adding to git.i0t.app

internal/compositor/tiles_test.go

@@ -0,0 +1,27 @@
+package compositor
+
+import "testing"
+
+func TestTileRect(t *testing.T) {
+	W, H := 1920, 1080
+	// A 1x1 tile at (0,0) in a 4x4 grid.
+	got := TileRect(W, H, 4, 4, 0, 0, 1, 1)
+	if got.W != W/4 || got.H != H/4 || got.X != 0 || got.Y != 0 {
+		t.Errorf("1x1 top-left: got %+v", got)
+	}
+	// A tile spanning the full width/height must reach the exact edges.
+	full := TileRect(W, H, 4, 4, 0, 0, 4, 4)
+	if full.X != 0 || full.Y != 0 || full.W != W || full.H != H {
+		t.Errorf("full-span: got %+v want full frame", full)
+	}
+	// A 3x3 main tile plus a right column: the main reaches 3/4 width, the
+	// side tile fills the remainder to the exact right edge.
+	main := TileRect(W, H, 4, 4, 0, 0, 3, 4)
+	side := TileRect(W, H, 4, 4, 3, 0, 1, 1)
+	if main.X+main.W != side.X {
+		t.Errorf("main right edge %d should meet side left edge %d", main.X+main.W, side.X)
+	}
+	if side.X+side.W != W {
+		t.Errorf("side tile right edge %d should reach %d", side.X+side.W, W)
+	}
+}