Restore the JS Spinning Cube demo

examples/js/cube.js

Index: examples/js/cube.js
diff --git a/examples/js/cube.js b/examples/js/cube.js
new file mode 100644
index 0000000000000000000000000000000000000000..0f772ecf3f9f3881aebce73badb2152e5a9f91a5
--- /dev/null
+++ b/examples/js/cube.js
@@ -0,0 +1,416 @@
+#!mojo:js_content_handler
+
+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+define("main", [
+  "console",
+  "mojo/services/public/js/application",
+  "mojo/services/public/interfaces/gpu/command_buffer.mojom",
+  "mojo/services/public/interfaces/geometry/geometry.mojom",
+  "mojo/services/public/interfaces/gpu/gpu.mojom",
+  "mojo/services/public/interfaces/native_viewport/native_viewport.mojom",
+  "mojo/services/public/interfaces/gpu/viewport_parameter_listener.mojom",
+  "mojo/public/js/core",
+  "services/js/modules/gl",
+  "services/js/modules/clock",
+  "timer",
+], function(console,
+            appModule,
+            cbModule,
+            geoModule,
+            gpuModule,
+            nvModule,
+            vplModule,
+            coreModule,
+            glModule,
+            clockModule,
+            timerModule) {
+
+  const VERTEX_SHADER_SOURCE = [
+    'uniform mat4 u_mvpMatrix;',
+    'attribute vec4 a_position;',
+    'void main()',
+    '{',
+    '   gl_Position = u_mvpMatrix * a_position;',
+    '}'
+  ].join('\n');
+
+  const FRAGMENT_SHADER_SOURCE = [
+    'precision mediump float;',
+    'void main()',
+    '{',
+    '  gl_FragColor = vec4( 0.0, 1.0, 0.0, 1.0 );',
+    '}'
+  ].join('\n');
+
+  class ESMatrix {
+    constructor() {
+      this.m = new Float32Array(16);
+    }
+
+    getIndex(x, y) {
+      return x * 4 + y;
+    }
+
+    set(x, y, v) {
+      this.m[this.getIndex(x, y)] = v;
+    }
+
+    get(x, y) {
+      return this.m[this.getIndex(x, y)];
+    }
+
+    loadZero() {
+      for (var i = 0; i < this.m.length; i++) {
+        this.m[i] = 0;
+      }
+    }
+
+    loadIdentity() {
+      this.loadZero();
+      for (var i = 0; i < 4; i++) {
+        this.set(i, i, 1);
+      }
+    }
+
+    multiply(a, b) {
+      var result = new ESMatrix();
+      for (var i = 0; i < 4; i++) {
+        result.set(i, 0,
+                   (a.get(i, 0) * b.get(0, 0)) +
+                   (a.get(i, 1) * b.get(1, 0)) +
+                   (a.get(i, 2) * b.get(2, 0)) +
+                   (a.get(i, 3) * b.get(3, 0)));
+
+        result.set(i, 1,
+                   (a.get(i, 0) * b.get(0, 1)) +
+                   (a.get(i, 1) * b.get(1, 1)) +
+                   (a.get(i, 2) * b.get(2, 1)) +
+                   (a.get(i, 3) * b.get(3, 1)));
+
+        result.set(i, 2,
+                   (a.get(i, 0) * b.get(0, 2)) +
+                   (a.get(i, 1) * b.get(1, 2)) +
+                   (a.get(i, 2) * b.get(2, 2)) +
+                   (a.get(i, 3) * b.get(3, 2)));
+
+        result.set(i, 3,
+                   (a.get(i, 0) * b.get(0, 3)) +
+                   (a.get(i, 1) * b.get(1, 3)) +
+                   (a.get(i, 2) * b.get(2, 3)) +
+                   (a.get(i, 3) * b.get(3, 3)));
+      }
+      for (var i = 0; i < result.m.length; i++) {
+        this.m[i] = result.m[i];
+      }
+    }
+
+    frustrum(left, right, bottom, top, nearZ, farZ) {
+      var deltaX = right - left;
