v1.3.0: simplify payouts to bet x symbol x shape

3 files changed, 71 insertions, 47 deletions

diff --git a/src/client/games/slots.rs b/src/client/games/slots.rs
index a417e7d..ad9ef5c 100644
--- a/src/client/games/slots.rs
+++ b/src/client/games/slots.rs
@@ -1,5 +1,5 @@
 use super::traits::{Game, GamePhase, GameState};
-use crate::slots::{paytable_lines, REELS, ROWS};
+use crate::slots::{paytable_lines, LINE_NAMES, REELS, ROWS};
 
 /// Height of the game board. It must never depend on the spin result.
 pub const SLOT_BOARD_LINES: usize = 10;
@@ -81,7 +81,21 @@ impl SlotsGame {
         }
         match state.data.get("win_lines").map(String::as_str) {
             Some(lines) if !lines.is_empty() && lines != "-" => {
-                format!("Winning lines: {lines}")
+                let named: Vec<String> = lines
+                    .split(',')
+                    .filter_map(|raw| raw.trim().parse::<usize>().ok())
+                    .map(|line| {
+                        let name = line
+                            .checked_sub(1)
+                            .and_then(|index| LINE_NAMES.get(index))
+                            .copied();
+                        match name {
+                            Some(name) => format!("{line} ({name})"),
+                            None => line.to_string(),
+                        }
+                    })
+                    .collect();
+                format!("Winning lines: {}", named.join(", "))
             }
             _ => String::new(),
         }
@@ -126,15 +140,14 @@ impl Game for SlotsGame {
         "SLOTS GAME\n\
         =========\n\
         5 reels x 3 rows, 5 paylines.\n\
-        Match 3, 4 or 5 symbols from the left on a payline.\n\
+        A win needs 3, 4 or 5 matching symbols from reel 1 on a payline.\n\
         \n\
-        Payouts (x total bet, 3/4/5 of a kind):\n\
-        C: 2 / 5 / 15\n\
-        L: 3 / 7 / 20\n\
-        O: 3 / 8 / 25\n\
-        G: 4 / 12 / 40\n\
-        D: 6 / 18 / 70\n\
-        S: 9 / 30 / 150\n\
+        Payout = total bet x symbol x shape\n\
+        Symbols: C=1 L=2 O=3 G=4 D=6 S=10\n\
+        Shapes: 3 of a kind=1, 4 of a kind=3, 5 of a kind=14\n\
+        \n\
+        Lines: 1 top, 2 middle, 3 bottom, 4 V, 5 inverted V\n\
+        Multiple winning lines are added together.\n\
         \n\
         Symbols: C=Cherry, L=Lemon, O=Orange, G=Grapes, D=Diamond, S=Seven\n\
         \n\
diff --git a/src/server/games/slots.rs b/src/server/games/slots.rs
index e9f58b1..298cd4c 100644
--- a/src/server/games/slots.rs
+++ b/src/server/games/slots.rs
@@ -1,5 +1,5 @@
 use super::traits::{Game, GameError, GamePhase, GameResult, GameState};
-use crate::slots::PAYTABLE;
+use crate::slots::{SHAPE_MULTIPLIERS, SYMBOL_MULTIPLIERS};
 use rand::Rng;
 use std::collections::HashMap;
 
@@ -27,10 +27,18 @@ pub struct SlotsGame {
 
 impl SlotsGame {
     pub fn new() -> Self {
-        let payouts = PAYTABLE
+        // payout = bet * symbol multiplier * shape multiplier
+        let payouts = SYMBOL_MULTIPLIERS
             .iter()
-            .map(|&(symbol, three, four, five)| {
-                (symbol, Payout { three, four, five })
+            .map(|&(symbol, symbol_multiplier)| {
+                (
+                    symbol,
+                    Payout {
+                        three: symbol_multiplier * SHAPE_MULTIPLIERS[0].1,
+                        four: symbol_multiplier * SHAPE_MULTIPLIERS[1].1,
+                        five: symbol_multiplier * SHAPE_MULTIPLIERS[2].1,
+                    },
+                )
             })
             .collect();
 
@@ -116,17 +124,15 @@ impl SlotsGame {
         let p4 = 5.0 / 7776.0;
         let p5 = 1.0 / 7776.0;
 
-        let per_line: f64 = self
-            .payouts
-            .values()
-            .map(|payout| {
-                p3 * payout.three as f64
-                    + p4 * payout.four as f64
-                    + p5 * payout.five as f64
-            })
+        let symbol_sum: f64 = SYMBOL_MULTIPLIERS
+            .iter()
+            .map(|(_, multiplier)| *multiplier as f64)
             .sum();
+        let shape_ev = p3 * SHAPE_MULTIPLIERS[0].1 as f64
+            + p4 * SHAPE_MULTIPLIERS[1].1 as f64
+            + p5 * SHAPE_MULTIPLIERS[2].1 as f64;
 
-        per_line * PAYLINES.len() as f64
+        symbol_sum * shape_ev * PAYLINES.len() as f64
     }
 }
 
diff --git a/src/slots.rs b/src/slots.rs
index a3b4ef4..9e41f05 100644
--- a/src/slots.rs
+++ b/src/slots.rs
@@ -13,33 +13,38 @@ pub const PAYLINES: [[usize; REELS]; 5] = [
     [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),
+pub const LINE_NAMES: [&str; 5] = ["top", "middle", "bottom", "V", "inverted V"];
+
+/// Symbol value multipliers.
+pub const SYMBOL_MULTIPLIERS: [(char, u64); 6] = [
+    ('C', 1),
+    ('L', 2),
+    ('O', 3),
+    ('G', 4),
+    ('D', 6),
+    ('S', 10),
 ];
 
-/// Paytable rendered under the reels, split so it fits a narrow terminal.
+/// (match length, shape multiplier): 3, 4 or 5 of a kind.
+pub const SHAPE_MULTIPLIERS: [(usize, u64); 3] = [(3, 1), (4, 3), (5, 14)];
+
+/// Paytable rendered under the reels.
+///
+/// `payout = bet * symbol_multiplier * shape_multiplier`.
 pub fn paytable_lines() -> Vec<String> {
-    let entries: Vec<String> = PAYTABLE
+    let symbols = SYMBOL_MULTIPLIERS
+        .iter()
+        .map(|(symbol, multiplier)| format!("{symbol}{multiplier}"))
+        .collect::<Vec<_>>()
+        .join(" ");
+    let shapes = SHAPE_MULTIPLIERS
         .iter()
-        .map(|(symbol, three, four, five)| format!("{symbol} {three}/{four}/{five}"))
-        .collect();
+        .map(|(length, multiplier)| format!("{length}:{multiplier}"))
+        .collect::<Vec<_>>()
+        .join(" ");
 
-    entries
-        .chunks(3)
-        .enumerate()
-        .map(|(index, chunk)| {
-            let prefix = if index == 0 {
-                "Pays 3/4/5 x bet: "
-            } else {
-                ""
-            };
-            format!("{}{}", prefix, chunk.join(" "))
-        })
-        .collect()
+    vec![
+        "Pays bet x symbol x shape".to_string(),
+        format!("Symbol {symbols}   Shape {shapes}"),
+    ]
 }