no-wrap option; pivoted exponential zoom

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)
+}