First pass at custom cursor display

cmd/view-menu/main.go

@@ -45,6 +45,13 @@ func main() {
 		log.Fatal("Couldn't create window: %v", err)
 	}
 
+	// TODO: move this into driver. It will need to be able to change cursor.
+	cursor, err := assets.Cursor(assetstore.UltPointer)
+	if err != nil {
+		log.Fatalf("Couldn't load cursor: %v", err)
+	}
+	win.SetCursor(cursor.Image)
+
 	if err := win.Run(); err != nil {
 		log.Fatal(err)
 	}

internal/assetstore/assetstore.go

@@ -34,6 +34,9 @@ type AssetStore struct {
 	entries entryMap
 
 	// These members are used to store things we've already loaded
+	cursorObj *Object
+
+	cursors map[CursorName]*Cursor
 	fonts   map[string]*Font
 	generic *data.Generic
 	maps    map[string]*Map
@@ -85,6 +88,8 @@ func (a *AssetStore) Refresh() error {
 	}
 
 	// Refresh
+	a.cursorObj = nil
+	a.cursors = make(map[CursorName]*Cursor)
 	a.entries = newEntryMap
 	a.fonts = make(map[string]*Font)
 	a.maps = make(map[string]*Map)

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
+}

internal/ordoor/ordoor.go

@@ -93,6 +93,13 @@ func Run(configFile string, overrideX, overrideY int) error {
 		return fmt.Errorf("Failed to create window: %v", err)
 	}
 
+	// TODO: move this into driver. It will need to be able to change cursor.
+	cursor, err := assets.Cursor(assetstore.UltPointer)
+	if err != nil {
+		log.Fatalf("Couldn't load cursor: %v", err)
+	}
+	win.SetCursor(cursor.Image)
+
 	ordoor.win = win
 
 	if err := ordoor.setupFlow(); err != nil {

internal/ui/window.go

@@ -3,6 +3,7 @@ package ui
 import (
 	"flag"
 	"fmt"
+	"image"
 	"log"
 	"os"
 	"runtime/debug"
@@ -23,11 +24,16 @@ var (
 	cpuprofile  = flag.String("cpuprofile", "", "write cpu profile to `file`")
 )
 
+// TODO: move all scaling into Window, so drivers only need to cope with one
+// coordinate space. This will allow us to draw custom mouse cursors in the
+// window, rather than in the driver.
 type Window struct {
 	Title             string
 	KeyUpHandlers     map[ebiten.Key]func()
 	MouseWheelHandler func(float64, float64)
 
+	cursor *ebiten.Image
+
 	// Allow the "game" to be switched out at any time
 	game Game
 
@@ -68,6 +74,17 @@ func (w *Window) Layout(_, _ int) (int, int) {
 	return w.xRes, w.yRes
 }
 
+func (w *Window) SetCursor(cursor *ebiten.Image) {
+	w.cursor = cursor
+
+	// Hide the system cursor if we have a custom one
+	if cursor == nil {
+		ebiten.SetCursorMode(ebiten.CursorModeVisible)
+	} else {
+		ebiten.SetCursorMode(ebiten.CursorModeHidden)
+	}
+}
+
 func (w *Window) Update(screen *ebiten.Image) (outErr error) {
 	// Ebiten does not like it if we panic inside its main loop
 	defer func() {
@@ -108,6 +125,16 @@ func (w *Window) Update(screen *ebiten.Image) (outErr error) {
 		return err
 	}
 
+	if w.cursor != nil {
+		// TODO: account for scaling, including the hotspot.
+		pos := image.Pt(ebiten.CursorPosition())
+		op := ebiten.DrawImageOptions{}
+		op.GeoM.Translate(float64(pos.X), float64(pos.Y))
+		if err := screen.DrawImage(w.cursor, &op); err != nil {
+			return err
+		}
+	}
+
 	if w.debug {
 		// Draw FPS, etc, to the screen
 		msg := fmt.Sprintf("tps=%0.2f fps=%0.2f", ebiten.CurrentTPS(), ebiten.CurrentFPS())