gogpu · kolkov · May 13, 2026 · May 13, 2026
@@ -5,11 +5,20 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
-## [0.1.22] — 2026-05-13
+## [0.1.23] — 2026-05-13
+
+### Added
+
+- **Custom font loading pipeline** (TASK-UI-CJK-001, gg#304) — plugins can now load custom fonts via `ctx.Assets.LoadFont("name", data)` and they are used for rendering. Follows Flutter/Qt6/Iced universal pattern: global `FontRegistry` singleton with CSS weight matching and Inter fallback.
+- **`FontRegistry`** (`internal/render/fontregistry.go`) — process-global, thread-safe (RWMutex) font registry. Pre-registers embedded Inter. Caches `*text.FontSource` by (family, weight, style). CSS weight matching via `theme/font.Registry`.
+- **`StyledTextDrawer`** optional interface (`widget/canvas.go`) — `DrawStyledText(text, bounds, TextStyle)` + `MeasureStyledText(text, TextStyle)`. Implemented by both Canvas and SceneCanvas. Uses type assertion pattern consistent with `ArcStroker`, `SVGFiller`, `DeviceScaler`.
+- **`TextWidget.FontFamily()`** builder method (`primitives/text.go`) — routes to `StyledTextDrawer` when custom font family set, falls back to regular `DrawText` with Inter.
+- **Plugin → Registry wiring** — `MemoryAssetLoader.LoadFont()` auto-registers fonts in `GlobalFontRegistry()`. `NewDefaultPluginContext()` creates real `MemoryAssetLoader` instead of noop.
+- **47 new tests** across fontregistry, canvas, scene_canvas, plugin, primitives, uitest packages.
 
 ### Fixed
 
-- **gg v0.46.9** — fix Mac Retina rendering (gg#308, @sverrehu). `MarkDirty()` used logical pixel dimensions for texture upload region — on Retina (scale=2.0), only 1/4 of the pixmap was uploaded to the GPU texture. Regression from gg v0.45.4. Includes 3 HiDPI regression tests with `mockHiDPIProvider`.
+- **gg v0.46.9** — fix Mac Retina rendering (gg#308, @sverrehu). `MarkDirty()` used logical pixel dimensions for texture upload region — on Retina (scale=2.0), only 1/4 of the pixmap was uploaded to the GPU texture. Regression from gg v0.45.4. Includes 3 HiDPI regression tests.
 
 ### Dependencies
 

@@ -1,6 +1,6 @@
 # gogpu/ui Roadmap
 
-> **Version:** 0.1.20 (Enterprise Render Pipeline + Layer Tree Compositor)
+> **Version:** 0.1.23 (Custom Font Pipeline + Mac Retina Fix + CJK)
 > **Updated:** May 2026
 > **Go Version:** 1.25+
 
@@ -283,13 +283,17 @@ v1.0.0  → Production (when ready)
 | ScreenBounds | Screen-space coordinate transform for overlay positioning |
 | Event Coordinate Transform | ScrollView mouse/wheel coordinate transforms |
 | Inter Font Unicode | Full Unicode Inter 4.1 (Cyrillic, Greek, Vietnamese) |
+| **Custom Font Loading Pipeline** | **FontRegistry (global singleton, CSS weight matching), StyledTextDrawer optional interface, Plugin→Registry wiring, TextWidget.FontFamily()** |
+| **Mac Retina Fix** | **gg v0.46.9 MarkDirty() logical→physical pixel fix (gg#308, @sverrehu)** |
+| **CJK IsCJK Propagation** | **gg v0.46.8 ShapedGlyph.IsCJK through scene/shaper paths (gg#304)** |
 
 **Remaining:**
 
 | Task | Description | Priority |
 |------|-------------|----------|
-| **Damage-aware compositor** | **LoadOpLoad + partial blit (gg-level). Spinner GPU 8% → <3%** | **P0** |
-| **Parent chain fix** | **BoxWidget SetParent → correct propagateDirtyUpward** | **P1** |
+| **GPU spinner <3%** | **scheduler.SetOnDirty needsRedraw lifecycle optimization** | **P0** |
+| **ListView hover rebuild** | **Painter pattern: hover = repaint, not widget rebuild (~15 LOC)** | **P1** |
+| **Texture GC** | **Prune orphaned boundaryTextures entries (~20 LOC)** | **P1** |
 | Accessibility adapters | Platform-specific AT-SPI / UIA adapters | P1 |
 | RichText widget | Styled text with inline formatting, links | P2 |
 | NumberField widget | Numeric input with increment/decrement, ranges | P2 |
@@ -348,16 +352,16 @@ Single-pass compositor (Flutter OffsetLayer / Chrome cc pattern):
 - **Pumper isolation**: ScheduleAnimationFrame only pumper trigger, data tickers don't restart 30fps
 - **34 integration tests**: multi-frame lifecycle, visibility matrix, damage rects, recording order
 
