1.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     1.2 +++ b/libs/drawtext/font.c	Sat Feb 01 19:58:19 2014 +0200
     1.3 @@ -0,0 +1,697 @@
     1.4 +/*
     1.5 +libdrawtext - a simple library for fast text rendering in OpenGL
     1.6 +Copyright (C) 2011  John Tsiombikas <nuclear@member.fsf.org>
     1.7 +
     1.8 +This program is free software: you can redistribute it and/or modify
     1.9 +it under the terms of the GNU Lesser General Public License as published by
    1.10 +the Free Software Foundation, either version 3 of the License, or
    1.11 +(at your option) any later version.
    1.12 +
    1.13 +This program is distributed in the hope that it will be useful,
    1.14 +but WITHOUT ANY WARRANTY; without even the implied warranty of
    1.15 +MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    1.16 +GNU Lesser General Public License for more details.
    1.17 +
    1.18 +You should have received a copy of the GNU Lesser General Public License
    1.19 +along with this program.  If not, see <http://www.gnu.org/licenses/>.
    1.20 +*/
    1.21 +#ifndef NO_FREETYPE
    1.22 +#define USE_FREETYPE
    1.23 +#endif
    1.24 +
    1.25 +#include <stdio.h>
    1.26 +#include <stdlib.h>
    1.27 +#include <string.h>
    1.28 +#include <math.h>
    1.29 +#include <limits.h>
    1.30 +#include <ctype.h>
    1.31 +#include <float.h>
    1.32 +#include <errno.h>
    1.33 +#ifdef USE_FREETYPE
    1.34 +#include <ft2build.h>
    1.35 +#include FT_FREETYPE_H
    1.36 +#endif
    1.37 +#include "drawtext.h"
    1.38 +#include "drawtext_impl.h"
    1.39 +
    1.40 +#define FTSZ_TO_PIXELS(x)	((x) / 64)
    1.41 +#define MAX_IMG_WIDTH		4096
    1.42 +
    1.43 +
    1.44 +#ifdef USE_FREETYPE
    1.45 +static int init_freetype(void);
    1.46 +static void cleanup(void);
    1.47 +
    1.48 +static void calc_best_size(int total_width, int max_glyph_height, int padding, int pow2, int *imgw, int *imgh);
    1.49 +static int next_pow2(int x);
    1.50 +
    1.51 +static FT_Library ft;
    1.52 +
    1.53 +
    1.54 +static int init_done;
    1.55 +
    1.56 +static int init_freetype(void)
    1.57 +{
    1.58 +	if(!init_done) {
    1.59 +		if(FT_Init_FreeType(&ft) != 0) {
    1.60 +			return -1;
    1.61 +		}
    1.62 +		atexit(cleanup);
    1.63 +		init_done = 1;
    1.64 +	}
    1.65 +	return 0;
    1.66 +}
    1.67 +
    1.68 +static void cleanup(void)
    1.69 +{
    1.70 +	if(init_done) {
    1.71 +		FT_Done_FreeType(ft);
    1.72 +	}
    1.73 +}
    1.74 +
    1.75 +struct dtx_font *dtx_open_font(const char *fname, int sz)
    1.76 +{
    1.77 +	struct dtx_font *fnt;
    1.78 +
    1.79 +	init_freetype();
    1.80 +
    1.81 +	if(!(fnt = calloc(1, sizeof *fnt))) {
