libdrawtext

annotate src/drawgl.c @ 0:bfe431dd1d80

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initial commit
author John Tsiombikas <nuclear@mutantstargoat.com>
date Thu, 15 Sep 2011 10:47:38 +0300
parents
children fe0c54e574ae
rev   line source
nuclear@0 1 #ifndef NO_OPENGL
nuclear@0 2 #include <math.h>
nuclear@0 3 #include <ctype.h>
nuclear@0 4
nuclear@0 5 #include <stdlib.h>
nuclear@0 6
nuclear@0 7 #if defined(__IPHONE_3_0) || defined(__IPHONE_3_2) || defined(__IPHONE_4_0)
nuclear@0 8 #include <OpenGLES/ES2/gl.h>
nuclear@0 9 #else
nuclear@0 10 #include <GL/glew.h>
nuclear@0 11 #endif
nuclear@0 12
nuclear@0 13 #include "drawtext.h"
nuclear@0 14 #include "drawtext_impl.h"
nuclear@0 15
nuclear@0 16 struct vertex {
nuclear@0 17 float x, y;
nuclear@0 18 float s, t;
nuclear@0 19 };
nuclear@0 20
nuclear@0 21 struct quad {
nuclear@0 22 struct vertex v[6];
nuclear@0 23 };
nuclear@0 24
nuclear@0 25 static int init(void);
nuclear@0 26 static void cleanup(void);
nuclear@0 27 static void add_glyph(struct glyph *g, float x, float y);
nuclear@0 28
nuclear@0 29 #define QBUF_SZ 512
nuclear@0 30 static struct quad *qbuf;
nuclear@0 31 static int num_quads;
nuclear@0 32 static int vattr = -1;
nuclear@0 33 static int tattr = -1;
nuclear@0 34 static unsigned int font_tex;
nuclear@0 35 static int buf_mode = DTX_LBF;
nuclear@0 36
nuclear@0 37 static struct dtx_font *font;
nuclear@0 38 static int font_sz;
nuclear@0 39
nuclear@0 40
nuclear@0 41 static int init(void)
nuclear@0 42 {
nuclear@0 43 if(qbuf) {
nuclear@0 44 return 0; /* already initialized */
nuclear@0 45 }
nuclear@0 46
nuclear@0 47 glewInit();
nuclear@0 48
nuclear@0 49 if(!(qbuf = malloc(QBUF_SZ * sizeof *qbuf))) {
nuclear@0 50 return -1;
nuclear@0 51 }
nuclear@0 52 num_quads = 0;
nuclear@0 53
nuclear@0 54 atexit(cleanup);
nuclear@0 55 return 0;
nuclear@0 56 }
nuclear@0 57
nuclear@0 58 static void cleanup(void)
nuclear@0 59 {
nuclear@0 60 free(qbuf);
nuclear@0 61 }
nuclear@0 62
nuclear@0 63
nuclear@0 64 void dtx_use_font(struct dtx_font *fnt, int sz)
nuclear@0 65 {
nuclear@0 66 init();
nuclear@0 67
nuclear@0 68 font = fnt;
nuclear@0 69 font_sz = sz;
nuclear@0 70 }
nuclear@0 71
nuclear@0 72 void dtx_vertex_attribs(int vert_attr, int tex_attr)
nuclear@0 73 {
nuclear@0 74 vattr = vert_attr;
nuclear@0 75 tattr = tex_attr;
nuclear@0 76 }
nuclear@0 77
nuclear@0 78 static void set_glyphmap_texture(struct dtx_glyphmap *gmap)
nuclear@0 79 {
nuclear@0 80 if(!gmap->tex) {
nuclear@0 81 glGenTextures(1, &gmap->tex);
nuclear@0 82 glBindTexture(GL_TEXTURE_2D, gmap->tex);
nuclear@0 83 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR);
nuclear@0 84 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
nuclear@0 85 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP);
nuclear@0 86 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP);
