OpenGL Shader ERROR: 0:1: '' : syntax error #version - opengl

Question

I'm using xcode to make a game with OpenGL. I have used GLUT to initialise a window. I have shaders that I wish to implement but when I try to compile them, I get two compile errors in the info log. My shaders look like this:
//FirstShader.vsh
#version 150 core
in vec3 position;
void main()
{
gl_Position = vec4(position, 1.0);
}
//FirstShader.fsh
#version 150 core
out vec4 fragData;
void main()
{
fragData = vec4(0.0, 0.0, 1.0, 1.0);
}
I'm reading the file and compiling it with this code:
GLuint createShaderFromFile(const GLchar *path, GLenum shaderType){
GLuint shaderID = glCreateShader(shaderType);
std::ifstream fin;
fin.open(path);
if(!fin.is_open()){
fin.close();
std::cout << "Shader Not Found" << std:: endl;
return 0;
}
std::string source((std::istreambuf_iterator<GLchar>(fin)),std::istreambuf_iterator<GLchar> ());
fin.close();
const GLchar* shaderSource = source.c_str();
glShaderSource(shaderID, 1, &shaderSource, NULL);
glCompileShader(shaderID);
GLint compileStatus;
glGetShaderiv(shaderID, GL_COMPILE_STATUS, &compileStatus);
if (compileStatus != GL_TRUE) {
std::cout << "Shader failed to compile" << std::endl;
GLint infoLoglength;
glGetShaderiv(shaderID, GL_INFO_LOG_LENGTH, &infoLoglength);
GLchar* infoLog = new GLchar[infoLoglength + 1];
glGetShaderInfoLog(shaderID, infoLoglength, NULL, infoLog);
std::cout << infoLog << std::endl;
delete infoLog;
return 0;
}
return shaderID;
}
Im getting these errors:
ERROR: 0:1: '' : version '150' is not supported
ERROR: 0:1: '' : syntax error #version
My OpenGL version is 2.1 and my glsl version is 1.20. Does anybody know how I can fix this?

Answer 1

You can tell OSX to use a newer version of OpenGL by setting it in your pixel format when you create the context. Here is an example of how to set it up.
Or if you're using glut, I think you want glutInitContextVersion(x, y); where x and y are the major and minor version numbers. GLSL 1.5 is supported in OpenGL 3.2, I think. (And you might also want glutInitContextProfile(GLUT_CORE_PROFILE);, I think.)

Answer 2

I re-wrote your shaders in a way that they will actually work in GLSL 1.20.
in must be replaced with attribute in a GLSL 1.20 vertex shader
out for fragment shader output is invalid, use gl_FragColor or gl_FragData [n] instead
Declaring a vertex attribute as vec3 and then doing something like vec4 (vtx, 1.0) is completely redundant
If you declare the attribute as vec4 and give it data using fewer than 4 components GLSL will automatically fill-in the attribute's missing components this way: vec4 (0.0, 0.0, 0.0, 1.0).
Fragment Shader:
#version 120
attribute vec4 position;
void main()
{
gl_Position = position;
}
Vertex Shader:
#version 120
void main()
{
gl_FragColor = vec4(0.0, 0.0, 1.0, 1.0);
}
Of course this does not really solve your problem, because if you have a version of OS X 10.7 or newer, it supports OpenGL 3.2 and therefore GLSL 1.50 core. You need to request a core profile context for this to work, however - otherwise you will get OpenGL 2.1 and GLSL 1.20.