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Diffstat (limited to 'libjava/classpath/gnu/java/awt/java2d/ScanlineConverter.java')
| -rw-r--r-- | libjava/classpath/gnu/java/awt/java2d/ScanlineConverter.java | 451 |
1 files changed, 0 insertions, 451 deletions
diff --git a/libjava/classpath/gnu/java/awt/java2d/ScanlineConverter.java b/libjava/classpath/gnu/java/awt/java2d/ScanlineConverter.java deleted file mode 100644 index 2c3481b6c10..00000000000 --- a/libjava/classpath/gnu/java/awt/java2d/ScanlineConverter.java +++ /dev/null @@ -1,451 +0,0 @@ -/* ScanlineConverter.java -- Rasterizes Shapes - Copyright (C) 2006, 2007 Free Software Foundation, Inc. - -This file is part of GNU Classpath. - -GNU Classpath is free software; you can redistribute it and/or modify -it under the terms of the GNU General Public License as published by -the Free Software Foundation; either version 2, or (at your option) -any later version. - -GNU Classpath is distributed in the hope that it will be useful, but -WITHOUT ANY WARRANTY; without even the implied warranty of -MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU -General Public License for more details. - -You should have received a copy of the GNU General Public License -along with GNU Classpath; see the file COPYING. If not, write to the -Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA -02110-1301 USA. - -Linking this library statically or dynamically with other modules is -making a combined work based on this library. Thus, the terms and -conditions of the GNU General Public License cover the whole -combination. - -As a special exception, the copyright holders of this library give you -permission to link this library with independent modules to produce an -executable, regardless of the license terms of these independent -modules, and to copy and distribute the resulting executable under -terms of your choice, provided that you also meet, for each linked -independent module, the terms and conditions of the license of that -module. An independent module is a module which is not derived from -or based on this library. If you modify this library, you may extend -this exception to your version of the library, but you are not -obligated to do so. If you do not wish to do so, delete this -exception statement from your version. */ - - -package gnu.java.awt.java2d; - -import gnu.java.math.Fixed; - -import java.awt.RenderingHints; -import java.awt.Shape; -import java.awt.geom.AffineTransform; -import java.awt.geom.PathIterator; - -/** - * Rasterizes {@link Shape} objects on an AbstractGraphics2D. - */ -public final class ScanlineConverter -{ - - /** - * The number of digits to use for fixed point arithmetics. - */ - private static int FIXED_DIGITS = 6; - - /** - * The fixed point constant for the number one. - */ - private static int ONE = Fixed.fixedValue(FIXED_DIGITS, 1); - - /** - * The actual number of scanlines. - */ - private int numScanlines; - - /** - * The number of scanlines. This can contain more elements than we have - * scanlines. The real number of scanlines is stored in - * {@link #numScanlines}. This can also contain null values for empty - * scanlines. - */ - private Scanline[] scanlines; - - /** - * The upper bounds which correspond to the index 0 in the scanline array. - * - * This is a fixed point value. - */ - private int upperBounds; - - /** - * The resolution of the scanline converter. - * - * This is a fixed point value. - */ - private int resolution; - - /** - * The number of significant bits for the 'Y' resolution. - */ - private int yResolution; - - /** - * One half step according to the resolution. This is stored to avoid - * unnecessary operations during rendering. - */ - private int halfStep; - - /** - * This is used in {@link #addShape(PathIterator, boolean)} to - * receive the coordinates of the path. - */ - private float[] coords; - - /** - * The active edges. - */ - private ActiveEdges activeEdges; - - private PolyEdge edgePool; - private PolyEdge edgePoolLast; - - private int minY; - private int maxY; - private int minX; - private int maxX; - - /** - * Holds