-> **Note:** `ui/compositor/` package (Layer Tree: OffsetLayer, PictureLayer, ClipRectLayer,
-> OpacityLayer, Compositor) is fully implemented and tested but **NOT connected to
-> production pipeline**. Phase 7 per-boundary GPU textures replaced it — direct texture
-> caching + blit is simpler. Layer Tree remains for future animated transforms/opacity.
+### Phase 4: Layer Tree + Damage-Aware Compositor (ADR-007 Phase D, ADR-030) ✅ Done
 
-### Phase 4: Damage-Aware Compositor — Next
-
-- **LoadOpLoad**: gg-level optimization — preserve previous framebuffer, blit only dirty regions
-- **Partial present**: PresentWithDamage sends dirty rects to OS compositor
-- **Expected result**: spinner GPU 8% → <3% (only 48×48 blit instead of full-screen)
+- **Layer Tree compositor in production** — `compositor/` drives render loop (OffsetLayer, PictureLayer, ClipRectLayer, OpacityLayer)
+- **Persistent Layer Tree** — `UpdateLayerTree()` reuses layers (97.9% fewer allocs, 613→13)
+- **O(1) frame skip** — flat dirty boundary set replaces O(n) tree walk (45× faster)
+- **Multi-rect damage** — per-draw dynamic scissor, ring buffer, 16-rect merge threshold
+- **LoadOpLoad** — preserve previous framebuffer, blit only damage rects
+- **Partial present** — `PresentWithDamage` sends dirty rects through full stack
+- **Overlay boundary pipeline** — dropdown/dialog content via same Layer Tree
+- **Remaining:** scheduler.SetOnDirty lifecycle → spinner GPU 10% → <3%
 
 ### Phase 5: Vello Compute Integration — Future
 
@@ -367,11 +371,11 @@ Full Vello 9-stage compute pipeline for GPU-accelerated path rendering:
 
 ### Performance Targets
 
-| Metric | Phase 2 | Phase 3 ✅ | Phase 4 | Phase 5 |
-|--------|---------|-----------|---------|---------|
-| GPU % (static UI) | 8% | **0%** | 0% | 0% |
-| GPU % (spinner) | 8% | **8%** | <3% | <1% |
-| GPU % (spinner offscreen) | 8% | **0%** | 0% | 0% |
+| Metric | Phase 2 | Phase 3 ✅ | Phase 4 ✅ | Phase 5 |
+|--------|---------|-----------|-----------|---------|
+| GPU % (static UI) | 8% | **0%** | **0%** | 0% |
+| GPU % (spinner) | 8% | 8% | **10%** (48×48 scissor) | <1% |
+| GPU % (spinner offscreen) | 8% | **0%** | **0%** | 0% |
 | GPU readback | 0 | 0 | 0 | 0 |
 
 ---
@@ -434,13 +438,13 @@ Full Vello 9-stage compute pipeline for GPU-accelerated path rendering:
 
 | Dependency | Version | Purpose | Status |
 |------------|---------|---------|--------|
-| gogpu/gg | v0.46.4 | 2D rendering + scene.Scene | ✅ Integrated |
+| gogpu/gg | v0.46.9 | 2D rendering + scene.Scene | ✅ Integrated |
 | gogpu/gpucontext | v0.18.0 | Shared interfaces | ✅ Integrated |
-| gogpu/gogpu | v0.34.0 | Windowing (examples) | ✅ Integrated |
+| gogpu/gogpu | v0.34.3 | Windowing (examples) | ✅ Integrated |
 | coregx/signals | v0.1.0 | State management | ✅ Integrated |
 | golang.org/x/image | v0.39.0 | Inter font (standard) | ✅ Integrated |
 
-**Indirect:** go-text/typesetting v0.3.4, gogpu/gputypes v0.5.0, gogpu/wgpu v0.27.1, gogpu/naga v0.17.13, golang.org/x/text v0.36.0
+**Indirect:** go-text/typesetting v0.3.4, gogpu/gputypes v0.5.0, gogpu/wgpu v0.27.3, gogpu/naga v0.17.13, golang.org/x/text v0.36.0
 