+      var deltaY = top - bottom;
+      var deltaZ = farZ - nearZ;
+
+      if (nearZ < 0 || farZ < 0 || deltaZ < 0 || deltaY < 0 || deltaX < 0) {
+        return;
+      }
+
+      var frust = new ESMatrix();
+      frust.set(0, 0, 2 * nearZ / deltaX);
+
+      frust.set(1, 1, 2 * nearZ / deltaY);
+
+      frust.set(2, 0, (right + left) / deltaX);
+      frust.set(2, 1, (top + bottom) / deltaY);
+      frust.set(2, 2, -(nearZ + farZ) / deltaZ);
+      frust.set(2, 3, -1);
+
+      frust.set(3, 2, -2 * nearZ * farZ / deltaZ);
+
+      this.multiply(frust, this);
+    }
+
+    perspective(fovY, aspect, nearZ, farZ) {
+      var frustrumH = Math.tan(fovY / 360 * Math.PI) * nearZ;
+      var frustrumW = frustrumH * aspect;
+      this.frustrum(-frustrumW, frustrumW, -frustrumH, frustrumH, nearZ, farZ);
+    }
+
+    translate(tx, ty, tz) {
+      this.set(3, 0, this.get(3, 0) + this.get(0, 0) *
+               tx + this.get(1, 0) * ty + this.get(2, 0) * tz);
+      this.set(3, 1, this.get(3, 1) + this.get(0, 1) *
+               tx + this.get(1, 1) * ty + this.get(2, 1) * tz);
+      this.set(3, 2, this.get(3, 2) + this.get(0, 2) *
+               tx + this.get(1, 2) * ty + this.get(2, 2) * tz);
+      this.set(3, 3, this.get(3, 3) + this.get(0, 3) *
+               tx + this.get(1, 3) * ty + this.get(2, 3) * tz);
+    }
+
+    rotate(angle, x, y, z) {
+      var mag = Math.sqrt(x * x + y * y + z * z);
+      var sinAngle = Math.sin(angle * Math.PI / 180);
+      var cosAngle = Math.cos(angle * Math.PI / 180);
+      if (mag <= 0) {
+        return;
+      }
+
+      var xx, yy, zz, xy, yz, zx, xs, ys, zs, oneMinusCos;
+      var rotation = new ESMatrix();
+
+      x /= mag;
+      y /= mag;
+      z /= mag;
+
+      xx = x * x;
+      yy = y * y;
+      zz = z * z;
+      xy = x * y;
+      yz = y * z;
+      zx = z * x;
+      xs = x * sinAngle;
+      ys = y * sinAngle;
+      zs = z * sinAngle;
+      oneMinusCos = 1 - cosAngle;
+
+      rotation.set(0, 0, (oneMinusCos * xx) + cosAngle);
+      rotation.set(0, 1, (oneMinusCos * xy) - zs);
+      rotation.set(0, 2, (oneMinusCos * zx) + ys);
+      rotation.set(0, 3, 0);
+
+      rotation.set(1, 0, (oneMinusCos * xy) + zs);
+      rotation.set(1, 1, (oneMinusCos * yy) + cosAngle);
+      rotation.set(1, 2, (oneMinusCos * yz) - xs);
+      rotation.set(1, 3, 0);
+
+      rotation.set(2, 0, (oneMinusCos * zx) - ys);
+      rotation.set(2, 1, (oneMinusCos * yz) + xs);
+      rotation.set(2, 2, (oneMinusCos * zz) + cosAngle);
+      rotation.set(2, 3, 0);
+
+      rotation.set(3, 0, 0);
+      rotation.set(3, 1, 0);
+      rotation.set(3, 2, 0);
+      rotation.set(3, 3, 1);
+
+      this.multiply(rotation, this);
+    }
+  }
+
+  function loadProgram(gl) {
+    var vertexShader = gl.createShader(gl.VERTEX_SHADER);
+    gl.shaderSource(vertexShader, VERTEX_SHADER_SOURCE);
+    gl.compileShader(vertexShader);
+
+    var fragmentShader = gl.createShader(gl.FRAGMENT_SHADER);
+    gl.shaderSource(fragmentShader, FRAGMENT_SHADER_SOURCE);
+    gl.compileShader(fragmentShader);
+
+    var program = gl.createProgram();
+    gl.attachShader(program, vertexShader);
+    gl.attachShader(program, fragmentShader);
+
+    gl.linkProgram(program);
+    // TODO(aa): Check for errors using getProgramiv and LINK_STATUS.