and manages information about the pixel coverage. - */ - private ScanlineCoverage scanlineCoverage; - - /** - * Create a new ScanlineConverter. - */ - ScanlineConverter() - { - scanlines = new Scanline[10]; - coords = new float[6]; - activeEdges = new ActiveEdges(); - edgePool = new PolyEdge(); - edgePoolLast = edgePool; - scanlineCoverage = new ScanlineCoverage(); - } - - /** - * Renders the specified shape using the specified clip and transform. - * - * @param p the pixelizer that receives the coverage information - * @param shape the shape to render - * @param clip the clip - * @param trans the transform - */ - public void renderShape(Pixelizer p, Shape shape, Shape clip, - AffineTransform trans, int res, int yRes, - RenderingHints hints) - { - // TODO: Do something useful with the rendering hints. Like, adjusting - // the resolution. - - // Prepare resolution and upper bounds. - clear(); - setResolution(res, yRes); - - boolean haveClip = clip != null; - - // Add shapes. - float flatness = Fixed.floatValue(FIXED_DIGITS, resolution / 2); - PathIterator path = shape.getPathIterator(trans, flatness); - addShape(path, false); - if (haveClip) - { - path= clip.getPathIterator(trans, flatness); - addShape(path, true); - } - - setUpperBounds(minY); - - PolyEdge edge = edgePool; - while (edge != edgePoolLast) - { - addEdge(edge); - edge = edge.poolNext; - } - - int y = upperBounds; - int index; - activeEdges.clear(); - // The render loop... - Scanline scanline = null; - int lastRealY = Fixed.intValue(FIXED_DIGITS, y); - while (y <= maxY) - { - // First we put together our list of active edges. - index = scanlineIndex(y); - // If we go outside the scanline array we still need to render the - // remaining edges until they end. - scanline = index < scanlines.length ? scanlines[index] : null; - if (scanline != null) - { - edge = scanline.getEdges(); - while (edge != null) - { - activeEdges.add(edge); - edge = edge.scanlineNext; - } - } - - // Then we intersect all active edges with the current scanline - // and sort them according to their intersection points. - activeEdges.intersectSortAndPack(FIXED_DIGITS, y + halfStep); - - // Ok, now we can perform the actual scanlining. - int realY = Fixed.intValue(FIXED_DIGITS, y + resolution); - boolean push = lastRealY != realY; - - doScanline(p, y, push, haveClip); - - // Remove obsolete active edges. - //activeEdges.remove(y + halfStep); - // Go on with the next line... - y += resolution; - lastRealY = realY; - - } - } - - /** - * Clears all scanlines. - */ - private void clear() - { - // Reset edge pool. - edgePoolLast = edgePool; - - // Reset scanlines. - for (int i = scanlines.length - 1; i >= 0 ; i--) - { - Scanline sl = scanlines[i]; - if (sl != null) - sl.clear(); - } - - // Reset scanline coverage. - scanlineCoverage.clear(); - - // Reset bounds. - minY = Integer.MAX_VALUE; - maxY = Integer.MIN_VALUE; - minX = Integer.MAX_VALUE; - maxX = Integer.MIN_VALUE; - } - - /** - * Performs the scanlining on the current set of active edges. - * - * @param p the pixelizer to receive the pixel coverage data - * @param y the Y coordinate - * @param push true when the scanline is ready to be pushed to the - * pixelizer - * @param haveClip true when there's a clip, false otherwise - */ - private void doScanline(Pixelizer p, int y, boolean push, - boolean haveClip) - { - // First, rewind the scanline coverage. - scanlineCoverage.rewind(); - - // We begin outside the clip and outside the shape. We only draw when - // we are inside the clip AND inside the shape. - boolean inClip = ! haveClip; - boolean inShape = false; - PolyEdge lastEdge = null; - int numEdges = activeEdges.getNumActiveEdges(); - for (int i = 0; i < numEdges; i++) - { - PolyEdge edge = activeEdges.getActiveEdge(i); - if (inClip && inShape) - { - assert lastEdge != null; - int x0 = lastEdge.xIntersection; - int x1 = edge.xIntersection; - assert x0 <= x1; - - int pix0 = Fixed.intValue(FIXED_DIGITS, x0); - int pix1 = Fixed.intValue(FIXED_DIGITS, x1); - int frac0 = ONE - Fixed.trunc(FIXED_DIGITS, x0); - int frac1 = ONE - Fixed.trunc(FIXED_DIGITS, x1); - // Only