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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
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package com.codename1.ui.util;
import com.codename1.ui.Component;
import com.codename1.ui.Display;
import com.codename1.ui.Graphics;
import com.codename1.ui.Image;
import com.codename1.ui.RGBImage;
/**
* Static utility class useful for simple visual effects that don't quite fit
* anywhere else in the core API.
*
* @author Shai Almog
*/
public class Effects {
private Effects() {}
/**
* Takes the given image and appends an effect of reflection below it that
* is similar to the way elements appear in water beneath them. This method
* shouldn't be used when numAlpha is very low.
*
* @param source image to add the reflection effect to
* @return new image with a reflection effect for the source image
*/
public static Image reflectionImage(Image source) {
return reflectionImage(source, 0.5f, 120);
}
/**
* Takes the given image and appends an effect of reflection below it that
* is similar to the way elements appear in water beneath them. This method
* shouldn't be used when numAlpha is very low.
*
* @param source image to add the reflection effect to
* @param mirrorRatio generally less than 1, a mirror ration of 0.5f will create a mirror image half the
* height of the image, 0.75f will create a 3 quarter height mirror etc.
* @param alphaRatio starting point for the alpha value in the mirror, this should be a number between 0 - 255
* (recommended larger than 0) indicating the opacity of the closest pixel. For a mirror thats completely
* opaque use 255. A recommended value would be between 128 to 90.
* @return new image with a reflection effect for the source image
*/
public static Image reflectionImage(Image source, float mirrorRatio, int alphaRatio) {
return reflectionImage(source, mirrorRatio, alphaRatio, 0);
}
/**
* Takes the given image and appends an effect of reflection below it that
* is similar to the way elements appear in water beneath them. This method
* shouldn't be used when numAlpha is very low.
*
* @param source image to add the reflection effect to
* @param mirrorRatio generally less than 1, a mirror ration of 0.5f will create a mirror image half the
* height of the image, 0.75f will create a 3 quarter height mirror etc.
* @param alphaRatio starting point for the alpha value in the mirror, this should be a number between 0 - 255
* (recommended larger than 0) indicating the opacity of the closest pixel. For a mirror thats completely
* opaque use 255. A recommended value would be between 128 to 90.
* @param spacing the distance in pixels between the image and its reflection
* @return new image with a reflection effect for the source image
*/
public static Image reflectionImage(Image source, float mirrorRatio, int alphaRatio, int spacing) {
int w = source.getWidth();
int h = source.getHeight();
int mirrorHeight = ((int)(h * mirrorRatio)) * w;
// create an array big enough to hold the mirror data
RGBImage rgbImg = new RGBImage(new int[w * (h + spacing) + mirrorHeight], w, h + ((int)(h * mirrorRatio) + spacing));
source.toRGB(rgbImg, 0, 0, 0, 0, w, h);
int[] imageData = rgbImg.getRGB();
int ilen = imageData.length;
for(int iter = 0 ; iter < mirrorHeight ; iter++) {
int sourcePos = w * h - iter - 1;
int off = iter % w;
off = w - off + iter - off;
int mirrorPos = ilen - (mirrorHeight - off) + (spacing * w);
int color = imageData[sourcePos];
// if the color is not transparent
if((color & 0xff000000) != 0 && mirrorPos < ilen) {
int alpha = (int)(alphaRatio * ((float)mirrorHeight - iter) / ((float)mirrorHeight));
imageData[mirrorPos] = (imageData[sourcePos] & 0xffffff) | ((alpha << 24) & 0xff000000);
}
}
return rgbImg;
}
/**
* Grows or shrinks the given component to its new preferred size, this method
* essentially takes a component whose preferred size has changed and creates a "growing"
* effect that lasts for the duration. Notice that some components (such as text areas)
* don't report proper preferred size untill they are laid out once. Hence the first time
* around a text area (or container containing a text area) will not produce the expected
* effect. This can be solved by invoking revalidate before the call to this method only the
* first time around!