    1.82 +		fperror("failed to allocate font structure");
    1.83 +		return 0;
    1.84 +	}
    1.85 +
    1.86 +	if(FT_New_Face(ft, fname, 0, (FT_Face*)&fnt->face) != 0) {
    1.87 +		fprintf(stderr, "failed to open font file: %s\n", fname);
    1.88 +		return 0;
    1.89 +	}
    1.90 +
    1.91 +	/* pre-create the extended ASCII range glyphmap */
    1.92 +	if(sz) {
    1.93 +		dtx_prepare_range(fnt, sz, 0, 256);
    1.94 +
    1.95 +		if(!dtx_font) {
    1.96 +			dtx_use_font(fnt, sz);
    1.97 +		}
    1.98 +	}
    1.99 +
   1.100 +	return fnt;
   1.101 +}
   1.102 +
   1.103 +void dtx_close_font(struct dtx_font *fnt)
   1.104 +{
   1.105 +	if(!fnt) return;
   1.106 +
   1.107 +	FT_Done_Face(fnt->face);
   1.108 +
   1.109 +	/* destroy the glyphmaps */
   1.110 +	while(fnt->gmaps) {
   1.111 +		void *tmp = fnt->gmaps;
   1.112 +		fnt->gmaps = fnt->gmaps->next;
   1.113 +		dtx_free_glyphmap(tmp);
   1.114 +	}
   1.115 +
   1.116 +	free(fnt);
   1.117 +}
   1.118 +
   1.119 +void dtx_prepare(struct dtx_font *fnt, int sz)
   1.120 +{
   1.121 +	dtx_get_font_glyphmap_range(fnt, sz, 0, 256);
   1.122 +}
   1.123 +
   1.124 +void dtx_prepare_range(struct dtx_font *fnt, int sz, int cstart, int cend)
   1.125 +{
   1.126 +	dtx_get_font_glyphmap_range(fnt, sz, cstart, cend);
   1.127 +}
   1.128 +
   1.129 +struct dtx_glyphmap *dtx_get_font_glyphmap(struct dtx_font *fnt, int sz, int code)
   1.130 +{
   1.131 +	struct dtx_glyphmap *gm;
   1.132 +
   1.133 +	/* check to see if the last we've given out fits the bill */
   1.134 +	if(fnt->last_gmap && code >= fnt->last_gmap->cstart && code < fnt->last_gmap->cend && fnt->last_gmap->ptsize == sz) {
   1.135 +		return fnt->last_gmap;
   1.136 +	}
   1.137 +
   1.138 +	/* otherwise search for the appropriate glyphmap */
   1.139 +	gm = fnt->gmaps;
   1.140 +	while(gm) {
   1.141 +		if(code >= gm->cstart && code < gm->cend && sz == gm->ptsize) {
   1.142 +			fnt->last_gmap = gm;
   1.143 +			return gm;
   1.144 +		}
   1.145 +		gm = gm->next;
   1.146 +	}
   1.147 +	return 0;
   1.148 +}
   1.149 +
   1.150 +struct dtx_glyphmap *dtx_get_font_glyphmap_range(struct dtx_font *fnt, int sz, int cstart, int cend)
   1.151 +{
   1.152 +	struct dtx_glyphmap *gm;
   1.153 +
   1.154 +	/* search the available glyphmaps to see if we've got one that includes
   1.155 +	 * the requested range
   1.156 +	 */
   1.157 +	gm = fnt->gmaps;
   1.158 +	while(gm) {
   1.159 +		if(gm->cstart <= cstart && gm->cend >= cend && gm->ptsize == sz) {
   1.160 +			return gm;
   1.161 +		}
   1.162 +		gm = gm->next;
   1.163 +	}
   1.164 +
   1.165 +	/* not found, create one and add it to the list */
