7179526: xrender : closed/sun/java2d/volatileImage/LineClipTest.java failed since jdk8b36
Reviewed-by: prr, jchen
diff --git a/test/java/awt/Graphics/LineClipTest.java b/test/java/awt/Graphics/LineClipTest.java
new file mode 100644
index 0000000..43410f9
--- /dev/null
+++ b/test/java/awt/Graphics/LineClipTest.java
@@ -0,0 +1,504 @@
+/*
+ * Copyright (c) 2002, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code 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
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/**
+ * @test
+ * @bug   4780022 4862193 7179526
+ * @summary  Tests that clipped lines are drawn over the same pixels
+ * as unclipped lines (within the clip bounds)
+ * @run main/timeout=600/othervm -Dsun.java2d.ddforcevram=true LineClipTest
+ * @run main/timeout=600/othervm LineClipTest
+ */
+
+
+/**
+ * This app tests whether we are drawing clipped lines the same
+ * as unclipped lines.  The problem occurred when we started
+ * clipping d3d lines using simple integer clipping, which did not
+ * account for sub-pixel precision and ended up drawing very different
+ * pixels than the same line drawn unclipped.  A supposed fix
+ * to that problem used floating-point clipping instead, but there
+ * was some problem with very limited precision inside of d3d
+ * (presumably in hardware) that caused some variation in pixels.
+ * We decided that whatever the fix was, we needed a serious
+ * line check test to make sure that all kinds of different
+ * lines would be drawn exactly the same inside the clip area,
+ * regardless of whether clipping was enabled.  This test should
+ * check all kinds of different cases, such as lines that fall
+ * completely outside, completely inside, start outside and
+ * end inside, etc., and lines should end and originate in
+ * all quadrants of the space divided up by the clip box.
+ *
+ * The test works as follows:
+ * We create nine quadrants using the spaces bisected by the
+ * edges of the clip bounds (note that only one of these
+ * quadrants is actually visible when clipping is enabled).
+ * We create several points in each of these quadrants
+ * (three in each of the invisible quadrants, nine in the
+ * center/visible quadrant).  Our resulting grid looks like
+ * this:
+ *
+ *  x         x|x    x    x|x         x
+ *             |           |
+ *             |           |
+ *             |           |
+ *             |           |
+ *             |           |
+ *  x          |           |          x
+ *  -----------------------------------
+ *  x          |x    x    x|          x
+ *             |           |
+ *             |           |
+ *  x          |x    x    x|          x
+ *             |           |
+ *             |           |
+ *  x          |x    x    x|          x
+ *  -----------------------------------
+ *  x          |           |          x
+ *             |           |
+ *             |           |
+ *             |           |
+ *             |           |
+ *             |           |
+ *  x         x|x    x    x|x         x
+ *
+ * The test then draws lines from every point to every other
+ * point.  First, we draw unclipped lines in blue and
+ * then we draw clipped lines in red.
+ * At certain times (after every point during the default
+ * test, after every quadrant of lines if you run with the -quick
+ * option), we check for errors and draw the current image
+ * to the screen.  Error checking consists of copying the
+ * VolatileImage to a BufferedImage (because we need access
+ * to the pixels directly) and checking every pixel in the
+ * image.  The check is simple: everything outside the
+ * clip bounds should be blue (or the background color) and
+ * everything inside the clip bounds should be red (or the
+ * background color).  So any blue pixel inside or red
+ * pixel outside means that there was a drawing error and
+ * the test fails.
+ * There are 4 modes that the test can run in (dynamic mode is
+ * exclusive to the other modes, but the other modes are combinable):
+ *
+ *      (default): the clip is set
+ *      to a default size (100x100) and the test is run.
+ *
+ *      -quick: The error
+ *      check is run only after every quadrant of lines is
+ *      drawn.  This speeds up the test considerably with
+ *      some less accuracy in error checking (because pixels
+ *      from some lines may overdrawn pixels from other lines
+ *      before we have verified the correctness of those
+ *      pixels).
+ *
+ *      -dynamic: There is no error checking, but this version
+ *      of the test automatically resizes the clip bounds and
+ *      reruns the test over and over.  Nothing besides the
+ *      visual check verifies that the test is running correctly.
+ *
+ *      -rect: Instead of drawing lines, the test draws rectangles
+ *      to/from all points in all quadrants.  This tests similar
+ *      clipping functionality for drawRect().
+ *
+ *      n (where "n" is a number): sets the clip size to the
+ *      given value.  Just like the default test except that
+ *      the clip size is as specified.
