1.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     1.2 +++ b/prototype/drawtext/drawgl.c	Thu Aug 23 18:03:11 2012 +0300
     1.3 @@ -0,0 +1,248 @@
     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_OPENGL
    1.22 +#include <math.h>
    1.23 +#include <ctype.h>
    1.24 +
    1.25 +#include <stdlib.h>
    1.26 +
    1.27 +#ifdef TARGET_IPHONE
    1.28 +#include <OpenGLES/ES2/gl.h>
    1.29 +#else
    1.30 +#include <GL/glew.h>
    1.31 +#endif
    1.32 +
    1.33 +#include "drawtext.h"
    1.34 +#include "drawtext_impl.h"
    1.35 +
    1.36 +struct vertex {
    1.37 +	float x, y;
    1.38 +	float s, t;
    1.39 +};
    1.40 +
    1.41 +struct quad {
    1.42 +	struct vertex v[6];
    1.43 +};
    1.44 +
    1.45 +static void cleanup(void);
    1.46 +static void add_glyph(struct glyph *g, float x, float y);
    1.47 +
    1.48 +#define QBUF_SZ		512
    1.49 +static struct quad *qbuf;
    1.50 +static int num_quads;
    1.51 +static int vattr = -1;
    1.52 +static int tattr = -1;
    1.53 +static unsigned int font_tex;
    1.54 +static int buf_mode = DTX_NBF;
    1.55 +
    1.56 +
    1.57 +int dtx_gl_init(void)
    1.58 +{
    1.59 +	if(qbuf) {
    1.60 +		return 0;	/* already initialized */
    1.61 +	}
    1.62 +
    1.63 +	glewInit();
    1.64 +
    1.65 +	if(!(qbuf = malloc(QBUF_SZ * sizeof *qbuf))) {
    1.66 +		return -1;
    1.67 +	}
    1.68 +	num_quads = 0;
    1.69 +
    1.70 +	atexit(cleanup);
    1.71 +	return 0;
    1.72 +}
    1.73 +
    1.74 +static void cleanup(void)
    1.75 +{
    1.76 +	free(qbuf);
    1.77 +}
    1.78 +
    1.79 +
    1.80 +void dtx_vertex_attribs(int vert_attr, int tex_attr)
    1.81 +{
    1.82 +	vattr = vert_attr;
    1.83 +	tattr = tex_attr;
    1.84 +}
    1.85 +
    1.86 +static void set_glyphmap_texture(struct dtx_glyphmap *gmap)
    1.87 +{
    1.88 +	if(!gmap->tex) {
    1.89 +		glGenTextures(1, &gmap->tex);
    1.90 +		glBindTexture(GL_TEXTURE_2D, gmap->tex);
    1.91 +		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR);
    1.92 +		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
    1.93 +		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP);
    1.94 +		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP);
    1.95 +
    1.96 +#ifdef GL_ES
    1.97 +		glTexImage2D(GL_TEXTURE_2D, 0, GL_ALPHA, gmap->xsz, gmap->ysz, 0, GL_ALPHA, GL_UNSIGNED_BYTE, gmap->pixels);
    1.98 +		glGenerateMipmap(GL_TEXTURE_2D);
    1.99 +#else
   1.100 +		gluBuild2DMipmaps(GL_TEXTURE_2D, GL_ALPHA, gmap->xsz, gmap->ysz, GL_ALPHA, GL_UNSIGNED_BYTE, gmap->pixels);
   1.101 +#endif
   1.102 +	}
   1.103 +
   1.104 +	if(font_tex != gmap->tex) {
   1.105 +		dtx_flush();
   1.106 +	}
   1.107 +	font_tex = gmap->tex;
   1.108 +}
   1.109 +
   1.110 +void dtx_glyph(int code)
   1.111 +{
   1.112 +	struct dtx_glyphmap *gmap;
   1.113 +
   1.114 +	if(!dtx_font || !(gmap = dtx_get_font_glyphmap(dtx_font, dtx_font_sz, code))) {
   1.115 +		return;
   1.116 +	}
   1.117 +	set_glyphmap_texture(gmap);
   1.118 +
   1.119 +	add_glyph(gmap->glyphs + code - gmap->cstart, 0, 0);
   1.120 +	dtx_flush();
   1.121 +}
   1.122 +
   1.123 +void dtx_string(const char *str)
   1.124 +{
   1.125 +	struct dtx_glyphmap *gmap;
   1.126 +	int should_flush = buf_mode == DTX_NBF;
   1.127 +	float pos_x = 0.0f;
   1.128 +	float pos_y = 0.0f;
   1.129 +
   1.130 +	if(!dtx_font) {
   1.131 +		return;
   1.132 +	}
   1.133 +
   1.134 +	while(*str) {
   1.135 +		float px, py;
   1.136 +		int code = dtx_utf8_char_code(str);
   1.137 +		str = dtx_utf8_next_char((char*)str);
