Refactored OpenGL embedder that works on Android, Mac or Linux.

samples/android_sample/assets/dart/main.dart

Index: samples/android_sample/assets/dart/main.dart
===================================================================
--- samples/android_sample/assets/dart/main.dart	(revision 16976)
+++ samples/android_sample/assets/dart/main.dart	(working copy)
@@ -1,359 +0,0 @@
-// Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
-// for details. All rights reserved. Use of this source code is governed by a
-// BSD-style license that can be found in the LICENSE file.
-
-import "dart:math" as Math;
-import "android_extension.dart";
-
-const FRAGMENT_PROGRAM = """
-  precision mediump float;
-
-  const vec3 lightDir = vec3(0.577350269, 0.577350269, -0.577350269);
-  varying vec3 vPosition;
-  uniform vec3 cameraPos;
-  uniform vec3 sphere1Center;
-  uniform vec3 sphere2Center;
-  uniform vec3 sphere3Center;
-
-  bool intersectSphere(vec3 center, vec3 lStart, vec3 lDir,
-                       out float dist) {
-    vec3 c = center - lStart;
-    float b = dot(lDir, c);
-    float d = b*b - dot(c, c) + 1.0;
-    if (d < 0.0) {
-      dist = 10000.0;
-      return false;
-    }
-
-    dist = b - sqrt(d);
-    if (dist < 0.0) {
-      dist = 10000.0;
-      return false;
-    }
-
-    return true;
-  }
-
-  vec3 lightAt(vec3 N, vec3 V, vec3 color) {
-    vec3 L = lightDir;
-    vec3 R = reflect(-L, N);
-
-    float c = 0.3 + 0.4 * pow(max(dot(R, V), 0.0), 30.0) + 0.7 * dot(L, N);
-
-    if (c > 1.0) {
-      return mix(color, vec3(1.6, 1.6, 1.6), c - 1.0);
-    }
-
-    return c * color;
-  }
-
-  bool intersectWorld(vec3 lStart, vec3 lDir, out vec3 pos,
-                      out vec3 normal, out vec3 color) {
-    float d1, d2, d3;
-    bool h1, h2, h3;
-
-    h1 = intersectSphere(sphere1Center, lStart, lDir, d1);
-    h2 = intersectSphere(sphere2Center, lStart, lDir, d2);
-    h3 = intersectSphere(sphere3Center, lStart, lDir, d3);
-
-    if (h1 && d1 < d2 && d1 < d3) {
-      pos = lStart + d1 * lDir;
-      normal = pos - sphere1Center;
-      color = vec3(0.0, 0.0, 0.9);
-      if (fract(pos.x / 1.5) > 0.5 ^^
-          fract(pos.y / 1.5) > 0.5 ^^
-          fract(pos.z / 1.5) > 0.5) {
-        color = vec3(1.0, 0.0, 1.0);
-      }
-      else {
-        color = vec3(1.0, 1.0, 0.0);
-      }
-    }
-    else if (h2 && d2 < d3) {
-      pos = lStart + d2 * lDir;
-      normal = pos - sphere2Center;
-      color = vec3(0.9, mod(normal.y * 2.5, 1.0), 0.0);
-    }
-    else if (h3) {
-      pos = lStart + d3 * lDir;
-      normal = pos - sphere3Center;
-      color = vec3(0.0, clamp(sphere3Center.y/1.5, 0.0, 0.9),
-                   clamp(0.9 - sphere3Center.y/1.5, 0.0, 0.9));
-    }
-    else if (lDir.y < -0.01) {
-      pos = lStart + ((lStart.y + 2.7) / -lDir.y) * lDir;
-      if (pos.x*pos.x + pos.z*pos.z > 30.0) {
-        return false;
-      }
-      normal = vec3(0.0, 1.0, 0.0);
-      if (fract(pos.x / 5.0) > 0.5 == fract(pos.z / 5.0) > 0.5) {
-        color = vec3(1.0);
-      }
-      else {
-        color = vec3(0.0);
-      }
-    }
-    else {
-     return false;
-    }
-
-    return true;
-  }
-
-  void main(void)
-  {
-    vec3 cameraDir = normalize(vPosition - cameraPos);
-
-    vec3 p1, norm, p2;
-    vec3 col, colT, colM, col3;
-    if (intersectWorld(cameraPos, cameraDir, p1,
-                       norm, colT)) {
-      col = lightAt(norm, -cameraDir, colT);
-      colM = (colT + vec3(0.2)) / 1.2;
-      cameraDir = reflect(cameraDir, norm);
-      if (intersectWorld(p1, cameraDir, p2, norm, colT)) {
