diff options
Diffstat (limited to 'jeu-test/Lemmini/0.84/src/Game/LevelCode.java')
| -rw-r--r-- | jeu-test/Lemmini/0.84/src/Game/LevelCode.java | 120 |
1 files changed, 120 insertions, 0 deletions
diff --git a/jeu-test/Lemmini/0.84/src/Game/LevelCode.java b/jeu-test/Lemmini/0.84/src/Game/LevelCode.java new file mode 100644 index 0000000..bfc707e --- /dev/null +++ b/jeu-test/Lemmini/0.84/src/Game/LevelCode.java @@ -0,0 +1,120 @@ +package Game;
+
+/*
+ * Copyright 2009 Volker Oth
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/**
+ * @author Volker Oth
+ * Create and evaluate lemmings level codes
+ * Based on the documentation and Basic code of Herman Perk (LemGen)
+ */
+public class LevelCode {
+ // nibble 0 | nibble 1 | nibble 2 | nibble 3 | nibble 4 | nibble 5 | nibble 6
+ // ----------|----------|----------|-----------|----------|----------|---------
+ // 3 2 1 0| 3 2 1 0|3 2 1 0| 3 2 1 0| 3 2 1 0|3 2 1 0|3 2 1 0
+ // ----------|----------|----------|-----------|----------|----------|---------
+ // L0 %0 S0 0|S1 L1 0 %1|0 L2 %2 S2|S4 S3 %3 L3|%4 0 L4 S5|0 %5 S6 L5|0 L6 0 %6
+
+ /* magic: S*/
+ private final static int MMASK[] = { 1, 2, 4, 24, 32, 64, 0};
+ private final static int MSHIFTL[] = { 1, 2, 0, 0, 0, 0, 0};
+ private final static int MSHIFTR[] = { 0, 0, 2, 1, 5, 5, 0};
+ /* level: L */
+ private final static int LMASK[] = { 1, 2, 4, 8, 16, 32, 64};
+ private final static int LSHIFTL[] = { 3, 1, 0, 0, 0, 0, 0};
+ private final static int LSHIFTR[] = { 0, 0, 0, 3, 3, 5, 4};
+ /* percent: % */
+ private final static int PMASK[] = { 1, 2, 4, 8, 16, 32, 64};
+ private final static int PSHIFTL[] = { 2, 0, 0, 0, 0, 0, 0};
+ private final static int PSHIFTR[] = { 0, 1, 1, 2, 1, 3, 6};
+
+ private final static int MAX_LVL_NUM = 127;
+
+
+ /**
+ * Create a level code from the given parameters
+ * @param seed The seed string used as base for the level code
+ * @param lvl The level number (0..127)
+ * @param percent Percentage of levels saved in the level won to get this code
+ * @param magic A "magic" number with more or less unknown sense
+ * @param offset Used to get a higher code for the first level
+ * @return String containing level code
+ */
+ public static String create(final String seed, int lvl, final int percent, final int magic, final int offset) {
+ if (lvl > MAX_LVL_NUM || percent > 127 || magic > 127 || seed==null || seed.length() != 10)
+ return null;
+ byte bi[] = seed.getBytes();
+ byte bo[] = new byte[bi.length];
+
+ // add offset and wrap around
+ int level = lvl + offset;
+ level %= (MAX_LVL_NUM+1);
+
+ // create first 7 bytes
+ int sum = 0;
+ for (int i=0; i<7; i++) {
+ bi[i] += (byte)(((magic & MMASK[i]) << MSHIFTL[i]) >>> MSHIFTR[i]);
+ bi[i] += (byte)(((level & LMASK[i]) << LSHIFTL[i]) >>> LSHIFTR[i]);
+ bi[i] += (byte)(((percent & PMASK[i]) << PSHIFTL[i]) >>> PSHIFTR[i]);
+ bo[(i + 8 - (level % 8)) % 7] = bi[i]; // rotate
+ sum += bi[i] & 0xff; // checksum
+ }
+ // create bytes 8th and 9th byte (level)
+ bo[7] = (byte)(bi[7] + (level & 0xf));
+ bo[8] = (byte)(bi[8] + ((level & 0xf0) >> 4));
+ sum += (bo[7] + bo[8]) & 0xff;
+ // create 10th byte (checksum)
+ bo[9] = (byte)(bi[9] + (sum & 0x0f));
+ return new String(bo);
+ }
+
+ /**
+ * Extract the level number from the level code and seed
+ * @param seed The seed string used as base for the level code
+ * @param code Code that contains the level number (amongst other things)
+ * @param offset Used to get a higher code for the first level
+ * @return Level number extracted from the level code (-1 in case of error)
+ */
+ public static int getLevel(final String seed, final String code, final int offset) {
+ byte bs[] = seed.getBytes();
+ byte bi[] = code.getBytes();
+ byte bo[] = new byte[bi.length];
+
+ if (seed.length() != 10 || code.length() != 10)
+ return -1;
+
+ int level = ((bi[7]-bs[7]) & 0xf) + (((bi[8]-bs[8])& 0xf)<<4);
+ // unrotate
+ for (int j=0; j<7; j++)
+ bo[(j + 6 + (level % 8)) % 7] = bi[j];
+ //decode
+ int level_ = 0;
+ int percent = 0;
+ for (int i=0; i<7; i++) {
+ int nibble = (bo[i] - bs[i]) & 0xff; // reconstruct nibble stored
+ level_ += ((nibble << LSHIFTR[i]) >> LSHIFTL[i]) & LMASK[i];
+ percent += ((nibble << PSHIFTR[i]) >> PSHIFTL[i]) & PMASK[i];
+ }
+ if (level != level_ || percent > 100)
+ return -1;
+
+ level -= offset;
+ while (level < 0)
+ level += MAX_LVL_NUM;
+
+ return level;
+ }
+}
|