src/dragonblocks/shader_program.cpp

   1 #include <fstream>
   2 #include <sstream>
   3 #include <stdexcept>
   4 #include <vector>
   5 #include <glm/gtc/type_ptr.hpp>
   6 #include "shader_program.hpp"
   7
   8 using namespace std;
   9 using namespace glm;
  10 using namespace dragonblocks;
  11
  12 map<string, GLenum> ShaderProgram::shadertypes = {
  13         {"vertex", GL_VERTEX_SHADER},
  14         {"fragment", GL_FRAGMENT_SHADER},
  15 };
  16
  17 ShaderProgram::ShaderProgram(const string &global_path)
  18 {
  19         int success;
  20         char buffer[1024] = {};
  21         vector<GLuint> shaders;
  22
  23         id = glCreateProgram();
  24
  25         for (auto it = ShaderProgram::shadertypes.begin(); it != ShaderProgram::shadertypes.end(); it++) {
  26                 const char *c_code;
  27                 GLuint shader;
  28                 string path, code;
  29                 ifstream file;
  30                 stringstream stream;
  31
  32                 path = global_path + "/" + it->first + ".glsl";
  33                 file.exceptions(ifstream::failbit | ifstream::badbit);
  34                 file.open(path);
  35                 stream << file.rdbuf();
  36                 code = stream.str();
  37                 c_code = code.c_str();
  38
  39                 shader = glCreateShader(it->second);
  40                 shaders.push_back(shader);
  41                 glShaderSource(shader, 1, &c_code, NULL);
  42                 glCompileShader(shader);
  43                 glGetShaderiv(shader, GL_COMPILE_STATUS, &success);
  44                 if (! success) {
  45                         glGetShaderInfoLog(shader, 1024, NULL, buffer);
  46                         throw runtime_error("Failed to compile " + it->first + " shader: " + buffer);
  47                 }
  48                 glAttachShader(id, shader);
  49         }
  50
  51         glLinkProgram(id);
  52         glGetProgramiv(id, GL_LINK_STATUS, &success);
  53         if (! success) {
  54                 glGetProgramInfoLog(id, 1024, NULL, buffer);
  55                 throw runtime_error(string("Failed to link shader program: ") + buffer);
  56         }
  57
  58         for (auto it = shaders.begin(); it != shaders.end(); it++) {
  59                 glDeleteShader(*it);
  60         }
  61 }
  62
  63 void ShaderProgram::use() const
  64 {
  65         glUseProgram(id);
  66 }
  67
  68 void ShaderProgram::set(const string &name, bool value)
  69 {
  70         use();
  71         glUniform1i(glGetUniformLocation(id, name.c_str()), (int) value);
  72 }
  73
  74 void ShaderProgram::set(const string &name, int value)
  75 {
  76         use();
  77         glUniform1i(glGetUniformLocation(id, name.c_str()), value);
  78 }
  79
  80 void ShaderProgram::set(const string &name, float value)
  81 {
  82         use();
  83         glUniform1f(glGetUniformLocation(id, name.c_str()), value);
  84 }
  85
  86 void ShaderProgram::set(const string &name, mat4 value)
  87 {
  88         use();
  89         glUniformMatrix4fv(glGetUniformLocation(id, name.c_str()), 1, GL_FALSE, value_ptr(value));
  90 }
  91
  92 void ShaderProgram::set(const string &name, vec3 value)
  93 {
  94         use();
  95         glUniform3f(glGetUniformLocation(id, name.c_str()), value.x, value.y, value.z);
  96 }
  97
  98 ShaderProgram::~ShaderProgram()
  99 {
 100         glDeleteProgram(id);
 101 }