+ *
+ * Note: this test must be run with the -Dsun.java2d.ddforcevram=true
+ * option to force the test image to stay in VRAM.  We currently
+ * punt VRAM images to system memory when we detect lots of
+ * reads.  Since we read the whole buffer on every error check
+ * to copy it to the BufferedImage), this causes us to punt the
+ * buffer.  A system memory surface will have no d3d capabilities,
+ * thus we are not testing the d3d line quality when this happens.
+ * By using the ddforcevram flag, we make sure the buffer
+ * stays put in VRAM and d3d is used to draw the lines.
+ */
+
+import javax.swing.*;
+import java.awt.*;
+import java.awt.image.*;
+
+
+public class LineClipTest extends Component implements Runnable {
+
+    int clipBumpVal = 5;
+    static int clipSize = 100;
+    int clipX1;
+    int clipY1;
+    static final int NUM_QUADS = 9;
+    Point quadrants[][] = new Point[NUM_QUADS][];
+    static boolean dynamic = false;
+    BufferedImage imageChecker = null;
+    Color unclippedColor = Color.blue;
+    Color clippedColor = Color.red;
+    int testW = -1, testH = -1;
+    VolatileImage testImage = null;
+    static boolean keepRunning = false;
+    static boolean quickTest = false;
+    static boolean rectTest = false;
+    static boolean runTestDone = false;
+    static Frame f = null;
+
+    /**
+     * Check for errors in the grid.  This error check consists of
+     * copying the buffer into a BufferedImage and reading all pixels
+     * in that image.  No pixel outside the clip bounds should be
+     * of the color clippedColor and no pixel inside should be
+     * of the color unclippedColor.  Any wrong color returns an error.
+     */
+    boolean gridError(Graphics g) {
+        boolean error = false;
+        if (imageChecker == null || (imageChecker.getWidth() != testW) ||
+            (imageChecker.getHeight() != testH))
+        {
+            // Recreate BufferedImage as necessary
+            GraphicsConfiguration gc = getGraphicsConfiguration();
+            ColorModel cm = gc.getColorModel();
+            WritableRaster wr =
+                cm.createCompatibleWritableRaster(getWidth(), getHeight());
+            imageChecker =
+                new BufferedImage(cm, wr,
+                                  cm.isAlphaPremultiplied(), null);
+        }
+        // Copy buffer to BufferedImage
+        Graphics gChecker = imageChecker.getGraphics();
+        gChecker.drawImage(testImage, 0, 0, this);
+
+        // Set up pixel colors to check against
+        int clippedPixelColor = clippedColor.getRGB();
+        int unclippedPixelColor = unclippedColor.getRGB();
+        int wrongPixelColor = clippedPixelColor;
+        boolean insideClip = false;
+        for (int row = 0; row < getHeight(); ++row) {
+            for (int col = 0; col < getWidth(); ++col) {
+                if (row >= clipY1 && row < (clipY1 + clipSize) &&
+                    col >= clipX1 && col < (clipX1 + clipSize))
+                {
+                    // Inside clip bounds - should not see unclipped color
+                    wrongPixelColor = unclippedPixelColor;
+                } else {
+                    // Outside clip - should not see clipped color
+                    wrongPixelColor = clippedPixelColor;
+                }
+                int pixel = imageChecker.getRGB(col, row);
+                if (pixel == wrongPixelColor) {
+                    System.out.println("FAILED: pixel = " +
+                                       Integer.toHexString(pixel) +
+                                       " at (x, y) = " + col + ", " + row);
+                    // Draw magenta rectangle around problem pixel in buffer
+                    // for visual feedback to user
+                    g.setColor(Color.magenta);
+                    g.drawRect(col - 1, row - 1, 2, 2);
+                    error = true;
+                }
+            }
+        }
+        return error;
+    }
+
+    /**
+     * Draw all test lines and check for errors (unless running
+     * with -dynamic option)
+     */
+    void drawLineGrid(Graphics screenGraphics, Graphics g) {
+        // Fill buffer with background color
+        g.setColor(Color.white);
+        g.fillRect(0, 0, getWidth(), getHeight());
+
+        // Now, iterate through all quadrants
+        for (int srcQuad = 0; srcQuad < NUM_QUADS; ++srcQuad) {
+            // Draw lines to all other quadrants
+            for (int dstQuad = 0; dstQuad < NUM_QUADS; ++dstQuad) {
+                for (int srcPoint = 0;
+                     srcPoint < quadrants[srcQuad].length;
+                     ++srcPoint)
+                {
+                    // For every point in the source quadrant
+                    int sx = quadrants[srcQuad][srcPoint].x;
+                    int sy = quadrants[srcQuad][srcPoint].y;
+                    for (int dstPoint = 0;
+                         dstPoint < quadrants[dstQuad].length;
