Draws the given BufferedImage to the canvas, centered, wholly contained within the bounds defined by the destination rectangle, and with preserved aspect ratio. - Java 2D Graphics

Java examples for 2D Graphics:BufferedImage Paint

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Description

Draws the given BufferedImage to the canvas, centered, wholly contained within the bounds defined by the destination rectangle, and with preserved aspect ratio.

Demo Code

/*//w  ww .ja v  a2  s  . co  m
 * Copyright (C) 2011 The Android Open Source Project
 *
 * 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 com.book2s;

import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Image;

import java.awt.Rectangle;
import java.awt.image.BufferedImage;

public class Main {
    /**
     * Draws the given {@link BufferedImage} to the canvas, centered, wholly contained within the
     * bounds defined by the destination rectangle, and with preserved aspect ratio.
     *
     * @param g       The destination canvas.
     * @param source  The source image.
     * @param dstRect The destination rectangle in the destination canvas into which to draw the
     *                image.
     */
    public static void drawCenterInside(Graphics2D g, BufferedImage source,
            Rectangle dstRect) {
        final int srcWidth = source.getWidth();
        final int srcHeight = source.getHeight();
        if (srcWidth * 1.0 / srcHeight > dstRect.width * 1.0
                / dstRect.height) {
            final int scaledWidth = Math.max(1, dstRect.width);
            final int scaledHeight = Math.max(1, dstRect.width * srcHeight
                    / srcWidth);
            Image scaledImage = scaledImage(source, scaledWidth,
                    scaledHeight);
            g.drawImage(scaledImage, dstRect.x, dstRect.y
                    + (dstRect.height - scaledHeight) / 2, dstRect.x
                    + dstRect.width, dstRect.y
                    + (dstRect.height - scaledHeight) / 2 + scaledHeight,
                    0, 0, 0 + scaledWidth, 0 + scaledHeight, null);
        } else {
            final int scaledWidth = Math.max(1, dstRect.height * srcWidth
                    / srcHeight);
            final int scaledHeight = Math.max(1, dstRect.height);
            Image scaledImage = scaledImage(source, scaledWidth,
                    scaledHeight);
            g.drawImage(scaledImage, dstRect.x
                    + (dstRect.width - scaledWidth) / 2, dstRect.y,
                    dstRect.x + (dstRect.width - scaledWidth) / 2
                            + scaledWidth, dstRect.y + dstRect.height, 0,
                    0, 0 + scaledWidth, 0 + scaledHeight, null);
        }
    }

    /**
     * Smoothly scales the given {@link BufferedImage} to the given width and height using the
     * {@link Image#SCALE_SMOOTH} algorithm (generally bicubic resampling or bilinear filtering).
     *
     * @param source The source image.
     * @param width  The destination width to scale to.
     * @param height The destination height to scale to.
     * @return A new, scaled image.
     */
    public static BufferedImage scaledImage(BufferedImage source,
            int width, int height) {
        Image scaledImage = source.getScaledInstance(width, height,
                Image.SCALE_SMOOTH);
        BufferedImage scaledBufImage = new BufferedImage(width, height,
                BufferedImage.TYPE_INT_ARGB);
        Graphics g = scaledBufImage.createGraphics();
        g.drawImage(scaledImage, 0, 0, null);
        g.dispose();
        return scaledBufImage;
    }
}

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