   1.166 +	if(!(gm = dtx_create_glyphmap_range(fnt, sz, cstart, cend))) {
   1.167 +		return 0;
   1.168 +	}
   1.169 +	return gm;
   1.170 +}
   1.171 +
   1.172 +struct dtx_glyphmap *dtx_create_glyphmap_range(struct dtx_font *fnt, int sz, int cstart, int cend)
   1.173 +{
   1.174 +	FT_Face face = fnt->face;
   1.175 +	struct dtx_glyphmap *gmap;
   1.176 +	int i, j;
   1.177 +	int gx, gy;
   1.178 +	int padding = 4;
   1.179 +	int total_width = padding;
   1.180 +	int max_height = 0;
   1.181 +
   1.182 +	FT_Set_Char_Size(fnt->face, 0, sz * 64, 72, 72);
   1.183 +
   1.184 +	if(!(gmap = calloc(1, sizeof *gmap))) {
   1.185 +		return 0;
   1.186 +	}
   1.187 +
   1.188 +	gmap->ptsize = sz;
   1.189 +	gmap->cstart = cstart;
   1.190 +	gmap->cend = cend;
   1.191 +	gmap->crange = cend - cstart;
   1.192 +	gmap->line_advance = FTSZ_TO_PIXELS((float)face->size->metrics.height);
   1.193 +	gmap->baseline = -FTSZ_TO_PIXELS((float)face->size->metrics.descender);
   1.194 +
   1.195 +	if(!(gmap->glyphs = malloc(gmap->crange * sizeof *gmap->glyphs))) {
   1.196 +		free(gmap);
   1.197 +		return 0;
   1.198 +	}
   1.199 +
   1.200 +	for(i=0; i<gmap->crange; i++) {
   1.201 +		int h;
   1.202 +
   1.203 +		FT_Load_Char(face, i + cstart, 0);
   1.204 +		h = FTSZ_TO_PIXELS(face->glyph->metrics.height);
   1.205 +
   1.206 +		if(h > max_height) {
   1.207 +			max_height = h;
   1.208 +		}
   1.209 +		total_width += FTSZ_TO_PIXELS(face->glyph->metrics.width) + padding;
   1.210 +	}
   1.211 +
   1.212 +	calc_best_size(total_width, max_height, padding, 1, &gmap->xsz, &gmap->ysz);
   1.213 +
   1.214 +	if(!(gmap->pixels = malloc(gmap->xsz * gmap->ysz))) {
   1.215 +		free(gmap->glyphs);
   1.216 +		free(gmap);
   1.217 +		return 0;
   1.218 +	}
   1.219 +	memset(gmap->pixels, 0, gmap->xsz * gmap->ysz);
   1.220 +
   1.221 +	gx = padding;
   1.222 +	gy = padding;
   1.223 +
   1.224 +	for(i=0; i<gmap->crange; i++) {
   1.225 +		float gwidth, gheight;
   1.226 +		unsigned char *src, *dst;
   1.227 +		FT_GlyphSlot glyph;
   1.228 +
   1.229 +		FT_Load_Char(face, i + cstart, FT_LOAD_RENDER);
   1.230 +		glyph = face->glyph;
   1.231 +		gwidth = FTSZ_TO_PIXELS((float)glyph->metrics.width);
   1.232 +		gheight = FTSZ_TO_PIXELS((float)glyph->metrics.height);
   1.233 +
   1.234 +		if(gx > gmap->xsz - gwidth - padding) {
   1.235 +			gx = padding;
   1.236 +			gy += max_height + padding;
   1.237 +		}
   1.238 +
   1.239 +		src = glyph->bitmap.buffer;
   1.240 +		dst = gmap->pixels + gy * gmap->xsz + gx;
   1.241 +
   1.242 +		for(j=0; j<glyph->bitmap.rows; j++) {
   1.243 +			memcpy(dst, src, glyph->bitmap.width);
   1.244 +			dst += gmap->xsz;
   1.245 +			src += glyph->bitmap.pitch;
