libdrawtext

annotate src/drawgl.c @ 15:462bcb69de15

find changesets by author, revision, files, or words in the commit message
added dtx_printf
author John Tsiombikas <nuclear@member.fsf.org>
date Thu, 28 Feb 2013 18:51:33 +0200
parents 55c034e70809
children baec6ad7b2dd
rev   line source
nuclear@5 1 /*
nuclear@5 2 libdrawtext - a simple library for fast text rendering in OpenGL
nuclear@12 3 Copyright (C) 2011-2012 John Tsiombikas <nuclear@member.fsf.org>
nuclear@5 4
nuclear@5 5 This program is free software: you can redistribute it and/or modify
nuclear@5 6 it under the terms of the GNU Lesser General Public License as published by
nuclear@5 7 the Free Software Foundation, either version 3 of the License, or
nuclear@5 8 (at your option) any later version.
nuclear@5 9
nuclear@5 10 This program is distributed in the hope that it will be useful,
nuclear@5 11 but WITHOUT ANY WARRANTY; without even the implied warranty of
nuclear@5 12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
nuclear@5 13 GNU Lesser General Public License for more details.
nuclear@5 14
nuclear@5 15 You should have received a copy of the GNU Lesser General Public License
nuclear@5 16 along with this program. If not, see <http://www.gnu.org/licenses/>.
nuclear@5 17 */
nuclear@0 18 #ifndef NO_OPENGL
nuclear@15 19 #include <stdarg.h>
nuclear@0 20 #include <math.h>
nuclear@0 21 #include <ctype.h>
nuclear@0 22
nuclear@0 23 #include <stdlib.h>
nuclear@0 24
nuclear@9 25 #ifdef TARGET_IPHONE
nuclear@0 26 #include <OpenGLES/ES2/gl.h>
nuclear@0 27 #else
nuclear@0 28 #include <GL/glew.h>
nuclear@0 29 #endif
nuclear@0 30
nuclear@0 31 #include "drawtext.h"
nuclear@0 32 #include "drawtext_impl.h"
nuclear@0 33
nuclear@0 34 struct vertex {
nuclear@0 35 float x, y;
nuclear@0 36 float s, t;
nuclear@0 37 };
nuclear@0 38
nuclear@0 39 struct quad {
nuclear@0 40 struct vertex v[6];
nuclear@0 41 };
nuclear@0 42
nuclear@0 43 static void cleanup(void);
nuclear@0 44 static void add_glyph(struct glyph *g, float x, float y);
nuclear@0 45
nuclear@0 46 #define QBUF_SZ 512
nuclear@0 47 static struct quad *qbuf;
nuclear@0 48 static int num_quads;
nuclear@0 49 static int vattr = -1;
nuclear@0 50 static int tattr = -1;
nuclear@0 51 static unsigned int font_tex;
nuclear@3 52 static int buf_mode = DTX_NBF;
nuclear@0 53
nuclear@0 54
nuclear@6 55 int dtx_gl_init(void)
nuclear@0 56 {
nuclear@0 57 if(qbuf) {
nuclear@0 58 return 0; /* already initialized */
nuclear@0 59 }
nuclear@0 60
nuclear@0 61 glewInit();
nuclear@0 62
nuclear@0 63 if(!(qbuf = malloc(QBUF_SZ * sizeof *qbuf))) {
nuclear@0 64 return -1;
nuclear@0 65 }
nuclear@0 66 num_quads = 0;
nuclear@0 67
nuclear@0 68 atexit(cleanup);
nuclear@0 69 return 0;
nuclear@0 70 }
nuclear@0 71
nuclear@0 72 static void cleanup(void)
nuclear@0 73 {
nuclear@0 74 free(qbuf);
nuclear@0 75 }
nuclear@0 76
nuclear@0 77
nuclear@0 78 void dtx_vertex_attribs(int vert_attr, int tex_attr)
nuclear@0 79 {
nuclear@0 80 vattr = vert_attr;
nuclear@0 81 tattr = tex_attr;
nuclear@0 82 }
nuclear@0 83
nuclear@0 84 static void set_glyphmap_texture(struct dtx_glyphmap *gmap)
nuclear@0 85 {
nuclear@0 86 if(!gmap->tex) {
nuclear@0 87 glGenTextures(1, &gmap->tex);
nuclear@0 88 glBindTexture(GL_TEXTURE_2D, gmap->tex);
nuclear@0 89 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR);
nuclear@0 90 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
