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24 
25 /**
26  * @test
27  * @bug 7047069
28  * @summary Array can dynamically change size when assigned to an object field
29  *
30  * @run main/othervm -Xbatch Test7047069
31  */
32 
33 import java.util.*;
34 import java.awt.geom.*;
35 
36 public class Test7047069 {
37     static boolean verbose;
38 
39     static final int GROW_SIZE = 24;    // Multiple of cubic & quad curve size
40 
41     float squareflat;           // Square of the flatness parameter
42                     // for testing against squared lengths
43 
44     int limit;              // Maximum number of recursion levels
45 
46     float hold[] = new float[14];   // The cache of interpolated coords
47                     // Note that this must be long enough
48                     // to store a full cubic segment and
49                     // a relative cubic segment to avoid
50                     // aliasing when copying the coords
51                     // of a curve to the end of the array.
52                     // This is also serendipitously equal
53                     // to the size of a full quad segment
54                     // and 2 relative quad segments.
55 
56     int holdEnd;            // The index of the last curve segment
57                     // being held for interpolation
58 
59     int holdIndex;          // The index of the curve segment
60                     // that was last interpolated.  This
61                     // is the curve segment ready to be
62                     // returned in the next call to
63                     // currentSegment().
64 
65     int levels[];           // The recursion level at which
66                     // each curve being held in storage
67                     // was generated.
68 
69     int levelIndex;         // The index of the entry in the
70                     // levels array of the curve segment
71                     // at the holdIndex
72 
subdivide(float src[], int srcoff, float left[], int leftoff, float right[], int rightoff)73     public static void subdivide(float src[], int srcoff,
74                                  float left[], int leftoff,
75                                  float right[], int rightoff)
76     {
77         float x1 = src[srcoff + 0];
78         float y1 = src[srcoff + 1];
79         float ctrlx = src[srcoff + 2];
80         float ctrly = src[srcoff + 3];
81         float x2 = src[srcoff + 4];
82         float y2 = src[srcoff + 5];
83         if (left != null) {
84             left[leftoff + 0] = x1;
85             left[leftoff + 1] = y1;
86         }
87         if (right != null) {
88             right[rightoff + 4] = x2;
89             right[rightoff + 5] = y2;
90         }
91         x1 = (x1 + ctrlx) / 2f;
92         y1 = (y1 + ctrly) / 2f;
93         x2 = (x2 + ctrlx) / 2f;
94         y2 = (y2 + ctrly) / 2f;
95         ctrlx = (x1 + x2) / 2f;
96         ctrly = (y1 + y2) / 2f;
97         if (left != null) {
98             left[leftoff + 2] = x1;
99             left[leftoff + 3] = y1;
100             left[leftoff + 4] = ctrlx;
101             left[leftoff + 5] = ctrly;
102         }
103         if (right != null) {
104             right[rightoff + 0] = ctrlx;
105             right[rightoff + 1] = ctrly;
106             right[rightoff + 2] = x2;
107             right[rightoff + 3] = y2;
108         }
109     }
110 
getFlatnessSq(float coords[], int offset)111     public static double getFlatnessSq(float coords[], int offset) {
112         return Line2D.ptSegDistSq(coords[offset + 0], coords[offset + 1],
113                                   coords[offset + 4], coords[offset + 5],
114                                   coords[offset + 2], coords[offset + 3]);
115     }
116 
Test7047069()117     public Test7047069() {
118         this.squareflat = .0001f * .0001f;
119         holdIndex = hold.length - 6;
120         holdEnd = hold.length - 2;
121         hold[holdIndex + 0] = (float) (Math.random() * 100);
122         hold[holdIndex + 1] = (float) (Math.random() * 100);
123         hold[holdIndex + 2] = (float) (Math.random() * 100);
124         hold[holdIndex + 3] = (float) (Math.random() * 100);
125         hold[holdIndex + 4] = (float) (Math.random() * 100);
126         hold[holdIndex + 5] = (float) (Math.random() * 100);
127         levelIndex = 0;
128         this.limit = 10;
129         this.levels = new int[limit + 1];
130     }
131 
132     /*
133      * Ensures that the hold array can hold up to (want) more values.
134      * It is currently holding (hold.length - holdIndex) values.
135      */
ensureHoldCapacity(int want)136     void ensureHoldCapacity(int want) {
137         if (holdIndex - want < 0) {
138             int have = hold.length - holdIndex;
139             int newsize = hold.length + GROW_SIZE;
140             float newhold[] = new float[newsize];
141             System.arraycopy(hold, holdIndex,
142                      newhold, holdIndex + GROW_SIZE,
143                      have);
144             if (verbose) System.err.println("old hold = "+hold+"["+hold.length+"]");
145             if (verbose) System.err.println("replacement hold = "+newhold+"["+newhold.length+"]");
146             hold = newhold;
147             if (verbose) System.err.println("new hold = "+hold+"["+hold.length+"]");
148             if (verbose) System.err.println("replacement hold still = "+newhold+"["+newhold.length+"]");
149             holdIndex += GROW_SIZE;
150             holdEnd += GROW_SIZE;
151         }
152     }
153 
next()154     private boolean next() {
155         if (holdIndex >= holdEnd) {
156             return false;
157         }
158 
159         int level = levels[levelIndex];
160         while (level < limit) {
161             if (getFlatnessSq(hold, holdIndex) < squareflat) {
162                 break;
163             }
164 
165             ensureHoldCapacity(4);
166             subdivide(hold, holdIndex,
167                       hold, holdIndex - 4,
168                       hold, holdIndex);
169             holdIndex -= 4;
170 
171             // Now that we have subdivided, we have constructed
172             // two curves of one depth lower than the original
173             // curve.  One of those curves is in the place of
174             // the former curve and one of them is in the next
175             // set of held coordinate slots.  We now set both
176             // curves level values to the next higher level.
177             level++;
178             levels[levelIndex] = level;
179             levelIndex++;
180             levels[levelIndex] = level;
181         }
182 
183         // This curve segment is flat enough, or it is too deep
184         // in recursion levels to try to flatten any more.  The
185         // two coordinates at holdIndex+4 and holdIndex+5 now
186         // contain the endpoint of the curve which can be the
187         // endpoint of an approximating line segment.
188         holdIndex += 4;
189         levelIndex--;
190         return true;
191     }
192 
main(String argv[])193     public static void main(String argv[]) {
194         verbose = (argv.length > 0);
195         for (int i = 0; i < 100000; i++) {
196             Test7047069 st = new Test7047069();
197             while (st.next()) {}
198         }
199     }
200 }
201