Geralt
c2844a5d32
* Extract rng manipulation to its own file * clang format * Get CPU cycles since game start to use for RNG * change a few things * clang format * Implement suggestions from @ricfehr3 * clang format * Fix rebase issue * clang format * Create RngInfo struct to hold seed and step * clang format * Make a note about rng_restore system not having been tested properly yet * Apply suggestions from @ricfehr3 Co-authored-by: Rickey <ric@rf3.xyz> * clang format --------- Co-authored-by: MathisMartin31 <mathis.martin31@gmail.com> Co-authored-by: Rickey <ric@rf3.xyz>
51 lines
937 B
C
51 lines
937 B
C
#include "random.h"
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#include "game_variables.h"
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#include <stdlib.h>
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#include <tonc.h>
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// Accumulate timer 1 into a bigger variable so we can generate more diverse seeds
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static u32 timer_acc = 0;
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// Timers usage docs: https://gbadev.net/tonc/timers.html
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void rng_init(void)
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{
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REG_TM1D = 0;
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REG_TM1CNT = TM_FREQ_1 | TM_ENABLE; // using timer with x1 prescale
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}
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void rng_update(void)
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{
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timer_acc += (u32)REG_TM1D;
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}
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void rng_set_seed(u32 seed)
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{
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g_game_vars.rng_info.seed = seed % (MAX_SEED + 1);
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g_game_vars.rng_info.step = 0;
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srand(g_game_vars.rng_info.seed);
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}
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void rng_shuffle_seed(void)
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{
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rng_set_seed(timer_acc);
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}
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u32 rng_get_u32(void)
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{
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g_game_vars.rng_info.step++;
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return rand();
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}
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void rng_restore(RngInfo info)
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{
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g_game_vars.rng_info = info;
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srand(g_game_vars.rng_info.seed);
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for (u32 i = 0; i < g_game_vars.rng_info.step; i++)
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{
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(void)rng_get_u32();
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}
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}
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