stb_easy_font.h
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1 // stb_easy_font.h - v0.6 - bitmap font for 3D rendering - public domain
2 // Sean Barrett, Feb 2015
3 //
4 // Easy-to-deploy,
5 // reasonably compact,
6 // extremely inefficient performance-wise,
7 // crappy-looking,
8 // ASCII-only,
9 // bitmap font for use in 3D APIs.
10 //
11 // Intended for when you just want to get some text displaying
12 // in a 3D app as quickly as possible.
13 //
14 // Doesn't use any textures, instead builds characters out of quads.
15 //
16 // DOCUMENTATION:
17 //
18 // int stb_easy_font_width(char *text)
19 //
20 // Takes a string without newlines and returns the horizontal size.
21 //
22 // int stb_easy_font_print(float x, float y,
23 // char *text, unsigned char color[4],
24 // void *vertex_buffer, int vbuf_size)
25 //
26 // Takes a string (which can contain '\n') and fills out a
27 // vertex buffer with renderable data to draw the string.
28 // Output data assumes increasing x is rightwards, increasing y
29 // is downwards.
30 //
31 // The vertex data is divided into quads, i.e. there are four
32 // vertices in the vertex buffer for each quad.
33 //
34 // The vertices are stored in an interleaved format:
35 //
36 // x:float
37 // y:float
38 // z:float
39 // color:uint8[4]
40 //
41 // You can ignore z and color if you get them from elsewhere
42 // This format was chosen in the hopes it would make it
43 // easier for you to reuse existing buffer-drawing code.
44 //
45 // If you pass in NULL for color, it becomes 255,255,255,255.
46 //
47 // Returns the number of quads.
48 //
49 // If the buffer isn't large enough, it will truncate.
50 // Expect it to use an average of ~270 bytes per character.
51 //
52 // If your API doesn't draw quads, build a reusable index
53 // list that allows you to render quads as indexed triangles.
54 //
55 // void stb_easy_font_spacing(float spacing)
56 //
57 // Use positive values to expand the space between characters,
58 // and small negative values (no smaller than -1.5) to contract
59 // the space between characters.
60 //
61 // E.g. spacing = 1 adds one "pixel" of spacing between the
62 // characters. spacing = -1 is reasonable but feels a bit too
63 // compact to me; -0.5 is a reasonable compromise as long as
64 // you're scaling the font up.
65 //
66 // SAMPLE CODE:
67 //
68 // Here's sample code for old OpenGL; it's a lot more complicated
69 // to make work on modern APIs, and that's your problem.
70 //
71 // LICENSE
72 //
73 // This software is in the public domain. Where that dedication is not
74 // recognized, you are granted a perpetual, irrevocable license to copy,
75 // distribute, and modify this file as you see fit.
76 //
77 // VERSION HISTORY
78 //
79 // (2016-01-26) some variables below must be static to have multiple modules with
80 // (2015-09-13) 0.6 #include <math.h>; updated license
81 // (2015-02-01) 0.5 First release
82 
83 #if 0
84 void print_string(float x, float y, char *text, float r, float g, float b)
85 {
86  static char buffer[99999]; // ~500 chars
87  int num_quads;
88 
89  num_quads = stb_easy_font_print(x, y, text, NULL, buffer, sizeof(buffer));
90 
91  glColor3f(r,g,b);
92  glEnableClientState(GL_VERTEX_ARRAY);
93  glVertexPointer(2, GL_FLOAT, 16, buffer);
94  glDrawArrays(GL_QUADS, 0, num_quads*4);
95  glDisableClientState(GL_VERTEX_ARRAY);
96 }
97 #endif
98 
99 #ifndef INCLUDE_STB_EASY_FONT_H
100 #define INCLUDE_STB_EASY_FONT_H
101 
102 #include <stdlib.h>
