43 lines
1.3 KiB
C++
43 lines
1.3 KiB
C++
//! PRNG service. Implemented by the core, do not reimplement. Use g_create() helper function to instantiate.
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class NOVTABLE genrand_service : public service_base
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{
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public:
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//! Seeds the PRNG with specified value.
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virtual void seed(unsigned val) = 0;
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//! Returns random value N, where 0 <= N < range.
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virtual unsigned genrand(unsigned range)=0;
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double genrand_f() { return (double)genrand(0xFFFFFFFF) / (double)0xFFFFFFFF; }
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void genrand_blob( void * out, size_t bytes ) {
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size_t dwords = bytes/4;
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uint32_t * out32 = (uint32_t*) out;
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for(size_t w = 0; w < dwords; ++w ) {
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out32[w] = genrand32();
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}
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size_t left = bytes % 4;
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if (left > 0) {
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auto leftptr = (uint8_t*) out + (bytes-left);
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for( size_t w = 0; w < left; ++w) leftptr[w] = genrand8();
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}
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}
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uint32_t genrand32() {
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return (uint32_t) genrand(0xFFFFFFFF);
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}
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uint8_t genrand8() {
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return (uint8_t) genrand(0x100);
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}
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static service_ptr_t<genrand_service> g_create() {return standard_api_create_t<genrand_service>();}
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void generate_random_order(t_size * out, t_size count) {
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unsigned genrandMax = (unsigned) pfc::min_t<size_t>(count, 0xFFFFFFFF);
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t_size n;
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for(n=0;n<count;n++) out[n]=n;
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for(n=0;n<count;n++) pfc::swap_t(out[n],out[genrand(genrandMax)]);
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}
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FB2K_MAKE_SERVICE_COREAPI(genrand_service);
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};
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