vec4 v_color;

// all shaders have a main function
void main() {
  // Multiply the position by the matrix.
  gl_Position = u_matrix * a_position;

  // Pass the color to the fragment shader.
  v_color = a_color;
}
`;

var fragmentShaderSource = `#version 300 es

precision highp float;

// the varied color passed from the vertex shader
in vec4 v_color;

// we need to declare an output for the fragment shader
out vec4 outColor;

void main() {
  outColor = v_color;
}
`;


function main() {
  // Get A WebGL con