feat: primitive styling

2026-03-07 17:01:22 +02:00
parent 477e656008
commit e4b956232f
18 changed files with 1264 additions and 175 deletions
@@ -0,0 +1,205 @@
+package world
+
+import (
+	"image/color"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestRender_AppliesStyleBeforeAddCommands_ForFirstItemInTile(t *testing.T) {
+	t.Parallel()
+
+	w := NewWorld(10, 10)
+	w.resetGrid(2 * SCALE)
+
+	// Create a derived circle style so we can observe a style application transition.
+	red := color.RGBA{R: 255, A: 255}
+	styleID := w.AddStyleCircle(StyleOverride{FillColor: red})
+
+	_, err := w.AddCircle(5, 5, 1, CircleWithStyleID(styleID), CircleWithPriority(100))
+	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{
+			BackgroundColor: color.RGBA{A: 255},
+		},
+	}
+
+	d := &fakePrimitiveDrawer{}
+	require.NoError(t, w.Render(d, params))
+
+	cmds := d.Commands()
+
+	iSetFill := indexOfFirstName(cmds, "SetFillColor")
+	iAddCircle := indexOfFirstName(cmds, "AddCircle")
+	require.NotEqual(t, -1, iSetFill)
+	require.NotEqual(t, -1, iAddCircle)
+
+	require.Less(t, iSetFill, iAddCircle, "style must be applied before AddCircle")
+}
+
+func TestRender_DoesNotReapplySameStyleAcrossMultipleObjects(t *testing.T) {
+	t.Parallel()
+
+	w := NewWorld(10, 10)
+	w.resetGrid(2 * SCALE)
+
+	// Two lines with the same default line style and same priority.
+	_, err := w.AddLine(1, 5, 9, 5, LineWithPriority(100))
+	require.NoError(t, err)
+	_, err = w.AddLine(1, 6, 9, 6, LineWithPriority(101)) // ensure deterministic order by priority
+	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{
+			BackgroundColor: color.RGBA{A: 255},
+		},
+	}
+
+	d := &fakePrimitiveDrawer{}
+	require.NoError(t, w.Render(d, params))
+
+	// We expect style application at least once.
+	setWidth := d.CommandsByName("SetLineWidth")
+	require.NotEmpty(t, setWidth)
+
+	// The key batching assertion: style setters should not be called twice *between* two AddLine calls.
+	cmds := d.Commands()
+	line1 := indexOfFirstName(cmds, "AddLine")
+	require.NotEqual(t, -1, line1)
+
+	line2 := indexOfNextName(cmds, "AddLine", line1+1)
+	require.NotEqual(t, -1, line2)
+
+	// Between line1 and line2 there must be no SetLineWidth / SetStrokeColor / SetDash / SetDashOffset,
+	// because StyleID is the same and the renderer caches lastStyleID.
+	for i := line1 + 1; i < line2; i++ {
+		switch cmds[i].Name {
+		case "SetLineWidth", "SetStrokeColor", "SetDash", "SetDashOffset", "SetFillColor":
+			t.Fatalf("unexpected style setter %q between two AddLine commands at index %d", cmds[i].Name, i)
+		}
+	}
+}
+
+func TestRender_ReappliesStyleWhenStyleIDChanges(t *testing.T) {
+	t.Parallel()
+
+	w := NewWorld(10, 10)
+	w.resetGrid(2 * SCALE)
+
+	// Two circles, different derived fill colors => different StyleIDs.
+	red := color.RGBA{R: 255, A: 255}
+	green := color.RGBA{G: 255, A: 255}
+
+	styleRed := w.AddStyleCircle(StyleOverride{FillColor: red})
+	styleGreen := w.AddStyleCircle(StyleOverride{FillColor: green})
+
+	_, err := w.AddCircle(4, 5, 1, CircleWithStyleID(styleRed), CircleWithPriority(100))
+	require.NoError(t, err)
+	_, err = w.AddCircle(6, 5, 1, CircleWithStyleID(styleGreen), CircleWithPriority(101))
+	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{
+			BackgroundColor: color.RGBA{A: 255},
+		},
+	}
+
+	d := &fakePrimitiveDrawer{}
+	require.NoError(t, w.Render(d, params))
+
+	cmds := d.Commands()
+	firstCircle := indexOfFirstName(cmds, "AddCircle")
+	secondCircle := indexOfNextName(cmds, "AddCircle", firstCircle+1)
+	require.NotEqual(t, -1, firstCircle)
+	require.NotEqual(t, -1, secondCircle)
+
+	// There must be at least one SetFillColor before each circle.
+	// And importantly, we expect a SetFillColor BETWEEN the two circles due to style change.
+	setBeforeFirst := lastIndexOfNameBefore(cmds, "SetFillColor", firstCircle)
+	require.NotEqual(t, -1, setBeforeFirst)
+
+	setBetween := indexOfFirstNameInRange(cmds, "SetFillColor", firstCircle+1, secondCircle)
+	require.NotEqual(t, -1, setBetween, "expected style reapply (SetFillColor) between circles with different StyleIDs")
+}
+
+/* ---------- helper functions for fake command slices ---------- */
+
+func indexOfFirstName(cmds []fakeDrawerCommand, name string) int {
+	for i, c := range cmds {
+		if c.Name == name {
+			return i
+		}
+	}
+	return -1
+}
+
+func indexOfNextName(cmds []fakeDrawerCommand, name string, start int) int {
+	for i := start; i < len(cmds); i++ {
+		if cmds[i].Name == name {
+			return i
+		}
+	}
+	return -1
+}
+
+func lastIndexOfNameBefore(cmds []fakeDrawerCommand, name string, before int) int {
+	if before > len(cmds) {
+		before = len(cmds)
+	}
+	for i := before - 1; i >= 0; i-- {
+		if cmds[i].Name == name {
+			return i
+		}
+	}
+	return -1
+}
+
+func indexOfFirstNameInRange(cmds []fakeDrawerCommand, name string, start, end int) int {
+	if start < 0 {
+		start = 0
+	}
+	if end > len(cmds) {
+		end = len(cmds)
+	}
+	for i := start; i < end; i++ {
+		if cmds[i].Name == name {
+			return i
+		}
+	}
+	return -1
+}