-        col += lightAt(norm, -cameraDir, colT) * colM;
-        colM *= (colT + vec3(0.2)) / 1.2;
-        cameraDir = reflect(cameraDir, norm);
-        if (intersectWorld(p2, cameraDir, p1, norm, colT)) {
-          col += lightAt(norm, -cameraDir, colT) * colM;
-        }
-      }
-
-      gl_FragColor = vec4(col, 1.0);
-    }
-    else {
-      gl_FragColor = vec4(0.0, 0.0, 0.0, 1.0);
-    }
-  }
-""";
-
-const VERTEX_PROGRAM = """
-  attribute vec2 aVertexPosition;
-  attribute vec3 aPlotPosition;
-
-  varying vec3 vPosition;
-
-  void main(void)
-  {
-    gl_Position = vec4(aVertexPosition, 1.0, 1.0);
-    vPosition = aPlotPosition;
- }
-""";
-
-loadShader(final type, final program) {
-  final shader = gl.createShader(type);
-  gl.shaderSource(shader, program);
-  gl.compileShader(shader);
-  if (gl.getShaderParameter(shader, WebGLRenderingContext.COMPILE_STATUS)
-      != WebGLRenderingContext.TRUE) {
-    log("Could not compile shader: ${gl.getShaderInfoLog(shader)}");
-    throw new Exception("Could not compile shader");
-  }
-  
-  return shader;
-}
-
-var shaderProgram;
-var aVertexPosition;
-var aPlotPosition;
-var cameraPos;
-var sphere1Center;
-var sphere2Center;
-var sphere3Center;
-var ratio;
-
-initShaders() {
-  var vertexShader = loadShader(WebGLRenderingContext.VERTEX_SHADER,
-      VERTEX_PROGRAM);
-  var fragmentShader = loadShader(WebGLRenderingContext.FRAGMENT_SHADER,
-      FRAGMENT_PROGRAM);
-
-  shaderProgram = gl.createProgram();
-  if (shaderProgram == 0) {
-    throw new Exception("Could not create program.");
-  }
-
-  gl.attachShader(shaderProgram, vertexShader);
-  gl.attachShader(shaderProgram, fragmentShader);
-  gl.linkProgram(shaderProgram);
-
-  if (gl.getProgramParameter(shaderProgram, WebGLRenderingContext.LINK_STATUS)
-      != WebGLRenderingContext.TRUE) {
-    log("Could not link program: ${gl.getProgramInfoLog(shaderProgram)}");
-    throw new Exception("Could not initialize shaders");
-  }
-  
-  gl.useProgram(shaderProgram);
-
-  aVertexPosition = gl.getAttribLocation(shaderProgram, "aVertexPosition");
-  gl.enableVertexAttribArray(aVertexPosition);
-
-  aPlotPosition = gl.getAttribLocation(shaderProgram, "aPlotPosition");
-  gl.enableVertexAttribArray(aPlotPosition);
-
-  cameraPos = gl.getUniformLocation(shaderProgram, "cameraPos");
-  sphere1Center = gl.getUniformLocation(shaderProgram, "sphere1Center");
-  sphere2Center = gl.getUniformLocation(shaderProgram, "sphere2Center");
-  sphere3Center = gl.getUniformLocation(shaderProgram, "sphere3Center");
-}
-
-initBuffers() {
-  var vertexPositionBuffer = gl.createBuffer();
-  gl.bindBuffer(WebGLRenderingContext.ARRAY_BUFFER, vertexPositionBuffer);
-  // TODO(gram): vertices should be a Float32Array to be consistent with WebGL.
-  var vertices = [
-                  1.0,  1.0,
-                  -1.0,  1.0,
-                  1.0, -1.0,
-                  -1.0, -1.0,
-                  ];
-
-  gl.bufferData(WebGLRenderingContext.ARRAY_BUFFER, vertices,
-      WebGLRenderingContext.STATIC_DRAW);
-  gl.bindBuffer(WebGLRenderingContext.ARRAY_BUFFER, vertexPositionBuffer);
-  gl.vertexAttribPointer(aVertexPosition, 2, WebGLRenderingContext.FLOAT,
-      false,0, 0);
-
-  var plotPositionBuffer = gl.createBuffer();
-  gl.bindBuffer(WebGLRenderingContext.ARRAY_BUFFER, plotPositionBuffer);
-  gl.vertexAttribPointer(aPlotPosition, 3, WebGLRenderingContext.FLOAT,
-      false, 0, 0);
-}
-
-class Vector {
-  var x;
-  var y;
-  var z;
-  Vector(this.x, this.y, this.z);
-}
-
-// TODO(gram): This should be using vector_math.
