Example usage for com.google.gwt.html5.client CanvasRenderingContext2D drawImage

Introduction

In this page you can find the example usage for com.google.gwt.html5.client CanvasRenderingContext2D drawImage.

Prototype

public final native void drawImage(ImageElement image, float dx, float dy) ;

Source Link

Usage

From source file:com.googlecode.gwtquake.client.GwtWebGLRenderer.java

License:Open Source License

public void setPicDataLowLevel(Image image, ImageElement img) {
    CanvasElement canvas = (CanvasElement) Document.get().createElement("canvas");
    int w = img.getWidth();
    int h = img.getHeight();
    canvas.setWidth(w);//from   w  ww. j  a v  a  2 s.c  o m
    canvas.setHeight(h);
    //      canvas.getStyle().setProperty("border", "solid 1px green");
    canvas.getStyle().setDisplay(Display.NONE);
    Document.get().getBody().appendChild(canvas);
    CanvasRenderingContext2D ctx = canvas.getContext2D();
    ctx.drawImage(img, 0, 0);
    ImageData data = ctx.getImageData(0, 0, w, h);
    CanvasPixelArray pixels = data.getData();

    int count = w * h * 4;
    byte[] pic = new byte[count];
    for (int i = 0; i < count; i += 4) {
        pic[i + 3] = (byte) pixels.get(i + 3); // alpha, then bgr
        pic[i + 2] = (byte) pixels.get(i + 2);
        pic[i + 1] = (byte) pixels.get(i + 1);
        pic[i] = (byte) pixels.get(i);
    }

    image.setData(pic, w, h, 32);
}

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