66 lines
1.5 KiB
C
66 lines
1.5 KiB
C
#include "global.h"
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#include "random.h"
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EWRAM_DATA static u8 sUnknown = 0;
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EWRAM_DATA static u32 sRandCount = 0;
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// IWRAM common
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u32 gRngValue;
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u32 gRng2Value;
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u16 Random(void)
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{
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gRngValue = ISO_RANDOMIZE1(gRngValue);
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sRandCount++;
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return gRngValue >> 16;
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}
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void SeedRng(u16 seed)
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{
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gRngValue = seed;
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sUnknown = 0;
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}
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void SeedRng2(u16 seed)
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{
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gRng2Value = seed;
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}
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u16 Random2(void)
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{
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gRng2Value = ISO_RANDOMIZE1(gRng2Value);
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return gRng2Value >> 16;
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}
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__attribute__((weak, alias("RandomUniformDefault")))
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u32 RandomUniform(enum RandomTag tag, u32 lo, u32 hi);
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__attribute__((weak, alias("RandomWeightedArrayDefault")))
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u32 RandomWeightedArray(enum RandomTag tag, u32 sum, u32 n, const u8 *weights);
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__attribute__((weak, alias("RandomElementArrayDefault")))
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const void *RandomElementArray(enum RandomTag tag, const void *array, size_t size, size_t count);
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u32 RandomUniformDefault(enum RandomTag tag, u32 lo, u32 hi)
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{
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return lo + (((hi - lo + 1) * Random()) >> 16);
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}
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u32 RandomWeightedArrayDefault(enum RandomTag tag, u32 sum, u32 n, const u8 *weights)
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{
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s32 i, targetSum;
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targetSum = (sum * Random()) >> 16;
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for (i = 0; i < n - 1; i++)
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{
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targetSum -= weights[i];
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if (targetSum < 0)
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return i;
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}
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return n - 1;
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}
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const void *RandomElementArrayDefault(enum RandomTag tag, const void *array, size_t size, size_t count)
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{
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return (const u8 *)array + size * RandomUniformDefault(tag, 0, count - 1);
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}
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