From cfd3d919426325797647e57034b9ff8051672a4c Mon Sep 17 00:00:00 2001
From: Fraser Graham <frasergraham@me.com>
Date: Wed, 6 Nov 2013 22:21:04 -0800
Subject: [PATCH] filter projectiles and objects by scanners

---
 game.go     | 34 +++++++++++++++++++++++++++++++++-
 obstacle.go | 12 ++++++++++++
 2 files changed, 45 insertions(+), 1 deletion(-)

diff --git a/game.go b/game.go
index e3b7ee6..893a2a6 100644
--- a/game.go
+++ b/game.go
@@ -165,7 +165,6 @@ func (g *game) send_update(payload *Boardstate) {
 	for p := range g.players {
 		// Copy the payload but only add the robots in scanner range
 		player_payload := NewBoardstate()
-		player_payload.Projectiles = payload.Projectiles
 		player_payload.Splosions = payload.Splosions
 		player_payload.Obstacles = payload.Obstacles
 		player_payload.AllBots = payload.AllBots
@@ -176,7 +175,11 @@ func (g *game) send_update(payload *Boardstate) {
 			player_payload.OtherRobots,
 			p.Robot.GetTruncatedDetails())
 
+		player_payload.Projectiles = []Projectile{}
+		player_payload.Obstacles = []Obstacle{}
+
 		if p.Robot.Health > 0 {
+			// Filter robots by scanner
 			for player := range g.players {
 				for _, scan_entry := range p.Robot.Scanners {
 					if player.Robot.Id == scan_entry.Id {
@@ -186,8 +189,37 @@ func (g *game) send_update(payload *Boardstate) {
 					}
 				}
 			}
+
+			// Filter projectiles
+			for proj := range g.projectiles {
+
+				if proj.Owner == p {
+					player_payload.Projectiles = append(
+						player_payload.Projectiles,
+						*proj)
+				}
+
+				for _, scan_entry := range p.Robot.Scanners {
+					if proj.Id == scan_entry.Id {
+						player_payload.Projectiles = append(
+							player_payload.Projectiles,
+							*proj)
+					}
+				}
+			}
+
+			// Filter objects
+			for _, ob := range g.obstacles {
+				if ob.distance_from_point(p.Robot.Position) < float32(p.Robot.Stats.ScannerRadius) {
+					player_payload.Obstacles = append(
+						player_payload.Obstacles,
+						ob)
+				}
+			}
 		} else {
 			player_payload.OtherRobots = payload.OtherRobots
+			player_payload.Projectiles = payload.Projectiles
+			player_payload.Obstacles = payload.Obstacles
 		}
 
 		// x, _ := json.Marshal(player_payload)
diff --git a/obstacle.go b/obstacle.go
index bbb9516..5f2aff2 100644
--- a/obstacle.go
+++ b/obstacle.go
@@ -2,6 +2,7 @@ package main
 
 import (
 	v "bitbucket.org/hackerbots/vector"
+	"math"
 	"math/rand"
 )
 
@@ -9,6 +10,17 @@ type Obstacle struct {
 	Bounds v.Rect2d `json:"bounds"`
 }
 
+func (o Obstacle) distance_from_point(p v.Point2d) float32 {
+	dist := math.MaxFloat32
+
+	dist = math.Min(dist, float64(p.Sub(o.Bounds.A).Mag()))
+	dist = math.Min(dist, float64(p.Sub(o.Bounds.B).Mag()))
+	dist = math.Min(dist, float64(p.Sub(v.Point2d{o.Bounds.A.X, o.Bounds.B.Y}).Mag()))
+	dist = math.Min(dist, float64(p.Sub(v.Point2d{o.Bounds.B.X, o.Bounds.A.Y}).Mag()))
+
+	return float32(dist)
+}
+
 func GenerateObstacles(count int, width, height float32) []Obstacle {
 	out := []Obstacle{}
 	for i := 0; i < count; i++ {