nothings-stb/stb_easy_font.h

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