Add game components 246-268; data.DrawSlot, Canvas.TextVeil

Health, mana and experience bars, quarter hearts, lives, a spinning
coin counter, score board, stage timer, minimap with fog, compass,
hotbar, paper-doll equipment, skill tree, skill buttons with cooldown
wipes, status effects, a boss bar, damage numbers, quest log and
tracker, party frames, character sheet, level-up screen and shop.
data exports DrawSlot so every slot looks alike; pixel adds TextVeil
for dissolving text. Messages the font cannot draw are fixed and
TestMessagesHaveGlyphs holds every message to the font.

data/inventory.go

@@ -38,12 +38,12 @@ func Inventory(c *ui.Context, text string, items []Item, selected *int, o Invent
 		panic(fmt.Sprintf("data: Inventory slot %d of %d", *selected, len(items)))
 	}
 	old := *selected
-	shell, base, st, _ := pixel.Pad(c, text, cols, len(items), slotSize, slotSize, selected, o.Disabled)
+	shell, base, st, _ := pixel.Pad(c, text, cols, len(items), SlotSize, SlotSize, selected, o.Disabled)
 	b := ui.Local(base, bagKey{}, func() bag { return bag{} })
 	res := InventoryResult{Element: shell, Changed: *selected != old}
 	px, py, _ := base.PointerPosition()
 	at := func() int {
-		col, row := int(px/k.Dot())/slotSize, int(py/k.Dot())/slotSize
+		col, row := int(px/k.Dot())/SlotSize, int(py/k.Dot())/SlotSize
 		if px < 0 || py < 0 || col >= cols || row*cols+col >= len(items) {
 			return -1
 		}
@@ -67,7 +67,7 @@ func Inventory(c *ui.Context, text string, items []Item, selected *int, o Invent
 	default:
 		b.dead = false
 	}
-	base.Description(itemName(items[*selected]))
+	base.Description(items[*selected].String())
 	drag := -1
 	if b.held && b.over != b.from {
 		drag = b.from
@@ -79,7 +79,7 @@ func Inventory(c *ui.Context, text string, items []Item, selected *int, o Invent
 			if i == drag {
 				it = Item{}
 			}
-			slot(g, i%cols*slotSize, i/cols*slotSize, it, 0, i == *selected)
+			DrawSlot(g, i%cols*SlotSize, i/cols*SlotSize, it, ItemSlotOptions{Selected: i == *selected})
 		}
 		// The dragged item rides with the pointer.
 		if drag >= 0 && shown[drag].Sprite != nil {

data/itemslot.go

@@ -28,43 +28,49 @@ type ItemSlotOptions struct {
 // ItemSlot shows an item, count, rarity edge and cooldown.
 func ItemSlot(c *ui.Context, it Item, o ItemSlotOptions) *ui.Element {
 	k := pixel.K(c)
-	if !(o.Cooldown >= 0 && o.Cooldown <= 1) {
-		panic(fmt.Sprintf("data: Cooldown %v outside 0–1", o.Cooldown))
-	}
-	return ui.Box(c).Role(ui.RoleImage).Label(itemName(it)).Size(k.D(slotSize), k.D(slotSize)).Draw(func(p *ui.Painter, r ui.Rect) {
-		slot(k.Canvas(p, r), 0, 0, it, o.Cooldown, o.Selected)
+	o.check()
+	return ui.Box(c).Role(ui.RoleImage).Label(it.String()).Size(k.D(SlotSize), k.D(SlotSize)).Draw(func(p *ui.Painter, r ui.Rect) {
+		DrawSlot(k.Canvas(p, r), 0, 0, it, o)
 	})
 }
 
-const slotSize = 22
+func (o ItemSlotOptions) check() {
+	if !(o.Cooldown >= 0 && o.Cooldown <= 1) {
+		panic(fmt.Sprintf("data: Cooldown %v outside 0–1", o.Cooldown))
+	}
+}
 
-// itemName reads an item with its count.
-func itemName(it Item) string {
+// SlotSize is a slot's side in dots.
+const SlotSize = 22
+
+// String reads an item with its count: "Potion ×3".
+func (it Item) String() string {
 	if it.Count > 1 {
 		return it.Name + " ×" + strconv.Itoa(it.Count)
 	}
 	return it.Name
 }
 
-// slot draws a slot with its top-left at x, y.
-func slot(g pixel.Canvas, x, y int, it Item, cool float64, chosen bool) {
+// DrawSlot paints a slot, top left at x, y.
+func DrawSlot(g pixel.Canvas, x, y int, it Item, o ItemSlotOptions) {
+	o.check()
 	edge := pixel.Edge
 	if it.Sprite != nil {
 		edge = it.Rarity.Slot()
 	}
-	if chosen {
-		g.Rect(x, y, slotSize, slotSize, pixel.Accent)
+	if o.Selected {
+		g.Rect(x, y, SlotSize, SlotSize, pixel.Accent)
 	}
-	g.Rect(x+1, y+1, slotSize-2, slotSize-2, edge)
-	g.Rect(x+2, y+2, slotSize-4, slotSize-4, pixel.Well)
+	g.Rect(x+1, y+1, SlotSize-2, SlotSize-2, edge)
+	g.Rect(x+2, y+2, SlotSize-4, SlotSize-4, pixel.Well)
 	if sp := it.Sprite; sp != nil {
-		g.Sprite(x+2+(slotSize-4-sp.W)/2, y+2+(slotSize-4-sp.H)/2, sp, 0, pixel.Ink, 1)
+		g.Sprite(x+2+(SlotSize-4-sp.W)/2, y+2+(SlotSize-4-sp.H)/2, sp, 0, pixel.Ink, 1)
 	}
-	if h := int(cool * (slotSize - 4)); h > 0 {
-		g.Veil(x+2, y+2, slotSize-4, h, pixel.Shade, 10)
+	if h := int(o.Cooldown * (SlotSize - 4)); h > 0 {
+		g.Veil(x+2, y+2, SlotSize-4, h, pixel.Shade, 10)
 	}
 	if it.Count > 1 {
 		n := strconv.Itoa(it.Count)
-		g.Micro(x+slotSize-2-pixel.MicroWidth(n), y+slotSize-8, n, pixel.Ink, 1)
+		g.Micro(x+SlotSize-2-pixel.MicroWidth(n), y+SlotSize-8, n, pixel.Ink, 1)
 	}
 }