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package sun.java2d.pipe;
/**
* This interface defines a general method for iterating through the
* rectangular "spans" that represent the interior of a filled path.
* <p>
* There can be many kinds of span iterators used in the rendering
* pipeline, the most basic being an iterator that scan converts a
* path defined by any PathIterator, or an nested iterator which
* intersects another iterator's spans with a clip region.
* Other iterators can be created for scan converting some of the
* primitive shapes more explicitly for speed or quality.
*
* @author Jim Graham
*/
public interface SpanIterator {
/**
* This method returns the bounding box of the spans that the
* iterator will be returning.
* The array must be of length at least 4 and upon return, it
* will be filled with the values:
* <pre>
* {PathMinX, PathMinY, PathMaxX, PathMaxY}.
* </pre>
*/
public void getPathBox(int pathbox[]);
/**
* This method constrains the spans returned by nextSpan() to the
* rectangle whose bounds are given.
*/
public void intersectClipBox(int lox, int loy, int hix, int hiy);
/**
* This method returns the next span in the shape being iterated.
* The array must be of length at least 4 and upon return, it
* will be filled with the values:
* <pre>
* {SpanMinX, SpanMinY, SpanMaxX, SpanMaxY}.
* </pre>
*/
public boolean nextSpan(int spanbox[]);
/**
* This method tells the iterator that it may skip all spans
* whose Y range is completely above the indicated Y coordinate.
* This method is used to provide feedback from the caller when
* clipping prevents the display of any data in a given Y range.
* Typically it will only be called when this iterator has returned
* a span whose MaxY coordinate is less than the indicated Y and
* the calling mechanism wants to avoid unnecessary iteration work.
* While this request could technically be ignored (i.e. a NOP),
* doing so could potentially cause the caller to make this callback
* for each span that is being skipped.
*/
public void skipDownTo(int 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:
* <pre>
* src/share/native/sun/java2d/pipe/SpanIterator.h
* </pre>
*/
public long getNativeIterator();
}