+
+    gl.deleteShader(vertexShader);
+    gl.deleteShader(fragmentShader);
+
+    return program;
+  }
+
+  var vboVertices;
+  var vboIndices;
+  function generateCube(gl) {
+    var numVertices = 24 * 3;
+    var numIndices = 12 * 3;
+
+    var cubeVertices = new Float32Array([
+      -0.5, -0.5, -0.5,
+      -0.5, -0.5,  0.5,
+      0.5, -0.5,  0.5,
+      0.5, -0.5, -0.5,
+      -0.5,  0.5, -0.5,
+      -0.5,  0.5,  0.5,
+      0.5,  0.5,  0.5,
+      0.5,  0.5, -0.5,
+      -0.5, -0.5, -0.5,
+      -0.5,  0.5, -0.5,
+      0.5,  0.5, -0.5,
+      0.5, -0.5, -0.5,
+      -0.5, -0.5, 0.5,
+      -0.5,  0.5, 0.5,
+      0.5,  0.5, 0.5,
+      0.5, -0.5, 0.5,
+      -0.5, -0.5, -0.5,
+      -0.5, -0.5,  0.5,
+      -0.5,  0.5,  0.5,
+      -0.5,  0.5, -0.5,
+      0.5, -0.5, -0.5,
+      0.5, -0.5,  0.5,
+      0.5,  0.5,  0.5,
+      0.5,  0.5, -0.5
+    ]);
+
+    var cubeIndices = new Uint16Array([
+      0, 2, 1,
+      0, 3, 2,
+      4, 5, 6,
+      4, 6, 7,
+      8, 9, 10,
+      8, 10, 11,
+      12, 15, 14,
+      12, 14, 13,
+      16, 17, 18,
+      16, 18, 19,
+      20, 23, 22,
+      20, 22, 21
+    ]);
+
+    // TODO(aa): The C++ program branches here on whether the pointer is
+    // non-NULL.
+    vboVertices = gl.createBuffer();
+    gl.bindBuffer(gl.ARRAY_BUFFER, vboVertices);
+    gl.bufferData(gl.ARRAY_BUFFER, cubeVertices, gl.STATIC_DRAW);
+    gl.bindBuffer(gl.ARRAY_BUFFER, 0);
+
+    vboIndices = gl.createBuffer();
+    gl.bindBuffer(gl.ELEMENT_ARRAY_BUFFER, vboIndices);
+    gl.bufferData(gl.ELEMENT_ARRAY_BUFFER, cubeIndices, gl.STATIC_DRAW);
+    gl.bindBuffer(gl.ELEMENT_ARRAY_BUFFER, 0);
+
+    return cubeIndices.length;
+  }
+
+  class GLES2ClientImpl {
+    constructor (remotePipe, size) {
+      this.gl_ = new glModule.Context(remotePipe, this.contextLost.bind(this));
+      this.lastTime_ = clockModule.seconds();
+      this.angle_ = 45;
+
+      this.program_ = loadProgram(this.gl_);
+      this.positionLocation_ =
+        this.gl_.getAttribLocation(this.program_, 'a_position');
+      this.mvpLocation_ =
+        this.gl_.getUniformLocation(this.program_, 'u_mvpMatrix');
+      this.numIndices_ = generateCube(this.gl_);
+      this.mvpMatrix_ = new ESMatrix();
+      this.mvpMatrix_.loadIdentity();
+
+      this.gl_.clearColor(0, 0, 0, 0);
+      this.setDimensions(size);
+      this.timer_ =
+          timerModule.createRepeating(16, this.handleTimer.bind(this));
+    }
+
+    setDimensions(size) {
+      this.width_ = size.width;
+      this.height_ = size.height;
+      this.gl_.resize(size.width, size.height, 1);
+    }
+
+    drawCube() {
+      this.gl_.viewport(0, 0, this.width_, this.height_);
+      this.gl_.clear(this.gl_.COLOR_BUFFER_BIT);
+      this.gl_.useProgram(this.program_);
+      this.gl_.bindBuffer(this.gl_.ARRAY_BUFFER, vboVertices);
+      this.gl_.bindBuffer(this.gl_.ELEMENT_ARRAY_BUFFER, vboIndices);
