loadTextureFromImage.java

public static int getInternalFormat(BufferedImage image) {
    switch (image.getType()) {
        case BufferedImage.TYPE_3BYTE_BGR:
            return GL_RGB;
        case BufferedImage.TYPE_4BYTE_ABGR:
            return GL_RGBA;
        default:
            throw new UnsupportedOperationException();
    }
}

public static int getFormat(BufferedImage image) {
    switch (image.getType()) {
        case BufferedImage.TYPE_3BYTE_BGR:
            return GL_BGR;
        case BufferedImage.TYPE_4BYTE_ABGR:
            return GL_ABGR_EXT;
        default:
            throw new UnsupportedOperationException();
    }
}

public static Texture loadTextureFromImage(BufferedImage image) {
    int texture = glGenTextures();
    glBindTexture(GL_TEXTURE_2D, texture);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
    byte[] array = ((DataBufferByte) image.getData().getDataBuffer()).getData();
    ByteBuffer buffer = ByteBuffer.allocateDirect(array.length)
            .order(ByteOrder.nativeOrder());
    buffer.put(array)
            .position(0);
    glTexImage2D(
            GL_TEXTURE_2D,
            0,
            getInternalFormat(image),
            image.getWidth(),
            image.getHeight(),
            0,
            getFormat(image),
            GL_UNSIGNED_BYTE,
            buffer);
    glBindTexture(GL_TEXTURE_2D, 0);
    return new Texture(texture, image.getWidth(), image.getHeight());
}