   1.138 +
   1.139 +		if(buf_mode == DTX_LBF && code == '\n') {
   1.140 +			should_flush = 1;
   1.141 +		}
   1.142 +
   1.143 +		px = pos_x;
   1.144 +		py = pos_y;
   1.145 +
   1.146 +		if((gmap = dtx_proc_char(code, &pos_x, &pos_y))) {
   1.147 +			int idx = code - gmap->cstart;
   1.148 +
   1.149 +			set_glyphmap_texture(gmap);
   1.150 +			add_glyph(gmap->glyphs + idx, px, py);
   1.151 +		}
   1.152 +	}
   1.153 +
   1.154 +	if(should_flush) {
   1.155 +		dtx_flush();
   1.156 +	}
   1.157 +}
   1.158 +
   1.159 +static void qvertex(struct vertex *v, float x, float y, float s, float t)
   1.160 +{
   1.161 +	v->x = x;
   1.162 +	v->y = y;
   1.163 +	v->s = s;
   1.164 +	v->t = t;
   1.165 +}
   1.166 +
   1.167 +static void add_glyph(struct glyph *g, float x, float y)
   1.168 +{
   1.169 +	struct quad *qptr = qbuf + num_quads;
   1.170 +
   1.171 +	x -= g->orig_x;
   1.172 +	y -= g->orig_y;
   1.173 +
   1.174 +	qvertex(qptr->v + 0, x, y, g->nx, g->ny + g->nheight);
   1.175 +	qvertex(qptr->v + 1, x + g->width, y, g->nx + g->nwidth, g->ny + g->nheight);
   1.176 +	qvertex(qptr->v + 2, x + g->width, y + g->height, g->nx + g->nwidth, g->ny);
   1.177 +
   1.178 +	qvertex(qptr->v + 3, x, y, g->nx, g->ny + g->nheight);
   1.179 +	qvertex(qptr->v + 4, x + g->width, y + g->height, g->nx + g->nwidth, g->ny);
   1.180 +	qvertex(qptr->v + 5, x, y + g->height, g->nx, g->ny);
   1.181 +
   1.182 +	if(++num_quads >= QBUF_SZ) {
   1.183 +		dtx_flush();
   1.184 +	}
   1.185 +}
   1.186 +
   1.187 +void dtx_flush(void)
   1.188 +{
   1.189 +	if(!num_quads) {
   1.190 +		return;
   1.191 +	}
   1.192 +
   1.193 +#ifndef GL_ES
   1.194 +	glPushAttrib(GL_ENABLE_BIT);
   1.195 +	glEnable(GL_TEXTURE_2D);
   1.196 +#endif
   1.197 +	glBindTexture(GL_TEXTURE_2D, font_tex);
   1.198 +
   1.199 +	if(vattr != -1 && glEnableVertexAttribArray) {
   1.200 +		glEnableVertexAttribArray(vattr);
   1.201 +		glVertexAttribPointer(vattr, 2, GL_FLOAT, 0, sizeof(struct vertex), qbuf);
   1.202 +#ifndef GL_ES
   1.203 +	} else {
   1.204 +		glEnableClientState(GL_VERTEX_ARRAY);
   1.205 +		glVertexPointer(2, GL_FLOAT, sizeof(struct vertex), qbuf);
   1.206 +#endif
   1.207 +	}
   1.208 +	if(tattr != -1 && glEnableVertexAttribArray) {
   1.209 +		glEnableVertexAttribArray(tattr);
   1.210 +		glVertexAttribPointer(tattr, 2, GL_FLOAT, 0, sizeof(struct vertex), &qbuf->v[0].s);
   1.211 +#ifndef GL_ES
   1.212 +	} else {
   1.213 +		glEnableClientState(GL_TEXTURE_COORD_ARRAY);
   1.214 +		glTexCoordPointer(2, GL_FLOAT, sizeof(struct vertex), &qbuf->v[0].s);
   1.215 +#endif
   1.216 +	}
   1.217 +
   1.218 +	glEnable(GL_BLEND);
   1.219 +	glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
   1.220 +
   1.221 +	glDepthMask(0);
   1.222 +
   1.223 +	glDrawArrays(GL_TRIANGLES, 0, num_quads * 6);
   1.224 +
   1.225 +	glDepthMask(1);
   1.226 +
   1.227 +	if(vattr != -1 && glDisableVertexAttribArray) {
   1.228 +		glDisableVertexAttribArray(vattr);
   1.229 +#ifndef GL_ES
   1.230 +	} else {
   1.231 +		glDisableClientState(GL_VERTEX_ARRAY);
   1.232 +#endif
   1.233 +	}
   1.234 +	if(tattr != -1 && glDisableVertexAttribArray) {
   1.235 +		glDisableVertexAttribArray(tattr);
   1.236 +#ifndef GL_ES
   1.237 +	} else {
   1.238 +		glDisableClientState(GL_TEXTURE_COORD_ARRAY);
   1.239 +#endif
   1.240 +	}
   1.241 +
   1.242 +#ifndef GL_ES
   1.243 +	glPopAttrib();
   1.244 +#else
   1.245 +	glDisable(GL_BLEND);
   1.246 +#endif
   1.247 +
   1.248 +	num_quads = 0;
   1.249 +}
   1.250 +
   1.251 +#endif	/* !def NO_OPENGL */