From 29c71cff88eb3798a86bdae6491c1d4f4636df77 Mon Sep 17 00:00:00 2001
From: Meoweg <meoweg@users.noreply.github.com>
Date: Mon, 9 Nov 2015 15:06:34 +0000
Subject: [PATCH] Add shader program structure

---
 data/shaders/textured/attrib.txt          |  3 ++
 data/shaders/{ => textured}/fragment.glsl |  0
 data/shaders/{ => textured}/vertex.glsl   |  0
 src/main.cpp                              | 24 +---------------
 src/program.cpp                           | 35 +++++++++++++++--------
 src/program.hpp                           |  6 +---
 6 files changed, 28 insertions(+), 40 deletions(-)
 create mode 100644 data/shaders/textured/attrib.txt
 rename data/shaders/{ => textured}/fragment.glsl (100%)
 rename data/shaders/{ => textured}/vertex.glsl (100%)

diff --git a/data/shaders/textured/attrib.txt b/data/shaders/textured/attrib.txt
new file mode 100644
index 0000000..18c7975
--- /dev/null
+++ b/data/shaders/textured/attrib.txt
@@ -0,0 +1,3 @@
+position
+tex_coord
+normal
diff --git a/data/shaders/fragment.glsl b/data/shaders/textured/fragment.glsl
similarity index 100%
rename from data/shaders/fragment.glsl
rename to data/shaders/textured/fragment.glsl
diff --git a/data/shaders/vertex.glsl b/data/shaders/textured/vertex.glsl
similarity index 100%
rename from data/shaders/vertex.glsl
rename to data/shaders/textured/vertex.glsl
diff --git a/src/main.cpp b/src/main.cpp
index 66d84fb..2d07a2e 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -11,8 +11,6 @@
 #include <emscripten/emscripten.h>
 #include <emscripten/html5.h>
 
-static Program build_program();
-
 static void iterate();
 
 static GLFWCALL void on_key(int key, int action);
@@ -56,7 +54,7 @@ int main()
   glfwSetKeyCallback(on_key);
   emscripten_set_mousemove_callback(nullptr, nullptr, false, on_em_mousemove);
 
-  Program program = build_program();
+  Program program("textured");
   program.use();
 
   mvp_uniform = program.get_uniform_location("mvp");
@@ -94,26 +92,6 @@ int main()
   emscripten_set_main_loop(iterate, 0, 1);
 }
 
-Program build_program()
-{
-  const Shader vertex_shader = Shader(GL_VERTEX_SHADER, "/data/shaders/vertex.glsl");
-  const Shader fragment_shader = Shader(GL_FRAGMENT_SHADER, "/data/shaders/fragment.glsl");
-
-  Program program;
-  program.attach_shader(vertex_shader);
-  program.attach_shader(fragment_shader);
-  program.bind_attrib_location(0, "position");
-  program.bind_attrib_location(1, "tex_coord");
-  program.bind_attrib_location(2, "normal");
-  program.link();
-
-  glEnableVertexAttribArray(0);
-  glEnableVertexAttribArray(1);
-  glEnableVertexAttribArray(2);
-
-  return program;
-}
-
 void iterate()
 {
   if (keys['W'])
diff --git a/src/program.cpp b/src/program.cpp
index 7b38581..dd254ca 100644
--- a/src/program.cpp
+++ b/src/program.cpp
@@ -1,23 +1,34 @@
 #include "program.hpp"
 
-Program::Program()
+#include "shader.hpp"
+
+#include <string>
+#include <fstream>
+
+Program::Program(const char *const name)
 {
+  const std::string path = std::string("/data/shaders/") + name + '/';
+
+  const Shader vertex_shader = Shader(GL_VERTEX_SHADER, (path + "vertex.glsl").c_str());
+  const Shader fragment_shader = Shader(GL_FRAGMENT_SHADER, (path + "fragment.glsl").c_str());
+
   _id = glCreateProgram();
-}
 
-void Program::attach_shader(const Shader &shader)
-{
-  glAttachShader(_id, shader.id());
-}
+  glAttachShader(_id, vertex_shader.id());
+  glAttachShader(_id, fragment_shader.id());
 
-void Program::bind_attrib_location(const GLuint index, const GLchar *const name)
-{
-  glBindAttribLocation(_id, index, name);
-}
+  std::ifstream file(path + "attrib.txt", std::ios::in);
+
+  std::string line;
+  int index = 0;
+
+  while (std::getline(file, line))
+    glBindAttribLocation(_id, index++, line.c_str());
 
-void Program::link()
-{
   glLinkProgram(_id);
+
+  for (int i = 0; i < index; ++i)
+    glEnableVertexAttribArray(i);
 }
 
 void Program::use() const
diff --git a/src/program.hpp b/src/program.hpp
index bf6cdfe..0d7fd43 100644
--- a/src/program.hpp
+++ b/src/program.hpp
@@ -2,15 +2,11 @@
 #define _PROGRAM_HPP_
 
 #include "gl.hpp"
-#include "shader.hpp"
 
 class Program
 {
 public:
-  Program();
-  void attach_shader(const Shader &shader);
-  void bind_attrib_location(GLuint index, const GLchar *name);
-  void link();
+  Program(const char *name);
   void use() const;
   GLuint get_uniform_location(const GLchar *name) const;