+                         ++dstPoint)
+                    {
+                        int dx = quadrants[dstQuad][dstPoint].x;
+                        int dy = quadrants[dstQuad][dstPoint].y;
+                        if (!rectTest) {
+                            // Draw unclipped/clipped lines to every
+                            // point in the dst quadrant
+                            g.setColor(unclippedColor);
+                            g.drawLine(sx, sy, dx, dy);
+                            g.setClip(clipX1, clipY1, clipSize, clipSize);
+                            g.setColor(clippedColor);
+                            g.drawLine(sx,sy, dx, dy);
+                        } else {
+                            // Draw unclipped/clipped rectangles to every
+                            // point in the dst quadrant
+                            g.setColor(unclippedColor);
+                            int w = dx - sx;
+                            int h = dy - sy;
+                            g.drawRect(sx, sy, w, h);
+                            g.setClip(clipX1, clipY1, clipSize, clipSize);
+                            g.setColor(clippedColor);
+                            g.drawRect(sx, sy, w, h);
+                        }
+                        g.setClip(null);
+                    }
+                    if (!dynamic) {
+                        // Draw screen update for visual feedback
+                        screenGraphics.drawImage(testImage, 0, 0, this);
+                        // On default test, check for errors after every
+                        // src point
+                        if (!quickTest && gridError(g)) {
+                            throw new java.lang.RuntimeException("Failed");
+                        }
+                    }
+                }
+            }
+            if (!dynamic && quickTest && gridError(g)) {
+                // On quick test, check for errors only after every
+                // src quadrant
+                throw new java.lang.RuntimeException("Failed");
+                //return;
+            }
+        }
+        if (!dynamic) {
+            System.out.println("PASSED");
+            if (!keepRunning) {
+                f.dispose();
+            }
+        }
+    }
+
+    /**
+     * If we have not yet run the test, or if the window size has
+     * changed, or if we are running the test in -dynamic mode,
+     * run the test.  Then draw the test buffer to the screen
+     */
+    public void paint(Graphics g) {
+        if (dynamic || testImage == null ||
+            getWidth() != testW || getHeight() != testH)
+        {
+            runTest(g);
+        }
+        if (testImage != null) {
+            g.drawImage(testImage, 0, 0, this);
+        }
+    }
+
+    /*
+     * Create the quadrant of points and run the test to draw all the lines
+     */
+    public void runTest(Graphics screenGraphics) {
+        if (getWidth() == 0 || getHeight() == 0) {
+            // May get here before window is really ready
+            return;
+        }
+        clipX1 = (getWidth() - clipSize) / 2;
+        clipY1 = (getHeight() - clipSize) / 2;
+        int clipX2 = clipX1 + clipSize;
+        int clipY2 = clipY1 + clipSize;
+        int centerX = getWidth()/2;
+        int centerY = getHeight()/2;
+        int leftX = 0;
+        int topY = 0;
+        int rightX = getWidth() - 1;
+        int bottomY = getHeight() - 1;
+        int quadIndex = 0;
+        // Offsets are used to force diagonal (versus hor/vert) lines
+        int xOffset = 0;
+        int yOffset = 0;
+
+        if (quadrants[0] == null) {
+            for (int i = 0; i < 9; ++i) {
+                int numPoints = (i == 4) ? 9 : 3;
+                quadrants[i] = new Point[numPoints];
+            }
+        }
+        // Upper-left
+        quadrants[quadIndex] = new Point[] {
+            new Point(leftX + xOffset,          clipY1 - 1 - yOffset),
+            new Point(leftX + xOffset,          topY + yOffset),
+            new Point(clipX1 - 1 - xOffset,     topY + yOffset),
+        };
+
+        quadIndex++;
+        yOffset++;
+        // Upper-middle
+        quadrants[quadIndex] = new Point[] {
+            new Point(clipX1 + 1 + xOffset,     topY + yOffset),
+            new Point(centerX + xOffset,        topY + yOffset),
+            new Point(clipX2 - 1 - xOffset,     topY + yOffset),
+        };
+
+        quadIndex++;
+        ++yOffset;
+        // Upper-right
+        quadrants[quadIndex] = new Point[] {
+            new Point(clipX2 + 1 + xOffset,     topY + yOffset),
+            new Point(rightX - xOffset,         topY + yOffset),
+            new Point(rightX - xOffset,         clipY1 - 1 - yOffset),
+        };
+
+        quadIndex++;
+        yOffset = 0;
+        ++xOffset;
+        // Middle-left
+        quadrants[quadIndex] = new Point[] {
