istereo2: libs/drawtext/drawgl.c annotate

istereo2

annotate libs/drawtext/drawgl.c @ 7:a3c4fcc9f8f3

- started a goatkit UI theme - font rendering with drawtext and shaders - asset manager (only used by drawtext for now, will replace respath eventually)

author	John Tsiombikas <nuclear@member.fsf.org>
date	Thu, 24 Sep 2015 06:49:25 +0300
parents
children

rev	line source
nuclear@7	1 /*
nuclear@7	2 libdrawtext - a simple library for fast text rendering in OpenGL
nuclear@7	3 Copyright (C) 2011-2012 John Tsiombikas <nuclear@member.fsf.org>
nuclear@7	4
nuclear@7	5 This program is free software: you can redistribute it and/or modify
nuclear@7	6 it under the terms of the GNU Lesser General Public License as published by
nuclear@7	7 the Free Software Foundation, either version 3 of the License, or
nuclear@7	8 (at your option) any later version.
nuclear@7	9
nuclear@7	10 This program is distributed in the hope that it will be useful,
nuclear@7	11 but WITHOUT ANY WARRANTY; without even the implied warranty of
nuclear@7	12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
nuclear@7	13 GNU Lesser General Public License for more details.
nuclear@7	14
nuclear@7	15 You should have received a copy of the GNU Lesser General Public License
nuclear@7	16 along with this program. If not, see <http://www.gnu.org/licenses/>.
nuclear@7	17 */
nuclear@7	18 #ifdef HAVE_CONFIG_H
nuclear@7	19 #include "config.h"
nuclear@7	20 #endif
nuclear@7	21
nuclear@7	22 #ifndef NO_OPENGL
nuclear@7	23 #include <stdarg.h>
nuclear@7	24 #include <math.h>
nuclear@7	25 #include <ctype.h>
nuclear@7	26
nuclear@7	27 #include <stdlib.h>
nuclear@7	28
nuclear@7	29 #ifndef _MSC_VER
nuclear@7	30 #include <alloca.h>
nuclear@7	31 #else
nuclear@7	32 #include <malloc.h>
nuclear@7	33 #endif
nuclear@7	34
nuclear@7	35 #ifdef TARGET_IPHONE
nuclear@7	36 #include <OpenGLES/ES2/gl.h>
nuclear@7	37 #define GL_ES
nuclear@7	38 #elif defined(ANDROID)
nuclear@7	39 #include <GLES2/gl2.h>
nuclear@7	40 #define GL_ES
nuclear@7	41 #else
nuclear@7	42 #include <GL/glew.h>
nuclear@7	43 #endif
nuclear@7	44
nuclear@7	45 #include "drawtext.h"
nuclear@7	46 #include "drawtext_impl.h"
nuclear@7	47
nuclear@7	48 struct vertex {
nuclear@7	49 float x, y;
nuclear@7	50 float s, t;
nuclear@7	51 };
nuclear@7	52
nuclear@7	53 struct quad {
nuclear@7	54 struct vertex v[6];
nuclear@7	55 };
nuclear@7	56
nuclear@7	57 static void cleanup(void);
nuclear@7	58 static void add_glyph(struct glyph *g, float x, float y);
nuclear@7	59
nuclear@7	60 #define QBUF_SZ 512
nuclear@7	61 static struct quad *qbuf;
nuclear@7	62 static int num_quads;
nuclear@7	63 static int vattr = -1;
nuclear@7	64 static int tattr = -1;
nuclear@7	65 static unsigned int font_tex;
nuclear@7	66 static int buf_mode = DTX_NBF;
nuclear@7	67
nuclear@7	68
nuclear@7	69 int dtx_gl_init(void)
nuclear@7	70 {
nuclear@7	71 if(qbuf) {
nuclear@7	72 return 0; /* already initialized */
nuclear@7	73 }
nuclear@7	74
nuclear@7	75 #ifdef __glew_h__
nuclear@7	76 glewInit();
nuclear@7	77 #endif
nuclear@7	78
nuclear@7	79 if(!(qbuf = malloc(QBUF_SZ * sizeof *qbuf))) {
nuclear@7	80 return -1;
nuclear@7	81 }
nuclear@7	82 num_quads = 0;
nuclear@7	83
nuclear@7	84 atexit(cleanup);
nuclear@7	85 return 0;
nuclear@7	86 }
nuclear@7	87
nuclear@7	88 static void cleanup(void)
nuclear@7	89 {
nuclear@7	90 free(qbuf);
nuclear@7	91 }
nuclear@7	92
nuclear@7	93
nuclear@7	94 void dtx_vertex_attribs(int vert_attr, int tex_attr)
nuclear@7	95 {
nuclear@7	96 vattr = vert_attr;
nuclear@7	97 tattr = tex_attr;