   1.246 +		}
   1.247 +
   1.248 +		gmap->glyphs[i].code = i;
   1.249 +		gmap->glyphs[i].x = gx - 1;
   1.250 +		gmap->glyphs[i].y = gy - 1;
   1.251 +		gmap->glyphs[i].width = gwidth + 2;
   1.252 +		gmap->glyphs[i].height = gheight + 2;
   1.253 +		gmap->glyphs[i].orig_x = -FTSZ_TO_PIXELS((float)glyph->metrics.horiBearingX) + 1;
   1.254 +		gmap->glyphs[i].orig_y = FTSZ_TO_PIXELS((float)glyph->metrics.height - glyph->metrics.horiBearingY) + 1;
   1.255 +		gmap->glyphs[i].advance = FTSZ_TO_PIXELS((float)glyph->metrics.horiAdvance);
   1.256 +		/* also precalc normalized */
   1.257 +		gmap->glyphs[i].nx = (float)gmap->glyphs[i].x / (float)gmap->xsz;
   1.258 +		gmap->glyphs[i].ny = (float)gmap->glyphs[i].y / (float)gmap->ysz;
   1.259 +		gmap->glyphs[i].nwidth = (float)gmap->glyphs[i].width / (float)gmap->xsz;
   1.260 +		gmap->glyphs[i].nheight = (float)gmap->glyphs[i].height / (float)gmap->ysz;
   1.261 +
   1.262 +		gx += gwidth + padding;
   1.263 +	}
   1.264 +
   1.265 +	/* add it to the glyphmaps list of the font */
   1.266 +	gmap->next = fnt->gmaps;
   1.267 +	fnt->gmaps = gmap;
   1.268 +
   1.269 +	return gmap;
   1.270 +}
   1.271 +#endif	/* USE_FREETYPE */
   1.272 +
   1.273 +void dtx_free_glyphmap(struct dtx_glyphmap *gmap)
   1.274 +{
   1.275 +	if(gmap) {
   1.276 +		free(gmap->pixels);
   1.277 +		free(gmap->glyphs);
   1.278 +		free(gmap);
   1.279 +	}
   1.280 +}
   1.281 +
   1.282 +unsigned char *dtx_get_glyphmap_pixels(struct dtx_glyphmap *gmap)
   1.283 +{
   1.284 +	return gmap->pixels;
   1.285 +}
   1.286 +
   1.287 +int dtx_get_glyphmap_width(struct dtx_glyphmap *gmap)
   1.288 +{
   1.289 +	return gmap->xsz;
   1.290 +}
   1.291 +
   1.292 +int dtx_get_glyphmap_height(struct dtx_glyphmap *gmap)
   1.293 +{
   1.294 +	return gmap->ysz;
   1.295 +}
   1.296 +
   1.297 +struct dtx_glyphmap *dtx_load_glyphmap(const char *fname)
   1.298 +{
   1.299 +	FILE *fp;
   1.300 +	struct dtx_glyphmap *gmap;
   1.301 +
   1.302 +	if(!(fp = fopen(fname, "r"))) {
   1.303 +		return 0;
   1.304 +	}
   1.305 +	gmap = dtx_load_glyphmap_stream(fp);
   1.306 +	fclose(fp);
   1.307 +	return gmap;
   1.308 +}
   1.309 +
   1.310 +struct dtx_glyphmap *dtx_load_glyphmap_stream(FILE *fp)
   1.311 +{
   1.312 +	char buf[512];
   1.313 +	int hdr_lines = 0;
   1.314 +	struct dtx_glyphmap *gmap;
   1.315 +	struct glyph *glyphs = 0;
   1.316 +	int min_code = INT_MAX;
   1.317 +	int max_code = INT_MIN;
   1.318 +	int i, max_pixval, num_pixels;
   1.319 +
   1.320 +	if(!(gmap = calloc(1, sizeof *gmap))) {
   1.321 +		fperror("failed to allocate glyphmap");
   1.322 +		return 0;
   1.323 +	}
   1.324 +
   1.325 +	while(hdr_lines < 3) {
   1.326 +		char *line = buf;
