topical media & game development

topical media & game development

[] readme course(s) preface I 1 2 II 3 4 III 5 6 7 IV 8 9 10 V 11 12 afterthought(s) appendix reference(s) example(s) resource(s) _

#graphic-flex-image-effects-05-Flex-ShaderWrapper.ax

#graphic-flex-image-effects-05-Flex-ShaderWrapper.ax [swf] [flash] flex


  package {
  
          import flash.display.Shader;
          import flash.events.Event;
          import flash.events.EventDispatcher;
          import flash.net.URLLoader;
          import flash.net.URLLoaderDataFormat;
          import flash.net.URLRequest;
          import flash.utils.ByteArray;

Class to handle loading or embedding, and passing values to a shader to make it easier dealing with the quirks of the Shader class and bytecode.


  
          public class @ax-graphic-flex-image-effects-05-Flex-ShaderWrapper extends EventDispatcher {
  
                  private var _shader:Shader;

Constructor. This accepts a path to a .pbj file to load or a shader bytecode class to instantiate. If a file needs to be loaded, the loading is initiated immediately. Completion of load will result in a COMPLETE event being fired.
parameter: pathOrClass Either the path to a .pbj file or the shader bytecode class.


  
                  public function @ax-graphic-flex-image-effects-05-Flex-ShaderWrapper(pathOrClass:Object) {
                          var shaderClass:Class = pathOrClass as Class;
                          // if a class is passed, immediately instantiate it
                          if (shaderClass != null) {
                                  createShader(ByteArray(new shaderClass()));
                          // if a file path is passed, immediately load it
                          } else if ((pathOrClass as String) != null) {
                                  load(pathOrClass as String);
                          } else {
                                  throw new Error("Invalid object passed to constructor.");
                          }
                  }

Creates the Shader instance from the bytecode.
parameter: data The ByteArray containing the shader bytecode.


  
                  private function createShader(data:ByteArray):void {
                          _shader = new Shader(data);
                          dispatchEvent(new Event(Event.COMPLETE));
                  }

Loads the specified .pbj file.
parameter: path The path to the .pbj file to load.


  
                  private function load(path:String):void {
                          var loader:URLLoader = new URLLoader();
                          loader.dataFormat = URLLoaderDataFormat.BINARY;
                          loader.addEventListener(Event.COMPLETE, onShaderLoaded);
                          loader.load(new URLRequest(path));
                  }

Handler for when the .pbj file completes loading.
parameter: event Event dispatched by URLLoader.


  
                  private function onShaderLoaded(event:Event):void {
                          var loader:URLLoader = event.target as URLLoader;
                          createShader(loader.data as ByteArray);
                  }

Returns the value of the specified parameter from the shader. This method ensures that float and int values are extracted from the Array that wraps them.
parameter: name The name of the parameter to retrieve.
returns: The value of the parameter.


  
                  public function getParameter(name:String):Object {
                          // check to see if parameter exists
                          if (_shader.data.hasOwnProperty(name)) {
                                  var value:Object = _shader.data[name].value;
                                  var type:String = _shader.data[name].type;
                                  // if type is float or int, grab the only value from the array
                                  if (type == "float" || type == "int") {
                                          value = (value as Array)[0];
                                  }
                                  return value;
                          }
                          return null;
                  }

Sets the value of the specified parameter of the shader. This method ensures that all values are passed as arrays to the shader, even if the parameter is scalar.
parameter: name The name of the parameter to set.
parameter: value The value to give the parameter.
returns: True if the parameter was found and set.


  
                  public function setParameter(name:String, value:Object):Boolean {
                          // check to see if parameter exists
                          if (_shader.data.hasOwnProperty(name)) {
                                  // wrap scalar values in an array
                                  if (!(value is Array)) {
                                          value = [value];
                                  }
                                  _shader.data[name].value = value;
                                  return true;
                          }
                          return false;
                  }

Returns the Shader instance this class wraps.
returns: The Shader instance managed by this class.


  
                  public function get shader():Shader {
                          return _shader;
                  }
  
          }
  
  }

[] readme course(s) preface I 1 2 II 3 4 III 5 6 7 IV 8 9 10 V 11 12 afterthought(s) appendix reference(s) example(s) resource(s) _

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