[core] Export Score::CENTIPAWNS_PER_POINT to the crate

This constant is a conversion factor of points to the internal fixed point unit
of centipawns. Points are more familiar to people because pawns are worth 1 pt.

Calculate the scores of the various piece shapes with this constant.

core/src/score.rs

@@ -31,7 +31,7 @@ impl Score {
     /// The maximum possible value of a score.
     pub const MAX: Score = Score(Value::MAX);
 
-    const CENTIPAWNS_PER_POINT: f32 = 100.0;
+    pub(crate) const CENTIPAWNS_PER_POINT: f32 = 100.0;
 
     #[must_use]
     pub const fn new(value: Value) -> Self {

core/src/shapes.rs

@@ -75,13 +75,16 @@ impl Shape {
     }
 
     #[must_use]
-    pub fn score(self) -> Score {
+    pub const fn score(self) -> Score {
+        #[allow(clippy::cast_possible_truncation)]
+        const CP_PER_PT: i32 = Score::CENTIPAWNS_PER_POINT as i32;
+
         match self {
-            Shape::Pawn => Score::new(100),
-            Shape::Knight | Shape::Bishop => Score::new(300),
-            Shape::Rook => Score::new(500),
-            Shape::Queen => Score::new(900),
-            Shape::King => Score::new(20000),
+            Shape::Pawn => Score::new(CP_PER_PT),
+            Shape::Knight | Shape::Bishop => Score::new(3 * CP_PER_PT),
+            Shape::Rook => Score::new(5 * CP_PER_PT),
+            Shape::Queen => Score::new(9 * CP_PER_PT),
+            Shape::King => Score::new(200 * CP_PER_PT),
         }
     }
 }