@24: 			break;
nuclear@24: 		}
nuclear@24: 	}
nuclear@24: 
nuclear@24: 	if(xsz > MAX_IMG_WIDTH) {
nuclear@24: 		xsz = MAX_IMG_WIDTH;
nuclear@24: 	}
nuclear@24: 
nuclear@24: 	*imgw = xsz;
nuclear@24: 	*imgh = ysz;
nuclear@24: }
nuclear@24: 
nuclear@24: 
nuclear@24: static int next_pow2(int x)
nuclear@24: {
nuclear@24: 	x--;
nuclear@24: 	x = (x >> 1) | x;
nuclear@24: 	x = (x >> 2) | x;
nuclear@24: 	x = (x >> 4) | x;
nuclear@24: 	x = (x >> 8) | x;
nuclear@24: 	x = (x >> 16) | x;
nuclear@24: 	return x + 1;
nuclear@24: }