warn low policy moves (kaorahi/lizzie#7)

src/draw_goban.js

@@ -733,6 +733,7 @@ function draw_branches(h, xy, radius, g) {
 
 // ref. https://github.com/featurecat/lizzie/issues/671#issuecomment-586090067
 function draw_loss(h, xy, radius, g) {
+    draw_low_policy(h, xy, radius, g)
     const {gain, punished} = h, NOTHING = []
     const [color, size, draw, min_width] = !truep(gain) ? NOTHING :
           (gain <= big_blunder_threshold) ? [RED, 1, rev_triangle_around, 0.7] :
@@ -746,6 +747,17 @@ function draw_loss(h, xy, radius, g) {
     draw(xy, radius * size - line_width, g)
 }
 
+function draw_low_policy(h, xy, radius, g) {
+    const very_low_policy = 0.01, low_policy = 0.1, very_high_policy = 0.7
+    const {policy, max_policy} = h; if (!max_policy) {return}
+    const draw = (line_width) => {
+        g.strokeStyle = '#888'; g.lineWidth = line_width
+        square_around(xy, radius * 0.7 - line_width, g)
+    }
+    max_policy > very_high_policy && policy < low_policy ? draw(3) :
+        policy < very_low_policy ? draw(1) : null
+}
+
 function draw_shadow_maybe(h, xy, radius, cheap_shadow_p, g) {
     if (!h.stone) {return}
     const {stone_image, style} = stone_style_for(h)

src/powered_goban.js

@@ -461,6 +461,10 @@ function winrate_from_game(engine_id) {
             merge(cur, {gain})
             s <= game.move_count && merge_to_stone_at(cur, {gain})
             record_punished(gain)
+            const {suggest} = prev; if (!suggest) {return}
+            const max_policy = Math.max(...suggest.map(h => h.prior))
+            const policy = (suggest.find(h => h.move === cur.move) || {}).prior || 0.0
+            merge_to_stone_at(cur, {policy, max_policy})
         }
         const record_punished = gain => {
             const prev_gain = (prev || {}).gain

src/util.js

@@ -56,6 +56,9 @@ E.handicap_komi = -0.5
 E.default_gorule = 'chinese'
 E.blunder_threshold = -2
 E.big_blunder_threshold = -5
+E.blunder_very_low_policy = 0.01
+E.blunder_low_policy = 0.1
+E.blunder_high_policy = 0.7
 E.black_to_play_p = (forced, bturn) => forced ? (forced === 'black') : bturn
 
 // seq(3) = [ 0, 1, 2 ], seq(3, 5) = [ 5, 6, 7 ], seq(-2) = []