no-wrap option; pivoted exponential zoom

client/world/camera_clamp.go

@@ -0,0 +1,117 @@
+package world
+
+// ClampCameraNoWrapViewport clamps camera center so that the VIEWPORT world-rect
+// stays within the bounded world [0..worldW) x [0..worldH), when possible.
+//
+// This is the correct clamp for user panning when wrap is disabled.
+// Margins (expanded canvas) are intentionally ignored here; they may extend outside the world.
+func ClampCameraNoWrapViewport(
+	cameraXWorldFp, cameraYWorldFp int,
+	viewportW, viewportH int,
+	zoomFp int,
+	worldW, worldH int,
+) (int, int) {
+	if zoomFp <= 0 {
+		panic("ClampCameraNoWrapViewport: invalid zoom")
+	}
+	if viewportW < 0 || viewportH < 0 {
+		panic("ClampCameraNoWrapViewport: negative viewport")
+	}
+	if worldW <= 0 || worldH <= 0 {
+		panic("ClampCameraNoWrapViewport: invalid world size")
+	}
+
+	spanW := PixelSpanToWorldFixed(viewportW, zoomFp)
+	spanH := PixelSpanToWorldFixed(viewportH, zoomFp)
+
+	halfW := spanW / 2
+	halfH := spanH / 2
+
+	cameraXWorldFp = clampCameraAxis(cameraXWorldFp, worldW, halfW)
+	cameraYWorldFp = clampCameraAxis(cameraYWorldFp, worldH, halfH)
+
+	return cameraXWorldFp, cameraYWorldFp
+}
+
+// ClampCameraNoWrapExpanded clamps camera center so that the EXPANDED CANVAS world-rect
+// (viewport + margins) stays within the bounded world, when possible.
+//
+// This is stricter than viewport-based clamp and can prevent panning when margins are large.
+func ClampCameraNoWrapExpanded(
+	cameraXWorldFp, cameraYWorldFp int,
+	viewportW, viewportH int,
+	marginX, marginY int,
+	zoomFp int,
+	worldW, worldH int,
+) (int, int) {
+	if zoomFp <= 0 {
+		panic("ClampCameraNoWrapExpanded: invalid zoom")
+	}
+	if viewportW < 0 || viewportH < 0 || marginX < 0 || marginY < 0 {
+		panic("ClampCameraNoWrapExpanded: negative sizes")
+	}
+	if worldW <= 0 || worldH <= 0 {
+		panic("ClampCameraNoWrapExpanded: invalid world size")
+	}
+
+	canvasW := viewportW + 2*marginX
+	canvasH := viewportH + 2*marginY
+
+	spanW := PixelSpanToWorldFixed(canvasW, zoomFp)
+	spanH := PixelSpanToWorldFixed(canvasH, zoomFp)
+
+	halfW := spanW / 2
+	halfH := spanH / 2
+
+	cameraXWorldFp = clampCameraAxis(cameraXWorldFp, worldW, halfW)
+	cameraYWorldFp = clampCameraAxis(cameraYWorldFp, worldH, halfH)
+
+	return cameraXWorldFp, cameraYWorldFp
+}
+
+func clampCameraAxis(cam, worldSize, halfSpan int) int {
+	// If viewport/span does not fit: force center.
+	if 2*halfSpan > worldSize {
+		return worldSize / 2
+	}
+
+	minCam := halfSpan
+	maxCam := worldSize - halfSpan
+
+	if cam < minCam {
+		return minCam
+	}
+	if cam > maxCam {
+		return maxCam
+	}
+	return cam
+}
+
+// ClampRenderParamsNoWrap clamps camera center in-place when wrap is disabled.
+// It uses viewport-based clamp (NOT expanded) so panning remains possible even with margins.
+func (w *World) ClampRenderParamsNoWrap(p *RenderParams) {
+	if p == nil {
+		return
+	}
+	allowWrap := true
+	if p.Options != nil && p.Options.DisableWrapScroll {
+		allowWrap = false
+	}
+	if allowWrap {
+		return
+	}
+
+	zoomFp, err := p.CameraZoomFp()
+	if err != nil || zoomFp <= 0 {
+		return
+	}
+
+	cx, cy := ClampCameraNoWrapViewport(
+		p.CameraXWorldFp, p.CameraYWorldFp,
+		p.ViewportWidthPx, p.ViewportHeightPx,
+		zoomFp,
+		w.W, w.H,
+	)
+	p.CameraXWorldFp = cx
+	p.CameraYWorldFp = cy
+}

