git subrepo clone https://github.com/HarbourMasters/soh.git

subrepo:
  subdir:   "soh"
  merged:   "ba904bbd0"
upstream:
  origin:   "https://github.com/HarbourMasters/soh.git"
  branch:   "master"
  commit:   "ba904bbd0"
git-subrepo:
  version:  "0.4.1"
  origin:   "???"
  commit:   "???"

1 files changed, 82 insertions, 0 deletions

diff --git a/soh/src/code/code_800FD970.c b/soh/src/code/code_800FD970.c
new file mode 100644
index 000000000..d1efcdc3a
--- /dev/null
+++ b/soh/src/code/code_800FD970.c
@@ -0,0 +1,82 @@
+#include "global.h"
+
+// The latest generated random number, used to generate the next number in the sequence.
+static u32 sRandInt = 1;
+
+// Space to store a value to be re-interpreted as a float.
+static u32 sRandFloat;
+
+/**
+ * Gets the next integer in the sequence of pseudo-random numbers.
+ */
+u32 Rand_Next(void) {
+    return sRandInt = (sRandInt * 1664525) + 1013904223;
+}
+
+/**
+ * Seeds the pseudo-random number generator by providing a starting value.
+ */
+void Rand_Seed(u32 seed) {
+    sRandInt = seed;
+}
+
+/**
+ * Returns a pseudo-random floating-point number between 0.0f and 1.0f, by generating
+ * the next integer and masking it to an IEEE-754 compliant floating-point number
+ * between 1.0f and 2.0f, returning the result subtract 1.0f.
+ */
+f32 Rand_ZeroOne(void) {
+    sRandInt = (sRandInt * 1664525) + 1013904223;
+    sRandFloat = ((sRandInt >> 9) | 0x3F800000);
+    return *((f32*)&sRandFloat) - 1.0f;
+}
+
+/**
+ * Returns a pseudo-random floating-point number between -0.5f and 0.5f by the same
+ * manner in which Rand_ZeroOne generates its result.
+ */
+f32 Rand_Centered(void) {
+    sRandInt = (sRandInt * 1664525) + 1013904223;
+    sRandFloat = ((sRandInt >> 9) | 0x3F800000);
+    return *((f32*)&sRandFloat) - 1.5f;
+}
+
+/**
+ * Seeds a pseudo-random number at rndNum with a provided seed.
+ */
+void Rand_Seed_Variable(u32* rndNum, u32 seed) {
+    *rndNum = seed;
+}
+
+/**
+ * Generates the next pseudo-random integer from the provided rndNum.
+ */
+u32 Rand_Next_Variable(u32* rndNum) {
+    return *rndNum = (*rndNum * 1664525) + 1013904223;
+}
+
+/**
+ * Generates the next pseudo-random floating-point number between 0.0f and
+ * 1.0f from the provided rndNum.
+ */
+f32 Rand_ZeroOne_Variable(u32* rndNum) {
+    u32 next = (*rndNum * 1664525) + 1013904223;
+
+    // clang-format off
+    *rndNum = next; sRandFloat = (next >> 9) | 0x3F800000;
+    // clang-format on
+    return *((f32*)&sRandFloat) - 1.0f;
+}
+
+/**
+ * Generates the next pseudo-random floating-point number between -0.5f and
+ * 0.5f from the provided rndNum.
+ */
+f32 Rand_Centered_Variable(u32* rndNum) {
+    u32 next = (*rndNum * 1664525) + 1013904223;
+
+    // clang-format off
+    *rndNum = next; sRandFloat = (next >> 9) | 0x3F800000;
+    // clang-format on
+    return *((f32*)&sRandFloat) - 1.5f;
+}