 ---
 

@@ -165,7 +165,7 @@
 
 | Package | Purpose | Key Types |
 |---------|---------|-----------|
-| `internal/render/` | Canvas, SceneCanvas, Renderer backed by gg | `Canvas`, `SceneCanvas`, `Renderer`, `SoftwareTarget`, `RenderConfig` |
+| `internal/render/` | Canvas, SceneCanvas, FontRegistry, Renderer backed by gg | `Canvas`, `SceneCanvas`, `FontRegistry`, `Renderer`, `SoftwareTarget`, `RenderConfig` |
 | `internal/layout/` | Layout engines | `FlexContainer`, `VStack`, `HStack`, `GridContainer`, `Engine` |
 | `internal/focus/` | Focus manager implementation | `Manager`, `Shortcut`, `DrawFocusRing`, traversal helpers |
 | `internal/dirty/` | Dirty region tracking | `Tracker`, `Collector`, merge algorithm, partial repaints |
@@ -303,6 +303,31 @@ Key design decisions:
 - Clip and transform use push/pop stacks (not Save/Restore)
 - PushTransform applies a translation offset (not a full matrix)
 
+### Custom Font Support (StyledTextDrawer)
+
+Canvas supports custom fonts via the optional `StyledTextDrawer` interface:
+
+```go
+// widget/canvas.go
+type TextStyle struct {
+    FontFamily string
+    FontSize   float32
+    Bold       bool
+    Italic     bool
+    Color      Color
+    Align      TextAlign
+}
+
+type StyledTextDrawer interface {
+    DrawStyledText(text string, bounds geometry.Rect, style TextStyle)
+    MeasureStyledText(text string, style TextStyle) float32
+}
+```
+
+Both `Canvas` and `SceneCanvas` implement `StyledTextDrawer`. Widgets use type assertion (`if sd, ok := canvas.(widget.StyledTextDrawer); ok { ... }`), consistent with `ArcStroker`, `SVGFiller`, `DeviceScaler`, and `TextModeController`.
+
+Font resolution uses a global `FontRegistry` (process-singleton, RWMutex) with CSS weight matching and Inter fallback. Plugins register fonts via `ctx.Assets.LoadFont("name", data)` which auto-registers in the global registry. This follows the universal pattern from Flutter (`FontCollection`), Qt6 (`QFontDatabase`), and Iced (`FontSystem`).
+
 ### Focusable Interface
 
 `Focusable` (`widget/focusable.go`) is an opt-in interface for widgets that accept keyboard focus:
@@ -879,7 +904,9 @@ Key functions:
 - Manages clip stack and transform stack internally
 - Clip intersection computed manually; visibility checked per draw call
 - Transform is translation-only (offset accumulation)
-- Text rendering uses Inter font (Regular/Bold) via `gg/text.FontSource`
+- Text rendering uses Inter font by default (Regular/Bold) via `gg/text.FontSource`
+- Custom fonts resolved via global `FontRegistry` (CSS weight matching, `*text.FontSource` caching)
+- Implements `StyledTextDrawer` for custom font rendering alongside standard `DrawText`
 - Color conversion: `widget.Color` (float32) to `gg.RGBA` (float64) via `ToGGColor`/`FromGGColor`
 
 ### Renderer
@@ -1370,7 +1397,7 @@ Implements `widget.Widget`, `a11y.Accessible`, and `widget.Lifecycle` (for signa
 
 ### TextWidget
 
-Renders text with configurable font size, color, bold, and alignment.
+Renders text with configurable font size, color, bold, alignment, and optional font family. The `FontFamily(name)` builder method routes to `StyledTextDrawer` for custom font rendering when available, with Inter fallback.
 