client/world/camera_clamp_test.go

@@ -0,0 +1,92 @@
+package world
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestClampCameraNoWrapViewport_ClampsToKeepViewportInsideWorld(t *testing.T) {
+	t.Parallel()
+
+	worldW := 100 * SCALE
+	worldH := 100 * SCALE
+	zoomFp := SCALE // 1.0x
+
+	// viewport 40px => span 40 units => half 20.
+	viewportW, viewportH := 40, 40
+
+	// Too far left/up => clamp to minCam=20
+	cx, cy := ClampCameraNoWrapViewport(
+		0, 0,
+		viewportW, viewportH,
+		zoomFp,
+		worldW, worldH,
+	)
+	require.Equal(t, 20*SCALE, cx)
+	require.Equal(t, 20*SCALE, cy)
+
+	// Too far right/down => clamp to maxCam=world-half=80
+	cx, cy = ClampCameraNoWrapViewport(
+		99*SCALE, 99*SCALE,
+		viewportW, viewportH,
+		zoomFp,
+		worldW, worldH,
+	)
+	require.Equal(t, 80*SCALE, cx)
+	require.Equal(t, 80*SCALE, cy)
+
+	// Inside range => unchanged
+	cx, cy = ClampCameraNoWrapViewport(
+		50*SCALE, 60*SCALE,
+		viewportW, viewportH,
+		zoomFp,
+		worldW, worldH,
+	)
+	require.Equal(t, 50*SCALE, cx)
+	require.Equal(t, 60*SCALE, cy)
+}
+
+func TestClampCameraNoWrapViewport_WhenViewportLargerThanWorld_ForcesCenter(t *testing.T) {
+	t.Parallel()
+
+	worldW := 50 * SCALE
+	worldH := 50 * SCALE
+	zoomFp := SCALE
+
+	// viewport 60px => span 60 units > world 50
+	viewportW, viewportH := 60, 60
+
+	cx, cy := ClampCameraNoWrapViewport(
+		0, 0,
+		viewportW, viewportH,
+		zoomFp,
+		worldW, worldH,
+	)
+
+	require.Equal(t, worldW/2, cx)
+	require.Equal(t, worldH/2, cy)
+}
+
+func TestWorldClampRenderParamsNoWrap_UsesViewportClamp(t *testing.T) {
+	t.Parallel()
+
+	w := NewWorld(100, 100)
+
+	p := RenderParams{
+		ViewportWidthPx:  40,
+		ViewportHeightPx: 40,
+		MarginXPx:        10,
+		MarginYPx:        10,
+		CameraZoom:       1.0,
+		CameraXWorldFp:   0,
+		CameraYWorldFp:   0,
+		Options:          &RenderOptions{DisableWrapScroll: true},
+	}
+
+	w.ClampRenderParamsNoWrap(&p)
+
+	// viewport half is 20, not 30 (margins ignored)
+	require.Equal(t, 20*SCALE, p.CameraXWorldFp)
+	require.Equal(t, 20*SCALE, p.CameraYWorldFp)
+}

client/world/pivot_zoom.go

@@ -0,0 +1,44 @@
+package world
+
+// PivotZoomCameraNoWrap adjusts camera center so that the world point under the cursor remains fixed
+// when zoom changes from oldZoomFp to newZoomFp.
+//
+// Coordinate conventions:
+// - CameraXWorldFp/YWorldFp is the center of the viewport in world-fixed units.
+// - cursorXPx/cursorYPx are pixel coordinates relative to the top-left of the viewport.
+// - viewportW/H are viewport size in pixels.
+//
+// This function does not clamp the result; caller should clamp for no-wrap mode using ClampCameraNoWrapViewport.
+func PivotZoomCameraNoWrap(
+	cameraXWorldFp, cameraYWorldFp int,
+	viewportW, viewportH int,
+	cursorXPx, cursorYPx int,
+	oldZoomFp, newZoomFp int,
+) (newCamX, newCamY int) {
+	if oldZoomFp <= 0 || newZoomFp <= 0 {
+		panic("PivotZoomCameraNoWrap: invalid zoom")
+	}
+	if viewportW <= 0 || viewportH <= 0 {
+		panic("PivotZoomCameraNoWrap: invalid viewport")
+	}
+
+	// Offset of cursor from viewport center in pixels.
+	offXPx := cursorXPx - viewportW/2
+	offYPx := cursorYPx - viewportH/2
+
+	// World-fixed per 1 pixel at each zoom.
+	// (Conservative: integer arithmetic, consistent with PixelSpanToWorldFixed.)
+	oldWorldPerPx := PixelSpanToWorldFixed(1, oldZoomFp)
+	newWorldPerPx := PixelSpanToWorldFixed(1, newZoomFp)
+
+	// World point under cursor before zoom:
+	// world = camera + offsetPx * worldPerPx
+	worldX := cameraXWorldFp + offXPx*oldWorldPerPx
+	worldY := cameraYWorldFp + offYPx*oldWorldPerPx
+
+	// Choose new camera so that the same world point stays under cursor:
+	// camera' = world - offsetPx * newWorldPerPx
+	newCamX = worldX - offXPx*newWorldPerPx
+	newCamY = worldY - offYPx*newWorldPerPx
+	return
+}

