feat: hit on primitives

2026-03-07 19:28:22 +02:00
parent e4b956232f
commit c076347d70
21 changed files with 1167 additions and 165 deletions
@@ -0,0 +1,152 @@
+package world
+
+import (
+	"image/color"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestHitTest_ReturnsBestByPriorityAndAllHits(t *testing.T) {
+	t.Parallel()
+
+	w := NewWorld(10, 10)
+
+	// Build index once renderer state is initialized.
+	params := RenderParams{
+		ViewportWidthPx:  100,
+		ViewportHeightPx: 100,
+		MarginXPx:        0,
+		MarginYPx:        0,
+		CameraXWorldFp:   5 * SCALE,
+		CameraYWorldFp:   5 * SCALE,
+		CameraZoom:       1.0,
+	}
+	w.IndexOnViewportChange(params.ViewportWidthPx, params.ViewportHeightPx, params.CameraZoom)
+
+	// Add overlapping objects near center.
+	idLine, err := w.AddLine(4.5, 5.0, 5.5, 5.0, LineWithPriority(100))
+	require.NoError(t, err)
+
+	idCircle, err := w.AddCircle(5.0, 5.0, 1.0, CircleWithPriority(300))
+	require.NoError(t, err)
+
+	idPoint, err := w.AddPoint(5.0, 5.0, PointWithPriority(200))
+	require.NoError(t, err)
+
+	// Force index rebuild from last state (Add already does it, but keep explicit).
+	w.Reindex()
+
+	buf := make([]Hit, 0, 8)
+	hits, err := w.HitTest(buf, &params, 50, 50) // center of viewport
+	require.NoError(t, err)
+
+	// Should find all three, best first (priority desc).
+	require.Len(t, hits, 3)
+	require.Equal(t, idCircle, hits[0].ID)
+	require.Equal(t, idPoint, hits[1].ID)
+	require.Equal(t, idLine, hits[2].ID)
+}
+
+func TestHitTest_BufferTooSmall_KeepsBestHits(t *testing.T) {
+	t.Parallel()
+
+	w := NewWorld(10, 10)
+
+	params := RenderParams{
+		ViewportWidthPx:  100,
+		ViewportHeightPx: 100,
+		MarginXPx:        0,
+		MarginYPx:        0,
+		CameraXWorldFp:   5 * SCALE,
+		CameraYWorldFp:   5 * SCALE,
+		CameraZoom:       1.0,
+	}
+	w.IndexOnViewportChange(params.ViewportWidthPx, params.ViewportHeightPx, params.CameraZoom)
+
+	_, _ = w.AddLine(4.5, 5.0, 5.5, 5.0, LineWithPriority(100))
+	idCircle, _ := w.AddCircle(5.0, 5.0, 1.0, CircleWithPriority(300))
+	_, _ = w.AddPoint(5.0, 5.0, PointWithPriority(200))
+	w.Reindex()
+
+	// Only room for 1 hit => must keep the best (highest priority).
+	buf := make([]Hit, 0, 1)
+	hits, err := w.HitTest(buf, &params, 50, 50)
+	require.NoError(t, err)
+	require.Len(t, hits, 1)
+	require.Equal(t, idCircle, hits[0].ID)
+}
+
+func TestHitTest_NoWrap_ClampsCameraAndStillHits(t *testing.T) {
+	t.Parallel()
+
+	w := NewWorld(10, 10)
+
+	params := RenderParams{
+		ViewportWidthPx:  100,
+		ViewportHeightPx: 100,
+		MarginXPx:        25,
+		MarginYPx:        25,
+		CameraXWorldFp:   -100000, // invalid camera, should be clamped
+		CameraYWorldFp:   -100000,
+		CameraZoom:       1.0,
+		Options:          &RenderOptions{DisableWrapScroll: true},
+	}
+	w.IndexOnViewportChange(params.ViewportWidthPx, params.ViewportHeightPx, params.CameraZoom)
+
+	_, err := w.AddPoint(0.0, 0.0, PointWithPriority(100))
+	require.NoError(t, err)
+	w.Reindex()
+
+	// Tap near top-left of viewport should still map to world and find the point.
+	buf := make([]Hit, 0, 8)
+	hits, err := w.HitTest(buf, &params, 0, 0)
+	require.NoError(t, err)
+	require.NotEmpty(t, hits)
+}
+
+func TestHitTest_CircleStrokeOnly_HitsNearRingNotCenter(t *testing.T) {
+	t.Parallel()
+
+	w := NewWorld(10, 10)
+
+	params := RenderParams{
+		ViewportWidthPx:  100,
+		ViewportHeightPx: 100,
+		MarginXPx:        0,
+		MarginYPx:        0,
+		CameraXWorldFp:   5 * SCALE,
+		CameraYWorldFp:   5 * SCALE,
+		CameraZoom:       1.0,
+	}
+	w.IndexOnViewportChange(params.ViewportWidthPx, params.ViewportHeightPx, params.CameraZoom)
+
+	// Stroke-only circle: FillColor alpha=0 => ring mode.
+	ov := StyleOverride{
+		FillColor:   color.RGBA{A: 0},
+		StrokeColor: color.RGBA{A: 255},
+	}
+	strokeStyle := w.AddStyleCircle(ov)
+
+	_, err := w.AddCircle(5.0, 5.0, 2.0,
+		CircleWithStyleID(strokeStyle),
+		CircleWithPriority(100),
+	)
+	require.NoError(t, err)
+
+	w.Reindex()
+
+	buf := make([]Hit, 0, 8)
+
+	// Center must NOT hit.
+	hits, err := w.HitTest(buf, &params, 50, 50)
+	require.NoError(t, err)
+	require.Empty(t, hits)
+
+	// Near ring should hit. For small circles we use a minimum visible ring radius (3px).
+	// So tapping at +3px from center should be within ring+slop.
+	hits, err = w.HitTest(buf, &params, 50+3, 50)
+	require.NoError(t, err)
+	require.NotEmpty(t, hits)
+	require.Equal(t, KindCircle, hits[0].Kind)
+}