Mega Code Archive
Creates PNG images of the specified color that fade from fully opaque to fully transparent
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/*
* Copyright (c) 2004 David Flanagan. All rights reserved.
* This code is from the book Java Examples in a Nutshell, 3nd Edition.
* It is provided AS-IS, WITHOUT ANY WARRANTY either expressed or implied.
* You may study, use, and modify it for any non-commercial purpose,
* including teaching and use in open-source projects.
* You may distribute it non-commercially as long as you retain this notice.
* For a commercial use license, or to purchase the book,
* please visit http://www.davidflanagan.com/javaexamples3.
*/
import java.io.*;
import java.awt.*;
import java.awt.image.*;
/*
* This program creates PNG images of the specified color that fade from fully
* opaque to fully transparent. Images of this sort are useful in web design
* where they can be used as background images and combined with background
* colors to produce two-color fades. (IE6 does not support PNG transparency).
*
* Images are produced in three sizes and with and 8 directions. The images are
* written into the current directory and are given names of the form:
* fade-to-color-speed-direction.png
*
* color: the color name specified on the command line speed: slow (1024px),
* medium (512px), fast(256px) direction: a compass point: N, E, S, W, NE, SE,
* SW, NW
*
* Invoke this program with a color name and three floating-point values
* specifying the red, green, and blue components of the color.
*/
public class MakeFades {
// A fast fade is a small image, and a slow fade is a large image
public static final String[] sizeNames = { "fast", "medium", "slow" };
public static final int[] sizes = { 256, 512, 1024 };
// Direction names and coordinates
public static final String[] directionNames = { "N", "E", "S", "W", "NE", "SE", "SW", "NW" };
public static float[][] directions = { new float[] { 0f, 1f, 0f, 0f }, // North
new float[] { 0f, 0f, 1f, 0f }, // East
new float[] { 0f, 0f, 0f, 1f }, // South
new float[] { 1f, 0f, 0f, 0f }, // West
new float[] { 0f, 1f, 1f, 0f }, // Northeast
new float[] { 0f, 0f, 1f, 1f }, // Southeast
new float[] { 1f, 0f, 0f, 1f }, // Southwest
new float[] { 1f, 1f, 0f, 0f } // Northwest
};
public static void main(String[] args) throws IOException, NumberFormatException {
// Create from and to colors based on those arguments
Color from = Color.RED; // transparent
Color to = Color.BLACK; // opaque
// Loop through the sizes and directions, and create an image for each
for (int s = 0; s < sizes.length; s++) {
for (int d = 0; d < directions.length; d++) {
// This is the size of the image
int size = sizes[s];
// Create a GradientPaint for this direction and size
Paint paint = new GradientPaint(directions[d][0] * size, directions[d][1] * size, from,
directions[d][2] * size, directions[d][3] * size, to);
// Start with a blank image that supports transparency
BufferedImage image = new BufferedImage(size, size, BufferedImage.TYPE_INT_ARGB);
// Now use fill the image with our color gradient
Graphics2D g = image.createGraphics();
g.setPaint(paint);
g.fillRect(0, 0, size, size);
// This is the name of the file we'll write the image to
File file = new File("fade-to-" + sizeNames[s] + "-" + directionNames[d]
+ ".png");
// Save the image in PNG format using the javax.imageio API
javax.imageio.ImageIO.write(image, "png", file);
// Show the user our progress by printing the filename
System.out.println(file);
}
}
}
}
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