client/world/pivot_zoom_test.go

@@ -0,0 +1,50 @@
+package world
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestPivotZoom_CursorAtCenter_KeepsCamera(t *testing.T) {
+	t.Parallel()
+
+	cx, cy := PivotZoomCameraNoWrap(
+		50*SCALE, 60*SCALE,
+		100, 80,
+		50, 40, // cursor at center
+		SCALE, 2*SCALE,
+	)
+	require.Equal(t, 50*SCALE, cx)
+	require.Equal(t, 60*SCALE, cy)
+}
+
+func TestPivotZoom_RightEdge_ZoomInMovesCameraRight(t *testing.T) {
+	t.Parallel()
+
+	// viewport 100px, cursor at x=100 (right edge), center is 50 => offX=50px
+	// zoom 1->2 halves worldPerPx, so camera must move towards the cursor to keep the same world point.
+	cx0 := 50 * SCALE
+
+	cx, _ := PivotZoomCameraNoWrap(
+		cx0, 50*SCALE,
+		100, 100,
+		100, 50,
+		SCALE, 2*SCALE,
+	)
+	require.Greater(t, cx, cx0)
+}
+
+func TestPivotZoom_LeftEdge_ZoomInMovesCameraLeft(t *testing.T) {
+	t.Parallel()
+
+	cx0 := 50 * SCALE
+
+	cx, _ := PivotZoomCameraNoWrap(
+		cx0, 50*SCALE,
+		100, 100,
+		0, 50,
+		SCALE, 2*SCALE,
+	)
+	require.Less(t, cx, cx0)
+}

client/world/renderer.go

@@ -21,6 +21,10 @@ type RenderOptions struct {
 	Style  *RenderStyle
 	// Incremental controls incremental pan behavior. If nil, defaults are used.
 	Incremental *IncrementalPolicy
+	// DisableWrapScroll controls whether the world is treated as a torus (false)
+	// or as a bounded plane without wrap (true).
+	// Default is false.
+	DisableWrapScroll bool
 }
 
 var (
@@ -66,7 +70,7 @@ func (p RenderParams) CanvasHeightPx() int { return p.ViewportHeightPx + 2*p.Mar
 
 // CameraZoomFp converts the UI-facing zoom value into the package fixed-point form.
 func (p RenderParams) CameraZoomFp() (int, error) {
-	return cameraZoomToWorldFixed(p.CameraZoom)
+	return CameraZoomToWorldFixed(p.CameraZoom)
 }
 
 // ExpandedCanvasWorldRect returns the world-space half-open rectangle covered by
@@ -210,6 +214,8 @@ func (w *World) Render(drawer PrimitiveDrawer, params RenderParams) error {
 		layers = params.Options.Layers
 	}
 
+	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 {
@@ -246,13 +252,13 @@ func (w *World) Render(drawer PrimitiveDrawer, params RenderParams) error {
 						switch layer {
 						case RenderLayerPoints:
 							applyPointStyle(drawer, style)
-							drawPointsFromPlanWithRadius(drawer, catchUpPlan, w.W, w.H, style.PointRadiusPx)
+							drawPointsFromPlanWithRadius(drawer, catchUpPlan, w.W, w.H, style.PointRadiusPx, allowWrap)
 						case RenderLayerCircles:
 							applyCircleStyle(drawer, style)
-							drawCirclesFromPlan(drawer, catchUpPlan, w.W, w.H)
+							drawCirclesFromPlan(drawer, catchUpPlan, w.W, w.H, allowWrap)
 						case RenderLayerLines:
 							applyLineStyle(drawer, style)
-							drawLinesFromPlan(drawer, catchUpPlan, w.W, w.H)
+							drawLinesFromPlan(drawer, catchUpPlan, w.W, w.H, allowWrap)
 						default:
 							panic("render: unknown layer")
 						}
@@ -319,13 +325,13 @@ func (w *World) Render(drawer PrimitiveDrawer, params RenderParams) error {
 				switch layer {
 				case RenderLayerPoints:
 					applyPointStyle(drawer, style)
-					drawPointsFromPlanWithRadius(drawer, dirtyPlan, w.W, w.H, style.PointRadiusPx)
+					drawPointsFromPlanWithRadius(drawer, dirtyPlan, w.W, w.H, style.PointRadiusPx, allowWrap)
 				case RenderLayerCircles:
 					applyCircleStyle(drawer, style)
-					drawCirclesFromPlan(drawer, dirtyPlan, w.W, w.H)
+					drawCirclesFromPlan(drawer, dirtyPlan, w.W, w.H, allowWrap)
 				case RenderLayerLines:
 					applyLineStyle(drawer, style)
-					drawLinesFromPlan(drawer, dirtyPlan, w.W, w.H)
+					drawLinesFromPlan(drawer, dirtyPlan, w.W, w.H, allowWrap)
 				default:
 					panic("render: unknown layer")
 				}
@@ -352,13 +358,13 @@ func (w *World) Render(drawer PrimitiveDrawer, params RenderParams) error {
 		switch layer {
 		case RenderLayerPoints:
 			applyPointStyle(drawer, style)
-			drawPointsFromPlanWithRadius(drawer, plan, w.W, w.H, style.PointRadiusPx)
+			drawPointsFromPlanWithRadius(drawer, plan, w.W, w.H, style.PointRadiusPx, allowWrap)
 		case RenderLayerCircles:
 			applyCircleStyle(drawer, style)
-			drawCirclesFromPlan(drawer, plan, w.W, w.H)
+			drawCirclesFromPlan(drawer, plan, w.W, w.H, allowWrap)
 		case RenderLayerLines:
 			applyLineStyle(drawer, style)
-			drawLinesFromPlan(drawer, plan, w.W, w.H)
+			drawLinesFromPlan(drawer, plan, w.W, w.H, allowWrap)
 		default:
 			panic("render: unknown layer")
 		}
@@ -448,6 +454,27 @@ func tileWorldRect(rect Rect, worldWidthFp, worldHeightFp int) []WorldTile {
 	return out
 }
 
