src/client/shader.c

   1 #include <stdio.h>
   2 #include <stdlib.h>
   3 #include <string.h>
   4 #include <unistd.h>
   5 #include "client/client_config.h"
   6 #include "client/opengl.h"
   7 #include "client/shader.h"
   8
   9 static GLuint compile_shader(GLenum type, const char *path, const char *name, GLuint program, const char *def)
  10 {
  11         char full_path[strlen(path) + 1 + strlen(name) + 1 + 4 + 1];
  12         sprintf(full_path, "%s/%s.glsl", path, name);
  13
  14         FILE *file = fopen(full_path, "r");
  15         if (!file) {
  16                 perror("fopen");
  17                 return 0;
  18         }
  19
  20         if (fseek(file, 0, SEEK_END) == -1) {
  21                 perror("fseek");
  22                 fclose(file);
  23                 return 0;
  24         }
  25
  26         long size = ftell(file);
  27
  28         if (size == 1) {
  29                 perror("ftell");
  30                 fclose(file);
  31                 return 0;
  32         }
  33
  34         if (fseek(file, 0, SEEK_SET) == -1) {
  35                 perror("fseek");
  36                 fclose(file);
  37                 return 0;
  38         }
  39
  40         char code[size];
  41
  42         if (fread(code, 1, size, file) != (size_t) size) {
  43                 perror("fread");
  44                 fclose(file);
  45                 return 0;
  46         }
  47
  48         fclose(file);
  49
  50         GLuint id = glCreateShader(type); GL_DEBUG
  51
  52         const char *version = client_config.texture_batching
  53                 ? "#version 400 core\n"
  54                 : "#version 330 core\n";
  55
  56         const char *code_list[3] = {
  57                 version,
  58                 def,
  59                 code,
  60         };
  61
  62         int size_list[3] = {
  63                 18,
  64                 strlen(def),
  65                 size,
  66         };
  67
  68         glShaderSource(id, 3, code_list, size_list); GL_DEBUG
  69
  70         glCompileShader(id); GL_DEBUG
  71
  72         GLint success;
  73         glGetShaderiv(id, GL_COMPILE_STATUS, &success); GL_DEBUG
  74         if (!success) {
  75                 char errbuf[BUFSIZ];
  76                 glGetShaderInfoLog(id, BUFSIZ, NULL, errbuf); GL_DEBUG
  77                 fprintf(stderr, "[error] failed to compile shader %s: %s", full_path, errbuf);
  78                 glDeleteShader(id); GL_DEBUG
  79                 return 0;
  80         }
  81
  82         glAttachShader(program, id); GL_DEBUG
  83
  84         return id;
  85 }
  86
  87 GLuint shader_program_create(const char *path, const char *def)
  88 {
  89         GLuint id = glCreateProgram(); GL_DEBUG
  90
  91         if (!def)
  92                 def = "";
  93
  94         GLuint vert, frag;
  95
  96         if (!(vert = compile_shader(GL_VERTEX_SHADER, path, "vertex", id, def))) {
  97                 glDeleteProgram(id); GL_DEBUG
  98                 abort();
  99         }
 100
 101         if (!(frag = compile_shader(GL_FRAGMENT_SHADER, path, "fragment", id, def))) {
 102                 glDeleteShader(vert); GL_DEBUG
 103                 glDeleteProgram(id); GL_DEBUG
 104                 abort();
 105         }
 106
 107         glLinkProgram(id); GL_DEBUG
 108         glDeleteShader(vert); GL_DEBUG
 109         glDeleteShader(frag); GL_DEBUG
 110
 111         GLint success;
 112         glGetProgramiv(id, GL_LINK_STATUS, &success); GL_DEBUG
 113         if (!success) {
 114                 char errbuf[BUFSIZ];
 115                 glGetProgramInfoLog(id, BUFSIZ, NULL, errbuf); GL_DEBUG
 116                 fprintf(stderr, "[error] failed to link shader program %s: %s\n", path, errbuf);
 117                 glDeleteProgram(id); GL_DEBUG
 118                 return false;
 119         }
 120
 121         return id;
 122 }