nuclear@0 91 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP);
nuclear@0 92 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP);
nuclear@0 93
nuclear@0 94 #ifdef GL_ES
nuclear@0 95 glTexImage2D(GL_TEXTURE_2D, 0, GL_ALPHA, gmap->xsz, gmap->ysz, 0, GL_ALPHA, GL_UNSIGNED_BYTE, gmap->pixels);
nuclear@0 96 glGenerateMipmap(GL_TEXTURE_2D);
nuclear@0 97 #else
nuclear@0 98 gluBuild2DMipmaps(GL_TEXTURE_2D, GL_ALPHA, gmap->xsz, gmap->ysz, GL_ALPHA, GL_UNSIGNED_BYTE, gmap->pixels);
nuclear@0 99 #endif
nuclear@0 100 }
nuclear@0 101
nuclear@0 102 if(font_tex != gmap->tex) {
nuclear@0 103 dtx_flush();
nuclear@0 104 }
nuclear@0 105 font_tex = gmap->tex;
nuclear@0 106 }
nuclear@0 107
nuclear@0 108 void dtx_glyph(int code)
nuclear@0 109 {
nuclear@0 110 struct dtx_glyphmap *gmap;
nuclear@0 111
nuclear@6 112 if(!dtx_font || !(gmap = dtx_get_font_glyphmap(dtx_font, dtx_font_sz, code))) {
nuclear@0 113 return;
nuclear@0 114 }
nuclear@0 115 set_glyphmap_texture(gmap);
nuclear@0 116
nuclear@0 117 add_glyph(gmap->glyphs + code - gmap->cstart, 0, 0);
nuclear@0 118 dtx_flush();
nuclear@0 119 }
nuclear@0 120
nuclear@15 121 static const char *put_char(const char *str, float *pos_x, float *pos_y, int *should_flush)
nuclear@15 122 {
nuclear@15 123 struct dtx_glyphmap *gmap;
nuclear@15 124 float px, py;
nuclear@15 125 int code = dtx_utf8_char_code(str);
nuclear@15 126 str = dtx_utf8_next_char((char*)str);
nuclear@15 127
nuclear@15 128 if(buf_mode == DTX_LBF && code == '\n') {
nuclear@15 129 *should_flush = 1;
nuclear@15 130 }
nuclear@15 131
nuclear@15 132 px = *pos_x;
nuclear@15 133 py = *pos_y;
nuclear@15 134
nuclear@15 135 if((gmap = dtx_proc_char(code, pos_x, pos_y))) {
nuclear@15 136 int idx = code - gmap->cstart;
nuclear@15 137
nuclear@15 138 set_glyphmap_texture(gmap);
nuclear@15 139 add_glyph(gmap->glyphs + idx, px, py);
nuclear@15 140 }
nuclear@15 141 return str;
nuclear@15 142 }
nuclear@15 143
nuclear@0 144 void dtx_string(const char *str)
nuclear@0 145 {
nuclear@0 146 int should_flush = buf_mode == DTX_NBF;
nuclear@0 147 float pos_x = 0.0f;
nuclear@0 148 float pos_y = 0.0f;
nuclear@0 149
nuclear@6 150 if(!dtx_font) {
nuclear@0 151 return;
nuclear@0 152 }
nuclear@0 153
nuclear@0 154 while(*str) {
nuclear@15 155 str = put_char(str, &pos_x, &pos_y, &should_flush);
nuclear@0 156 }
nuclear@0 157
nuclear@0 158 if(should_flush) {
nuclear@0 159 dtx_flush();
nuclear@0 160 }
nuclear@0 161 }
nuclear@0 162
nuclear@15 163 void dtx_printf(const char *fmt, ...)
nuclear@15 164 {
nuclear@15 165 va_list ap;
nuclear@15 166 int buf_size;
nuclear@15 167 char *buf, tmp;
nuclear@15 168
nuclear@15 169 if(!dtx_font) {
nuclear@15 170 return;
nuclear@15 171 }
nuclear@15 172
nuclear@15 173 va_start(ap, fmt);
nuclear@15 174 buf_size = vsnprintf(&tmp, 0, fmt, ap);
nuclear@15 175 va_end(ap);
nuclear@15 176
nuclear@15 177 if(buf_size == -1) {
nuclear@15 178 buf_size = 512;
nuclear@15 179 }
nuclear@15 180
nuclear@15 181 buf = alloca(buf_size + 1);
nuclear@15 182 va_start(ap, fmt);
nuclear@15 183 vsnprintf(buf, buf_size + 1, fmt, ap);
nuclear@15 184 va_end(ap);
nuclear@15 185
nuclear@15 186 dtx_string(buf);
nuclear@15 187 }
nuclear@15 188
nuclear@0 189 static void qvertex(struct vertex *v, float x, float y, float s, float t)
nuclear@0 190 {
nuclear@0 191 v->x = x;
nuclear@0 192 v->y = y;
nuclear@0 193 v->s = s;
nuclear@0 194 v->t = t;
nuclear@0 195 }
nuclear@0 196
nuclear@0 197 static void add_glyph(struct glyph *g, float x, float y)