+// tileWorldRectNoWrap returns 0..1 tiles for a bounded world (no wrap).
+// It intersects the expanded unwrapped rect with the canonical world [0..W)x[0..H).
+func tileWorldRectNoWrap(worldRect Rect, W, H int) []WorldTile {
+	ix0 := max(worldRect.minX, 0)
+	iy0 := max(worldRect.minY, 0)
+	ix1 := min(worldRect.maxX, W)
+	iy1 := min(worldRect.maxY, H)
+
+	if ix0 >= ix1 || iy0 >= iy1 {
+		return nil
+	}
+
+	return []WorldTile{
+		{
+			Rect:    Rect{minX: ix0, maxX: ix1, minY: iy0, maxY: iy1},
+			OffsetX: 0,
+			OffsetY: 0,
+		},
+	}
+}
+
 func isEmptyRectPx(r RectPx) bool {
 	return r.W <= 0 || r.H <= 0
 }

client/world/renderer_circles.go

@@ -1,18 +1,20 @@
 package world
 
 // renderCirclesStageA performs a full expanded-canvas redraw but renders ONLY Circle primitives.
-func (w *World) renderCirclesStageA(drawer PrimitiveDrawer, params RenderParams) error {
-	plan, err := w.buildRenderPlanStageA(params)
-	if err != nil {
-		return err
-	}
+// func (w *World) renderCirclesStageA(drawer PrimitiveDrawer, params RenderParams) error {
+// 	plan, err := w.buildRenderPlanStageA(params)
+// 	if err != nil {
+// 		return err
+// 	}
 
-	drawCirclesFromPlan(drawer, plan, w.W, w.H)
-	return nil
-}
+// 	allowWrap := params.Options == nil || !params.Options.DisableWrapScroll
+
+// 	drawCirclesFromPlan(drawer, plan, w.W, w.H, allowWrap)
+// 	return nil
+// }
 
 // drawCirclesFromPlan executes a circles-only draw from an already built render plan.
-func drawCirclesFromPlan(drawer PrimitiveDrawer, plan RenderPlan, worldW, worldH int) {
+func drawCirclesFromPlan(drawer PrimitiveDrawer, plan RenderPlan, worldW, worldH int, allowWrap bool) {
 	for _, td := range plan.Tiles {
 		if td.ClipW <= 0 || td.ClipH <= 0 {
 			continue
@@ -40,7 +42,12 @@ func drawCirclesFromPlan(drawer PrimitiveDrawer, plan RenderPlan, worldW, worldH
 		copiesToDraw := make([]circleCopy, 0, len(circles))
 
 		for _, c := range circles {
-			shifts := circleWrapShifts(c, worldW, worldH)
+			var shifts []wrapShift
+			if allowWrap {
+				shifts = circleWrapShifts(c, worldW, worldH)
+			} else {
+				shifts = []wrapShift{{dx: 0, dy: 0}}
+			}
 			for _, s := range shifts {
 				if circleCopyIntersectsTile(c, s.dx, s.dy, td.Tile, worldW, worldH) {
 					copiesToDraw = append(copiesToDraw, circleCopy{c: c, dx: s.dx, dy: s.dy})

client/world/renderer_circles_test.go

@@ -36,7 +36,7 @@ func TestDrawCirclesFromPlan_DuplicatesAcrossTilesAndClips(t *testing.T) {
 	require.NoError(t, err)
 
 	d := &fakePrimitiveDrawer{}
-	drawCirclesFromPlan(d, plan, w.W, w.H)
+	drawCirclesFromPlan(d, plan, w.W, w.H, true)
 