   1.327 +		if(!fgets(buf, sizeof buf, fp)) {
   1.328 +			fperror("unexpected end of file");
   1.329 +			goto err;
   1.330 +		}
   1.331 +
   1.332 +		while(isspace(*line)) {
   1.333 +			line++;
   1.334 +		}
   1.335 +
   1.336 +		if(line[0] == '#') {
   1.337 +			struct glyph *g;
   1.338 +			int c;
   1.339 +			float x, y, xsz, ysz, res;
   1.340 +
   1.341 +			res = sscanf(line + 1, "%d: %fx%f+%f+%f\n", &c, &xsz, &ysz, &x, &y);
   1.342 +			if(res != 5) {
   1.343 +				fprintf(stderr, "%s: invalid glyph info line\n", __FUNCTION__);
   1.344 +				goto err;
   1.345 +			}
   1.346 +
   1.347 +			if(!(g = malloc(sizeof *g))) {
   1.348 +				fperror("failed to allocate glyph");
   1.349 +				goto err;
   1.350 +			}
   1.351 +			g->code = c;
   1.352 +			g->x = x;
   1.353 +			g->y = y;
   1.354 +			g->width = xsz;
   1.355 +			g->height = ysz;
   1.356 +			g->next = glyphs;
   1.357 +			glyphs = g;
   1.358 +
   1.359 +			if(c < min_code) {
   1.360 +				min_code = c;
   1.361 +			}
   1.362 +			if(c > max_code) {
   1.363 +				max_code = c;
   1.364 +			}
   1.365 +		} else {
   1.366 +			switch(hdr_lines) {
   1.367 +			case 0:
   1.368 +				if(0[line] != 'P' || 1[line] != '6') {
   1.369 +					fprintf(stderr, "%s: invalid file format (magic)\n", __FUNCTION__);
   1.370 +					goto err;
   1.371 +				}
   1.372 +				break;
   1.373 +
   1.374 +			case 1:
   1.375 +				if(sscanf(line, "%d %d", &gmap->xsz, &gmap->ysz) != 2) {
   1.376 +					fprintf(stderr, "%s: invalid file format (dim)\n", __FUNCTION__);
   1.377 +					goto err;
   1.378 +				}
   1.379 +				break;
   1.380 +
   1.381 +			case 2:
   1.382 +				{
   1.383 +					char *endp;
   1.384 +					max_pixval = strtol(line, &endp, 10);
   1.385 +					if(endp == line) {
   1.386 +						fprintf(stderr, "%s: invalid file format (maxval)\n", __FUNCTION__);
   1.387 +						goto err;
   1.388 +					}
   1.389 +				}
   1.390 +				break;
   1.391 +
   1.392 +			default:
   1.393 +				break;	/* can't happen */
   1.394 +			}
   1.395 +			hdr_lines++;
   1.396 +		}
   1.397 +	}
   1.398 +
   1.399 +	num_pixels = gmap->xsz * gmap->ysz;
   1.400 +	if(!(gmap->pixels = malloc(num_pixels))) {
   1.401 +		fperror("failed to allocate pixels");
   1.402 +		goto err;
   1.403 +	}
   1.404 +
   1.405 +	for(i=0; i<num_pixels; i++) {
   1.406 +		long c = fgetc(fp);
   1.407 +		if(c == -1) {
   1.408 +			fprintf(stderr, "unexpected end of file while reading pixels\n");
   1.409 +			goto err;
   1.410 +		}
   1.411 +		gmap->pixels[i] = 255 * c / max_pixval;
   1.412 +		fseek(fp, 2, SEEK_CUR);
   1.413 +	}
   1.414 +
   1.415 +	gmap->cstart = min_code;
   1.416 +	gmap->cend = max_code + 1;
