Example usage for com.google.gwt.corp.gfx.client.canvas CanvasRenderingContext2D getImageData

Introduction

In this page you can find the example usage for com.google.gwt.corp.gfx.client.canvas CanvasRenderingContext2D getImageData.

Prototype

public final native ImageData getImageData(float sx, float sy, float sw, float sh) ;

Source Link

Document

Returns an image data object for the screen area denoted by sx, sy, sw and sh.

Usage

From source file:jake2.gwt.client.GwtWebGLRenderer.java

License:Open Source License

@Override
protected void GL_ResampleTexture(int[] in, int inwidth, int inheight, int[] out, int outwidth, int outheight) {

    if (canvas1.getWidth() < inwidth) {
        canvas1.setWidth(inwidth);//from ww w  .j av  a 2s  . co  m
    }
    if (canvas1.getHeight() < inheight) {
        canvas1.setHeight(inheight);
    }

    CanvasRenderingContext2D inCtx = canvas1.getContext2D();
    ImageData data = inCtx.createImageData(inwidth, inheight);
    CanvasPixelArray pixels = data.getData();

    int len = inwidth * inheight;
    int p = 0;

    for (int i = 0; i < len; i++) {
        int abgr = in[i];
        pixels.set(p, (abgr & 255));
        pixels.set(p + 1, (abgr >> 8) & 255);
        pixels.set(p + 2, (abgr >> 16) & 255);
        pixels.set(p + 3, (abgr >> 24) & 255);
        p += 4;
    }
    inCtx.putImageData(data, 0, 0);

    if (canvas2.getWidth() < outwidth) {
        canvas2.setWidth(outwidth);
    }
    if (canvas2.getHeight() < outheight) {
        canvas2.setHeight(outheight);
    }

    CanvasRenderingContext2D outCtx = canvas2.getContext2D();
    outCtx.drawImage(canvas1, 0, 0, inwidth, inheight, 0, 0, outwidth, outheight);

    data = outCtx.getImageData(0, 0, outwidth, outheight);
    pixels = data.getData();

    len = outwidth * outheight;
    p = 0;

    for (int i = 0; i < len; i++) {
        int r = pixels.get(p) & 255;
        int g = pixels.get(p + 1) & 255;
        int b = pixels.get(p + 2) & 255;
        int a = pixels.get(p + 3) & 255;
        p += 4;
        out[i] = (a << 24) | (b << 16) | (g << 8) | r;
    }
}

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From source file:jake2.gwt.client.GwtWebGLRenderer.java

License:Open Source License

public void setPicDataLowLevel(image_t image, ImageElement img) {
    CanvasElement canvas = (CanvasElement) Document.get().createElement("canvas");
    int w = img.getWidth();
    int h = img.getHeight();
    canvas.setWidth(w);/*from www.j  a va 2  s.c om*/
    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);
    }

    GL_SetPicData(image, pic, w, h, 32);
}

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