 	// Expect 4 circle copies, one per tile that covers the expanded canvas.
 	wantNames := []string{
@@ -118,7 +118,7 @@ func TestDrawCirclesFromPlan_SkipsTilesWithoutCircles(t *testing.T) {
 	require.NoError(t, err)
 
 	d := &fakePrimitiveDrawer{}
-	drawCirclesFromPlan(d, plan, w.W, w.H)
+	drawCirclesFromPlan(d, plan, w.W, w.H, true)
 
 	// No circles => no commands.
 	require.Empty(t, d.Commands())
@@ -149,7 +149,7 @@ func TestDrawCirclesFromPlan_ProjectsRadiusWithZoom(t *testing.T) {
 	require.NoError(t, err)
 
 	d := &fakePrimitiveDrawer{}
-	drawCirclesFromPlan(d, plan, w.W, w.H)
+	drawCirclesFromPlan(d, plan, w.W, w.H, true)
 
 	// There should be at least one AddCircle.
 	cmds := d.CommandsByName("AddCircle")
@@ -161,3 +161,39 @@ func TestDrawCirclesFromPlan_ProjectsRadiusWithZoom(t *testing.T) {
 		require.Equal(t, 4.0, c.Args[2])
 	}
 }
+
+func TestCircles_NoWrap_DoesNotDuplicateAcrossEdges(t *testing.T) {
+	t.Parallel()
+
+	w := NewWorld(10, 10)
+	w.resetGrid(2 * SCALE)
+
+	_, err := w.AddCircle(9, 9, 2)
+	require.NoError(t, err)
+	for _, obj := range w.objects {
+		w.indexObject(obj)
+	}
+
+	params := RenderParams{
+		ViewportWidthPx:  10,
+		ViewportHeightPx: 10,
+		MarginXPx:        0,
+		MarginYPx:        0,
+		CameraXWorldFp:   5 * SCALE,
+		CameraYWorldFp:   5 * SCALE,
+		CameraZoom:       1.0,
+		Options: &RenderOptions{
+			DisableWrapScroll: true,
+			Layers:            []RenderLayer{RenderLayerCircles},
+		},
+	}
+
+	d := &fakePrimitiveDrawer{}
+	require.NoError(t, w.Render(d, params))
+
+	cmds := d.CommandsByName("AddCircle")
+	require.Len(t, cmds, 1)
+
+	// Center must be at (9,9) only, no (-1,*) or (*,-1).
+	require.Equal(t, []float64{9, 9, 2}, cmds[0].Args)
+}

client/world/renderer_circles_wrap_test.go

@@ -74,7 +74,7 @@ func TestCircles_WrapCopies_AppearInsideViewportWhenViewportEqualsWorld(t *testi
 			require.NoError(t, err)
 
 			d := &fakePrimitiveDrawer{}
-			drawCirclesFromPlan(d, plan, w2.W, w2.H)
+			drawCirclesFromPlan(d, plan, w2.W, w2.H, true)
 
 			cmds := d.CommandsByName("AddCircle")
 			require.Len(t, cmds, len(tt.wantCenters))

client/world/renderer_lines.go

@@ -2,15 +2,17 @@ package world
 
 // renderLinesStageB performs a full expanded-canvas redraw but renders ONLY Line primitives.
 // It uses the Stage A render plan: tiles + per-tile clip + per-tile candidates.
-func (w *World) renderLinesStageB(drawer PrimitiveDrawer, params RenderParams) error {
-	plan, err := w.buildRenderPlanStageA(params)
-	if err != nil {
-		return err
-	}
+// func (w *World) renderLinesStageB(drawer PrimitiveDrawer, params RenderParams) error {
+// 	plan, err := w.buildRenderPlanStageA(params)
+// 	if err != nil {
+// 		return err
+// 	}
 
-	drawLinesFromPlan(drawer, plan, w.W, w.H)
-	return nil
-}
+// 	allowWrap := params.Options == nil || !params.Options.DisableWrapScroll
+
+// 	drawLinesFromPlan(drawer, plan, w.W, w.H, allowWrap)
+// 	return nil
+// }
 
 // lineSeg is one canonical segment (endpoints in [0..W) x [0..H)) to be drawn.
 // It represents part of the torus-shortest polyline for a Line primitive after wrap splitting.
@@ -20,7 +22,7 @@ type lineSeg struct {
 }
 