nuclear@7	98 }
nuclear@7	99
nuclear@7	100 static void set_glyphmap_texture(struct dtx_glyphmap *gmap)
nuclear@7	101 {
nuclear@7	102 if(!gmap->tex) {
nuclear@7	103 glGenTextures(1, &gmap->tex);
nuclear@7	104 glBindTexture(GL_TEXTURE_2D, gmap->tex);
nuclear@7	105 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR);
nuclear@7	106 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
nuclear@7	107 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
nuclear@7	108 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
nuclear@7	109
nuclear@7	110 #ifdef GL_ES
nuclear@7	111 glTexImage2D(GL_TEXTURE_2D, 0, GL_ALPHA, gmap->xsz, gmap->ysz, 0, GL_ALPHA, GL_UNSIGNED_BYTE, gmap->pixels);
nuclear@7	112 glGenerateMipmap(GL_TEXTURE_2D);
nuclear@7	113 #else
nuclear@7	114 gluBuild2DMipmaps(GL_TEXTURE_2D, GL_ALPHA, gmap->xsz, gmap->ysz, GL_ALPHA, GL_UNSIGNED_BYTE, gmap->pixels);
nuclear@7	115 #endif
nuclear@7	116 }
nuclear@7	117
nuclear@7	118 if(font_tex != gmap->tex) {
nuclear@7	119 dtx_flush();
nuclear@7	120 }
nuclear@7	121 font_tex = gmap->tex;
nuclear@7	122 }
nuclear@7	123
nuclear@7	124 void dtx_glyph(int code)
nuclear@7	125 {
nuclear@7	126 struct dtx_glyphmap *gmap;
nuclear@7	127
nuclear@7	128 if(!dtx_font \|\| !(gmap = dtx_get_font_glyphmap(dtx_font, dtx_font_sz, code))) {
nuclear@7	129 return;
nuclear@7	130 }
nuclear@7	131 set_glyphmap_texture(gmap);
nuclear@7	132
nuclear@7	133 add_glyph(gmap->glyphs + code - gmap->cstart, 0, 0);
nuclear@7	134 dtx_flush();
nuclear@7	135 }
nuclear@7	136
nuclear@7	137 static const char put_char(const char str, float pos_x, float pos_y, int *should_flush)
nuclear@7	138 {
nuclear@7	139 struct dtx_glyphmap *gmap;
nuclear@7	140 float px, py;
nuclear@7	141 int code = dtx_utf8_char_code(str);
nuclear@7	142 str = dtx_utf8_next_char((char*)str);
nuclear@7	143
nuclear@7	144 if(buf_mode == DTX_LBF && code == '\n') {
nuclear@7	145 *should_flush = 1;
nuclear@7	146 }
nuclear@7	147
nuclear@7	148 px = *pos_x;
nuclear@7	149 py = *pos_y;
nuclear@7	150
nuclear@7	151 if((gmap = dtx_proc_char(code, pos_x, pos_y))) {
nuclear@7	152 int idx = code - gmap->cstart;
nuclear@7	153
nuclear@7	154 set_glyphmap_texture(gmap);
nuclear@7	155 add_glyph(gmap->glyphs + idx, px, py);
nuclear@7	156 }
nuclear@7	157 return str;
nuclear@7	158 }
nuclear@7	159
nuclear@7	160 void dtx_string(const char *str)
nuclear@7	161 {
nuclear@7	162 int should_flush = buf_mode == DTX_NBF;
nuclear@7	163 float pos_x = 0.0f;
nuclear@7	164 float pos_y = 0.0f;
nuclear@7	165
nuclear@7	166 if(!dtx_font) {
nuclear@7	167 return;
nuclear@7	168 }
nuclear@7	169
nuclear@7	170 while(*str) {
nuclear@7	171 str = put_char(str, &pos_x, &pos_y, &should_flush);
nuclear@7	172 }
nuclear@7	173
nuclear@7	174 if(should_flush) {
nuclear@7	175 dtx_flush();
nuclear@7	176 }
nuclear@7	177 }
nuclear@7	178
nuclear@7	179 void dtx_printf(const char *fmt, ...)
nuclear@7	180 {
nuclear@7	181 va_list ap;
nuclear@7	182 int buf_size;
nuclear@7	183 char *buf, tmp;
nuclear@7	184
nuclear@7	185 if(!dtx_font) {
nuclear@7	186 return;
nuclear@7	187 }
nuclear@7	188
nuclear@7	189 va_start(ap, fmt);
nuclear@7	190 buf_size = vsnprintf(&tmp, 0, fmt, ap);
nuclear@7	191 va_end(ap);
nuclear@7	192
nuclear@7	193 if(buf_size == -1) {
nuclear@7	194 buf_size = 512;
nuclear@7	195 }
nuclear@7	196
nuclear@7	197 buf = alloca(buf_size + 1);
nuclear@7	198 va_start(ap, fmt);
nuclear@7	199 vsnprintf(buf, buf_size + 1, fmt, ap);
nuclear@7	200 va_end(ap);
nuclear@7	201
nuclear@7	202 dtx_string(buf);
nuclear@7	203 }
