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| Rev 287 | Rev 288 | ||
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| Line 173... | Line 173... | ||
| 173 | return abs(a-b); |
173 | return abs(a-b); |
| 174 | } |
174 | } |
| 175 | 175 | ||
| 176 | uint16_t gFactoryRndIndexCounter = 0; |
176 | uint16_t gFactoryRndIndexCounter = 0; |
| 177 | uint32_t gFactoryRndLookup[56]; |
177 | uint32_t gFactoryRndLookup[56]; |
| - | 178 | uint32_t gFactoryRndSeed; |
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| - | 179 | uint32_t gFactoryRndSeedSave; |
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| 178 | 180 | ||
| 179 | int32_t factory_rnd(int32_t a, int32_t b) { |
181 | void factory_fill_rnd_lookup(uint32_t seed); |
| 180 | // Algorithm of Filter Factory |
- | |
| 181 | 182 | ||
| - | 183 | uint32_t factory_rnd(uint32_t a, uint32_t b) { |
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| 182 | uint16_t rndCounterA, rndCounterB; |
184 | uint16_t rndCounterA, rndCounterB; |
| 183 | uint32_t result; |
185 | uint32_t result; |
| 184 | int32_t range; |
186 | int32_t range; |
| 185 | 187 | ||
| - | 188 | if (gFactoryRndSeed != gFactoryRndSeedSave) { |
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| - | 189 | // (Intentional) behavior of Filter Foundry |
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| - | 190 | factory_fill_rnd_lookup(gFactoryRndSeed); |
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| - | 191 | gFactoryRndIndexCounter = 0; |
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| - | 192 | } |
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| - | 193 | ||
| - | 194 | // Algorithm of Filter Factory |
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| - | 195 | ||
| 186 | rndCounterA = gFactoryRndIndexCounter % 55 + 1; |
196 | rndCounterA = gFactoryRndIndexCounter % 55 + 1; |
| 187 | rndCounterB = (gFactoryRndIndexCounter + 31) % 55 + 1; |
197 | rndCounterB = (gFactoryRndIndexCounter + 31) % 55 + 1; |
| 188 | gFactoryRndIndexCounter = rndCounterA; |
198 | gFactoryRndIndexCounter = rndCounterA; |
| 189 | 199 | ||
| 190 | result = gFactoryRndLookup[rndCounterA] - gFactoryRndLookup[rndCounterB]; |
200 | result = gFactoryRndLookup[rndCounterA] - gFactoryRndLookup[rndCounterB]; |
| Line 194... | Line 204... | ||
| 194 | range = b - a; |
204 | range = b - a; |
| 195 | if (range < 0) return 0; |
205 | if (range < 0) return 0; |
| 196 | return a + (result % (range+1)); |
206 | return a + (result % (range + 1)); |
| 197 | } |
207 | } |
| 198 | 208 | ||
| 199 | void factory_fill_rnd_lookup(int32_t seed) { |
209 | void factory_fill_rnd_lookup(uint32_t seed) { |
| 200 | // Algorithm of Filter Factory |
210 | // Algorithm of Filter Factory |
| 201 | 211 | ||
| 202 | unsigned int i, j; |
212 | uint32_t i, j; |
| 203 | unsigned int v1, v2, v3; |
213 | uint32_t v1, v2, v3; |
| 204 | 214 | ||
| 205 | // 161803398 = 1.61803398 * 10^8 ~= phi * 10^8 |
215 | // 161803398 = 1.61803398 * 10^8 ~= phi * 10^8 |
| 206 | v2 = 161803398 - (seed & 0x7fff); |
216 | v2 = 161803398 - (seed & 0x7fff); |
| 207 | gFactoryRndLookup[55] = v2; |
217 | gFactoryRndLookup[55] = v2; |
| 208 | 218 | ||
| Line 218... | Line 228... | ||
| 218 | for (j=1; j<=55;) { |
228 | for (j=1; j<=55;) { |
| 219 | gFactoryRndLookup[j++] = gFactoryRndLookup[j] - gFactoryRndLookup[((j + 30) % 55) + 1]; |
229 | gFactoryRndLookup[j++] = gFactoryRndLookup[j] - gFactoryRndLookup[((j + 30) % 55) + 1]; |
| 220 | } |
230 | } |
| 221 | } |
231 | } |
| 222 | 232 | ||
| - | 233 | gFactoryRndSeedSave = seed; |
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| - | 234 | ||
| 223 | return; |
235 | return; |
| 224 | } |
236 | } |
| 225 | 237 | ||
| 226 | int32_t factory_rst(int32_t seed) { |
238 | int32_t factory_rst(uint32_t seed) { |
| 227 | // We implement rst(i) differently in Filter Foundry: |
239 | // We implement rst(i) differently in Filter Foundry: |
| 228 | // Every call of rst() will renew the lookup table, |
240 | // Every call of rst() will renew the lookup table, |
| 229 | // while in Filter Factory, there are strange things going |
241 | // while in Filter Factory, there are strange things going |
| 230 | // on, like only setting the state in pixel [0,0,0] and |
242 | // on, like only setting the state in pixel [0,0,0] and |
| 231 | // only before rnd() is called, etc. |
243 | // only before rnd() is called, etc. |
| 232 | 244 | ||
| 233 | gFactoryRndIndexCounter = 0; |
245 | gFactoryRndSeed = seed; |
| 234 | factory_fill_rnd_lookup(seed); |
- | |
| 235 | 246 | ||
| 236 | return 0; |
247 | return 0; |
| 237 | } |
248 | } |
| 238 | 249 | ||
| 239 | void factory_initialize_rnd_variables() { |
250 | void factory_initialize_rnd_variables() { |
| 240 | const int32_t DEFAULT_SEED = 0; |
- | |
| 241 | gFactoryRndIndexCounter = 0; |
251 | gFactoryRndSeed = 0; // default seed |
| 242 | factory_fill_rnd_lookup(DEFAULT_SEED); |
252 | gFactoryRndSeedSave = gFactoryRndSeed + 1; // force rnd() to call factory_fill_rnd_lookup() |
| 243 | } |
253 | } |
| 244 | 254 | ||
| 245 | /* rnd(a,b) Random number between a and b, inclusive */ |
255 | /* rnd(a,b) Random number between a and b, inclusive */ |
| 246 | value_type ff_rnd(value_type a,value_type b){ |
256 | value_type ff_rnd(value_type a,value_type b){ |
| 247 | return factory_rnd(a,b); |
257 | return factory_rnd(a,b); |