/*
   Custom fragment shader: a user-defined world-space clip plane
  
   More info on custom shaders:
  
   http://scenejs.wikispaces.com/shader
  
   */
  
  SceneJS.createScene({
  
    type: "scene",
    id: "theScene",
    canvasId: "theCanvas",
    loggingElementId: "theLoggingDiv",
  
    nodes: [
  
      /*----------------------------------------------------------------------
       * View and projection transforms
       *--------------------------------------------------------------------*/
      {
        type: "lookAt",
        eye : { x: 0.0, y: 10.0, z: 15 },
        look : { y:1.0 },
        up : { y: 1.0 },
  
        nodes: [
          {
            type: "camera",
            optics: {
              type: "perspective",
              fovy : 25.0,
              aspect : 1.47,
              near : 0.10,
              far : 300.0
            },
  
            nodes: [
  
              /*----------------------------------------------------------------------
               * Lighting
               *--------------------------------------------------------------------*/
  
              {
                type: "light",
                mode:          "dir",
                color:         { r: 1.0, g: 1.0, b: 1.0 },
                diffuse:        true,
                specular:        true,
                dir:          { x: 1.0, y: -0.5, z: -1.0 }
              },
  
              {
                type: "light",
                mode:          "dir",
                color:         { r: 1.0, g: 1.0, b: 0.8 },
                diffuse:        true,
                specular:        false,
                dir:          { x: 0.0, y: -0.5, z: -1.0 }
              },
  
              /*----------------------------------------------------------------------
               * Modelling transforms
               *--------------------------------------------------------------------*/
  
              {
                type: "rotate",
                id: "pitch",
                angle: 0.0,
                x : 1.0,
  
                nodes: [
                  {
                    type: "rotate",
                    id: "yaw",
                    angle: 0.0,
                    y : 1.0,
  
                    nodes: [
  
                      /*----------------------------------------------------------------------
                       * Material properties
                       *--------------------------------------------------------------------*/
  
                      {
                        type: "material",
                        emit: 0,
                        baseColor:   { r: 0.3, g: 0.3, b: 1.0 },
                        specularColor: { r: 0.9, g: 0.9, b: 0.9 },
                        specular:    0.7,
                        shine:     10.0,
  
                        nodes: [
  
                          /*----------------------------------------------------------------------
                           * Custom shader which creates a user-defined world-space clipping plane
                           *--------------------------------------------------------------------*/
  
                          {
                            type: "shader",
                            id: "myShader",
  
                            shaders: [
  
                              /* Fragment shader
                               */
                              {
                                stage: "fragment",
  
                                code: [
  
                                  "uniform bool clipEnabled;",
                                  "uniform bool clipInside;",
                                  "uniform vec4 clipNormalAndDist;",
  
                                  "vec4 myWorldPosFunc(vec4 pos){",
                                  "  if (clipEnabled) {",
                                  "    float dist = dot(pos.xyz, clipNormalAndDist.xyz) - clipNormalAndDist.w;",
                                  "    if (clipInside) {",
                                  "      if (dist < 0.0) { discard; }",
                                  "    } else {",
                                  "      if (dist > 0.0) { discard; }",
                                  "    }",
                                  "  }",
                                  "  return pos;",
                                  "}"],
  
                                /* Bind our custom function to a SceneJS fragment shader hook
                                 */
                                hooks: {
                                  worldPos: "myWorldPosFunc"
                                }
                              }
                            ],
  
                            /* Default shader params - can also be overridden with a
                             * shaderParams node - see other examples
                             */
                            params: {
                              clipEnabled: true,
                              clipInside: false,
                              clipNormalAndDist: [0.8, 0.0, 0.1, 0.0]
                            },
  
                            nodes: [
  
                              /*----------------------------------------------------------------------
                               * Teapot which will be clipped
                               *--------------------------------------------------------------------*/
                              {
                                type : "teapot"
                              }
                            ]
                          }
                        ]
                      }
                    ]
                  }
                ]
              }
            ]
          }
        ]
      }
    ]
  });
  
  /*----------------------------------------------------------------------
   * Scene rendering loop and mouse handler stuff follows
   *---------------------------------------------------------------------*/
  
  var scene = SceneJS.scene("theScene");
  var pitchRotate = scene.findNode("pitch");
  var yawRotate = scene.findNode("yaw");
  
  var yaw = 0;
  var pitch = 0;
  var lastX;
  var lastY;
  var dragging = false;
  
  var canvas = document.getElementById("theCanvas");
  
  function mouseDown(event) {
    lastX = event.clientX;
    lastY = event.clientY;
    dragging = true;
  }
  
  function touchStart(event) {
    lastX = event.targetTouches[0].clientX;
    lastY = event.targetTouches[0].clientY;
    dragging = true;
  }
  
  function mouseUp() {
    dragging = false;
  }
  
  function touchEnd() {
    dragging = false;
  }
  
  function mouseMove(event) {
    var posX = event.clientX;
    var posY = event.clientY;
    actionMove(posX,posY);
  }
  
  function touchMove(event) {
    var posX = event.targetTouches[0].clientX;
    var posY = event.targetTouches[0].clientY;
    actionMove(posX,posY);
  }
  
  /* On a mouse/touch drag, we'll re-render the scene, passing in
   * incremented angles in each time.
   */
  function actionMove(posX, posY) {
    if (dragging) {
      yaw += (posX - lastX) * 0.5;
      pitch += (posY - lastY) * 0.5;
  
      yawRotate.set("angle", yaw);
      pitchRotate.set("angle", pitch);
  
      lastX = posX;
      lastY = posY;
    }
  }
  
  canvas.addEventListener('mousedown', mouseDown, true);
  canvas.addEventListener('mousemove', mouseMove, true);
  canvas.addEventListener('mouseup', mouseUp, true);
  canvas.addEventListener('touchstart', touchStart, true);
  canvas.addEventListener('touchmove', touchMove, true);
  canvas.addEventListener('touchend', touchEnd, true);
  
  scene.start();