src/client/font.c

   1 #include <string.h>
   2 #include <ft2build.h>
   3 #include FT_FREETYPE_H
   4 #include "client/client.h"
   5 #include "client/font.h"
   6 #include "client/hud.h"
   7
   8 #define NUM_CHARS 128
   9
  10
  11 typedef struct
  12 {
  13         Texture *texture;
  14         v2s32 bearing;
  15         u32 advance;
  16 } Character;
  17
  18 static struct
  19 {
  20         FT_Library library;
  21         FT_Face face;
  22         Character chars[NUM_CHARS];
  23         GLfloat height;
  24 } font;
  25
  26 typedef struct
  27 {
  28         GLfloat x, y;
  29 } __attribute__((packed)) VertexFontPosition;
  30
  31 typedef struct
  32 {
  33         GLfloat s, t;
  34 } __attribute__((packed)) VertexFontTextureCoordinates;
  35
  36 typedef struct
  37 {
  38         VertexFontPosition position;
  39         VertexFontTextureCoordinates textureCoordinates;
  40 } __attribute__((packed)) VertexFont;
  41
  42 static VertexAttribute vertex_attributes[2] = {
  43         // position
  44         {
  45                 .type = GL_FLOAT,
  46                 .length = 2,
  47                 .size = sizeof(VertexFontPosition),
  48         },
  49         // textureCoordinates
  50         {
  51                 .type = GL_FLOAT,
  52                 .length = 2,
  53                 .size = sizeof(VertexFontTextureCoordinates),
  54         },
  55 };
  56
  57 static VertexLayout vertex_layout = {
  58         .attributes = vertex_attributes,
  59         .count = 2,
  60         .size = sizeof(VertexFont),
  61 };
  62
  63 bool font_init()
  64 {
  65         if (FT_Init_FreeType(&font.library)) {
  66                 fprintf(stderr, "Failed to initialize Freetype\n");
  67                 return false;
  68         }
  69
  70         if (FT_New_Face(font.library, RESSOURCEPATH "fonts/Minecraftia.ttf", 0, &font.face)) {
  71                 fprintf(stderr, "Failed to load Minecraftia.ttf\n");
  72                 return false;
  73         }
  74
  75         glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
  76         FT_Set_Pixel_Sizes(font.face, 0, 16);
  77
  78         for (unsigned char c = 0; c < NUM_CHARS; c++) {
  79                 if (FT_Load_Char(font.face, c, FT_LOAD_RENDER)) {
  80                         fprintf(stderr, "Failed to load glyph %c\n", c);
  81
  82                         font.chars[c] = (Character) {
  83                                 .texture = NULL,
  84                                 .bearing = {0, 0},
  85                                 .advance = 0,
  86                         };
  87                 } else {
  88                         font.chars[c] = (Character) {
  89                                 .texture = texture_create(font.face->glyph->bitmap.buffer, font.face->glyph->bitmap.width, font.face->glyph->bitmap.rows, GL_RED),
  90                                 .bearing = {font.face->glyph->bitmap_left, font.face->glyph->bitmap_top},
  91                                 .advance = font.face->glyph->advance.x,
  92                         };
  93                 }
  94         }
  95
  96         font.height = font.chars['|'].texture->height;
  97
  98         FT_Done_Face(font.face);
  99         FT_Done_FreeType(font.library);
 100
 101         return true;
 102 }
 103
 104 void font_deinit()
 105 {
 106         for (unsigned char c = 0; c < NUM_CHARS; c++) {
 107                 if (font.chars[c].texture)
 108                         texture_delete(font.chars[c].texture);
 109         }
 110 }
 111
 112 Font *font_create(char *text)
 113 {
 114         Font *fnt = malloc(sizeof(fnt));
 115
 116         size_t len = strlen(text);
 117
 118         fnt->meshes = malloc(sizeof(Mesh *) * len);
 119         fnt->meshes_count = len;
 120
 121         GLfloat offset = 0.0f;
 122
 123         for (size_t i = 0; i < len; i++) {
 124                 unsigned char c = text[i];
 125
 126                 if (c >= NUM_CHARS || ! font.chars[c].texture)
 127                         c = '?';
 128
 129                 Character *ch = &font.chars[c];
 130
 131                 GLfloat width = ch->texture->width;
 132         GLfloat height = ch->texture->height;
 133
 134                 GLfloat x = ch->bearing.x + offset;
 135         GLfloat y = font.height - ch->bearing.y;
 136
 137         VertexFont vertices[6] = {
 138             {{x,         y         }, {0.0f, 0.0f}},
 139             {{x,         y + height}, {0.0f, 1.0f}},
 140             {{x + width, y + height}, {1.0f, 1.0f}},
 141             {{x,         y         }, {0.0f, 0.0f}},
 142             {{x + width, y + height}, {1.0f, 1.0f}},
 143             {{x + width, y         }, {1.0f, 0.0f}},
 144         };
 145
 146                 Mesh *mesh = fnt->meshes[i] = mesh_create();
 147                 mesh->textures = &ch->texture->id;
 148                 mesh->textures_count = 1;
 149                 mesh->free_textures = false;
 150                 mesh->vertices = vertices;
 151                 mesh->vertices_count = 6;
 152                 mesh->free_vertices = false;
 153                 mesh->layout = &vertex_layout;
 154                 mesh_configure(mesh);
 155
 156                 offset += ch->advance >> 6;
 157         }
 158
 159         return fnt;
 160 }
 161
 162 void font_delete(Font *fnt)
 163 {
 164         for (size_t i = 0; i < fnt->meshes_count; i++)
 165                 mesh_delete(fnt->meshes[i]);
 166
 167         free(fnt);
 168 }
 169
 170 void font_render(Font *fnt)
 171 {
 172         for (size_t i = 0; i < fnt->meshes_count; i++)
 173                 mesh_render(fnt->meshes[i]);
 174 }