   1.417 +	gmap->crange = gmap->cend - gmap->cstart;
   1.418 +
   1.419 +	if(!(gmap->glyphs = calloc(gmap->crange, sizeof *gmap->glyphs))) {
   1.420 +		fperror("failed to allocate glyph info");
   1.421 +		goto err;
   1.422 +	}
   1.423 +
   1.424 +	while(glyphs) {
   1.425 +		struct glyph *g = glyphs;
   1.426 +		glyphs = glyphs->next;
   1.427 +
   1.428 +		gmap->glyphs[g->code - gmap->cstart] = *g;
   1.429 +		free(g);
   1.430 +	}
   1.431 +	return gmap;
   1.432 +
   1.433 +err:
   1.434 +	dtx_free_glyphmap(gmap);
   1.435 +	while(glyphs) {
   1.436 +		void *tmp = glyphs;
   1.437 +		glyphs = glyphs->next;
   1.438 +		free(tmp);
   1.439 +	}
   1.440 +	return 0;
   1.441 +}
   1.442 +
   1.443 +int dtx_save_glyphmap(const char *fname, const struct dtx_glyphmap *gmap)
   1.444 +{
   1.445 +	FILE *fp;
   1.446 +	int res;
   1.447 +
   1.448 +	if(!(fp = fopen(fname, "wb"))) {
   1.449 +		fprintf(stderr, "%s: failed to open file: %s: %s\n", __FUNCTION__, fname, strerror(errno));
   1.450 +		return -1;
   1.451 +	}
   1.452 +	res = dtx_save_glyphmap_stream(fp, gmap);
   1.453 +	fclose(fp);
   1.454 +	return res;
   1.455 +}
   1.456 +
   1.457 +int dtx_save_glyphmap_stream(FILE *fp, const struct dtx_glyphmap *gmap)
   1.458 +{
   1.459 +	int i, num_pixels;
   1.460 +	struct glyph *g = gmap->glyphs;
   1.461 +
   1.462 +	fprintf(fp, "P6\n%d %d\n", gmap->xsz, gmap->ysz);
   1.463 +	for(i=0; i<gmap->crange; i++) {
   1.464 +		fprintf(fp, "# %d: %fx%f+%f+%f\n", g->code, g->width, g->height, g->x, g->y);
   1.465 +		g++;
   1.466 +	}
   1.467 +	fprintf(fp, "255\n");
   1.468 +
   1.469 +	num_pixels = gmap->xsz * gmap->ysz;
   1.470 +	for(i=0; i<num_pixels; i++) {
   1.471 +		int c = gmap->pixels[i];
   1.472 +		fputc(c, fp);
   1.473 +		fputc(c, fp);
   1.474 +		fputc(c, fp);
   1.475 +	}
   1.476 +	return 0;
   1.477 +}
   1.478 +
   1.479 +
   1.480 +void dtx_use_font(struct dtx_font *fnt, int sz)
   1.481 +{
   1.482 +	dtx_gl_init();
   1.483 +
   1.484 +	dtx_font = fnt;
   1.485 +	dtx_font_sz = sz;
   1.486 +}
   1.487 +
   1.488 +float dtx_line_height(void)
   1.489 +{
   1.490 +	struct dtx_glyphmap *gmap = dtx_get_font_glyphmap(dtx_font, dtx_font_sz, '\n');
   1.491 +
   1.492 +	return gmap->line_advance;
   1.493 +}
   1.494 +
   1.495 +float dtx_baseline(void)
   1.496 +{
   1.497 +	struct dtx_glyphmap *gmap = dtx_get_font_glyphmap(dtx_font, dtx_font_sz, '\n');
   1.498 +
   1.499 +	return gmap->baseline;
   1.500 +}
   1.501 +
   1.502 +void dtx_glyph_box(int code, struct dtx_box *box)
   1.503 +{
   1.504 +	int cidx;
   1.505 +	struct dtx_glyphmap *gmap;
   1.506 +	gmap = dtx_get_font_glyphmap(dtx_font, dtx_font_sz, code);
   1.507 +
   1.508 +	cidx = code - gmap->cstart;