+      this.gl_.vertexAttribPointer(this.positionLocation_, 3, this.gl_.FLOAT,
+                                   false, 12, 0);
+      this.gl_.enableVertexAttribArray(this.positionLocation_);
+      this.gl_.uniformMatrix4fv(this.mvpLocation_, false, this.mvpMatrix_.m);
+      this.gl_.drawElements(this.gl_.TRIANGLES, this.numIndices_,
+                            this.gl_.UNSIGNED_SHORT, 0);
+      this.gl_.swapBuffers();
+    };
+
+    handleTimer() {
+      var now = clockModule.seconds();
+      var secondsDelta = now - this.lastTime_;
+      this.lastTime_ = now;
+
+      this.angle_ += this.getRotationForTimeDelta(secondsDelta);
+      this.angle_ = this.angle_ % 360;
+
+      var aspect = this.width_ / this.height_;
+
+      var perspective = new ESMatrix();
+      perspective.loadIdentity();
+      perspective.perspective(60, aspect, 1, 20);
+
+      var modelView = new ESMatrix();
+      modelView.loadIdentity();
+      modelView.translate(0, 0, -2);
+      modelView.rotate(this.angle_, 1, 0, 1);
+
+      this.mvpMatrix_.multiply(modelView, perspective);
+
+      this.drawCube();
+    };
+
+    getRotationForTimeDelta(secondsDelta) {
+      return secondsDelta * 40;
+    };
+
+    contextLost() {
+      console.log('GLES2ClientImpl.prototype.contextLost');
+    };
+
+    quit() {
+      if (this.timer_) {
+        console.log("CANCEL");
+        this.timer_.cancel();
+        this.timer_ = null;
+      }
+    }
+  }
+
+  class CubeDemo extends appModule.Application {
+    initialize(args) {
+      this.viewport = this.shell.connectToService(
+          "mojo:native_viewport_service", nvModule.NativeViewport, this);
+
+      this.gpu = this.shell.connectToService(
+          "mojo:native_viewport_service", gpuModule.Gpu);
+
+      var app = this;
+      var viewportSize = new geoModule.Size({width: 800, height: 600});
+      this.viewport.create(viewportSize).then(
+        function(result) {
+          app.onViewportCreated(result.native_viewport_id, viewportSize);
+        });
+
+      this.eventDispatcher =
+          new nvModule.NativeViewportEventDispatcher.stubClass(this);
+      this.viewport.setEventDispatcher(this.eventDispatcher);
+      this.viewport.show();
+    }
+
+    onViewportCreated(id, size) {
+      this.vpl = new vplModule.ViewportParameterListener.stubClass({
+        onVSyncParametersUpdated: function(timebase, interval) {
+          console.log("onVSyncParametersUpdated");
+        }
+      });
+      var pipe = coreModule.createMessagePipe();
+      this.gpu.createOnscreenGLES2Context(id, size, pipe.handle1, this.vpl);
+      this.gles2_ = new GLES2ClientImpl(pipe.handle0, size);
+    }
+
+    onEvent(event) {
+      return Promise.resolve(); // This just gates the next event delivery
+    }
+
+    onSizeChanged(size) {
+      if (this.gles2_)
+        this.gles2_.setDimensions(size);
+    }
+
+    onDestroyed() {
+      this.quit();
+    }
+  }
+
+  return CubeDemo;
+});