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package sun.java2d.pipe;

This class implements the ShapeIterator interface for a Region. This is useful as the source iterator of a device clip region (in its native guise), and also as the result of clipping a Region to a rectangle.
/** * This class implements the ShapeIterator interface for a Region. * This is useful as the source iterator of a device clip region * (in its native guise), and also as the result of clipping a * Region to a rectangle. */
public class RegionSpanIterator implements SpanIterator { // The RegionIterator that we use to do the work RegionIterator ri; // Clipping bounds int lox, loy, hix, hiy; // Current Y band limits int curloy, curhiy; // Are we done? boolean done = false; // Is the associated Region rectangular? boolean isrect; /* REMIND: For native implementation long pData; // Private storage of rect info static { initIDs(); } public static native void initIDs(); */
Constructs an instance based on the given Region
/** * Constructs an instance based on the given Region */
public RegionSpanIterator(Region r) { int[] bounds = new int[4]; r.getBounds(bounds); lox = bounds[0]; loy = bounds[1]; hix = bounds[2]; hiy = bounds[3]; isrect = r.isRectangular(); ri = r.getIterator(); }
Gets the bbox of the available region spans.
/** * Gets the bbox of the available region spans. */
public void getPathBox(int pathbox[]) { pathbox[0] = lox; pathbox[1] = loy; pathbox[2] = hix; pathbox[3] = hiy; }
Intersect the box used for clipping the output spans with the given box.
/** * Intersect the box used for clipping the output spans with the * given box. */
public void intersectClipBox(int clox, int cloy, int chix, int chiy) { if (clox > lox) { lox = clox; } if (cloy > loy) { loy = cloy; } if (chix < hix) { hix = chix; } if (chiy < hiy) { hiy = chiy; } done = lox >= hix || loy >= hiy; }
Fetches the next span that needs to be operated on. If the return value is false then there are no more spans.
/** * Fetches the next span that needs to be operated on. * If the return value is false then there are no more spans. */
public boolean nextSpan(int spanbox[]) { // Quick test for end conditions if (done) { return false; } // If the Region is rectangular, we store our bounds (possibly // clipped via intersectClipBox()) in spanbox and return true // so that the caller will process the single span. We set done // to true to ensure that this will be the last span processed. if (isrect) { getPathBox(spanbox); done = true; return true; } // Local cache of current span's bounds int curlox, curhix; int curloy = this.curloy; int curhiy = this.curhiy; while (true) { if (!ri.nextXBand(spanbox)) { if (!ri.nextYRange(spanbox)) { done = true; return false; } // Update the current y band and clip it curloy = spanbox[1]; curhiy = spanbox[3]; if (curloy < loy) { curloy = loy; } if (curhiy > hiy) { curhiy = hiy; } // Check for moving below the clip rect if (curloy >= hiy) { done = true; return false; } continue; } // Clip the x box curlox = spanbox[0]; curhix = spanbox[2]; if (curlox < lox) { curlox = lox; } if (curhix > hix) { curhix = hix; } // If it's non- box, we're done if (curlox < curhix && curloy < curhiy) { break; } } // Update the result and the store y range spanbox[0] = curlox; spanbox[1] = this.curloy = curloy; spanbox[2] = curhix; spanbox[3] = this.curhiy = curhiy; return true; }
This method tells the iterator that it may skip all spans whose Y range is completely above the indicated Y coordinate.
/** * This method tells the iterator that it may skip all spans * whose Y range is completely above the indicated Y coordinate. */
public void skipDownTo(int y) { loy = y; }
This method returns a native pointer to a function block that can be used by a native method to perform the same iteration cycle that the above methods provide while avoiding upcalls to the Java object. The definition of the structure whose pointer is returned by this method is defined in:
    src/share/native/sun/java2d/pipe/SpanIterator.h
/** * This method returns a native pointer to a function block that * can be used by a native method to perform the same iteration * cycle that the above methods provide while avoiding upcalls to * the Java object. * The definition of the structure whose pointer is returned by * this method is defined in: * <pre> * src/share/native/sun/java2d/pipe/SpanIterator.h * </pre> */
public long getNativeIterator() { return 0; } /* * Cleans out all internal data structures. * REMIND: Native implementation public native void dispose(); protected void finalize() { dispose(); } */ }