-crossProd(v1, v2) {
-  return
-    new Vector(
-               v1.y*v2.z - v2.y*v1.z,
-               v1.z*v2.x - v2.z*v1.x,
-               v1.x*v2.y - v2.x*v1.y);
-}
-
-normalize(v) {
-  var l = Math.sqrt(v.x*v.x + v.y*v.y + v.z*v.z);
-  return new Vector( v.x/l, v.y/l, v.z/l );
-}
-
-vectAdd(v1, v2) {
-  return new Vector( v1.x + v2.x, v1.y + v2.y, v1.z + v2.z );
-}
-
-vectSub(v1, v2) {
-  return new Vector( v1.x - v2.x, v1.y - v2.y, v1.z - v2.z );
-}
-
-vectMul(v, l) {
-  return new Vector( v.x*l, v.y*l, v.z*l );
-}
-
-pushVec(v, arr) {
-  arr.addAll([v.x, v.y, v.z]);
-}
-
-var t = 0;
-int width, height;
-
-drawScene() {
-  var x1 = Math.sin(t * 1.1) * 1.5;
-  var y1 = Math.cos(t * 1.3) * 1.5;
-  var z1 = Math.sin(t + Math.PI/3) * 1.5;
-  var x2 = Math.cos(t * 1.2) * 1.5;
-  var y2 = Math.sin(t * 1.4) * 1.5;
-  var z2 = Math.sin(t*1.25 - Math.PI/3) * 1.5;
-  var x3 = Math.cos(t * 1.15) * 1.5;
-  var y3 = Math.sin(t * 1.37) * 1.5;
-  var z3 = Math.sin(t*1.27) * 1.5;
-
-  var cameraFrom = new Vector(
-                          Math.sin(t * 0.4) * 18,
-                          Math.sin(t * 0.13) * 5 + 5,
-                          Math.cos(t * 0.4) * 18 );
-  var cameraTo = new Vector(0.0, 0.0, 0.0);
-  var cameraPersp = 6.0;
-  var up = new Vector(0.0, 1.0, 0.0);
-  var cameraDir = normalize(vectSub(cameraTo, cameraFrom));
-
-  var cameraLeft = normalize(crossProd(cameraDir, up));
-  var cameraUp = normalize(crossProd(cameraLeft, cameraDir));
-  // cameraFrom + cameraDir * cameraPersp
-  var cameraCenter = vectAdd(cameraFrom, vectMul(cameraDir, cameraPersp));
-
-  // cameraCenter + cameraUp + cameraLeft * ratio
-  var cameraTopLeft  = vectAdd(vectAdd(cameraCenter, cameraUp),
-                               vectMul(cameraLeft, ratio));
-  var cameraBotLeft  = vectAdd(vectSub(cameraCenter, cameraUp),
-                               vectMul(cameraLeft, ratio));
-  var cameraTopRight = vectSub(vectAdd(cameraCenter, cameraUp),
-                               vectMul(cameraLeft, ratio));
-  var cameraBotRight = vectSub(vectSub(cameraCenter, cameraUp),
-                               vectMul(cameraLeft, ratio));
-
-  // TODO(gram): corners should be a Float32Array to be consistent with WebGL.
-  var corners = [];
-  pushVec(cameraTopRight, corners);
-  pushVec(cameraTopLeft, corners);
-  pushVec(cameraBotRight, corners);
-  pushVec(cameraBotLeft, corners);
-
-  gl.bufferData(WebGLRenderingContext.ARRAY_BUFFER, corners,
-      WebGLRenderingContext.STATIC_DRAW);
-
-  gl.uniform3f(cameraPos, cameraFrom.x, cameraFrom.y, cameraFrom.z);
-  gl.uniform3f(sphere1Center, x1, y1, z1);
-  gl.uniform3f(sphere2Center, x2, y2, z2);
-  gl.uniform3f(sphere3Center, x3, y3, z3);
-
-  gl.drawArrays(WebGLRenderingContext.TRIANGLE_STRIP, 0, 4);
-
-  t += 0.03;
-  if (t > Math.PI * 200) {
-    t -= Math.PI * 200;
-  }
-}
-
-setup(int w, int h) {
-  initShaders();
-  gl.clearColor(0.0, 0.0, 0.0, 1.0);
-  gl.clearDepth(1.0);
-  initBuffers();
-  resize(w, h);
-  playBackground("music/la_ere_gymnopedie.mp3");
-}
-
-resize(int w, int h) {
-  width = w;
-  height = h;
-  ratio = width / height;
-  gl.viewport(0, 0, width, height);
-  t -= 0.03;
-  drawScene();
-}
-
-update() {
-  drawScene();
-  eglSwapBuffers();
-}
-
-onMotionDown(num when, num x, num y) {
-  t = (x / width) * Math.PI * 200;
-}
-
-onMotionUp(num when, num x, num y) {}
-onMotionMove(num when, num x, num y) {}
-onMotionCancel(num when, num x, num y) {}
-onMotionOutside(num when, num x, num y) {}
-onMotionPointerDown(num when, num x, num y) {}
-onMotionPointerUp(num when, num x, num y) {}
-onKeyDown(num when, int flags, int keycode, int metastate, int repeat) {}
-onKeyUp(num when, int flags, int keycode, int metastate, int repeat) {}
-onKeyMultiple(num when, int flags, int keycode, int metastate, int repeat) {
-}
-