#extension GL_OES_element_index : enable
    // This shader is basic
    attribute vec3 aVertexPosition;
    attribute vec4 aVertexColour;
    attribute vec3 aVertexNormal;

    uniform mat4 uMVMatrix;
    uniform mat4 uMVINVMatrix;
    uniform mat4 uPMatrix;

    varying lowp vec4 vColor;

    varying lowp vec4 eyePos;

    uniform float pixelZoom;

    void main(void) {
    vec4 screenZ = uMVINVMatrix*vec4(0.0,0.0,1.0,1.0);

    //
    vec3 norm = normalize(aVertexNormal);
    vec3 lineY = vec3(norm.y*screenZ.z-norm.z*screenZ.y,
                      norm.z*screenZ.x-norm.x*screenZ.z,
                      norm.x*screenZ.y-norm.y*screenZ.x);
    lineY = normalize(lineY);
    float lineSize = pixelZoom*sqrt(aVertexNormal.x*aVertexNormal.x+aVertexNormal.y*aVertexNormal.y+aVertexNormal.z*aVertexNormal.z);

    gl_Position =  uPMatrix * uMVMatrix * vec4(aVertexPosition+lineSize*lineY,1.0);
    vColor = aVertexColour;

    eyePos = uMVMatrix * vec4(aVertexPosition,1.0);
    //
    
      //vec4 theVert = vec4(aVertexPosition+aVertexNormal,1.0);

      //gl_Position = uPMatrix * uMVMatrix * theVert;
      //vColor = aVertexColour;

      //eyePos = uMVMatrix * theVert;

    }