keep the first 4 digits after the point. - frac0 = frac0 >> (FIXED_DIGITS - yResolution); - frac1 = frac1 >> (FIXED_DIGITS - yResolution); - scanlineCoverage.add(pix0, 1 * (1 << yResolution), frac0); - scanlineCoverage.add(pix1, -1 * (1 << yResolution), -frac1); - } - if (edge.isClip) - inClip = ! inClip; - else - inShape = ! inShape; - - lastEdge = edge; - } - - // Push out the whole scanline to the pixelizer. - if (push && ! scanlineCoverage.isEmpty()) - { - p.renderScanline(Fixed.intValue(FIXED_DIGITS, y), scanlineCoverage); - scanlineCoverage.clear(); - } - } - - - /** - * Sets the resolution. A value of 0 rasterizes the shape normally without - * anti-aliasing. Greater values renders with a resolution of 2 ^ res. - * - * @param res the resolution - */ - private void setResolution(int res, int yRes) - { - int scanlinesPerPixel = 1 << res; - int one = Fixed.fixedValue(FIXED_DIGITS, 1); - resolution = one / (scanlinesPerPixel); - halfStep = resolution / 2; - - scanlineCoverage.setMaxCoverage(scanlinesPerPixel << yResolution); - - yResolution = yRes; - } - - /** - * Sets the vertical bounds of that shape that is beeing rendered. - * - * @param y0 the upper bounds - */ - private void setUpperBounds(int y0) - { - upperBounds = fit(y0); - } - - /** - * Add a shape to the scanline converter. - * - * @param path - * @param clip - */ - private void addShape(PathIterator path, boolean clip) - { - int startX = 0; - int startY = 0; - int lastX = 0; - int lastY = 0; - while (! path.isDone()) - { - int type = path.currentSegment(coords); - switch (type) - { - case PathIterator.SEG_MOVETO: - startX = lastX = Fixed.fixedValue(FIXED_DIGITS, coords[0]); - startY = lastY = Fixed.fixedValue(FIXED_DIGITS, coords[1]); - minY = Math.min(startY, minY); - maxY = Math.max(startY, maxY); - minX = Math.min(startX, minX); - maxX = Math.max(startX, maxX); - break; - case PathIterator.SEG_LINETO: - int x = Fixed.fixedValue(FIXED_DIGITS, coords[0]); - int y = Fixed.fixedValue(FIXED_DIGITS, coords[1]); - edgePoolAdd(lastX, lastY, x, y, clip); - lastX = x; - lastY = y; - minY = Math.min(lastY, minY); - maxY = Math.max(lastY, maxY); - minX = Math.min(lastX, minX); - maxX = Math.max(lastX, maxX); - break; - case PathIterator.SEG_CLOSE: - edgePoolAdd(lastX, lastY, startX, startY, clip); - lastX = startX; - lastY = startY; - break; - case PathIterator.SEG_CUBICTO: - case PathIterator.SEG_QUADTO: - default: - assert false; - } - path.next(); - } - } - - /** - * Adds an edge into the scanline array. - */ - private void addEdge(PolyEdge edge) - { - // Determine index. - int upper = Math.min(edge.y0, edge.y1); - // Fit to raster. - int index = scanlineIndex(upper); - // Grow array when necessary. - if (index >= scanlines.length) - { - int oldSize = scanlines.length; - int newSize = Math.max(oldSize + oldSize / 2 + 1, index + 10); - Scanline[] newScanlines = new Scanline[newSize]; - System.arraycopy(scanlines, 0, newScanlines, 0, oldSize); - scanlines = newScanlines; - } - - // Add edge. - if (scanlines[index] == null) - { - scanlines[index] = new Scanline(); - } - scanlines[index].addEdge(edge); - } - - /** - * Fits an Y coordinate to the grid. - * - * @param y the Y coordinate to fit - * - * @return the fitted Y coordinate - */ - private int fit(int y) - { - int val1 = Fixed.div(FIXED_DIGITS, y, resolution); - int rounded = Fixed.round(FIXED_DIGITS, val1); - return Fixed.mul(FIXED_DIGITS, rounded, resolution); - } - - /** - * Calculates the scanline index for the specified y coordinate. - * - * @param y the y coordinate as fixed point value - * - * @return the scanline index - */ - private int scanlineIndex(int y) - { - int fitted = fit(y); - // Cleverly skip the fixed point conversions here. - return (fitted - upperBounds)/ resolution; - } - - private void edgePoolAdd(int x0, int y0, int x1, int y1, boolean clip) - { - // Don't need no horizontal edges. - if (y0 != y1) - { - edgePoolLast.init(FIXED_DIGITS, x0, y0, x1, y1, clip); - if (edgePoolLast.poolNext == null) - { - edgePoolLast.poolNext = new PolyEdge(); - } - edgePoolLast = edgePoolLast.poolNext; - } - } -} |