Implement kick system (badly, because I think it actually doesn't work yet...)

2 files changed, 54 insertions, 32 deletions

diff --git a/tris/move.go b/tris/move.go
index 26dd568..127ce06 100644
--- a/tris/move.go
+++ b/tris/move.go
@@ -1,11 +1,57 @@
 package tris
 
+// As at the bottom of https://tetris.fandom.com/wiki/SRS but Y inverse because we start Y at the top
+type Kicks map[Rotation][]Point
+
+var K3CW = Kicks{
+	0: {{X:0, Y:0}, {X:-1, Y:0}, {X:-1, Y: -1}, {X:0, Y:2}, {X:-1, Y:2}},
+	1: {{X:0, Y:0}, {X:1, Y:0}, {X:1, Y: 1}, {X:0, Y:-2}, {X:1, Y:-2}},
+	2: {{X:0, Y:0}, {X:1, Y:0}, {X:1, Y: -1}, {X:0, Y:2}, {X:1, Y:2}},
+	3: {{X:0, Y:0}, {X:-1, Y:0}, {X:-1, Y: 1}, {X:0, Y:-2}, {X:-1, Y:-2}},
+}
+
+var LCW = Kicks{
+	0: {{X:0, Y:0}, {X:-2, Y:0}, {X:1, Y: 0}, {X:-2, Y:1}, {X:1, Y:-2}},
+	1: {{X:0, Y:0}, {X:-1, Y:0}, {X:2, Y: 0}, {X:-1, Y:-2}, {X:2, Y:1}},
+	2: {{X:0, Y:0}, {X:2, Y:0}, {X:-1, Y: 0}, {X:2, Y:-1}, {X:-1, Y:2}},
+	3: {{X:0, Y:0}, {X:1, Y:0}, {X:-2, Y: 0}, {X:1, Y:2}, {X:-2, Y:-1}},
+}
+
+func (ks Kicks) Try(rot Rotation, reverse bool, p Placement, f Field) (np Placement) {
+	orot := (rot + 3)%4
+	if reverse { // for going backwards, you start from one more
+		rot--
+		orot = (rot + 1)%4
+	}
+	for _, k := range ks[rot] {
+		np = p
+		x, y := k.X, k.Y
+		if reverse {
+			x, y = -x, -y
+		}
+		np.X, np.Y = p.X+x, p.Y+y
+		if !np.Collide(f) {
+			return np
+		}
+	}
+	p.Rot = orot
+	return p
+}
+
 func (p Placement) Floor(f Field) bool {
 	fp := p
 	fp.Y++
 	return fp.Collide(f)
 }
 
+// CW checks if the rotation from r to nr is a Clockwise rotation
+func (r Rotation) CW(nr Rotation) bool {
+	r += 4
+	return (r - nr)%4 == 1 // if nr is 1 modulo 4 higher than r, it is a CW rotation
+}
+
+// Move tries the move indicated by the parameters, applies kicks to fix when it doesn't work,
+// and returns if the piece is on the floor or topping out
 func (p Placement) Move(f Field, rot Rotation, x, y int) (np Placement, floor, topout bool) {
 	np = p
 	np.Rot = rot
@@ -14,6 +60,14 @@ func (p Placement) Move(f Field, rot Rotation, x, y int) (np Placement, floor, t
 	if !np.Collide(f) { // free air
 		return np, np.Floor(f), false
 	}
+	// start handling kicks
+	switch p.piece {
+	case IPiece:
+		np = LCW.Try(rot, np.Rot.CW(rot), np, f)
+	case JPiece, SPiece, ZPiece, TPiece, LPiece:
+		np = K3CW.Try(rot, np.Rot.CW(rot), np, f)
+	}
+
 	np = p // last resort reset p
 	if np.Floor(f) && np.Y < 0 {
 		return np, true, true
diff --git a/tris/srs.go b/tris/srs.go
deleted file mode 100644
index d6c8220..0000000
--- a/tris/srs.go
+++ /dev/null
@@ -1,32 +0,0 @@
-package tris
-
-// As at the bottom of https://tetris.fandom.com/wiki/SRS but Y inverse because we start Y at the top
-type Kicks map[Rotation][]Point
-
-var K3CW = Kicks{
-	0: {{X:0, Y:0}, {X:-1, Y:0}, {X:-1, Y: -1}, {X:0, Y:2}, {X:-1, Y:2}},
-	1: {{X:0, Y:0}, {X:1, Y:0}, {X:1, Y: 1}, {X:0, Y:-2}, {X:1, Y:-2}},
-	2: {{X:0, Y:0}, {X:1, Y:0}, {X:1, Y: -1}, {X:0, Y:2}, {X:1, Y:2}},
-	3: {{X:0, Y:0}, {X:-1, Y:0}, {X:-1, Y: 1}, {X:0, Y:-2}, {X:-1, Y:-2}},
-}
-
-var K3CCW = Kicks{
-	1: {{X:0, Y:0}, {X:1, Y:0}, {X:1, Y: 1}, {X:0, Y:-2}, {X:1, Y:-2}},
-	2: {{X:0, Y:0}, {X:-1, Y:0}, {X:-1, Y:-1}, {X:0, Y:2}, {X:-1, Y:2}},
-	3: {{X:0, Y:0}, {X:-1, Y:0}, {X:-1, Y: 1}, {X:0, Y:-2}, {X:-1, Y:-2}},
-	0: {{X:0, Y:0}, {X:1, Y:0}, {X:1, Y: -1}, {X:0, Y:2}, {X:1, Y:2}},
-}
-
-var LCW = Kicks{
-	0: {{X:0, Y:0}, {X:-2, Y:0}, {X:1, Y: 0}, {X:-2, Y:1}, {X:1, Y:-2}},
-	1: {{X:0, Y:0}, {X:-1, Y:0}, {X:2, Y: 0}, {X:-1, Y:-2}, {X:2, Y:1}},
-	2: {{X:0, Y:0}, {X:2, Y:0}, {X:-1, Y: 0}, {X:2, Y:-1}, {X:-1, Y:2}},
-	3: {{X:0, Y:0}, {X:1, Y:0}, {X:-2, Y: 0}, {X:1, Y:2}, {X:-2, Y:-1}},
-}
-
-var LCCW = Kicks{
-	1: {{X:0, Y:0}, {X:2, Y:0}, {X:-1, Y: 0}, {X:2, Y:-1}, {X:-1, Y:2}},
-	2: {{X:0, Y:0}, {X:1, Y:0}, {X:-2, Y: 0}, {X:1, Y:2}, {X:-2, Y:-1}},
-	3: {{X:0, Y:0}, {X:-2, Y:0}, {X:1, Y: 0}, {X:-2, Y:1}, {X:1, Y:-2}},
-	0: {{X:0, Y:0}, {X:-1, Y:0}, {X:2, Y: 0}, {X:-1, Y:-2}, {X:2, Y:1}},
-}