*
* @param c the component to grow/shrink, its size must be different from its preferred size
* @param duration the duration in milliseconds for the grow/shrink animation
* @deprecated use Component.growShrink instead
*/
public static void growShrink(final Component c, int duration) {
c.growShrink(duration);
}
/**
* Skews an image in a faux perspective transform on the vertical axis, this is effectively a fast scale
* algorithm that both shrinks the image vertically and reduces the width
* @param topScaleRatio the amount by which the top portion should be scaled where 1.0 means none
* @param bottomScaleRatio the amount by which the bottom portion should be scaled where 1.0 means none
* @param verticalShrink the scale ratio for the image height where 1.0 means none
* @return the perspective translated image
*/
public static Image verticalPerspective(Image i, float topScaleRatio, float bottomScaleRatio, float verticalShrink) {
int[] imageData = i.getRGB();
int sourceWidth = i.getWidth();
int sourceHeight = i.getHeight();
int destinationWidth = (int)(Math.max(topScaleRatio, bottomScaleRatio) * sourceWidth);
int destinationHeight = (int)(verticalShrink * sourceHeight);
int[] destinationArray = new int[destinationWidth * destinationHeight];
// faster than math.min
float diff;
if(bottomScaleRatio < topScaleRatio) {
float smaller = bottomScaleRatio;
float larger = topScaleRatio;
diff = smaller - larger;
} else {
float larger = bottomScaleRatio;
float smaller = topScaleRatio;
diff = larger - smaller;
}
if(destinationWidth > sourceWidth) {
for(int y = 0 ; y < destinationHeight ; y++) {
float positionY = ((float)y) / ((float)destinationHeight - 1);
int sourceY = (int)((float)(sourceHeight - 1) * positionY);
float currentRowRatio = (topScaleRatio + (diff * positionY)) / bottomScaleRatio;
//int minX = (int)(((float)destinationWidth - sourceWidth) / 2.0f * currentRowRatio);
int minX = (int)(((float)destinationWidth) * (1 - currentRowRatio));
int maxX = destinationWidth - minX;
float distance = maxX - minX;
for(int x = minX ; x < maxX ; x++) {
int sourceX = (int)(((float)sourceWidth) * (((float)x - minX) / distance));
destinationArray[x + y * destinationWidth] = imageData[sourceY * sourceWidth + sourceX];
}
}
} else {
for(int y = 0 ; y < destinationHeight ; y++) {
float positionY = ((float)y) / ((float)destinationHeight);
int sourceY = (int)((float)sourceHeight * positionY);
float currentRowRatio = topScaleRatio + (diff * positionY);
int minX = (int)(((float)destinationWidth) * (1 - currentRowRatio));
int maxX = destinationWidth - minX;
float distance = maxX - minX;
for(int x = minX ; x < maxX ; x++) {
int sourceX = (int)(((float)sourceWidth) * (((float)x - minX) / distance));
destinationArray[x + y * destinationWidth] = imageData[sourceY * sourceWidth + sourceX];
}
}
}
return Image.createImage(destinationArray, destinationWidth, destinationHeight);
}
/**
* Create a blur image from the given image.
* The algorithm is gaussian blur - https://en.wikipedia.org/wiki/Gaussian_blur
*
* @param image the image to blur
* @param radius the radius to be used in the algorithm
*/
public static Image gaussianBlurImage(Image image, float radius){
return Display.getInstance().gaussianBlurImage(image, radius);
}
/**
* Returns true if gaussian blur is supported on this platform
*
* @return true if gaussian blur is supported.
*/
public static boolean isGaussianBlurSupported(){
return Display.getInstance().isGaussianBlurSupported();
}
/**
* Generates a shadow for the source image and returns a new larger image containing the shadow
*
* @param source the source image for whom the shadow should be generated
* @param blurRadius a shadow is blurred using a gaussian blur when available, a value of 10 is often satisfactory
* @param opacity the opacity of the shadow between 0 - 1 where 1 is completely opaque
* @param xDistance the distance on the x axis from the main image body in pixels e.g. a negative value will represent a lightsource from the right (shadow on the left)
* @param yDistance the distance on the y axis from the main image body in pixels e.g. a negative value will represent a lightsource from the bottom (shadow on top)
* @return a new image whose size incorporates x/yDistance
*/
public static Image dropshadow(Image source, int blurRadius, float opacity, int xDistance, int yDistance) {
Image s = dropshadow(source, blurRadius, opacity);
Image n = Image.createImage(source.getWidth() + Math.abs(xDistance), source.getHeight() + Math.abs(yDistance), 0);
Graphics g = n.getGraphics();
int shadowX = 0, imageX = 0, shadowY = 0, imageY = 0;
if(xDistance < 0) {
imageX = xDistance * -1;
} else {
shadowX = xDistance;
}
if(yDistance < 0) {
imageY = yDistance * -1;
} else {
shadowY = yDistance;
}
g.drawImage(s, shadowX, shadowY);
g.drawImage(source, imageX, imageY);
return n;
}
/**
* Generates a shadow for the source image and returns either the shadow itself or the image merged with the
* shadow.
*
* @param source the source image for whom the shadow should be generated
* @param blurRadius a shadow is blurred using a gaussian blur when available, a value of 10 is often satisfactory
* @param opacity the opacity of the shadow between 0 - 1 where 1 is completely opaque
* @return an image containing the shadow for source
*/
public static Image dropshadow(Image source, int blurRadius, float opacity) {
int[] rgb = source.getRGB();
for(int iter = 0 ; iter < rgb.length ; iter++) {
float f = rgb[iter] & 0xff000000;
f *= opacity;
rgb[iter] = (int)f;
}
Image shadow = Image.createImage(rgb, source.getWidth(), source.getHeight());
if(Display.getInstance().isGaussianBlurSupported()) {
shadow = Display.getInstance().gaussianBlurImage(shadow, blurRadius);
}
return shadow;
}
}