Internalise the map rect

internal/assetstore/map.go

@@ -47,12 +47,7 @@ func (a *AssetStore) Map(name string) (*Map, error) {
 	}
 
 	m := &Map{
-		Rect: image.Rect(
-			int(raw.MinWidth),
-			int(raw.MinLength),
-			int(raw.MaxWidth),
-			int(raw.MaxLength),
-		),
+		Rect: raw.Rect(),
 		assets: a,
 		raw:    raw,
 		set:    set,
@@ -65,8 +60,8 @@ func (a *AssetStore) Map(name string) (*Map, error) {
 
 func (m *Map) LoadSprites() error {
 	// Eager load the sprites we use
-	for x := m.Rect.Min.X; x <= m.Rect.Max.X; x++ {
-		for y := m.Rect.Min.Y; y <= m.Rect.Max.Y; y++ {
+	for x := m.Rect.Min.X; x < m.Rect.Max.X; x++ {
+		for y := m.Rect.Min.Y; y < m.Rect.Max.Y; y++ {
 			for z := 0; z < maps.MaxHeight; z++ {
 				if _, err := m.SpritesForCell(x, y, z); err != nil {
 					return err

internal/maps/maps.go

@@ -5,6 +5,7 @@ import (
 	"compress/gzip"
 	"encoding/binary"
 	"fmt"
+	"image"
 	"io"
 	"io/ioutil"
 	"log"
@@ -173,6 +174,15 @@ type GameMap struct {
 	Text string
 }
 
+func (m *GameMap) Rect() image.Rectangle {
+	return image.Rect(
+		int(m.Header.MinWidth),
+		int(m.Header.MinLength),
+		int(m.Header.MaxWidth),
+		int(m.Header.MaxLength),
+	)
+}
+
 // A game map contains a .txt and a .map. If they're in the same directory,
 // just pass the directory + basename to load both
 func LoadGameMap(prefix string) (*GameMap, error) {