   1.509 +
   1.510 +	box->x = gmap->glyphs[cidx].orig_x;
   1.511 +	box->y = gmap->glyphs[cidx].orig_y;
   1.512 +	box->width = gmap->glyphs[cidx].width;
   1.513 +	box->height = gmap->glyphs[cidx].height;
   1.514 +}
   1.515 +
   1.516 +float dtx_glyph_width(int code)
   1.517 +{
   1.518 +	struct dtx_box box;
   1.519 +	dtx_glyph_box(code, &box);
   1.520 +	return box.width;
   1.521 +}
   1.522 +
   1.523 +float dtx_glyph_height(int code)
   1.524 +{
   1.525 +	struct dtx_box box;
   1.526 +	dtx_glyph_box(code, &box);
   1.527 +	return box.height;
   1.528 +}
   1.529 +
   1.530 +void dtx_string_box(const char *str, struct dtx_box *box)
   1.531 +{
   1.532 +	int code;
   1.533 +	float pos_x = 0.0f, pos_y = 0.0f;
   1.534 +	struct glyph *g = 0;
   1.535 +	float x0, y0, x1, y1;
   1.536 +
   1.537 +	x0 = y0 = FLT_MAX;
   1.538 +	x1 = y1 = -FLT_MAX;
   1.539 +
   1.540 +	while(*str) {
   1.541 +		float px, py;
   1.542 +		struct dtx_glyphmap *gmap;
   1.543 +
   1.544 +		code = dtx_utf8_char_code(str);
   1.545 +		str = dtx_utf8_next_char((char*)str);
   1.546 +
   1.547 +		px = pos_x;
   1.548 +		py = pos_y;
   1.549 +
   1.550 +		if((gmap = dtx_proc_char(code, &pos_x, &pos_y))) {
   1.551 +			g = gmap->glyphs + code - gmap->cstart;
   1.552 +
   1.553 +			if(px + g->orig_x < x0) {
   1.554 +				x0 = px + g->orig_x;
   1.555 +			}
   1.556 +			if(py - g->orig_y < y0) {
   1.557 +				y0 = py - g->orig_y;
   1.558 +			}
   1.559 +			if(px + g->orig_x + g->width > x1) {
   1.560 +				x1 = px + g->orig_x + g->width;
   1.561 +			}
   1.562 +			if(py - g->orig_y + g->height > y1) {
   1.563 +				y1 = py - g->orig_y + g->height;
   1.564 +			}
   1.565 +		}
   1.566 +	}
   1.567 +
   1.568 +	box->x = x0;
   1.569 +	box->y = y0;
   1.570 +	box->width = x1 - x0;
   1.571 +	box->height = y1 - y0;
   1.572 +}
   1.573 +
   1.574 +float dtx_string_width(const char *str)
   1.575 +{
   1.576 +	struct dtx_box box;
   1.577 +
   1.578 +	dtx_string_box(str, &box);
   1.579 +	return box.width;
   1.580 +}
   1.581 +
   1.582 +float dtx_string_height(const char *str)
   1.583 +{
   1.584 +	struct dtx_box box;
   1.585 +
   1.586 +	dtx_string_box(str, &box);
   1.587 +	return box.height;
   1.588 +}
   1.589 +
   1.590 +float dtx_char_pos(const char *str, int n)
   1.591 +{
   1.592 +	int i;
   1.593 +	float pos = 0.0;
   1.594 +	struct dtx_glyphmap *gmap;
   1.595 +
   1.596 +	for(i=0; i<n; i++) {
   1.597 +		int code = dtx_utf8_char_code(str);
   1.598 +		str = dtx_utf8_next_char((char*)str);
   1.599 +
   1.600 +		gmap = dtx_get_font_glyphmap(dtx_font, dtx_font_sz, code);
   1.601 +		pos += gmap->glyphs[i].advance;
   1.602 +	}
   1.603 +	return pos;
