Games: Pong, Snake and Tetris as seeded state machines, and a tune

The rules of the three Games (issue #101), with no screen and no keyboard in them: time and keys go in, the new state and what happened come out, and a seed decides the dice. With a player for a tune a note at a time, and Korobeiniki's notes. Host-tested. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_0162FokPdvY2KsS4NBfwyWPk
2026-10-13 22:59:05 +02:00
parent 5c660d866d
commit 68d50b320f
9 changed files with 1417 additions and 0 deletions
@@ -0,0 +1,25 @@
+#pragma once
+
+#include <cstdint>
+
+namespace roro::games {
+
+// The Games' own dice (issue #101): the same seed gives the same game, which is what lets their
+// rules be tested. xorshift32; never 0.
+class Rng {
+   public:
+    explicit Rng(uint32_t seed) : s_(seed ? seed : 0x9E3779B9u) {}
+    uint32_t next() {
+        s_ ^= s_ << 13;
+        s_ ^= s_ >> 17;
+        s_ ^= s_ << 5;
+        return s_;
+    }
+    int below(int n) { return n <= 1 ? 0 : static_cast<int>(next() % static_cast<uint32_t>(n)); }
+    float unit() { return (next() >> 8) / 16777216.0f; }  // 0 up to 1
+
+   private:
+    uint32_t s_;
+};
+
+}  // namespace roro::games