diff --git a/src/cmd/math/main.go b/src/cmd/math/main.go
index bcaac25..c538014 100644
--- a/src/cmd/math/main.go
+++ b/src/cmd/math/main.go
@@ -35,16 +35,19 @@ func main() {
 	fmt.Println(l1.Crosses(l2))
 	fmt.Println(l1.ContainsPoint(gx.Point{1, 4}))
 	
-	t := gx.Triangle{
-		gx.Point{0, 0},
-		gx.Point{0, 100},
-		gx.Point{100, 0},
+	t := gx.Rectangle{
+		Transform: gx.Transform{
+			S: gx.Vector{1, 1},
+			P: gx.Point{0, 200},
+		},
+		W: 100,
+		H: 200,
 	}
 	
 	points := []gx.Point{
 		gx.Point{},
 		gx.Point{100, 0},
-		gx.Point{0, 100},
+		gx.Point{0, 99},
 		gx.Point{.1, .1},
 		gx.Point{-1, -1},
 		gx.Point{1, 1},
@@ -53,9 +56,14 @@ func main() {
 		gx.Point{50, 1},
 	}
 	
+	ts := t.Triangles()
+	t1 := ts[0]
+	t2 := ts[1]
+	fmt.Printf("Rectangle triangles:\n\t%v\n\t%v\n", t1, t2)
 	for _, p := range points {
-		fmt.Println(t, p, t.ContainsPoint(p))
+		fmt.Println(p, t.ContainsPoint(p))
 	}
+	
 }
 
 
diff --git a/src/cmd/test/main.go b/src/cmd/test/main.go
index 64ed6b2..9cf2f81 100644
--- a/src/cmd/test/main.go
+++ b/src/cmd/test/main.go
@@ -55,6 +55,8 @@ func (r *Rect) Update(e *gx.Engine) error {
 
 var (
 	playerImg *gx.Image
+	player *Player
+	rect *Rect
 )
 
 func NewPlayer() *Player {
@@ -79,6 +81,19 @@ func NewPlayer() *Player {
 	return ret
 }
 
+func (p *Player) Draw(e *gx.Engine, i *gx.Image) {
+	p.Sprite.Draw(e, i)
+	r := &gx.DrawableRectangle{
+		Rectangle: gx.Rectangle{
+			Transform: p.Transform,
+			W: 10,
+			H: 10,
+		},
+		Color: gx.Color{0, 0, gx.MaxColorV, gx.MaxColorV},
+	}
+	r.Draw(e, i)
+}
+
 func (p *Player) Start(e *gx.Engine, v ...any) {
 	fmt.Println("starting")
 	c := e.Camera()
@@ -153,7 +168,14 @@ func (d *Debug) Draw(
 	for _, k := range e.Keys() {
 		keyStrs = append(keyStrs, k.String())
 	}
-	e.DebugPrint(i, strings.Join(keyStrs, ", "))
+	
+	if rect.ContainsPoint(player.P) {
+		keyStrs = append(keyStrs, "THIS IS SHIT")
+	}
+	
+	e.DebugPrint(i,
+		strings.Join(keyStrs, ", "))
+	
 }
 
 func (d *Debug) IsVisible() bool {return true}
@@ -173,8 +195,12 @@ func main() {
 	}
 
 
-	e.Add(0, NewPlayer())
+	player = NewPlayer()
+	rect = NewRect()
+	
 	e.Add(1, &Debug{})
-	e.Add(-1, NewRect())
+	e.Add(0, player)
+	e.Add(-1, rect)
+	
 	e.Run()
 }
diff --git a/src/gx/camera.go b/src/gx/camera.go
index 4388aea..58d070b 100644
--- a/src/gx/camera.go
+++ b/src/gx/camera.go
@@ -14,17 +14,13 @@ type Camera struct {
 //  need to calculate it each time for each object. )
 func (c *Camera)RealMatrix(
 	e *Engine,
-	scale bool,
 ) Matrix {
 	g := &Matrix{}
 
-
-	if scale {
-		g.Scale(
-			c.S.X,
-			c.S.Y,
-		)
-	}
+	g.Scale(
+		c.S.X,
+		c.S.Y,
+	)
 
 	g.Translate(
 		-c.P.X,
diff --git a/src/gx/img.go b/src/gx/img.go
index ed551fc..5b3fcc5 100644
--- a/src/gx/img.go
+++ b/src/gx/img.go
@@ -37,6 +37,11 @@ func LoadImage(input io.Reader) (*Image, error) {
 	return ret, nil
 }
 
+func NewImage(w, h int) (*Image) {
+	return ebiten.NewImage(w, h)
+}
+
+
 func (c Color) RGBA() (r, g, b, a uint32) {
 	return uint32(c.R), uint32(c.G), uint32(c.B), uint32(c.A)
 }
diff --git a/src/gx/point.go b/src/gx/point.go
deleted file mode 100644
index 704e26c..0000000
--- a/src/gx/point.go
+++ /dev/null
@@ -1,4 +0,0 @@
-package gx
-
-type Point Vector
-
diff --git a/src/gx/rect.go b/src/gx/rect.go
index 2220f7f..c1caf63 100644
--- a/src/gx/rect.go
+++ b/src/gx/rect.go
@@ -39,26 +39,24 @@ func (r Rectangle) Corners() []Point {
 
