From e82fb3dbfe9cad5905aea2b448501c942dd5951b Mon Sep 17 00:00:00 2001
From: Marc Di Luzio <marc.diluzio@gmail.com>
Date: Sun, 7 Jun 2020 22:36:11 +0100
Subject: [PATCH] Pepper the world with rocks

---
 pkg/game/atlas.go      | 17 +++++++++++++++--
 pkg/game/atlas_test.go |  4 ++--
 pkg/game/tile.go       |  6 +++---
 pkg/game/world.go      |  2 +-
 4 files changed, 21 insertions(+), 8 deletions(-)

diff --git a/pkg/game/atlas.go b/pkg/game/atlas.go
index 4f9f684..d5d9a5a 100644
--- a/pkg/game/atlas.go
+++ b/pkg/game/atlas.go
@@ -3,6 +3,7 @@ package game
 import (
 	"fmt"
 	"log"
+	"math/rand"
 )
 
 // Chunk represents a fixed square grid of tiles
@@ -46,9 +47,21 @@ func NewAtlas(size int, chunkSize int) Atlas {
 	return a
 }
 
-// SpawnAtlasBorder surrounds the current atlas in a border wall
-func (a *Atlas) SpawnAtlasBorder() error {
+// SpawnWorld spawns the current world
+func (a *Atlas) SpawnWorld() error {
 	extent := a.ChunkSize * (a.Size / 2)
+
+	// Pepper the current world with rocks
+	for i := -extent; i < extent; i++ {
+		for j := -extent; j < extent; j++ {
+			if rand.Int()%16 == 0 {
+				if err := a.SetTile(Vector{i, j}, TileRock); err != nil {
+					return err
+				}
+			}
+		}
+	}
+
 	// Surround the atlas in walls
 	for i := -extent; i < extent; i++ {
 
diff --git a/pkg/game/atlas_test.go b/pkg/game/atlas_test.go
index 9571f8a..bb7fee5 100644
--- a/pkg/game/atlas_test.go
+++ b/pkg/game/atlas_test.go
@@ -135,13 +135,13 @@ func TestAtlas_Grown(t *testing.T) {
 	assert.Equal(t, Tile(3), tile)
 }
 
-func TestAtlas_SpawnAtlasBorder(t *testing.T) {
+func TestAtlas_SpawnWorld(t *testing.T) {
 	// Start with a small example
 	a := NewAtlas(2, 2)
 	assert.NotNil(t, a)
 	assert.Equal(t, 4, len(a.Chunks))
 
-	assert.NoError(t, a.SpawnAtlasBorder())
+	assert.NoError(t, a.SpawnWorld())
 	tile, err := a.GetTile(Vector{0, 0})
 	assert.NoError(t, err)
 	assert.Equal(t, TileEmpty, tile)
diff --git a/pkg/game/tile.go b/pkg/game/tile.go
index b0d1fb8..954f571 100644
--- a/pkg/game/tile.go
+++ b/pkg/game/tile.go
@@ -5,8 +5,8 @@ type Tile byte
 
 const (
 	TileEmpty = Tile(0)
+	TileRover = Tile(1)
 
-	TileWall = Tile(1)
-
-	TileRover = Tile(2)
+	TileWall = Tile(2)
+	TileRock = Tile(3)
 )
diff --git a/pkg/game/world.go b/pkg/game/world.go
index f6a3965..68ece50 100644
--- a/pkg/game/world.go
+++ b/pkg/game/world.go
@@ -38,7 +38,7 @@ func NewWorld() *World {
 
 // SpawnWorldBorder spawns a border at the edge of the world atlas
 func (w *World) SpawnWorldBorder() error {
-	return w.Atlas.SpawnAtlasBorder()
+	return w.Atlas.SpawnWorld()
 }
 
 // SpawnRover adds an rover to the game