nuclear@0 87
nuclear@0 88 #ifdef GL_ES
nuclear@0 89 glTexImage2D(GL_TEXTURE_2D, 0, GL_ALPHA, gmap->xsz, gmap->ysz, 0, GL_ALPHA, GL_UNSIGNED_BYTE, gmap->pixels);
nuclear@0 90 glGenerateMipmap(GL_TEXTURE_2D);
nuclear@0 91 #else
nuclear@0 92 gluBuild2DMipmaps(GL_TEXTURE_2D, GL_ALPHA, gmap->xsz, gmap->ysz, GL_ALPHA, GL_UNSIGNED_BYTE, gmap->pixels);
nuclear@0 93 #endif
nuclear@0 94 }
nuclear@0 95
nuclear@0 96 if(font_tex != gmap->tex) {
nuclear@0 97 dtx_flush();
nuclear@0 98 }
nuclear@0 99 font_tex = gmap->tex;
nuclear@0 100 }
nuclear@0 101
nuclear@0 102 void dtx_glyph(int code)
nuclear@0 103 {
nuclear@0 104 struct dtx_glyphmap *gmap;
nuclear@0 105
nuclear@0 106 if(!font || !(gmap = dtx_get_font_glyphmap(font, font_sz, code))) {
nuclear@0 107 return;
nuclear@0 108 }
nuclear@0 109 set_glyphmap_texture(gmap);
nuclear@0 110
nuclear@0 111 add_glyph(gmap->glyphs + code - gmap->cstart, 0, 0);
nuclear@0 112 dtx_flush();
nuclear@0 113 }
nuclear@0 114
nuclear@0 115 void dtx_string(const char *str)
nuclear@0 116 {
nuclear@0 117 struct dtx_glyphmap *gmap;
nuclear@0 118 int should_flush = buf_mode == DTX_NBF;
nuclear@0 119 float pos_x = 0.0f;
nuclear@0 120 float pos_y = 0.0f;
nuclear@0 121
nuclear@0 122 if(!font) {
nuclear@0 123 return;
nuclear@0 124 }
nuclear@0 125
nuclear@0 126 while(*str) {
nuclear@0 127 int code = dtx_utf8_char_code(str);
nuclear@0 128 str = dtx_utf8_next_char((char*)str);
nuclear@0 129
nuclear@0 130 switch(code) {
nuclear@0 131 case '\n':
nuclear@0 132 if(buf_mode == DTX_LBF) {
nuclear@0 133 should_flush = 1;
nuclear@0 134 }
nuclear@0 135 pos_x = 0.0;
nuclear@0 136 pos_y -= gmap->line_advance;
nuclear@0 137 break;
nuclear@0 138
nuclear@0 139 case '\t':
nuclear@0 140 pos_x = fmod(pos_x, 4.0) + 4.0;
nuclear@0 141 break;
nuclear@0 142
nuclear@0 143 case '\r':
nuclear@0 144 pos_x = 0.0;
nuclear@0 145 break;
nuclear@0 146
nuclear@0 147 default:
nuclear@0 148 if((gmap = dtx_get_font_glyphmap(font, font_sz, code))) {
nuclear@0 149 int idx = code - gmap->cstart;
nuclear@0 150
nuclear@0 151 set_glyphmap_texture(gmap);
nuclear@0 152 add_glyph(gmap->glyphs + idx, pos_x, pos_y);
nuclear@0 153 pos_x += gmap->glyphs[idx].advance;
nuclear@0 154 }
nuclear@0 155 }
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@0 163 static void qvertex(struct vertex *v, float x, float y, float s, float t)
nuclear@0 164 {
nuclear@0 165 v->x = x;
nuclear@0 166 v->y = y;
nuclear@0 167 v->s = s;
nuclear@0 168 v->t = t;
nuclear@0 169 }
nuclear@0 170
nuclear@0 171 static void add_glyph(struct glyph *g, float x, float y)
nuclear@0 172 {
nuclear@0 173 struct quad *qptr = qbuf + num_quads;
nuclear@0 174
nuclear@0 175 x -= g->orig_x;
nuclear@0 176 y -= g->orig_y;
nuclear@0 177
nuclear@0 178 qvertex(qptr->v + 0, x, y, g->nx, g->ny + g->nheight);
