v1.2.0: show the symbol paytable on the slots board

1 files changed, 33 insertions, 0 deletions

diff --git a/src/slots.rs b/src/slots.rs
new file mode 100644
index 0000000..561c449
--- /dev/null
+++ b/src/slots.rs
@@ -0,0 +1,33 @@
+//! Shared slots rules used by both the server engine and the client board.
+
+pub const REELS: usize = 5;
+pub const ROWS: usize = 3;
+pub const SYMBOLS: [char; 6] = ['C', 'L', 'O', 'G', 'D', 'S'];
+
+/// Five paylines, each entry is the row used on reel 0..4.
+pub const PAYLINES: [[usize; REELS]; 5] = [
+    [0, 0, 0, 0, 0], // line 1: top
+    [1, 1, 1, 1, 1], // line 2: middle
+    [2, 2, 2, 2, 2], // line 3: bottom
+    [0, 1, 2, 1, 0], // line 4: V
+    [2, 1, 0, 1, 2], // line 5: inverted V
+];
+
+/// (symbol, 3-of-a-kind, 4-of-a-kind, 5-of-a-kind) multipliers of total bet.
+pub const PAYTABLE: [(char, u64, u64, u64); 6] = [
+    ('C', 2, 5, 15),
+    ('L', 3, 7, 20),
+    ('O', 3, 8, 25),
+    ('G', 4, 12, 40),
+    ('D', 6, 18, 70),
+    ('S', 9, 30, 150),
+];
+
+/// One-line paytable rendered under the reels.
+pub fn paytable_line() -> String {
+    let entries: Vec<String> = PAYTABLE
+        .iter()
+        .map(|(symbol, three, four, five)| format!("{symbol} {three}/{four}/{five}"))
+        .collect();
+    format!("Pays 3/4/5 x bet: {}", entries.join(" "))
+}