Merge pull request #67 from Next-Flip/fix-random

Explain RNG differences, Fix JS Math.random()
Next-Flip · Apr 2, 2024 · 0f5e763 · 0f5e763
2 parents b8b25b0 + c5dcea0
commit 0f5e763
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Showing 3 changed files with 7 additions and 3 deletions.
diff --git a/applications/external b/applications/external
diff --git a/applications/system/js_app/modules/js_math.c b/applications/system/js_app/modules/js_math.c
@@ -211,7 +211,7 @@ void js_math_random(struct mjs* mjs) {
         mjs_return(mjs, MJS_UNDEFINED);
     }
     const uint32_t random_val = furi_hal_random_get();
-    double rnd = (double)random_val / RAND_MAX;
+    double rnd = (double)random_val / FURI_HAL_RANDOM_MAX;
     mjs_return(mjs, mjs_mk_number(mjs, rnd));
 }
 

diff --git a/targets/furi_hal_include/furi_hal_random.h b/targets/furi_hal_include/furi_hal_random.h
@@ -6,12 +6,16 @@
 extern "C" {
 #endif
 
+#define FURI_HAL_RANDOM_MAX 0xFFFFFFFF
+
 /** Initialize random subsystem */
 void furi_hal_random_init(void);
 
 /** Get random value
+ * furi_hal_random_get() gives up to FURI_HAL_RANDOM_MAX
+ * rand() and random() give up to RAND_MAX
  *
- * @return     random value
+ * @return     32 bit random value (up to FURI_HAL_RANDOM_MAX)
  */
 uint32_t furi_hal_random_get(void);