 ### ImageWidget
 
@@ -1395,7 +1422,8 @@ type Plugin interface {
 - `Manager` handles registration, dependency resolution, and initialization order
 - `PluginContext` provides access to widget registry, theme registry, and asset loader
 - `Dependency` declares required plugins with version constraints
-- `AssetLoader` handles asset management for plugins
+- `AssetLoader` handles asset management for plugins (fonts, icons, images)
+- `MemoryAssetLoader.LoadFont()` auto-registers fonts in the global `FontRegistry` — loaded fonts are immediately available to all widgets via `StyledTextDrawer`
 
 ---
 
@@ -1413,7 +1441,7 @@ The `registry/` package provides a global registry for widget factories:
 
 | Dependency | Purpose | Version |
 |------------|---------|---------|
-| `github.com/gogpu/gg` | 2D graphics + scene.Scene tile-parallel rendering | v0.46.7 |
+| `github.com/gogpu/gg` | 2D graphics + scene.Scene tile-parallel rendering | v0.46.9 |
 | `github.com/gogpu/gpucontext` | Window/Platform provider interfaces | v0.18.0 |
 | `github.com/gogpu/gogpu` | Application framework, windowing (examples only) | v0.34.3 |
 | `github.com/coregx/signals` | Reactive state management | v0.1.0 |
@@ -1497,4 +1525,4 @@ All types in `geometry/` are small structs passed by value. Operations return ne
 
 ---
 
-*This document reflects the actual codebase as of May 11, 2026 (v0.1.20 — Layer Tree compositor, O(1) frame skip, persistent tree, multi-rect damage, overlay boundary pipeline, software backend e2e tests, ~120 new tests).*
+*This document reflects the actual codebase as of May 13, 2026 (v0.1.23 — custom font loading pipeline, FontRegistry, StyledTextDrawer, Mac Retina fix, CJK IsCJK fix).*
@@ -513,6 +513,73 @@ func (c *Canvas) MeasureText(s string, fontSize float32, bold bool) float32 {
 	return float32(w)
 }
 
+// DrawStyledText draws text within the given bounding rectangle using
+// a font resolved from the global [FontRegistry]. This enables rendering
+// with custom fonts (CJK, icon fonts, etc.) loaded via the plugin system.
+//
+// If the FontFamily is empty or not found, the default Inter font is used.
+func (c *Canvas) DrawStyledText(s string, bounds geometry.Rect, style widget.TextStyle) {
+	if s == "" {
+		return
+	}
+
+	bounds = c.applyTransform(bounds)
+	if !c.isVisible(bounds) {
+		return
+	}
+
+	source := c.resolveStyledFont(style)
+	if source == nil {
+		return
+	}
+
+	face := source.Face(float64(style.FontSize))
+	c.dc.SetFont(face)
+	c.dc.SetRGBA(float64(style.Color.R), float64(style.Color.G), float64(style.Color.B), float64(style.Color.A))
+
+	// Calculate baseline Y by centering text vertically within bounds.
+	metrics := face.Metrics()
+	textHeight := metrics.Ascent + metrics.Descent
+	baselineY := math.Round(float64(bounds.Min.Y) + (float64(bounds.Height())-textHeight)/2 + metrics.Ascent)
+
+	// Calculate x position based on alignment.
+	w, _ := c.dc.MeasureString(s)
+	available := float64(bounds.Width())
+	x := float64(bounds.Min.X)
+	if w < available {
+		x += (available - w) * style.Align.Float64()
+	}
+	x = math.Round(x)
+
+	c.dc.DrawString(s, x, baselineY)
+}
+
+// MeasureStyledText returns the width in pixels of the given text string
+// when rendered with the specified [widget.TextStyle]. The font is resolved
+// from the global [FontRegistry].
+func (c *Canvas) MeasureStyledText(s string, style widget.TextStyle) float32 {
+	if s == "" {
+		return 0
+	}
+
+	source := c.resolveStyledFont(style)
+	if source == nil {
+		return float32(len([]rune(s))) * style.FontSize * 0.5
+	}
+
+	face := source.Face(float64(style.FontSize))
+	c.dc.SetFont(face)
+	w, _ := c.dc.MeasureString(s)
+	return float32(w)
+}
+
+// resolveStyledFont resolves a [text.FontSource] from a [widget.TextStyle]
+// using the global [FontRegistry]. Falls back to the default Inter font
+// when the family is empty or not found.
+func (c *Canvas) resolveStyledFont(style widget.TextStyle) *text.FontSource {
+	return resolveStyledFontSource(style)
+}
+
 // DrawImage draws an image at the specified position.
 //
 // The image is composited using source-over blending via gg.DrawImage.
@@ -716,3 +783,6 @@ var _ widget.Canvas = (*Canvas)(nil)
 
 // Verify Canvas implements widget.ArcStroker.
 var _ widget.ArcStroker = (*Canvas)(nil)
+
+// Verify Canvas implements widget.StyledTextDrawer.
+var _ widget.StyledTextDrawer = (*Canvas)(nil)