dorkbox.util.jna.windows.HBITMAPWrap Maven / Gradle / Ivy

/*
 * Copyright 2017 dorkbox, llc
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package dorkbox.util.jna.windows;

import static com.sun.jna.platform.win32.WinDef.HBITMAP;
import static com.sun.jna.platform.win32.WinDef.HDC;
import static dorkbox.util.jna.windows.User32.User32;

import java.awt.AlphaComposite;
import java.awt.Graphics2D;
import java.awt.image.BufferedImage;
import java.awt.image.Raster;

import com.sun.jna.Pointer;
import com.sun.jna.platform.win32.WinGDI;
import com.sun.jna.ptr.PointerByReference;

public class HBITMAPWrap extends HBITMAP {

    // https://github.com/twall/jna/blob/master/contrib/alphamaskdemo/com/sun/jna/contrib/demo/AlphaMaskDemo.java
    private static
    HBITMAP createBitmap(BufferedImage image) {
        int w = image.getWidth(null);
        int h = image.getHeight(null);
        HDC screenDC = User32.GetDC(null);
        HDC memDC = GDI32.CreateCompatibleDC(screenDC);
        HBITMAP hBitmap = null;

        try {
            BufferedImage buf = new BufferedImage(w, h, BufferedImage.TYPE_INT_ARGB_PRE);
            Graphics2D g = (Graphics2D) buf.getGraphics();
            g.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_OVER));
            g.drawImage(image, 0, 0, w, h, null);

            WinGDI.BITMAPINFO bmi = new WinGDI.BITMAPINFO();
            bmi.bmiHeader.biWidth = w;
            bmi.bmiHeader.biHeight = h;
            bmi.bmiHeader.biPlanes = 1;
            bmi.bmiHeader.biBitCount = 32;
            bmi.bmiHeader.biCompression = WinGDI.BI_RGB;
            bmi.bmiHeader.biSizeImage = w * h * 4;

            PointerByReference ppbits = new PointerByReference();
            hBitmap = GDI32.CreateDIBSection(memDC, bmi, WinGDI.DIB_RGB_COLORS, ppbits, null, 0);
            Pointer pbits = ppbits.getValue();

            Raster raster = buf.getData();
            int[] pixel = new int[4];
            int[] bits = new int[w * h];
            for (int y = 0; y < h; y++) {
                for (int x = 0; x < w; x++) {
                    raster.getPixel(x, h - y - 1, pixel);
                    int red = (pixel[2] & 0xFF) << 0;
                    int green = (pixel[1] & 0xFF) << 8;
                    int blue = (pixel[0] & 0xFF) << 16;
                    int alpha = (pixel[3] & 0xFF) << 24;
                    bits[x + y * w] = alpha | red | green | blue;
                }
            }
            pbits.write(0, bits, 0, bits.length);
            return hBitmap;
        } finally {
            User32.ReleaseDC(null, screenDC);
            GDI32.DeleteDC(memDC);
        }
    }

    BufferedImage img;

    public HBITMAPWrap(BufferedImage img) {
        setPointer(createBitmap(img).getPointer());

        this.img = img;
    }

    @Override
    protected void finalize() throws Throwable {
        close();
        super.finalize();
    }

    public void close() {
        if (Pointer.nativeValue(getPointer()) != 0) {
            GDI32.DeleteObject(this);
            setPointer(new Pointer(0));
        }
    }

    public BufferedImage getImage() {
        return img;
    }
}