   1.604 +}
   1.605 +
   1.606 +int dtx_char_at_pt(const char *str, float pt)
   1.607 +{
   1.608 +	int i;
   1.609 +	float prev_pos = 0.0f, pos = 0.0f;
   1.610 +	struct dtx_glyphmap *gmap;
   1.611 +
   1.612 +	for(i=0; *str; i++) {
   1.613 +		int code = dtx_utf8_char_code(str);
   1.614 +		str = dtx_utf8_next_char((char*)str);
   1.615 +
   1.616 +		gmap = dtx_get_font_glyphmap(dtx_font, dtx_font_sz, code);
   1.617 +		pos += gmap->glyphs[i].advance;
   1.618 +
   1.619 +		if(fabs(pt - prev_pos) < fabs(pt - pos)) {
   1.620 +			break;
   1.621 +		}
   1.622 +		prev_pos = pos;
   1.623 +	}
   1.624 +	return i;
   1.625 +}
   1.626 +
   1.627 +struct dtx_glyphmap *dtx_proc_char(int code, float *xpos, float *ypos)
   1.628 +{
   1.629 +	struct dtx_glyphmap *gmap;
   1.630 +	gmap = dtx_get_font_glyphmap(dtx_font, dtx_font_sz, code);
   1.631 +
   1.632 +	switch(code) {
   1.633 +	case '\n':
   1.634 +		*xpos = 0.0;
   1.635 +		if(gmap) {
   1.636 +			*ypos -= gmap->line_advance;
   1.637 +		}
   1.638 +		return 0;
   1.639 +
   1.640 +	case '\t':
   1.641 +		if(gmap) {
   1.642 +			*xpos = (fmod(*xpos, 4.0) + 4.0) * gmap->glyphs[0].advance;
   1.643 +		}
   1.644 +		return 0;
   1.645 +
   1.646 +	case '\r':
   1.647 +		*xpos = 0.0;
   1.648 +		return 0;
   1.649 +
   1.650 +	default:
   1.651 +		break;
   1.652 +	}
   1.653 +
   1.654 +	if(gmap) {
   1.655 +		*xpos += gmap->glyphs[code - gmap->cstart].advance;
   1.656 +	}
   1.657 +	return gmap;
   1.658 +}
   1.659 +
   1.660 +static void calc_best_size(int total_width, int max_glyph_height, int padding, int pow2, int *imgw, int *imgh)
   1.661 +{
   1.662 +	int xsz, ysz, num_rows;
   1.663 +	float aspect;
   1.664 +
   1.665 +	for(xsz=2; xsz<=MAX_IMG_WIDTH; xsz *= 2) {
   1.666 +		num_rows = total_width / xsz + 1;
   1.667 +
   1.668 +		/* take into account the one extra padding for each row after the first */
   1.669 +		num_rows = (total_width + padding * (num_rows - 1)) / xsz + 1;
   1.670 +
   1.671 +		ysz = num_rows * (max_glyph_height + padding) + padding;
   1.672 +		if(pow2) {
   1.673 +			ysz = next_pow2(ysz);
   1.674 +		}
   1.675 +		aspect = (float)xsz / (float)ysz;
   1.676 +
   1.677 +		if(aspect >= 1.0) {
   1.678 +			break;
   1.679 +		}
   1.680 +	}
   1.681 +
   1.682 +	if(xsz > MAX_IMG_WIDTH) {
   1.683 +		xsz = MAX_IMG_WIDTH;
   1.684 +	}
   1.685 +
   1.686 +	*imgw = xsz;
   1.687 +	*imgh = ysz;
   1.688 +}
   1.689 +
   1.690 +
   1.691 +static int next_pow2(int x)
   1.692 +{
   1.693 +	x--;
   1.694 +	x = (x >> 1) | x;
   1.695 +	x = (x >> 2) | x;
   1.696 +	x = (x >> 4) | x;
   1.697 +	x = (x >> 8) | x;
   1.698 +	x = (x >> 16) | x;
   1.699 +	return x + 1;
   1.700 +}