src/client/texture.c

   1 #define STB_IMAGE_IMPLEMENTATION
   2 #include <stb/stb_image.h>
   3 #include <stdbool.h>
   4 #include <dragonstd/tree.h>
   5 #include "client/client_config.h"
   6 #include "client/texture.h"
   7
   8 static Tree textures;
   9
  10 typedef struct {
  11         char *path;
  12         Texture texture;
  13 } TextureLookup;
  14
  15 static int cmp_texture(TextureLookup *texture, char *path)
  16 {
  17         return strcmp(texture->path, path);
  18 }
  19
  20 static bool lookup_texture(char *path, Texture **texture)
  21 {
  22         TreeNode **node = tree_nfd(&textures, path, &cmp_texture);
  23
  24         if (*node) {
  25                 *texture = &((TextureLookup *) &(*node)->dat)->texture;
  26                 return true;
  27         }
  28
  29         TextureLookup *lookup = malloc(sizeof *lookup);
  30         lookup->path = strdup(path);
  31         *texture = &lookup->texture;
  32
  33         tree_nmk(&textures, node, lookup);
  34         return false;
  35 }
  36
  37 static void delete_texture(TextureLookup *lookup)
  38 {
  39         free(lookup->path);
  40         texture_destroy(&lookup->texture);
  41         free(lookup);
  42 }
  43
  44 __attribute__((constructor(101))) static void textures_init()
  45 {
  46         tree_ini(&textures);
  47 }
  48
  49 __attribute__((destructor)) static void textures_deinit()
  50 {
  51         tree_clr(&textures, &delete_texture, NULL, NULL, 0);
  52 }
  53
  54 Texture *texture_load(char *path, bool mipmap)
  55 {
  56         Texture *texture;
  57         if (lookup_texture(path, &texture))
  58                 return texture;
  59
  60         unsigned char *data = stbi_load(path,
  61                 &texture->width, &texture->height, &texture->channels, 0);
  62         if (!data) {
  63                 fprintf(stderr, "[error] failed to load texture %s\n", path);
  64                 exit(EXIT_FAILURE);
  65         }
  66
  67         texture_upload(texture, data, GL_RGBA, mipmap);
  68         stbi_image_free(data);
  69
  70         return texture;
  71 }
  72
  73 Texture *texture_load_cubemap(char *path)
  74 {
  75         Texture *texture;
  76         if (lookup_texture(path, &texture))
  77                 return texture;
  78
  79         glGenTextures(1, &texture->txo);
  80         glBindTexture(GL_TEXTURE_CUBE_MAP, texture->txo);
  81
  82         const char *directions[6] = {
  83                 "right",
  84                 "left",
  85                 "top",
  86                 "bottom",
  87                 "front",
  88                 "back",
  89         };
  90
  91         for (int i = 0; i < 6; i++) {
  92                 char filename[strlen(path) + 1 + strlen(directions[i]) + 1 + 3 + 1];
  93                 sprintf(filename, "%s/%s.png", path, directions[i]);
  94
  95                 unsigned char *data = stbi_load(filename,
  96                         &texture->width, &texture->height, &texture->channels, 0);
  97                 if (!data) {
  98                         fprintf(stderr, "[error] failed to load texture %s\n", filename);
  99                         exit(EXIT_FAILURE);
 100                 }
 101
 102                 glTexImage2D(GL_TEXTURE_CUBE_MAP_POSITIVE_X + i, 0, GL_RGBA,
 103                         texture->width, texture->height, 0, GL_RGBA, GL_UNSIGNED_BYTE, data);
 104                 stbi_image_free(data);
 105         }
 106
 107         glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
 108         glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
 109         glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
 110         glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
 111         glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_WRAP_R, GL_CLAMP_TO_EDGE);
 112
 113         return texture;
 114 }
 115
 116 void texture_upload(Texture *texture, unsigned char *data, GLenum format, bool mipmap)
 117 {
 118         glGenTextures(1, &texture->txo);
 119         glBindTexture(GL_TEXTURE_2D, texture->txo);
 120
 121         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, (mipmap && client_config.mipmap)
 122                 ? GL_NEAREST_MIPMAP_NEAREST : GL_NEAREST);
 123         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
 124         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
 125         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
 126
 127         glTexImage2D(GL_TEXTURE_2D, 0, format,
 128                 texture->width, texture->height, 0, format, GL_UNSIGNED_BYTE, data);
 129         glGenerateMipmap(GL_TEXTURE_2D);
 130 }
 131
 132 void texture_destroy(Texture *texture)
 133 {
 134         glDeleteTextures(1, &texture->txo);
 135 }