Fix shaders

src/shader.cpp

@@ -88,7 +88,6 @@ shader_result Shader::init()
   const GLchar* const vertex_source_array[] = {
     vertex_source.c_str()
   };
-  std::cout << vertex_source;
 
   // Set vertex source
   glShaderSource(vertex_shader_id, 1, vertex_source_array, NULL);
@@ -114,7 +113,6 @@ shader_result Shader::init()
   const GLchar* const fragment_source_array[] = {
     fragment_source.c_str()
   };
-  std::cout << fragment_source;
 
   // Set fragment source
   glShaderSource(fragment_shader_id, 1, fragment_source_array, NULL);

src/simple.frag

@@ -1,5 +1,7 @@
 #version 300 es
 
+precision mediump float;
+
 out vec4 fragment_color;
 
 void main()

src/simple.vert

@@ -7,4 +7,4 @@ layout (location = 0) in vec2 vertex_pos_2d;
 void main()
 {
     gl_Position = vec4(vertex_pos_2d.x, vertex_pos_2d.y, 0.0, 1.0);
-} // foo bar
+}