nuclear@0 198 {
nuclear@0 199 struct quad *qptr = qbuf + num_quads;
nuclear@0 200
nuclear@0 201 x -= g->orig_x;
nuclear@0 202 y -= g->orig_y;
nuclear@0 203
nuclear@0 204 qvertex(qptr->v + 0, x, y, g->nx, g->ny + g->nheight);
nuclear@0 205 qvertex(qptr->v + 1, x + g->width, y, g->nx + g->nwidth, g->ny + g->nheight);
nuclear@0 206 qvertex(qptr->v + 2, x + g->width, y + g->height, g->nx + g->nwidth, g->ny);
nuclear@0 207
nuclear@0 208 qvertex(qptr->v + 3, x, y, g->nx, g->ny + g->nheight);
nuclear@0 209 qvertex(qptr->v + 4, x + g->width, y + g->height, g->nx + g->nwidth, g->ny);
nuclear@0 210 qvertex(qptr->v + 5, x, y + g->height, g->nx, g->ny);
nuclear@0 211
nuclear@0 212 if(++num_quads >= QBUF_SZ) {
nuclear@0 213 dtx_flush();
nuclear@0 214 }
nuclear@0 215 }
nuclear@0 216
nuclear@0 217 void dtx_flush(void)
nuclear@0 218 {
nuclear@12 219 int vbo;
nuclear@12 220
nuclear@0 221 if(!num_quads) {
nuclear@0 222 return;
nuclear@0 223 }
nuclear@0 224
nuclear@12 225 if(glBindBuffer) {
nuclear@12 226 glGetIntegerv(GL_ARRAY_BUFFER_BINDING, &vbo);
nuclear@12 227 glBindBuffer(GL_ARRAY_BUFFER, 0);
nuclear@12 228 }
nuclear@12 229
nuclear@0 230 #ifndef GL_ES
nuclear@0 231 glPushAttrib(GL_ENABLE_BIT);
nuclear@0 232 glEnable(GL_TEXTURE_2D);
nuclear@0 233 #endif
nuclear@0 234 glBindTexture(GL_TEXTURE_2D, font_tex);
nuclear@0 235
nuclear@0 236 if(vattr != -1 && glEnableVertexAttribArray) {
nuclear@0 237 glEnableVertexAttribArray(vattr);
nuclear@0 238 glVertexAttribPointer(vattr, 2, GL_FLOAT, 0, sizeof(struct vertex), qbuf);
nuclear@0 239 #ifndef GL_ES
nuclear@0 240 } else {
nuclear@0 241 glEnableClientState(GL_VERTEX_ARRAY);
nuclear@0 242 glVertexPointer(2, GL_FLOAT, sizeof(struct vertex), qbuf);
nuclear@0 243 #endif
nuclear@0 244 }
nuclear@0 245 if(tattr != -1 && glEnableVertexAttribArray) {
nuclear@0 246 glEnableVertexAttribArray(tattr);
nuclear@0 247 glVertexAttribPointer(tattr, 2, GL_FLOAT, 0, sizeof(struct vertex), &qbuf->v[0].s);
nuclear@0 248 #ifndef GL_ES
nuclear@0 249 } else {
nuclear@0 250 glEnableClientState(GL_TEXTURE_COORD_ARRAY);
nuclear@0 251 glTexCoordPointer(2, GL_FLOAT, sizeof(struct vertex), &qbuf->v[0].s);
nuclear@0 252 #endif
nuclear@0 253 }
nuclear@0 254
nuclear@0 255 glEnable(GL_BLEND);
nuclear@0 256 glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
nuclear@0 257
nuclear@0 258 glDepthMask(0);
nuclear@0 259
nuclear@0 260 glDrawArrays(GL_TRIANGLES, 0, num_quads * 6);
nuclear@0 261
nuclear@0 262 glDepthMask(1);
nuclear@0 263
nuclear@0 264 if(vattr != -1 && glDisableVertexAttribArray) {
nuclear@0 265 glDisableVertexAttribArray(vattr);
nuclear@0 266 #ifndef GL_ES
nuclear@0 267 } else {
nuclear@0 268 glDisableClientState(GL_VERTEX_ARRAY);
nuclear@0 269 #endif
nuclear@0 270 }
nuclear@0 271 if(tattr != -1 && glDisableVertexAttribArray) {
nuclear@0 272 glDisableVertexAttribArray(tattr);
nuclear@0 273 #ifndef GL_ES
nuclear@0 274 } else {
nuclear@0 275 glDisableClientState(GL_TEXTURE_COORD_ARRAY);
nuclear@0 276 #endif
nuclear@0 277 }
nuclear@0 278
nuclear@0 279 #ifndef GL_ES
nuclear@0 280 glPopAttrib();
nuclear@0 281 #else
nuclear@0 282 glDisable(GL_BLEND);
nuclear@0 283 #endif
nuclear@0 284
nuclear@12 285 if(glBindBuffer && vbo) {
nuclear@12 286 glBindBuffer(GL_ARRAY_BUFFER, vbo);
nuclear@12 287 }
nuclear@12 288
nuclear@0 289 num_quads = 0;
nuclear@0 290 }
nuclear@0 291
nuclear@0 292 #endif /* !def NO_OPENGL */