nuclear@0 179 qvertex(qptr->v + 1, x + g->width, y, g->nx + g->nwidth, g->ny + g->nheight);
nuclear@0 180 qvertex(qptr->v + 2, x + g->width, y + g->height, g->nx + g->nwidth, g->ny);
nuclear@0 181
nuclear@0 182 qvertex(qptr->v + 3, x, y, g->nx, g->ny + g->nheight);
nuclear@0 183 qvertex(qptr->v + 4, x + g->width, y + g->height, g->nx + g->nwidth, g->ny);
nuclear@0 184 qvertex(qptr->v + 5, x, y + g->height, g->nx, g->ny);
nuclear@0 185
nuclear@0 186 if(++num_quads >= QBUF_SZ) {
nuclear@0 187 dtx_flush();
nuclear@0 188 }
nuclear@0 189 }
nuclear@0 190
nuclear@0 191 void dtx_flush(void)
nuclear@0 192 {
nuclear@0 193 if(!num_quads) {
nuclear@0 194 return;
nuclear@0 195 }
nuclear@0 196
nuclear@0 197 #ifndef GL_ES
nuclear@0 198 glPushAttrib(GL_ENABLE_BIT);
nuclear@0 199 glEnable(GL_TEXTURE_2D);
nuclear@0 200 #endif
nuclear@0 201 glBindTexture(GL_TEXTURE_2D, font_tex);
nuclear@0 202
nuclear@0 203 if(vattr != -1 && glEnableVertexAttribArray) {
nuclear@0 204 glEnableVertexAttribArray(vattr);
nuclear@0 205 glVertexAttribPointer(vattr, 2, GL_FLOAT, 0, sizeof(struct vertex), qbuf);
nuclear@0 206 #ifndef GL_ES
nuclear@0 207 } else {
nuclear@0 208 glEnableClientState(GL_VERTEX_ARRAY);
nuclear@0 209 glVertexPointer(2, GL_FLOAT, sizeof(struct vertex), qbuf);
nuclear@0 210 #endif
nuclear@0 211 }
nuclear@0 212 if(tattr != -1 && glEnableVertexAttribArray) {
nuclear@0 213 glEnableVertexAttribArray(tattr);
nuclear@0 214 glVertexAttribPointer(tattr, 2, GL_FLOAT, 0, sizeof(struct vertex), &qbuf->v[0].s);
nuclear@0 215 #ifndef GL_ES
nuclear@0 216 } else {
nuclear@0 217 glEnableClientState(GL_TEXTURE_COORD_ARRAY);
nuclear@0 218 glTexCoordPointer(2, GL_FLOAT, sizeof(struct vertex), &qbuf->v[0].s);
nuclear@0 219 #endif
nuclear@0 220 }
nuclear@0 221
nuclear@0 222 glEnable(GL_BLEND);
nuclear@0 223 glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
nuclear@0 224
nuclear@0 225 glDepthMask(0);
nuclear@0 226
nuclear@0 227 glDrawArrays(GL_TRIANGLES, 0, num_quads * 6);
nuclear@0 228
nuclear@0 229 glDepthMask(1);
nuclear@0 230
nuclear@0 231 if(vattr != -1 && glDisableVertexAttribArray) {
nuclear@0 232 glDisableVertexAttribArray(vattr);
nuclear@0 233 #ifndef GL_ES
nuclear@0 234 } else {
nuclear@0 235 glDisableClientState(GL_VERTEX_ARRAY);
nuclear@0 236 #endif
nuclear@0 237 }
nuclear@0 238 if(tattr != -1 && glDisableVertexAttribArray) {
nuclear@0 239 glDisableVertexAttribArray(tattr);
nuclear@0 240 #ifndef GL_ES
nuclear@0 241 } else {
nuclear@0 242 glDisableClientState(GL_TEXTURE_COORD_ARRAY);
nuclear@0 243 #endif
nuclear@0 244 }
nuclear@0 245
nuclear@0 246 #ifndef GL_ES
nuclear@0 247 glPopAttrib();
nuclear@0 248 #else
nuclear@0 249 glDisable(GL_BLEND);
nuclear@0 250 #endif
nuclear@0 251
nuclear@0 252 num_quads = 0;
nuclear@0 253 }
nuclear@0 254
nuclear@0 255 #endif /* !def NO_OPENGL */