 // Get 2 triangles that the rectangle consists of.
 func (r Rectangle) Triangles() Triangles {
-	return Triangles{}
-}
-
-/*func MustNewImage(w, h int) (*Image) {
-	img, err := NewImage(w, h)
-	if err != nil {
-		panic(err)
-	}
+	m := r.Matrix()
+	p1 := r.P.Apply(&m)
+	p2 := r.P.Add(Vector{r.W, 0}).Apply(&m)
+	p3 := r.P.Add(Vector{r.W, -r.H}).Apply(&m)
+	p4 := r.P.Add(Vector{0, -r.H}).Apply(&m)
 	
-	return img
-}*/
+	return Triangles{
+		Triangle{p1, p2, p3},
+		Triangle{p1, p4, p3},
+	}
+}
 
+// Check whether the rectangle contains the point.
 func (r Rectangle) ContainsPoint(p Point) bool {
-	return false
-}
-
-func NewImage(w, h int) (*Image) {
-	return ebiten.NewImage(w, h)
+	return r.Triangles().ContainsPoint(p)
 }
 
+// Check whether the drawable rectangle should be drawn.
 func (r *DrawableRectangle) IsVisible() bool {
 	return r.Visible
 }
@@ -77,8 +75,8 @@ func (r *DrawableRectangle) Draw(
 		t.S.X *= r.W
 		t.S.Y *= r.H
 		
-		m := t.Matrix(e)
-		rm := e.Camera().RealMatrix(e, true)
+		m := t.Matrix()
+		rm := e.Camera().RealMatrix(e)
 		
 		m.Concat(rm)
 		
@@ -108,8 +106,8 @@ func (r *DrawableRectangle) Draw(
 	}
 	
 	
-	rm := e.Camera().RealMatrix(e, true)
-	m := t.Matrix(e)
+	rm := e.Camera().RealMatrix(e)
+	m := t.Matrix()
 	m.Concat(rm)
 	
 	// Drawing with shader.
diff --git a/src/gx/sprite.go b/src/gx/sprite.go
index ac5b0e4..0ac95c1 100644
--- a/src/gx/sprite.go
+++ b/src/gx/sprite.go
@@ -21,11 +21,10 @@ func (s *Sprite) Draw(
 	
 	m := &Matrix{}
 
-	m.Concat(s.Matrix(e))
+	m.Concat(s.Matrix())
 	if !s.Floating {
 		m.Concat(e.Camera().RealMatrix(
 			e,
-			true,
 		))
 	}
 
diff --git a/src/gx/transform.go b/src/gx/transform.go
index 080e7b0..a8f51bb 100644
--- a/src/gx/transform.go
+++ b/src/gx/transform.go
@@ -22,7 +22,7 @@ func T() Transform {
 
 // Returns the GeoM with corresponding
 // to the transfrom transformation 
-func (t Transform)Matrix(e *Engine) Matrix {
+func (t Transform)Matrix() Matrix {
 	g := &Matrix{}
 
 	g.Scale(t.S.X, t.S.Y)
diff --git a/src/gx/triangle.go b/src/gx/triangle.go
index e1e5bac..8228e65 100644
--- a/src/gx/triangle.go
+++ b/src/gx/triangle.go
@@ -55,6 +55,16 @@ func (t Triangle) Sgn() Float {
 		(t[1].X - t[2].X) * (t[0].Y - t[2].Y)
 }
 
+func (ts Triangles) ContainsPoint(p Point) bool {
+	for _, t := range ts {
+		if t.ContainsPoint(p) {
+			return true
+		}
+	}
+	
+	return false
+}
+
 //func (t Triangle)
 /*
 func (r *DrawableRectangle) Draw(
diff --git a/src/gx/vector.go b/src/gx/vector.go
index 8ecc726..1cecca8 100644
--- a/src/gx/vector.go
+++ b/src/gx/vector.go
@@ -8,6 +8,9 @@ import (
 type Vector struct {
 	X, Y Float
 }
+type Point = Vector
+
+type Vectors []Vector
 
 func V(x, y Float) Vector {
 	return Vector{x, y}
@@ -19,6 +22,34 @@ func (v Vector) Apply(m *Matrix) Vector {
 	return V(x, y)
 }
 
+// Adds the vector to other one returning the result.
+func (v Vector) Add(a ...Vector) Vector {
+	for _, r := range a {
+		v.X += r.X
+		v.Y += r.Y
+	}
+	
+	return v
+}
+
+// Returns the subtraction of all the vectors from the current one.
+func (v Vector) Sub(s ...Vector) Vector {
+	for _, r := range s {
+		v.X -= r.X
+		v.Y -= r.Y
+	}
+	
+	return v
+}
+
+// Returns the negative version of the vector.
+func (v Vector) Neg() Vector {
+	return Vector{
+		-v.X,
+		-v.Y,
+	}
+}
+
 // Returns the vector rotated by "a" angle in radians.
 func (v Vector) Rotate(a Float) Vector {
 	m := &Matrix{}