r2.js

var shaderProgram  = null;
var vertexBuffer = null;
var indexBufferTriangles = null;
var indexBufferEdges = null;
var currentAngle = 0;
var incAngle = 0.3;
var sunLightDirection = SglVec4.normalize([1.5, 2.5, 0.5, 1.0]);

//// Initialize the buffers
////
function createObjectBuffers(gl, obj, n = true) {
  if(n)ComputeNormals(obj)
  else console.log("Not computing normals")
  obj.vertexBuffer = gl.createBuffer();
  gl.bindBuffer(gl.ARRAY_BUFFER, obj.vertexBuffer);
  gl.bufferData(gl.ARRAY_BUFFER, obj.vertices, gl.STATIC_DRAW);
  gl.bindBuffer(gl.ARRAY_BUFFER, null);


  if (obj.textureCoordinates||0){
    obj.texturePositionBuffer = gl.createBuffer();
    gl.bindBuffer(gl.ARRAY_BUFFER, obj.texturePositionBuffer);
    gl.bufferData(gl.ARRAY_BUFFER, obj.textureCoordinates, gl.STATIC_DRAW);
    gl.bindBuffer(gl.ARRAY_BUFFER, null);
  }
  obj.normalBuffer = gl.createBuffer();
  gl.bindBuffer(gl.ARRAY_BUFFER, obj.normalBuffer);
  gl.bufferData(gl.ARRAY_BUFFER, obj.vertex_normal, gl.STATIC_DRAW);
  gl.bindBuffer(gl.ARRAY_BUFFER, null);

  obj.indexBufferTriangles = gl.createBuffer();
  gl.bindBuffer(gl.ELEMENT_ARRAY_BUFFER, obj.indexBufferTriangles);
  gl.bufferData(gl.ELEMENT_ARRAY_BUFFER, obj.triangleIndices, gl.STATIC_DRAW);
  gl.bindBuffer(gl.ELEMENT_ARRAY_BUFFER, null);

  // create edges
  var edges = new Uint16Array(obj.numTriangles * 3 * 2);
  for (var i = 0; i < obj.numTriangles; ++i) {
    edges[i * 6 + 0] = obj.triangleIndices[i * 3 + 0];
    edges[i * 6 + 1] = obj.triangleIndices[i * 3 + 1];
    edges[i * 6 + 2] = obj.triangleIndices[i * 3 + 0];
    edges[i * 6 + 3] = obj.triangleIndices[i * 3 + 2];
    edges[i * 6 + 4] = obj.triangleIndices[i * 3 + 1];
    edges[i * 6 + 5] = obj.triangleIndices[i * 3 + 2];
  }

  obj.indexBufferEdges = gl.createBuffer();
  gl.bindBuffer(gl.ELEMENT_ARRAY_BUFFER, obj.indexBufferEdges);
  gl.bufferData(gl.ELEMENT_ARRAY_BUFFER, edges, gl.STATIC_DRAW);
  gl.bindBuffer(gl.ELEMENT_ARRAY_BUFFER, null);
};


///// Initialize the shaders
/////
function initShaders(gl) {
  shaderProgram = lambertianSingleColorShader(gl)
  // create the vertex shader
  var vertexShader = shaderProgram.vertexShader

  // create the fragment shader
  var fragmentShader = shaderProgram.fragmentShader

  // Create the shader program
}

function initialize(gl, primitive, n=true) {
  createObjectBuffers(gl, primitive, n);
  initShaders(gl);
  gl.useProgram(shaderProgram)
}

///// Draw the given primitives with solid wireframe
/////
//
function getViewMatrix(gl){

  var canvas = document.getElementById('canvas');
  var width = canvas.clientWidth;
  var height = canvas.clientHeight;

  gl.viewport(0, 0, width, height);

  projMat = SglMat4.perspective(0.8, width/height, 0.1, 1000.0);
  viewMat = SglMat4.lookAt([0,2,6], [0,0,0], [0,1,0]);
}
function drawObject(gl, obj, shader, fillColor, stack) {
  // Draw the primitive
  gl.bindBuffer(gl.ARRAY_BUFFER, obj.vertexBuffer);
  gl.enableVertexAttribArray(shader.aPositionIndex);
  gl.vertexAttribPointer(shader.aPositionIndex, 3, gl.FLOAT, false, 0, 0);

  if (shader.aColorIndex && obj.colorBuffer) {
    gl.bindBuffer(gl.ARRAY_BUFFER, obj.colorBuffer);
    gl.enableVertexAttribArray(shader.aColorIndex);
    gl.vertexAttribPointer(shader.aColorIndex, 4, gl.FLOAT, false, 0, 0);
  }

  if (obj.textureCoordinates||0) {
    gl.bindBuffer(gl.ARRAY_BUFFER, obj.texturePositionBuffer);
    gl.enableVertexAttribArray(shader.aCheckerTexPositionIndex);
    gl.vertexAttribPointer(shader.aCheckerTextPositionIndex, 2, gl.FLOAT, false, 0, 0);
  }
  gl.bindBuffer(gl.ARRAY_BUFFER, obj.normalBuffer);
  gl.enableVertexAttribArray(shader.aNormalIndex);
  gl.vertexAttribPointer(shader.aNormalIndex, 3, gl.FLOAT, false, 0, 0);

  gl.uniform4fv(shader.uColorLocation, fillColor);
  gl.uniform4fv(shader.uLightColorLocation, [1, 1, 1, 1]);
  gl.uniform4fv(shader.uLightDirectionLocation, sunLightDirection);

  gl.enable(gl.POLYGON_OFFSET_FILL);

  gl.polygonOffset(1.0, 1.0);

  gl.bindBuffer(gl.ELEMENT_ARRAY_BUFFER, obj.indexBufferTriangles);
  gl.drawElements(gl.TRIANGLES, obj.triangleIndices.length, gl.UNSIGNED_SHORT, 0);
  gl.bindBuffer(gl.ARRAY_BUFFER, null);

};