added test for all implementations

internal/viz/viz_test.go

@@ -0,0 +1,73 @@
+package viz
+
+import (
+	"bytes"
+	"os"
+	"path/filepath"
+	"testing"
+
+	"bspviz/internal/bsp"
+	"bspviz/internal/geom"
+	"bspviz/internal/mapfmt"
+)
+
+func TestEmitDOT(t *testing.T) {
+	root := &bsp.Node{
+		O: geom.V(0, 0),
+		D: geom.V(1, 0),
+		Left: &bsp.Node{
+			Leaf: &bsp.Leaf{Segs: []geom.Seg{{A: geom.V(0, 0), B: geom.V(1, 1)}}},
+		},
+		Right: &bsp.Node{
+			Leaf: &bsp.Leaf{},
+		},
+	}
+	out := filepath.Join(t.TempDir(), "tree.dot")
+	if err := EmitDOT(root, out); err != nil {
+		t.Fatalf("EmitDOT error: %v", err)
+	}
+	got, err := os.ReadFile(out)
+	if err != nil {
+		t.Fatalf("ReadFile: %v", err)
+	}
+	expect := "digraph BSP {\n" +
+		"  node [fontname=\"Helvetica\"];\n" +
+		"  n0 [label=\"Split\\nO=(0,0) D=(1,0)\"];\n" +
+		"  n1 [label=\"Leaf\\nSegs=1\", shape=ellipse, style=filled, fillcolor=lightgray];\n" +
+		"  n2 [label=\"Leaf\\nSegs=0\", shape=ellipse, style=filled, fillcolor=lightgray];\n" +
+		"  n0 -> n1 [label=\"L\"];\n" +
+		"  n0 -> n2 [label=\"R\"];\n" +
+		"}\n"
+	if string(got) != expect {
+		t.Fatalf("unexpected DOT output:\n%s", got)
+	}
+}
+
+func TestRenderPNGProducesFile(t *testing.T) {
+	m := &mapfmt.MapData{
+		Vertices: []mapfmt.Vertex{{X: 0, Y: 0}, {X: 64, Y: 0}, {X: 64, Y: 64}},
+		Linedefs: []mapfmt.Linedef{
+			{V1: 0, V2: 1},
+			{V1: 1, V2: 2},
+			{V1: 2, V2: 0},
+		},
+	}
+	root := &bsp.Node{
+		O:     geom.V(0, 0),
+		D:     geom.V(1, 0),
+		Left:  &bsp.Node{Leaf: &bsp.Leaf{Segs: []geom.Seg{{A: geom.V(0, 0), B: geom.V(64, 64)}}}},
+		Right: &bsp.Node{Leaf: &bsp.Leaf{}},
+	}
+	out := filepath.Join(t.TempDir(), "render.png")
+	if err := RenderPNG(m, root, out); err != nil {
+		t.Fatalf("RenderPNG error: %v", err)
+	}
+	data, err := os.ReadFile(out)
+	if err != nil {
+		t.Fatalf("ReadFile: %v", err)
+	}
+	pngMagic := []byte{0x89, 'P', 'N', 'G', '\r', '\n', 0x1a, '\n'}
+	if len(data) < len(pngMagic) || !bytes.Equal(data[:len(pngMagic)], pngMagic) {
+		t.Fatalf("output is not a PNG")
+	}
+}