 // drawLinesFromPlan executes a lines-only draw from an already built render plan.
-func drawLinesFromPlan(drawer PrimitiveDrawer, plan RenderPlan, worldW, worldH int) {
+func drawLinesFromPlan(drawer PrimitiveDrawer, plan RenderPlan, worldW, worldH int, allowWrap bool) {
 	for _, td := range plan.Tiles {
 		if td.ClipW <= 0 || td.ClipH <= 0 {
 			continue
@@ -42,7 +44,12 @@ func drawLinesFromPlan(drawer PrimitiveDrawer, plan RenderPlan, worldW, worldH i
 		// Collect segments that actually intersect this tile's canonical rect.
 		segsToDraw := make([]lineSeg, 0, len(lines))
 		for _, l := range lines {
-			segs := torusShortestLineSegments(l, worldW, worldH)
+			var segs []lineSeg
+			if allowWrap {
+				segs = torusShortestLineSegments(l, worldW, worldH)
+			} else {
+				segs = []lineSeg{{x1: l.X1, y1: l.Y1, x2: l.X2, y2: l.Y2}}
+			}
 			for _, s := range segs {
 				if segmentIntersectsRect(s, td.Tile.Rect) {
 					segsToDraw = append(segsToDraw, s)

client/world/renderer_lines_test.go

@@ -31,7 +31,7 @@ func TestDrawLinesFromPlan_WrapX_SplitsAndDrawsInThreeXTiles(t *testing.T) {
 	require.NoError(t, err)
 
 	d := &fakePrimitiveDrawer{}
-	drawLinesFromPlan(d, plan, w.W, w.H)
+	drawLinesFromPlan(d, plan, w.W, w.H, true)
 
 	// Expect drawing in 3 X tiles (left partial, middle full, right partial) for the central Y tile:
 	// Each tile group: Save, ClipRect, AddLine(s), Stroke, Restore
@@ -95,7 +95,7 @@ func TestDrawLinesFromPlan_WrapY_SplitsAndDrawsInThreeYTiles(t *testing.T) {
 	require.NoError(t, err)
 
 	d := &fakePrimitiveDrawer{}
-	drawLinesFromPlan(d, plan, w.W, w.H)
+	drawLinesFromPlan(d, plan, w.W, w.H, true)
 
 	// Here we expect 3 Y tiles for the central X tile:
 	// Top partial, middle full (two segments), bottom partial.
@@ -156,3 +156,40 @@ func TestTorusShortestLineSegments_TieCaseIsDeterministicAndSplits(t *testing.T)
 	require.Equal(t, lineSeg{x1: 1000, y1: 5000, x2: 0, y2: 5000}, segs[0])
 	require.Equal(t, lineSeg{x1: 10000, y1: 5000, x2: 6000, y2: 5000}, segs[1])
 }
+
+func TestLines_NoWrap_TieCaseDoesNotWrap(t *testing.T) {
+	t.Parallel()
+
+	w := NewWorld(10, 10)
+	w.resetGrid(2 * SCALE)
+
+	// Tie-case along X: 1 -> 6 in world of 10.
+	_, err := w.AddLine(1, 5, 6, 5)
+	require.NoError(t, err)
+	for _, obj := range w.objects {
+		w.indexObject(obj)
+	}
+
+	params := RenderParams{
+		ViewportWidthPx:  10,
+		ViewportHeightPx: 10,
+		MarginXPx:        0,
+		MarginYPx:        0,
+		CameraXWorldFp:   5 * SCALE,
+		CameraYWorldFp:   5 * SCALE,
+		CameraZoom:       1.0,
+		Options: &RenderOptions{
+			DisableWrapScroll: true,
+			Layers:            []RenderLayer{RenderLayerLines},
+		},
+	}
+
+	d := &fakePrimitiveDrawer{}
+	require.NoError(t, w.Render(d, params))
+
+	lines := d.CommandsByName("AddLine")
+	require.Len(t, lines, 1)
+
+	// At zoom=1 and margin=0, world==canvas, so pixels equal world units.
+	require.Equal(t, []float64{1, 5, 6, 5}, lines[0].Args)
+}

client/world/renderer_plan.go

@@ -59,7 +59,13 @@ func (w *World) buildRenderPlanStageA(params RenderParams) (RenderPlan, error) {
 		return RenderPlan{}, err
 	}
 
-	tiles := tileWorldRect(worldRect, w.W, w.H)
+	allowWrap := params.Options == nil || !params.Options.DisableWrapScroll
+	var tiles []WorldTile
+	if allowWrap {
+		tiles = tileWorldRect(worldRect, w.W, w.H)
+	} else {
+		tiles = tileWorldRectNoWrap(worldRect, w.W, w.H)
+	}
 
