org.apache.tapestry.contrib.services.impl.ShadowRenderer Maven / Gradle / Ivy
package org.apache.tapestry.contrib.services.impl;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.awt.image.Raster;
import java.awt.image.WritableRaster;
/**
*
*/
public class ShadowRenderer {
// size of the shadow in pixels (defines the fuzziness)
private int size = 5;
// opacity of the shadow
private float opacity = 0.5f;
// color of the shadow
private Color color = Color.BLACK;
/**
* A shadow renderer needs three properties to generate shadows.
* These properties are:
*
* - size: The size, in pixels, of the shadow. This property also
* defines the fuzzyness.
* - opacity: The opacity, between 0.0 and 1.0, of the shadow.
* - color: The color of the shadow. Shadows are not meant to be
* black only.
*
* @param size the size of the shadow in pixels. Defines the fuzziness.
* @param opacity the opacity of the shadow.
* @param color the color of the shadow.
*/
public ShadowRenderer(final int size, final float opacity, final Color color) {
setSize(size);
setOpacity(opacity);
setColor(color);
}
/**
* Gets the color used by the renderer to generate shadows.
* @return this renderer's shadow color
*/
public Color getColor() {
return color;
}
/**
* Sets the color used by the renderer to generate shadows.
* Consecutive calls to {@link #createShadow} will all use this color
* until it is set again.
* If the color provided is null, the previous color will be retained.
* @param shadowColor the generated shadows color
*/
public void setColor(final Color shadowColor) {
if (shadowColor != null) {
Color oldColor = this.color;
this.color = shadowColor;
}
}
/**
* Gets the opacity used by the renderer to generate shadows.
* The opacity is comprised between 0.0f and 1.0f; 0.0f being fully
* transparent and 1.0f fully opaque.
* @return this renderer's shadow opacity
*/
public float getOpacity() {
return opacity;
}
/**
* Sets the opacity used by the renderer to generate shadows.
* Consecutive calls to {@link #createShadow} will all use this opacity
* until it is set again.
* The opacity is comprised between 0.0f and 1.0f; 0.0f being fully
* transparent and 1.0f fully opaque. If you provide a value out of these
* boundaries, it will be restrained to the closest boundary.
* @param shadowOpacity the generated shadows opacity
*/
public void setOpacity(final float shadowOpacity) {
float oldOpacity = this.opacity;
if (shadowOpacity < 0.0) {
this.opacity = 0.0f;
} else if (shadowOpacity > 1.0f) {
this.opacity = 1.0f;
} else {
this.opacity = shadowOpacity;
}
}
/**
* Gets the size in pixel used by the renderer to generate shadows.
* @return this renderer's shadow size
*/
public int getSize() {
return size;
}
/**
* Sets the size, in pixels, used by the renderer to generate shadows.
* The size defines the blur radius applied to the shadow to create the
* fuzziness.
* There is virtually no limit to the size. The size cannot be negative.
* If you provide a negative value, the size will be 0 instead.
* @param shadowSize the generated shadows size in pixels (fuzziness)
*/
public void setSize(final int shadowSize) {
int oldSize = this.size;
if (shadowSize < 0) {
this.size = 0;
} else {
this.size = shadowSize;
}
}
/**
* Generates the shadow for a given picture and the current properties
* of the renderer.
* The generated image dimensions are computed as following:
*
* width = imageWidth + 2 * shadowSize
* height = imageHeight + 2 * shadowSize
*
* @param image the picture from which the shadow must be cast
* @return the picture containing the shadow of image
*/
public BufferedImage createShadow(final BufferedImage image) {
// Written by Sesbastien Petrucci
int shadowSize = size * 2;
int srcWidth = image.getWidth();
int srcHeight = image.getHeight();
int dstWidth = srcWidth + shadowSize;
int dstHeight = srcHeight + shadowSize;
int left = size;
int right = shadowSize - left;
int yStop = dstHeight - right;
int shadowRgb = color.getRGB() & 0x00FFFFFF;
int[] aHistory = new int[shadowSize];
int historyIdx;
int aSum;
BufferedImage dst = new BufferedImage(dstWidth, dstHeight,
BufferedImage.TYPE_INT_ARGB);
int[] dstBuffer = new int[dstWidth * dstHeight];
int[] srcBuffer = new int[srcWidth * srcHeight];
getPixels(image, 0, 0, srcWidth, srcHeight, srcBuffer);
int lastPixelOffset = right * dstWidth;
float hSumDivider = 1.0f / shadowSize;
float vSumDivider = opacity / shadowSize;
int[] hSumLookup = new int[256 * shadowSize];
for (int i = 0; i < hSumLookup.length; i++) {
hSumLookup[i] = (int) (i * hSumDivider);
}
int[] vSumLookup = new int[256 * shadowSize];
for (int i = 0; i < vSumLookup.length; i++) {
vSumLookup[i] = (int) (i * vSumDivider);
}
int srcOffset;
// horizontal pass : extract the alpha mask from the source picture and
// blur it into the destination picture
for (int srcY = 0, dstOffset = left * dstWidth; srcY < srcHeight; srcY++) {
// first pixels are empty
for (historyIdx = 0; historyIdx < shadowSize; ) {
aHistory[historyIdx++] = 0;
}
aSum = 0;
historyIdx = 0;
srcOffset = srcY * srcWidth;
// compute the blur average with pixels from the source image
for (int srcX = 0; srcX < srcWidth; srcX++) {
int a = hSumLookup[aSum];
dstBuffer[dstOffset++] = a << 24; // store the alpha value only
// the shadow color will be added in the next pass
aSum -= aHistory[historyIdx]; // substract the oldest pixel from the sum
// extract the new pixel ...
