1 files changed, 108 insertions, 0 deletions
diff --git a/src/webGLClient.js b/src/webGLClient.js
new file mode 100644
index 00000000..736b1ae3
--- /dev/null
+++ b/src/webGLClient.js
@@ -0,0 +1,108 @@
+// WebGLWorker client code
+
+function assert(x) {
+  if (!x) throw 'failed assert';
+}
+
+function WebGLClient() {
+  var objects = {};
+
+  function fixArgs(command, args) {
+    switch (command) {
+      case 'getProgramParameter':
+      case 'getShaderParameter':
+      case 'uniform1i':
+      case 'uniform1f':
+      case 'uniform4fv':
+      case 'uniformMatrix4fv':
+      case 'getUniformLocation':
+      case 'useProgram':
+      case 'linkProgram':
+      case 'bindAttribLocation':
+      case 'compileShader':
+      case 'shaderSource': args[0] = objects[args[0]]; break;
+      case 'attachShader': args[0] = objects[args[0]]; args[1] = objects[args[1]]; break;
+      case 'bindTexture':
+      case 'bindBuffer': args[1] = args[1] ? objects[args[1]] : null; break;
+    }
+    return args;
+  }
+
+  function renderCommands(buffer) {
+    var ctx = Module.ctx;
+    var i = 0;
+    var len = buffer.length;
+    //dump('issuing commands, buffer len: ' + len + '\n');
+    while (i < len) {
+      var command = buffer[i++];
+      assert(typeof command === 'string')
+      var numArgs = buffer[i++];
+      assert(typeof numArgs === 'number', command);
+      //dump('issue ' + [command, numArgs, 'peek:' + buffer.slice(i, i+5)] + '\n');
+      if (numArgs === 0) {
+        //dump('issue: ' + command + '\n');
+        if (command === 'getError') {
+          assert(ctx.getError() === ctx.NO_ERROR, 'we cannot handle errors, we are async proxied WebGL');
+        } else {
+          ctx[command]();
+        }
+      } else if (numArgs > 0) {
+        var args = fixArgs(command, buffer.slice(i, i+numArgs));
+        i += numArgs;
+        //dump('issue+: ' + command + '(' + args + '), ' + numArgs + '\n');
+        if (command === 'getShaderParameter' || command === 'getProgramParameter') {
+          assert(ctx[command](args[0], args[1]), 'we cannot handle errors, we are async proxied WebGL');
+        } else {
+          ctx[command].apply(ctx, args);
+        }
+      } else {
+        // negative means a constructor, last argument is the id to save as
+        numArgs = -numArgs - 1;
+        var args = fixArgs(command, buffer.slice(i, i+numArgs));
+        i += numArgs;
+        var id = buffer[i++];
+        //dump('issue-: ' + command + '(' + args + '), ' + numArgs + '\n');
+        objects[id] = ctx[command].apply(ctx, args);
+      }
+      assert(i <= len);
+    }
+  }
+
+  var commandBuffers = [];
+
+  function renderAllCommands() {
+    // TODO: we can avoid running commands from buffers that are not the last, if they
+    //       have no side effects, as each buffer is from a different frame
+    for (var i = 0; i < commandBuffers.length; i++) {
+      renderCommands(commandBuffers[i]);
+    }
+    commandBuffers.length = 0;
+  }
+
+  this.onmessage = function(msg) {
+    //dump('client GL got ' + JSON.stringify(msg) + '\n');
+    switch(msg.op) {
+      case 'render': {
+        if (commandBuffers.length === 0) {
+          // requestion a new frame, we will clear the buffers after rendering them
+          window.requestAnimationFrame(renderAllCommands);
+        }
+        commandBuffers.push(msg.commandBuffer);
+        break;
+      }
+      default: throw 'weird gl onmessage ' + JSON.stringify(msg);
+    }
+  };
+}
+
+WebGLClient.prefetch = function() {
+  var canvas = document.createElement('canvas');
+  var ctx = canvas.getContext('webgl-experimental') || canvas.getContext('webgl');
+  if (!ctx) return;
+  var parameters = {};
+  ['MAX_VERTEX_ATTRIBS', 'MAX_TEXTURE_IMAGE_UNITS'].forEach(function(name) {
+    parameters[ctx[name]] = ctx.getParameter(ctx[name]);
+  });
+  worker.postMessage({ target: 'gl', op: 'setPrefetched', parameters: parameters, extensions: ctx.getSupportedExtensions() });
+};
+