 	// Query candidates per tile.
 	batches, err := w.collectCandidatesForTiles(tiles)

client/world/renderer_points.go

@@ -3,33 +3,35 @@ package world
 import "math"
 
 // renderPointsStageA performs a full expanded-canvas redraw but renders ONLY Point primitives.
-func (w *World) renderPointsStageA(drawer PrimitiveDrawer, params RenderParams) error {
-	plan, err := w.buildRenderPlanStageA(params)
-	if err != nil {
-		return err
-	}
+// func (w *World) renderPointsStageA(drawer PrimitiveDrawer, params RenderParams) error {
+// 	plan, err := w.buildRenderPlanStageA(params)
+// 	if err != nil {
+// 		return err
+// 	}
 
-	style := DefaultRenderStyle()
-	if params.Options != nil && params.Options.Style != nil {
-		style = *params.Options.Style
-	}
+// 	style := DefaultRenderStyle()
+// 	if params.Options != nil && params.Options.Style != nil {
+// 		style = *params.Options.Style
+// 	}
 
-	applyPointStyle(drawer, style)
-	drawPointsFromPlanWithRadius(drawer, plan, w.W, w.H, style.PointRadiusPx)
-	return nil
-}
+// 	allowWrap := params.Options == nil || !params.Options.DisableWrapScroll
+
+// 	applyPointStyle(drawer, style)
+// 	drawPointsFromPlanWithRadius(drawer, plan, w.W, w.H, style.PointRadiusPx, allowWrap)
+// 	return nil
+// }
 
 // drawPointsFromPlan keeps backward compatibility for older tests/helpers.
-func drawPointsFromPlan(drawer PrimitiveDrawer, plan RenderPlan) {
+func drawPointsFromPlan(drawer PrimitiveDrawer, plan RenderPlan, allowWrap bool) {
 	// Default world sizes are unknown here, so this wrapper is no longer suitable for wrap-aware points.
 	// Keep it for historical call sites only if they pass through Render().
 	// Prefer calling drawPointsFromPlanWithRadius with world sizes.
-	drawPointsFromPlanWithRadius(drawer, plan, 0, 0, DefaultRenderStyle().PointRadiusPx)
+	drawPointsFromPlanWithRadius(drawer, plan, 0, 0, DefaultRenderStyle().PointRadiusPx, allowWrap)
 }
 
 // drawPointsFromPlanWithRadius executes a points-only draw from an already built render plan,
 // using the provided screen-space radius. If worldW/worldH are zero, wrap copies are disabled.
-func drawPointsFromPlanWithRadius(drawer PrimitiveDrawer, plan RenderPlan, worldW, worldH int, radiusPx float64) {
+func drawPointsFromPlanWithRadius(drawer PrimitiveDrawer, plan RenderPlan, worldW, worldH int, radiusPx float64, allowWrap bool) {
 	// Convert screen radius to world-fixed conservatively (ceil), so wrap copies are not missed.
 	rPxInt := int(math.Ceil(radiusPx))
 	if rPxInt < 0 {
@@ -65,7 +67,12 @@ func drawPointsFromPlanWithRadius(drawer PrimitiveDrawer, plan RenderPlan, world
 		copiesToDraw := make([]pointCopy, 0, len(points))
 
 		for _, p := range points {
-			shifts := pointWrapShifts(p, rWorldFp, worldW, worldH)
+			var shifts []wrapShift
+			if allowWrap {
+				shifts = pointWrapShifts(p, rWorldFp, worldW, worldH)
+			} else {
+				shifts = []wrapShift{{dx: 0, dy: 0}}
+			}
 			for _, s := range shifts {
 				if pointCopyIntersectsTile(p, rWorldFp, s.dx, s.dy, td.Tile) {
 					copiesToDraw = append(copiesToDraw, pointCopy{p: p, dx: s.dx, dy: s.dy})

client/world/renderer_points_test.go

@@ -39,7 +39,7 @@ func TestDrawPointsFromPlan_DuplicatesAcrossTilesAndClips(t *testing.T) {
 	require.NoError(t, err)
 
 	d := &fakePrimitiveDrawer{}
-	drawPointsFromPlan(d, plan)
+	drawPointsFromPlan(d, plan, true)
 
 	// We expect 4 point copies:
 	// (tx=0,ty=0), (tx=0,ty=1), (tx=1,ty=0), (tx=1,ty=1)
@@ -124,7 +124,7 @@ func TestDrawPointsFromPlan_SkipsTilesWithoutPoints(t *testing.T) {
 	require.NoError(t, err)
 
 	d := &fakePrimitiveDrawer{}
-	drawPointsFromPlan(d, plan)
+	drawPointsFromPlan(d, plan, true)
 