103 #include <math.h>
104 
105 struct {
106  unsigned char advance;
107  unsigned char h_seg;
108  unsigned char v_seg;
109 } static stb_easy_font_charinfo[96] = {
110  { 5, 0, 0 }, { 3, 0, 0 }, { 5, 1, 1 }, { 7, 1, 4 },
111  { 7, 3, 7 }, { 7, 6, 12 }, { 7, 8, 19 }, { 4, 16, 21 },
112  { 4, 17, 22 }, { 4, 19, 23 }, { 23, 21, 24 }, { 23, 22, 31 },
113  { 20, 23, 34 }, { 22, 23, 36 }, { 19, 24, 36 }, { 21, 25, 36 },
114  { 6, 25, 39 }, { 6, 27, 43 }, { 6, 28, 45 }, { 6, 30, 49 },
115  { 6, 33, 53 }, { 6, 34, 57 }, { 6, 40, 58 }, { 6, 46, 59 },
116  { 6, 47, 62 }, { 6, 55, 64 }, { 19, 57, 68 }, { 20, 59, 68 },
117  { 21, 61, 69 }, { 22, 66, 69 }, { 21, 68, 69 }, { 7, 73, 69 },
118  { 9, 75, 74 }, { 6, 78, 81 }, { 6, 80, 85 }, { 6, 83, 90 },
119  { 6, 85, 91 }, { 6, 87, 95 }, { 6, 90, 96 }, { 7, 92, 97 },
120  { 6, 96,102 }, { 5, 97,106 }, { 6, 99,107 }, { 6,100,110 },
121  { 6,100,115 }, { 7,101,116 }, { 6,101,121 }, { 6,101,125 },
122  { 6,102,129 }, { 7,103,133 }, { 6,104,140 }, { 6,105,145 },
123  { 7,107,149 }, { 6,108,151 }, { 7,109,155 }, { 7,109,160 },
124  { 7,109,165 }, { 7,118,167 }, { 6,118,172 }, { 4,120,176 },
125  { 6,122,177 }, { 4,122,181 }, { 23,124,182 }, { 22,129,182 },
126  { 4,130,182 }, { 22,131,183 }, { 6,133,187 }, { 22,135,191 },
127  { 6,137,192 }, { 22,139,196 }, { 5,144,197 }, { 22,147,198 },
128  { 6,150,202 }, { 19,151,206 }, { 21,152,207 }, { 6,155,209 },
129  { 3,160,210 }, { 23,160,211 }, { 22,164,216 }, { 22,165,220 },
130  { 22,167,224 }, { 22,169,228 }, { 21,171,232 }, { 21,173,233 },
131  { 5,178,233 }, { 22,179,234 }, { 23,180,238 }, { 23,180,243 },
132  { 23,180,248 }, { 22,189,248 }, { 22,191,252 }, { 5,196,252 },
133  { 3,203,252 }, { 5,203,253 }, { 22,210,253 }, { 0,214,253 },
134 };
135 
136 static unsigned char stb_easy_font_hseg[214] = {
137  97,37,69,84,28,51,2,18,10,49,98,41,65,25,81,105,33,9,97,1,97,37,37,36,
138  81,10,98,107,3,100,3,99,58,51,4,99,58,8,73,81,10,50,98,8,73,81,4,10,50,
139  98,8,25,33,65,81,10,50,17,65,97,25,33,25,49,9,65,20,68,1,65,25,49,41,
140  11,105,13,101,76,10,50,10,50,98,11,99,10,98,11,50,99,11,50,11,99,8,57,
141  58,3,99,99,107,10,10,11,10,99,11,5,100,41,65,57,41,65,9,17,81,97,3,107,
142  9,97,1,97,33,25,9,25,41,100,41,26,82,42,98,27,83,42,98,26,51,82,8,41,
143  35,8,10,26,82,114,42,1,114,8,9,73,57,81,41,97,18,8,8,25,26,26,82,26,82,
144  26,82,41,25,33,82,26,49,73,35,90,17,81,41,65,57,41,65,25,81,90,114,20,
145  84,73,57,41,49,25,33,65,81,9,97,1,97,25,33,65,81,57,33,25,41,25,
146 };
147 
148 static unsigned char stb_easy_font_vseg[253] = {
149  4,2,8,10,15,8,15,33,8,15,8,73,82,73,57,41,82,10,82,18,66,10,21,29,1,65,
150  27,8,27,9,65,8,10,50,97,74,66,42,10,21,57,41,29,25,14,81,73,57,26,8,8,
151  26,66,3,8,8,15,19,21,90,58,26,18,66,18,105,89,28,74,17,8,73,57,26,21,
152  8,42,41,42,8,28,22,8,8,30,7,8,8,26,66,21,7,8,8,29,7,7,21,8,8,8,59,7,8,
153  8,15,29,8,8,14,7,57,43,10,82,7,7,25,42,25,15,7,25,41,15,21,105,105,29,
154  7,57,57,26,21,105,73,97,89,28,97,7,57,58,26,82,18,57,57,74,8,30,6,8,8,
155  14,3,58,90,58,11,7,74,43,74,15,2,82,2,42,75,42,10,67,57,41,10,7,2,42,
156  74,106,15,2,35,8,8,29,7,8,8,59,35,51,8,8,15,35,30,35,8,8,30,7,8,8,60,
157  36,8,45,7,7,36,8,43,8,44,21,8,8,44,35,8,8,43,23,8,8,43,35,8,8,31,21,15,
158  20,8,8,28,18,58,89,58,26,21,89,73,89,29,20,8,8,30,7,
159 };
160 
161 typedef struct
162 {
163  unsigned char c[4];
165 
166 static int stb_easy_font_draw_segs(float x, float y, unsigned char *segs, int num_segs, int vertical, stb_easy_font_color c, char *vbuf, int vbuf_size, int offset)
