From 33650b2e39a51cf3f1b130a0ef5ee28f71cd07b0 Mon Sep 17 00:00:00 2001
From: Luke Meyers <n.luke.meyers@gmail.com>
Date: Wed, 5 Feb 2020 19:26:53 -0800
Subject: [PATCH] Add phantom obstacle.

---
 game.go   | 18 +++++++++++++++---
 render.go | 44 ++++++++++++++++++++++++++++++++++++++------
 2 files changed, 53 insertions(+), 9 deletions(-)

diff --git a/game.go b/game.go
index 2de213e..6650a2b 100644
--- a/game.go
+++ b/game.go
@@ -6,8 +6,9 @@ import (
 )
 
 type state struct {
-	teams    []team
-	gameOver bool
+	teams     []team
+	obstacles []obstacle
+	gameOver  bool
 }
 
 func newState() state {
@@ -29,6 +30,12 @@ func newState() state {
 
 	return state{
 		teams: teams,
+		obstacles: []obstacle{
+			{
+				lane: 0,
+				pos:  steps / 3,
+			},
+		},
 	}
 }
 
@@ -49,6 +56,11 @@ type baton struct {
 	holder *bot
 }
 
+type obstacle struct {
+	lane int
+	pos  int
+}
+
 func updateState(sOld state) state {
 	s := sOld
 
@@ -120,7 +132,7 @@ func gameOver(s state) bool {
 const (
 	steps    = 400
 	numBots  = 10
-	numTeams = 1
+	numTeams = 2
 	maxA     = 3
 	maxV     = 20
 )
diff --git a/render.go b/render.go
index 4f39f54..88858e2 100644
--- a/render.go
+++ b/render.go
@@ -11,11 +11,13 @@ import (
 )
 
 func render(s state, w *pixelgl.Window, d time.Duration, colors map[*team]pixel.RGBA) {
+	renderBots(s, w, d, colors)
+	renderObstacles(s, w)
+}
+
+func renderBots(s state, w *pixelgl.Window, d time.Duration, colors map[*team]pixel.RGBA) {
 	b := w.Bounds()
 	im := imdraw.New(nil)
-	hOffset := b.Size().X / steps
-	vOffset := b.Size().Y / (numTeams + 1)
-	width := 20
 
 	for i, t := range s.teams {
 		for j, bot := range t.bots {
@@ -24,19 +26,45 @@ func render(s state, w *pixelgl.Window, d time.Duration, colors map[*team]pixel.
 			} else {
 				im.Color = colors[&s.teams[i]]
 			}
-			from := pixel.V(b.Min.X+float64(width)/2, b.Min.Y+float64(i+1)*vOffset)
-			pos := from.Add(pixel.V(float64(bot.pos)*hOffset, 0))
+
+			pos := lanePos(bot.pos, i, botWidth, b)
 
 			im.Push(pos)
 
 			im.Clear()
-			im.Circle(float64(width), 0)
+			im.Circle(float64(botWidth), 0)
 
 			im.Draw(w)
 		}
 	}
 }
 
+func lanePos(pos, lane int, width float64, bounds pixel.Rect) pixel.Vec {
+	hOffset := bounds.Size().X / steps
+	vOffset := bounds.Size().Y / (numTeams + 1)
+
+	return pixel.V(bounds.Min.X+width/2+float64(pos)*hOffset,
+		bounds.Min.Y+float64(lane+1)*vOffset)
+}
+
+func renderObstacles(s state, w *pixelgl.Window) {
+	b := w.Bounds()
+	im := imdraw.New(nil)
+
+	for _, o := range s.obstacles {
+		im.Color = pixel.RGB(1, 0, 1)
+
+		pos := lanePos(o.pos, o.lane, botWidth, b)
+
+		im.Push(pos)
+
+		im.Clear()
+		im.Circle(float64(botWidth), 0)
+
+		im.Draw(w)
+	}
+}
+
 func teamColors(ts []team) map[*team]pixel.RGBA {
 	m := make(map[*team]pixel.RGBA)
 	for i := range ts {
@@ -55,3 +83,7 @@ func teamColors(ts []team) map[*team]pixel.RGBA {
 	}
 	return m
 }
+
+const (
+	botWidth float64 = 20
+)