 	// No points => no drawing commands at all.
 	require.Empty(t, d.Commands())

client/world/renderer_points_wrap_test.go

@@ -82,7 +82,7 @@ func TestPoints_WrapCopies_AppearInsideViewportWhenViewportEqualsWorld(t *testin
 			style.PointRadiusPx = 2.0
 
 			applyPointStyle(d, style)
-			drawPointsFromPlanWithRadius(d, plan, w.W, w.H, style.PointRadiusPx)
+			drawPointsFromPlanWithRadius(d, plan, w.W, w.H, style.PointRadiusPx, true)
 
 			cmds := d.CommandsByName("AddPoint")
 			require.Len(t, cmds, len(tt.wantCenters))

client/world/renderer_schedule.go

@@ -55,6 +55,7 @@ func (s *RenderScheduler) runOnUIThread() {
 		params := s.latest
 		s.mu.Unlock()
 
+		s.w.ClampRenderParamsNoWrap(&params)
 		_ = s.w.Render(s.drawer, params) // handle error in real code
 
 		s.mu.Lock()

client/world/renderer_smoke_all_primitives_test.go

@@ -44,9 +44,9 @@ func TestSmoke_DrawPointsCirclesLinesFromSamePlan(t *testing.T) {
 	d := &fakePrimitiveDrawer{}
 
 	// Execute all three passes over the same plan.
-	drawPointsFromPlan(d, plan)
-	drawCirclesFromPlan(d, plan, w.W, w.H)
-	drawLinesFromPlan(d, plan, w.W, w.H)
+	drawPointsFromPlan(d, plan, true)
+	drawCirclesFromPlan(d, plan, w.W, w.H, true)
+	drawLinesFromPlan(d, plan, w.W, w.H, true)
 
 	names := d.CommandNames()
 

client/world/renderer_smoke_mixed_test.go

@@ -35,8 +35,8 @@ func TestSmoke_DrawPointsAndCirclesFromSamePlan(t *testing.T) {
 	require.NoError(t, err)
 
 	d := &fakePrimitiveDrawer{}
-	drawPointsFromPlan(d, plan)
-	drawCirclesFromPlan(d, plan, w.W, w.H)
+	drawPointsFromPlan(d, plan, true)
+	drawCirclesFromPlan(d, plan, w.W, w.H, true)
 
 	names := d.CommandNames()
 	require.Contains(t, names, "AddPoint")

client/world/util.go

@@ -217,7 +217,7 @@ func shortestWrappedDelta(from, to, size int) (a int, b int) {
 	return
 }
 
-// cameraZoomToWorldFixed converts a UI-facing zoom multiplier into the package
+// CameraZoomToWorldFixed converts a UI-facing zoom multiplier into the package
 // fixed-point representation used by world-space calculations.
 //
 // The input zoom is expected to be a finite positive real value where 1.0 means
@@ -225,7 +225,7 @@ func shortestWrappedDelta(from, to, size int) (a int, b int) {
 //
 // An error is returned when the input is invalid or when rounding would produce
 // a non-positive fixed-point zoom.
-func cameraZoomToWorldFixed(cameraZoom float64) (int, error) {
+func CameraZoomToWorldFixed(cameraZoom float64) (int, error) {
 	if cameraZoom <= 0 || math.IsNaN(cameraZoom) || math.IsInf(cameraZoom, 0) {
 		return 0, errInvalidCameraZoom
 	}
@@ -242,7 +242,7 @@ func cameraZoomToWorldFixed(cameraZoom float64) (int, error) {
 // cameraZoomToWorldFixed. It is intended for internal code paths where invalid
 // zoom is considered a programmer or integration error and must fail fast.
 func mustCameraZoomToWorldFixed(cameraZoom float64) int {
-	zoomFp, err := cameraZoomToWorldFixed(cameraZoom)
+	zoomFp, err := CameraZoomToWorldFixed(cameraZoom)
 	if err != nil {
 		panic(err)
 	}

client/world/util_test.go

@@ -302,7 +302,7 @@ func TestCameraZoomToWorldFixed(t *testing.T) {
 		t.Run(tt.name, func(t *testing.T) {
 			t.Parallel()
 
-			got, err := cameraZoomToWorldFixed(tt.cameraZoom)
+			got, err := CameraZoomToWorldFixed(tt.cameraZoom)
 			require.NoError(t, err)
 			require.Equal(t, tt.want, got)
 		})
@@ -347,7 +347,7 @@ func TestCameraZoomToWorldFixedReturnsError(t *testing.T) {
 		t.Run(tt.name, func(t *testing.T) {
 			t.Parallel()
 
-			got, err := cameraZoomToWorldFixed(tt.cameraZoom)
+			got, err := CameraZoomToWorldFixed(tt.cameraZoom)
 			require.ErrorIs(t, err, errInvalidCameraZoom)
 			require.Zero(t, got)
 		})