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

Introduction

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

Prototype

public final native void drawImage(ImageElement image, float sx, float sy, float sw, float sh, float dx,
        float dy, float dw, float dh) ;

Source Link

Document

Draws a scaled subset of an image.

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);/*  w w  w  .  ja v a 2 s .  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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