+            new Point(leftX + xOffset,          clipY1 + 1 + yOffset),
+            new Point(leftX + xOffset,          centerY + yOffset),
+            new Point(leftX + xOffset,          clipY2 - 1 - yOffset),
+        };
+
+        quadIndex++;
+        ++yOffset;
+        // Middle-middle
+        quadrants[quadIndex] = new Point[] {
+            new Point(clipX1 + 1 + xOffset,     clipY1 + 1 + yOffset),
+            new Point(centerX + xOffset,        clipY1 + 1 + yOffset),
+            new Point(clipX2 - 1 - xOffset,     clipY1 + 1 + yOffset),
+            new Point(clipX1 + 1 + xOffset,     centerY + yOffset),
+            new Point(centerX + xOffset,        centerY + yOffset),
+            new Point(clipX2 - 1 - xOffset,     centerY + yOffset),
+            new Point(clipX1 + 1 + xOffset,     clipY2 - 1 - yOffset),
+            new Point(centerX + xOffset,        clipY2 - 1 - yOffset),
+            new Point(clipX2 - 1 - xOffset,     clipY2 - 1 - yOffset),
+        };
+
+        quadIndex++;
+        ++yOffset;
+        // Middle-right
+        quadrants[quadIndex] = new Point[] {
+            new Point(rightX - xOffset,         clipY1 + 1 + yOffset),
+            new Point(rightX - xOffset,         centerY + yOffset),
+            new Point(rightX - xOffset,         clipY2 - 1 - yOffset),
+        };
+
+        quadIndex++;
+        yOffset = 0;
+        ++xOffset;
+        // Lower-left
+        quadrants[quadIndex] = new Point[] {
+            new Point(leftX + xOffset,          clipY2 + 1 + yOffset),
+            new Point(leftX + xOffset,          bottomY - yOffset),
+            new Point(clipX1 - 1 - xOffset,     bottomY - yOffset),
+        };
+
+        quadIndex++;
+        ++yOffset;
+        // Lower-middle
+        quadrants[quadIndex] = new Point[] {
+            new Point(clipX1 + 1 + xOffset,     bottomY - yOffset),
+            new Point(centerX + xOffset,        bottomY - yOffset),
+            new Point(clipX2 - 1 - xOffset,     bottomY - yOffset),
+        };
+
+        quadIndex++;
+        ++yOffset;
+        // Lower-right
+        quadrants[quadIndex] = new Point[] {
+            new Point(clipX2 + 1 + xOffset,     bottomY - yOffset),
+            new Point(rightX - xOffset,         bottomY - yOffset),
+            new Point(rightX - xOffset,         clipY2 + 1 + yOffset),
+        };
+
+
+        if (testImage != null) {
+            testImage.flush();
+        }
+        testW = getWidth();
+        testH = getHeight();
+        testImage = createVolatileImage(testW, testH);
+        Graphics g = testImage.getGraphics();
+        do {
+            int valCode = testImage.validate(getGraphicsConfiguration());
+            if (valCode == VolatileImage.IMAGE_INCOMPATIBLE) {
+                testImage.flush();
+                testImage = createVolatileImage(testW, testH);
+                g = testImage.getGraphics();
+            }
+            drawLineGrid(screenGraphics, g);
+        } while (testImage.contentsLost());
+        if (dynamic) {
+            // Draw clip box if dynamic
+            g.setClip(null);
+            g.setColor(Color.black);
+            g.drawRect(clipX1, clipY1, clipSize, clipSize);
+            screenGraphics.drawImage(testImage, 0, 0, this);
+        }
+        runTestDone = true;
+    }
+
+    /**
+     * When running -dynamic, resize the clip bounds and run the test
+     * over and over
+     */
+    public void run() {
+        while (true) {
+            clipSize += clipBumpVal;
+            if (clipSize > getWidth() || clipSize < 0) {
+                clipBumpVal = -clipBumpVal;
+                clipSize += clipBumpVal;
+            }
+            update(getGraphics());
+            try {
+                Thread.sleep(50);
+            } catch (Exception e) {}
+        }
+    }
+
+    public static void main(String args[]) {
+        for (int i = 0; i < args.length; ++i) {
+            if (args[i].equals("-dynamic")) {
+                dynamic = true;
+            } else if (args[i].equals("-rect")) {
+                rectTest = true;
+            } else if (args[i].equals("-quick")) {
+                quickTest = true;
+            } else if (args[i].equals("-keep")) {
+                keepRunning = true;
+            } else {
+                // could be clipSize
+                try {
+                    clipSize = Integer.parseInt(args[i]);
+                } catch (Exception e) {}
+            }
+        }
+        f = new Frame();
+        f.setSize(500, 500);
+        LineClipTest test = new LineClipTest();
+        f.add(test);
+        if (dynamic) {
+            Thread t = new Thread(test);
+            t.start();
+        }
+        f.setVisible(true);
+        while (!runTestDone) {
+            // need to make sure jtreg doesn't exit before the
+            // test is done...
+            try {
+                Thread.sleep(50);
+            } catch (Exception e) {}
+        }
+    }
+}