//Set x,y position coordinates to be used to extract data from one plane of our data cube
//remember, z we handle as a 1 layer of our cube which is composed of a stack of x-y planes.
const oneLayerVertices = new Float32Array(size * size * 2);
count = 0;
for (var j = 0; j < (size); j++) {
    for (var i = 0; i < (size); i++) {
        oneLayerVertices[count] = i;
        count++;

        oneLayerVertices[count] = j;
        count++;

        //oneLayerVertices[count] = 0;
        //count++;

        //oneLayerVertices[count] = 0;
        //count++;

    }
}

const bufferInfo = twgl.createBufferInfoFromArrays(gl, {
   position: {
      numComponents: 2,
      data: oneLayerVertices,
   },
});

gl.useProgram(computeProgramInfo.program);
   twgl.setBuffersAndAttributes(gl, computeProgramInfo, bufferInfo);

   gl.viewport(0, 0, size, size); //remember size = 4

   outFramebuffers.forEach((fb, ndx) => {
      gl.bindFramebuffer(gl.FRAMEBUFFER, fb);
      gl.drawBuffers([
         gl.COLOR_ATTACHMENT0,
         gl.COLOR_ATTACHMENT1,
         gl.COLOR_ATTACHMENT2,
         gl.COLOR_ATTACHMENT3
      ]);

      const baseLayerTexCoord = (ndx * numLayersPerFramebuffer);
      console.log("My baseLayerTexCoord is "+baseLayerTexCoord);
      twgl.setUniforms(computeProgramInfo, {
         baseLayerTexCoord,
         u_kernel: [
             0, 0, 0,
             0, 0, 0,
             0, 0, 0,

             0, 0, 1,
             0, 0, 0,
             0, 0, 0,

             0, 0, 0,
             0, 0, 0,
             0, 0, 0,
         ],
         u_position: inPos,
         u_velocity: inVel,
         loopCounter: loopCounter,

         numLayersPerFramebuffer: numLayersPerFramebuffer
      });
      gl.drawArrays(gl.POINTS, 0, (16));
   });

const compute_vs = `#version 300 es
  precision highp float;
  in vec4 position;
  void main() {
    gl_Position = position;
  }
`;

const compute_fs = `#version 300 es
precision highp float;

out vec4 ourOutput[4];

void main() {
   ourOutput[0] = vec4(0,1,0,1);
   ourOutput[1] = vec4(0,1,0,1);
   ourOutput[2] = vec4(0,1,0,1);
   ourOutput[3] = vec4(0,1,0,1);
}
`;