nuclear@7	204
nuclear@7	205 static void qvertex(struct vertex *v, float x, float y, float s, float t)
nuclear@7	206 {
nuclear@7	207 v->x = x;
nuclear@7	208 v->y = y;
nuclear@7	209 v->s = s;
nuclear@7	210 v->t = t;
nuclear@7	211 }
nuclear@7	212
nuclear@7	213 static void add_glyph(struct glyph *g, float x, float y)
nuclear@7	214 {
nuclear@7	215 struct quad *qptr = qbuf + num_quads;
nuclear@7	216
nuclear@7	217 x -= g->orig_x;
nuclear@7	218 y -= g->orig_y;
nuclear@7	219
nuclear@7	220 qvertex(qptr->v + 0, x, y, g->nx, g->ny + g->nheight);
nuclear@7	221 qvertex(qptr->v + 1, x + g->width, y, g->nx + g->nwidth, g->ny + g->nheight);
nuclear@7	222 qvertex(qptr->v + 2, x + g->width, y + g->height, g->nx + g->nwidth, g->ny);
nuclear@7	223
nuclear@7	224 qvertex(qptr->v + 3, x, y, g->nx, g->ny + g->nheight);
nuclear@7	225 qvertex(qptr->v + 4, x + g->width, y + g->height, g->nx + g->nwidth, g->ny);
nuclear@7	226 qvertex(qptr->v + 5, x, y + g->height, g->nx, g->ny);
nuclear@7	227
nuclear@7	228 if(++num_quads >= QBUF_SZ) {
nuclear@7	229 dtx_flush();
nuclear@7	230 }
nuclear@7	231 }
nuclear@7	232
nuclear@7	233 void dtx_flush(void)
nuclear@7	234 {
nuclear@7	235 int vbo;
nuclear@7	236
nuclear@7	237 if(!num_quads) {
nuclear@7	238 return;
nuclear@7	239 }
nuclear@7	240
nuclear@7	241 glGetIntegerv(GL_ARRAY_BUFFER_BINDING, &vbo);
nuclear@7	242 glBindBuffer(GL_ARRAY_BUFFER, 0);
nuclear@7	243
nuclear@7	244 #ifndef GL_ES
nuclear@7	245 glPushAttrib(GL_ENABLE_BIT);
nuclear@7	246 glEnable(GL_TEXTURE_2D);
nuclear@7	247 #endif
nuclear@7	248 glBindTexture(GL_TEXTURE_2D, font_tex);
nuclear@7	249
nuclear@7	250 if(vattr != -1) {
nuclear@7	251 glEnableVertexAttribArray(vattr);
nuclear@7	252 glVertexAttribPointer(vattr, 2, GL_FLOAT, 0, sizeof(struct vertex), qbuf);
nuclear@7	253 #ifndef GL_ES
nuclear@7	254 } else {
nuclear@7	255 glEnableClientState(GL_VERTEX_ARRAY);
nuclear@7	256 glVertexPointer(2, GL_FLOAT, sizeof(struct vertex), qbuf);
nuclear@7	257 #endif
nuclear@7	258 }
nuclear@7	259 if(tattr != -1) {
nuclear@7	260 glEnableVertexAttribArray(tattr);
nuclear@7	261 glVertexAttribPointer(tattr, 2, GL_FLOAT, 0, sizeof(struct vertex), &qbuf->v[0].s);
nuclear@7	262 #ifndef GL_ES
nuclear@7	263 } else {
nuclear@7	264 glEnableClientState(GL_TEXTURE_COORD_ARRAY);
nuclear@7	265 glTexCoordPointer(2, GL_FLOAT, sizeof(struct vertex), &qbuf->v[0].s);
nuclear@7	266 #endif
nuclear@7	267 }
nuclear@7	268
nuclear@7	269 glEnable(GL_BLEND);
nuclear@7	270 glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
nuclear@7	271
nuclear@7	272 glDepthMask(0);
nuclear@7	273
nuclear@7	274 glDrawArrays(GL_TRIANGLES, 0, num_quads * 6);
nuclear@7	275
nuclear@7	276 glDepthMask(1);
nuclear@7	277
nuclear@7	278 if(vattr != -1) {
nuclear@7	279 glDisableVertexAttribArray(vattr);
nuclear@7	280 #ifndef GL_ES
nuclear@7	281 } else {
nuclear@7	282 glDisableClientState(GL_VERTEX_ARRAY);
nuclear@7	283 #endif
nuclear@7	284 }
nuclear@7	285 if(tattr != -1) {
nuclear@7	286 glDisableVertexAttribArray(tattr);
nuclear@7	287 #ifndef GL_ES
nuclear@7	288 } else {
nuclear@7	289 glDisableClientState(GL_TEXTURE_COORD_ARRAY);
nuclear@7	290 #endif
nuclear@7	291 }
nuclear@7	292
nuclear@7	293 #ifndef GL_ES
nuclear@7	294 glPopAttrib();
nuclear@7	295 #else
nuclear@7	296 glDisable(GL_BLEND);
nuclear@7	297 #endif
nuclear@7	298
nuclear@7	299 if(vbo) {
nuclear@7	300 glBindBuffer(GL_ARRAY_BUFFER, vbo);
nuclear@7	301 }
nuclear@7	302
nuclear@7	303 num_quads = 0;
nuclear@7	304 }
nuclear@7	305
nuclear@7	306 #endif /* !def NO_OPENGL */