Trabajo Con Gráficos 2d en Java
-
Upload
pcdproyecto -
Category
Documents
-
view
217 -
download
0
Transcript of Trabajo Con Gráficos 2d en Java
-
8/16/2019 Trabajo Con Gráficos 2d en Java
1/1
Download Ebooks
Download JDK Search Java Tutorials Hide TOC
Home Page > 2D Graphics > Advanced Topics in Java2D Advanced Topics in Java2D
Transforming Shapes,
Text, and Images
Clipping the Drawing
Region
Compositing Graphics
Controlling Rendering
Quality
Constructing Complex
Shapes from Geometry
Primitives
Supporting User
Interaction
« Previous • Trail • Next »
Compositing Graphics
The AlphaComposite class encapsulates various compositing styles, which determine how overlapping objects are rendered. An AlphaComposite
can also have an alpha value that specifies the degree of transparency: alpha = 1.0 is totally opaque, alpha = 0.0 totally transparent (clear).
AlphaComposite supports most of the standard Porter-Duff compositing rules shown in the following table.
Compositing Rule Description
Source-over (SRC_OVER)
If pixels in the object being rendered (the source) have the same location as previously rendered pixels (the
destination), the source pixels are rendered over the destination pixels.
Source-in (SRC_IN)
If pixels in the source and the destination overlap, only the source pixels in the overlapping area are rendered.
Source-out (SRC_OUT)
If pixels in the source and the destination overlap, only the source pixels outside of the overlapping area are rendered.
The pixels in the overlapping area are cleared.
Destination-over (DST_OVER)
If pixels in the source and the destination overlap, only the source pixels outside of the overlapping area are rendered.
The pixels in the overlapping area are not changed.
Destination-in (DST_IN)
If pixels in the source and the destination overlap, the alpha from the source is applied to the destination pixels in the
overlapping area. If the alpha = 1.0, the pixels in the overlapping area are unchanged; if the alpha is 0.0, pixels in the
overlapping area are cleared.
Destination-out (DST_OUT)
If pixels in the source and the destination overlap, the alpha from the source is applied to the destination pixels in the
overlapping area. If the alpha = 1.0, the pixels in the overlapping area are cleared; if the alpha is 0.0, the pixels in the
overlapping area are unchanged.
Clear (CLEAR)
If the pixels in the source and the destination overlap, the pixels in the overlapping area are cleared.
To change the compositing style used by the Graphics2D class, create an AlphaComposite object and pass it into the setComposite method.
Example: Composite
This program illustrates the effects of various compositing style and alpha combinations.
Note: If you don't see the applet running, you need to install at least the Java SE Development Kit (JDK) 7 release.
Composite.java. contains the full code for this applet.
A newAlphaComposite object ac is constructed by calling AlphaComposite.getInstance and specifying the desired compositing rule.
AlphaComposite ac =
AlphaComposite.getInstance(AlphaComposite.SRC);
When a different compositing rule or alpha value is selected, AlphaComposite.getInstance is called again, and the new AlphaComposite is
assigned to ac . The selected alpha is applied in addition to the per-pixel alpha value and is passed as a second parameter to
AlphaComposite.getInstance.
ac = AlphaComposite.getInstance(getRule(rule), alpha);
The composite attribute is modified by passing the AlphaComposite object to Graphics 2D setComposite. The objects are rendered into a
BufferedImage and are later copied to the screen, so the composite attribute is set on the Graphics2D context for the BufferedImage:
BufferedImage buffImg = new BufferedImage(w, h,
BufferedImage.TYPE_INT_ARGB);
Graphics2D gbi = buffImg.createGraphics();
...
gbi.setComposite(ac);
« Previous • Trail • Next »
Your use of this page and all the material on pages under "The Java Tutorials" banner is subject to these legal notices.
Copyright © 1995, 2015 Oracle and/or its affiliates. Al l rights reserved.
Problems with the examples? Try Compiling and Running the Examples: FAQs.
Complaints? Compliments? Suggestions? Give us your feedback.
Documentation
The Java™ Tutorials