a = srcBuffer[srcOffset + srcX] >>> 24;
aHistory[historyIdx] = a; // ... and store its value into history
aSum += a; // ... and add its value to the sum
if (++historyIdx >= shadowSize) {
historyIdx -= shadowSize;
}
}
// blur the end of the row - no new pixels to grab
for (int i = 0; i < shadowSize; i++) {
int a = hSumLookup[aSum];
dstBuffer[dstOffset++] = a << 24;
// substract the oldest pixel from the sum ... and nothing new to add !
aSum -= aHistory[historyIdx];
if (++historyIdx >= shadowSize) {
historyIdx -= shadowSize;
}
}
}
// vertical pass
for (int x = 0, bufferOffset = 0; x < dstWidth; x++, bufferOffset = x) {
aSum = 0;
// first pixels are empty
for (historyIdx = 0; historyIdx < left;) {
aHistory[historyIdx++] = 0;
}
// and then they come from the dstBuffer
for (int y = 0; y < right; y++, bufferOffset += dstWidth) {
int a = dstBuffer[bufferOffset] >>> 24; // extract alpha
aHistory[historyIdx++] = a; // store into history
aSum += a; // and add to sum
}
bufferOffset = x;
historyIdx = 0;
// compute the blur avera`ge with pixels from the previous pass
for (int y = 0; y < yStop; y++, bufferOffset += dstWidth) {
int a = vSumLookup[aSum];
dstBuffer[bufferOffset] = a << 24 | shadowRgb; // store alpha value + shadow color
aSum -= aHistory[historyIdx]; // substract the oldest pixel from the sum
a = dstBuffer[bufferOffset + lastPixelOffset] >>> 24; // extract the new pixel ...
aHistory[historyIdx] = a; // ... and store its value into history
aSum += a; // ... and add its value to the sum
if (++historyIdx >= shadowSize) {
historyIdx -= shadowSize;
}
}
// blur the end of the column - no pixels to grab anymore
for (int y = yStop; y < dstHeight; y++, bufferOffset += dstWidth) {
int a = vSumLookup[aSum];
dstBuffer[bufferOffset] = a << 24 | shadowRgb;
aSum -= aHistory[historyIdx]; // substract the oldest pixel from the sum
if (++historyIdx >= shadowSize) {
historyIdx -= shadowSize;
}
}
}
setPixels(dst, 0, 0, dstWidth, dstHeight, dstBuffer);
return dst;
}
/**
* Returns an array of pixels, stored as integers, from a
* BufferedImage. The pixels are grabbed from a rectangular
* area defined by a location and two dimensions. Calling this method on
* an image of type different from BufferedImage.TYPE_INT_ARGB
* and BufferedImage.TYPE_INT_RGB will unmanage the image.
*
* @param img the source image
* @param x the x location at which to start grabbing pixels
* @param y the y location at which to start grabbing pixels
* @param w the width of the rectangle of pixels to grab
* @param h the height of the rectangle of pixels to grab
* @param pixels a pre-allocated array of pixels of size w*h; can be null
* @return pixels if non-null, a new array of integers
* otherwise
* @throws IllegalArgumentException is pixels is non-null and
* of length < w*h
*/
public static int[] getPixels(BufferedImage img,
int x, int y, int w, int h, int[] pixels) {
if (w == 0 || h == 0) {
return new int[0];
}
if (pixels == null) {
pixels = new int[w * h];
} else if (pixels.length < w * h) {
throw new IllegalArgumentException("pixels array must have a length" +
" >= w*h");
}
int imageType = img.getType();
if (imageType == BufferedImage.TYPE_INT_ARGB ||
imageType == BufferedImage.TYPE_INT_RGB) {
Raster raster = img.getRaster();
return (int[]) raster.getDataElements(x, y, w, h, pixels);
}
// Unmanages the image
return img.getRGB(x, y, w, h, pixels, 0, w);
}
/**
* Writes a rectangular area of pixels in the destination
* BufferedImage. Calling this method on
* an image of type different from BufferedImage.TYPE_INT_ARGB
* and BufferedImage.TYPE_INT_RGB will unmanage the image.
*
* @param img the destination image
* @param x the x location at which to start storing pixels
* @param y the y location at which to start storing pixels
* @param w the width of the rectangle of pixels to store
* @param h the height of the rectangle of pixels to store
* @param pixels an array of pixels, stored as integers
* @throws IllegalArgumentException is pixels is non-null and
* of length < w*h
*/
public static void setPixels(BufferedImage img,
int x, int y, int w, int h, int[] pixels) {
if (pixels == null || w == 0 || h == 0) {
return;
} else if (pixels.length < w * h) {
throw new IllegalArgumentException("pixels array must have a length" +
" >= w*h");
}
int imageType = img.getType();
if (imageType == BufferedImage.TYPE_INT_ARGB ||
imageType == BufferedImage.TYPE_INT_RGB) {
WritableRaster raster = img.getRaster();
raster.setDataElements(x, y, w, h, pixels);
} else {
// Unmanages the image
img.setRGB(x, y, w, h, pixels, 0, w);
}
}
}
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