167 {
168  int i,j;
169  for (i=0; i < num_segs; ++i) {
170  int len = segs[i] & 7;
171  x += (float) ((segs[i] >> 3) & 1);
172  if (len && offset+64 <= vbuf_size) {
173  float y0 = y + (float) (segs[i]>>4);
174  for (j=0; j < 4; ++j) {
175  * (float *) (vbuf+offset+0) = x + (j==1 || j==2 ? (vertical ? 1 : len) : 0);
176  * (float *) (vbuf+offset+4) = y0 + ( j >= 2 ? (vertical ? len : 1) : 0);
177  * (float *) (vbuf+offset+8) = 0.f;
178  * (stb_easy_font_color *) (vbuf+offset+12) = c;
179  offset += 16;
180  }
181  }
182  }
183  return offset;
184 }
185 
186 static float stb_easy_font_spacing_val = 0;
187 static void stb_easy_font_spacing(float spacing)
188 {
189  stb_easy_font_spacing_val = spacing;
190 }
191 
192 static int stb_easy_font_print(float x, float y, char *text, unsigned char color[4], void *vertex_buffer, int vbuf_size)
193 {
194  char *vbuf = (char *) vertex_buffer;
195  float start_x = x;
196  int offset = 0;
197 
198  stb_easy_font_color c = { 255,255,255,255 }; // use structure copying to avoid needing depending on memcpy()
199  if (color) { c.c[0] = color[0]; c.c[1] = color[1]; c.c[2] = color[2]; c.c[3] = color[3]; }
200 
201  while (*text && offset < vbuf_size) {
202  if (*text == '\n') {
203  y += 12;
204  x = start_x;
205  } else {
206  unsigned char advance = stb_easy_font_charinfo[*text-32].advance;
207  float y_ch = advance & 16 ? y+1 : y;
208  int h_seg, v_seg, num_h, num_v;
209  h_seg = stb_easy_font_charinfo[*text-32 ].h_seg;
210  v_seg = stb_easy_font_charinfo[*text-32 ].v_seg;
211  num_h = stb_easy_font_charinfo[*text-32+1].h_seg - h_seg;
212  num_v = stb_easy_font_charinfo[*text-32+1].v_seg - v_seg;
213  offset = stb_easy_font_draw_segs(x, y_ch, &stb_easy_font_hseg[h_seg], num_h, 0, c, vbuf, vbuf_size, offset);
214  offset = stb_easy_font_draw_segs(x, y_ch, &stb_easy_font_vseg[v_seg], num_v, 1, c, vbuf, vbuf_size, offset);
215  x += advance & 15;
217  }
218  ++text;
219  }
220  return (unsigned) offset/64;
221 }
222 
223 static int stb_easy_font_width(char *text)
224 {
225  float len = 0;
226  while (*text) {
227  len += stb_easy_font_charinfo[*text-32].advance & 15;
229  ++text;
230  }
231  return (int) ceil(len);
232 }
233 #endif
GLboolean GLboolean g
Definition: glext.h:1104
struct @8 stb_easy_font_charinfo[96]
GLint GLint GLint GLint GLint GLint y
Definition: glext.h:114
static int stb_easy_font_print(float x, float y, char *text, unsigned char color[4], void *vertex_buffer, int vbuf_size)
static void stb_easy_font_spacing(float spacing)
unsigned char c[4]
GLuint buffer
Definition: glext.h:528
GLenum GLsizei len
Definition: glext.h:3213
static unsigned char stb_easy_font_hseg[214]
unsigned char h_seg
const GLubyte * c
Definition: glext.h:11542
static float stb_easy_font_spacing_val
GLintptr offset
Definition: glext.h:533
static int stb_easy_font_draw_segs(float x, float y, unsigned char *segs, int num_segs, int vertical, stb_easy_font_color c, char *vbuf, int vbuf_size, int offset)
GLboolean GLboolean GLboolean b
Definition: glext.h:1104
unsigned char v_seg
static unsigned char stb_easy_font_vseg[253]
static int stb_easy_font_width(char *text)
GLuint GLfloat GLfloat y0
Definition: glext.h:8966
unsigned char advance
GLdouble GLdouble GLdouble r
Definition: glext.h:247
GLint GLint GLint GLint GLint x
Definition: glext.h:114


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Author(s): Sergey Dorodnicov , Mark Horn , Reagan Lopez
autogenerated on Fri Mar 13 2020 03:16:17