themes and styles

client/world/renderer.go

@@ -171,15 +171,23 @@ func (w *World) Render(drawer PrimitiveDrawer, params RenderParams) error {
 		return err
 	}
 
-	bg := color.RGBA{A: 255} // default black
+	var bg color.Color = color.RGBA{A: 255} // default black
+
 	if params.Options != nil && params.Options.BackgroundColor != nil {
 		if v, ok := params.Options.BackgroundColor.(color.RGBA); !ok {
 			panic("Options.BackgroundColor is not color.RGBA type")
 		} else {
 			bg = v
 		}
+	} else {
+		tc := w.Theme().BackgroundColor()
+		if alphaNonZero(tc) {
+			bg = tc
+		}
 	}
 
+	allowWrap := params.Options == nil || !params.Options.DisableWrapScroll
+
 	defer func() {
 		if !params.Debug {
 			return
@@ -217,8 +225,6 @@ func (w *World) Render(drawer PrimitiveDrawer, params RenderParams) error {
 		policy = *params.Options.Incremental
 	}
 
-	allowWrap := params.Options == nil || !params.Options.DisableWrapScroll
-
 	// --- Try incremental path first when state is initialized and geometry matches ---
 	dxPx, dyPx, derr := w.ComputePanShiftPx(params)
 	if derr == nil {
@@ -243,6 +249,7 @@ func (w *World) Render(drawer PrimitiveDrawer, params RenderParams) error {
 				if len(toDraw) > 0 {
 					for _, r := range toDraw {
 						drawer.ClearRectTo(r.X, r.Y, r.W, r.H, bg)
+						w.drawBackground(drawer, params, r)
 					}
 
 					plan, err := w.buildRenderPlanStageA(params)
@@ -295,6 +302,7 @@ func (w *World) Render(drawer PrimitiveDrawer, params RenderParams) error {
 
 			for _, r := range dirtyToDraw {
 				drawer.ClearRectTo(r.X, r.Y, r.W, r.H, bg)
+				w.drawBackground(drawer, params, r)
 			}
 
 			// Additionally redraw a bounded portion of deferred dirty regions.
@@ -328,6 +336,7 @@ func (w *World) Render(drawer PrimitiveDrawer, params RenderParams) error {
 	}
 
 	drawer.ClearAllTo(bg)
+	w.drawBackground(drawer, params, RectPx{X: 0, Y: 0, W: params.CanvasWidthPx(), H: params.CanvasHeightPx()})
 	w.drawPlanSinglePass(drawer, plan, allowWrap)
 	return w.CommitFullRedrawState(params)
 }