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.

game/statuseffects.go

@@ -0,0 +1,54 @@
+package game
+
+import (
+	"fmt"
+	"strconv"
+	"strings"
+
+	"github.com/egoist/mygo/ui"
+
+	"git.zacharyzhang.com/ZacharyZhang-NY/8bitMyGoUI/pixel"
+)
+
+// Effect is a buff, or a debuff, with turns left.
+type Effect struct {
+	Sprite *pixel.Sprite
+	Name   string
+	// Turns left; zero hides the count.
+	Turns  int
+	Debuff bool
+}
+
+type StatusEffectsOptions struct{}
+
+// StatusEffects rows effect icons: buffs edged Good, debuffs Bad.
+func StatusEffects(c *ui.Context, text string, effects []Effect, o StatusEffectsOptions) *ui.Element {
+	k := pixel.K(c)
+	parts := make([]string, len(effects))
+	for i, ef := range effects {
+		if ef.Sprite == nil || ef.Turns < 0 {
+			panic(fmt.Sprintf("game: effect %q has no sprite or %d turns", ef.Name, ef.Turns))
+		}
+		parts[i] = ef.Name
+		if ef.Turns > 0 {
+			parts[i] += " " + strconv.Itoa(ef.Turns)
+		}
+	}
+	return ui.Box(c).Role(ui.RoleImage).Label(text).Description(strings.Join(parts, ", ")).Size(k.D(len(effects)*17), k.D(16)).Draw(func(p *ui.Painter, r ui.Rect) {
+		g := k.Canvas(p, r)
+		for i, ef := range effects {
+			x, edge := i*17, pixel.Good
+			if ef.Debuff {
+				edge = pixel.Bad
+			}
+			g.Frame(x, 0, 16, 16, pixel.Flat, pixel.Well)
+			g.Rect(x+1, 1, 14, 1, edge)
+			g.Sprite(x+(16-ef.Sprite.W)/2, (16-ef.Sprite.H)/2, ef.Sprite, 0, pixel.Ink, 1)
+			if ef.Turns > 0 {
+				n := strconv.Itoa(ef.Turns)
+				g.Rect(x+15-pixel.MicroWidth(n)-2, 9, pixel.MicroWidth(n)+2, 7, edge)
+				g.Micro(x+14-pixel.MicroWidth(n), 10, n, pixel.AccentInk, 1)
+			}
+		}
+	})
+}