topical media & game development
#graphic-flex-image-effects-04-Flex-GradientMapTest.ax
#graphic-flex-image-effects-04-Flex-GradientMapTest.ax
[swf]
[flash]
flex
package {
import flash.display.BitmapData;
import flash.display.GradientType;
import flash.display.Shape;
import flash.filters.ColorMatrixFilter;
import flash.geom.Matrix;
import flash.geom.Point;
[SWF(width=300, height=330, backgroundColor=0x000000)]
Demonstrates the use of BitmapData's paletteMap() to remap an image's color palette to a custom gradient.
public class @ax-graphic-flex-image-effects-04-Flex-GradientMapTest extends graphic_flex_image_effects_04_Flex_AbstractImageLoader {
Constructor. Passes path of image to load to super class.
public function @ax-graphic-flex-image-effects-04-Flex-GradientMapTest() {
super("graphic-flex-image-effects-04-assets-goat.jpg");
}
Run after the image loads in super class. This creates a shape and draws into it a gradient which can then
be used to populate color arrays with values for use a palette remapping of the loaded image.
override protected function runPostImageLoad():void {
var bitmapData:BitmapData = _loadedBitmap.bitmapData;
var width:uint = stage.stageWidth;
var height:uint = stage.stageHeight;
// gradient values to use for the custom gradient remapping
var colors:Array = [0x0066FD, 0xFFFFFF, 0xFFFFFF, 0x996600, 0xFFCC00, 0xFFFFFF];
var ratios:Array = [0, 95, 124, 130, 165, 255];
var alphas:Array = [1, 1, 1, 1, 1, 1];
var matrix:Matrix = new Matrix();
matrix.createGradientBox(256, height);
// draw gradient into shape so that its data can be captured
var shape:Shape = new Shape();
shape.graphics.beginGradientFill(GradientType.LINEAR, colors, alphas, ratios, matrix);
shape.graphics.drawRect(0, 0, 256, height);
shape.graphics.endFill();
var gradient:BitmapData = new BitmapData(256, height);
gradient.draw(shape);
// run through all 256 horizontal pixels of gradient to determine the colors
var red:Array = [];
var zeros:Array = [];
var color:uint;
for (var i:uint = 0; i < 256; i++) {
color = gradient.getPixel(i, 0);
// color only needs to be pushed into one channel array since
// all three channels are combined in final palette remapping
red.push(color);
// a 0 is pushed into the other array, which will be used for both green and blue arrays
zeros.push(0);
}
gradient.dispose();
// add the shape to the stage so that gradient can be seen and compared
shape.scaleX = width/256;
addChild(shape);
// desaturate the image before its palette is remapped
desaturate(bitmapData);
bitmapData.paletteMap(
bitmapData,
bitmapData.rect,
new Point(),
red,
zeros,
zeros
);
addChild(_loadedBitmap);
}
Fully desaturates the specified image using the ColorMatrixFilter.
parameter: bitmapData The image ot desaturate.
private function desaturate(bitmapData:BitmapData):void {
var matrix:Array = [
0.3, 0.59, 0.11, 0, 0,
0.3, 0.59, 0.11, 0, 0,
0.3, 0.59, 0.11, 0, 0,
0, 0, 0, 1, 0
];
bitmapData.applyFilter(
bitmapData,
bitmapData.rect,
new Point(),
new ColorMatrixFilter(matrix)
);
}
}
}
(C) Æliens
04/09/2009
You may not copy or print any of this material without explicit permission of the author or the publisher.
In case of other copyright issues, contact the author.
