A bare minimum set of shaders necessary to get something rendering in OpenGL 3.2+

default3.2+shader

/** ======= VERTEX SHADER ==============*/

#version 150

in vec4 position;
in vec2 texcoord;

uniform mat4 modelViewProjectionMatrix;


void main(){
    
	//get our current vertex position so we can modify it
	vec4 pos = modelViewProjectionMatrix * position;
		
	//finally set the pos to be that actual position rendered
	gl_Position = pos;
}

/** ======= FRAGMENT SHADER ==============*/
#version 150


uniform vec4 globalColor;

out vec4 fragColor;

void main(){
	//this is the fragment shader
	//this is where the pixel level drawing happens
	//gl_FragCoord gives us the x and y of the current pixel its drawing
	
	//we grab the x and y and store them in an int
	float xVal = gl_FragCoord.x;
	float yVal = gl_FragCoord.y;
    
    fragColor = globalColor;

}