First pass at custom cursor display

internal/assetstore/cursor.go

@@ -0,0 +1,100 @@
+package assetstore
+
+import (
+	"image"
+
+	"github.com/hajimehoshi/ebiten"
+)
+
+// These are just offsets into the Cursors.cur file
+type CursorName int
+
+type Cursor struct {
+	Hotspot image.Point
+	Image   *ebiten.Image
+}
+
+const (
+	UltPointer   CursorName = 0
+	ChaosPointer CursorName = 1
+	UltWaiter    CursorName = 2
+	ChaosWaiter  CursorName = 3
+
+	// I think these cursors are used in drag + drop
+	ChaosMarine1 CursorName = 4
+	ChaosMarine2 CursorName = 5
+	ChaosMarine3 CursorName = 6
+
+	UltMarine1 CursorName = 7
+	UltMarine2 CursorName = 8
+	UltMarine3 CursorName = 9
+	UltMarine4 CursorName = 10
+	UltMarine5 CursorName = 11
+
+	ChaosHeavy1 CursorName = 12
+	ChaosHeavy2 CursorName = 13
+
+	UltHeavy1 CursorName = 14
+	UltHeavy2 CursorName = 15
+	UltHeavy3 CursorName = 16
+	UltHeavy4 CursorName = 17
+	UltHeavy5 CursorName = 18
+	UltHeavy6 CursorName = 19
+
+	ChaosTerminator1 CursorName = 20
+	ChaosTerminator2 CursorName = 21
+
+	UltTerminator1 CursorName = 22
+	UltTerminator2 CursorName = 23
+	UltTerminator3 CursorName = 24
+	UltTerminator4 CursorName = 25
+	UltTerminator5 CursorName = 26
+
+	Deny CursorName = 27 // Red X
+
+	UltLogo         CursorName = 28
+	UltSquadMarine  CursorName = 29
+	UltSquadHeavy   CursorName = 30
+	UltSquadAssault CursorName = 31
+
+	UltCaptain    CursorName = 32
+	UltChaplain   CursorName = 33 // (maybe?)
+	UltApothecary CursorName = 34
+	UltTechmarine CursorName = 35
+	UltLibrarian  CursorName = 36
+
+	DenyAgain CursorName = 37 // Identical to Deny as far as I can see *shrug*
+)
+
+func (a *AssetStore) Cursor(name CursorName) (*Cursor, error) {
+	if cur, ok := a.cursors[name]; ok {
+		return cur, nil
+	}
+
+	if a.cursorObj == nil {
+		filename, err := a.lookup("Cursors.cur", "", "Cursor")
+		if err != nil {
+			return nil, err
+		}
+
+		obj, err := a.ObjectByPath(filename)
+		if err != nil {
+			return nil, err
+		}
+
+		a.cursorObj = obj
+	}
+
+	spr, err := a.cursorObj.Sprite(int(name))
+	if err != nil {
+		return nil, err
+	}
+
+	// TODO: hotspot info. We're using Cursor.cur because it's object format,
+	// but we do also have .ani files that might contain hotspots.
+	cur := &Cursor{Image: spr.Image}
+
+	a.cursors[name] = cur
+
+	return cur, nil
+}