Use Ebitens coordinate system for showing.

src/cmd/math/main.go

@@ -37,11 +37,11 @@ func main() {
 	
 	t := gx.Rectangle{
 		Transform: gx.Transform{
-			S: gx.Vector{1, 1},
+			S: gx.Vector{100, 200},
 			P: gx.Point{0, 200},
+			RA: gx.Point{0, 0},
+			R: 0,
 		},
-		W: 100,
-		H: 200,
 	}
 	
 	points := []gx.Point{

src/cmd/test/main.go

@@ -26,9 +26,12 @@ type Rect struct {
 func NewRect() *Rect {
 	return &Rect{&gx.DrawableRectangle{
 			Rectangle: gx.Rectangle{
-				Transform: gx.T(),
-				W: 200,
-				H: 400,
+				Transform: gx.Transform{
+					S: gx.Vector{
+						X: 200,
+						Y: 400,
+					},
+				},
 			},
 			Color: gx.Color{
 				gx.MaxColorV,
@@ -85,9 +88,10 @@ 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,
+			Transform: gx.Transform{
+				P: player.P,
+				S: gx.Vector{10, 10},
+			},
 		},
 		Color: gx.Color{0, 0, gx.MaxColorV, gx.MaxColorV},
 	}
@@ -97,7 +101,7 @@ func (p *Player) Draw(e *gx.Engine, i *gx.Image) {
 func (p *Player) Start(e *gx.Engine, v ...any) {
 	fmt.Println("starting")
 	c := e.Camera()
-	c.RA = gx.V(360, -240)
+	c.RA = gx.V(360, 240)
 }
 
 func (p *Player) Update(e *gx.Engine) error {

src/gx/camera.go

@@ -16,22 +16,10 @@ func (c *Camera)RealMatrix(
 	e *Engine,
 ) Matrix {
 	g := &Matrix{}
-
-	g.Scale(
-		c.S.X,
-		c.S.Y,
-	)
-
-	g.Translate(
-		-c.P.X,
-		c.P.Y,
-	)
-	g.Rotate(-c.R)
-
-	g.Translate(
-		c.RA.X,
-		-c.RA.Y,
-	)
+	g.Scale(c.S.X, c.S.Y)
+	g.Translate(-c.P.X, -c.P.Y)
+	g.Rotate(c.R)
+	g.Translate(c.RA.X, c.RA.Y)
 
 	return *g
 }

src/gx/circle.go

@@ -2,16 +2,7 @@ package gx
 
 // The structure represents any circles.
 type Circle struct {
-	// Position.
-	P Point
-	// Radius.
-	R Float
+	Transform
 }
 
-func (c Circle) ColliderSimplify() Rectangle {
-	return Rectangle{
-		W: c.R * 2,
-		H: c.R * 2,
-	}
-}
 

src/gx/engine.go

@@ -5,7 +5,7 @@ import (
 	"github.com/hajimehoshi/ebiten/v2/inpututil"
 	"github.com/surdeus/godat/src/sparsex"
 	"github.com/surdeus/godat/src/poolx"
-	//"fmt"
+	"fmt"
 	"time"
 )
 
@@ -56,6 +56,9 @@ func (e *Engine) Keys() []Key {
 func New(
 	cfg *WindowConfig,
 ) *Engine {
+	w := Float(cfg.Width)
+	h := Float(cfg.Height)
+	fmt.Println("res:", w, h)
 	return &Engine{
 		wcfg: cfg,
 		layers: sparsex.New[
@@ -65,6 +68,7 @@ func New(
 		camera: &Camera{
 			Transform: Transform{
 					S: Vector{1, 1},
+					RA: V(w/2, h/2),
 			},
 		},
 		updaters: poolx.New[Updater](),

src/gx/rect.go

@@ -12,10 +12,8 @@ type Rectangle struct {
 	// Position of up left corner
 	// and the point to
 	// rotate around(relatively of position, not absolute).
+	// Scale represent width and height.
 	Transform
-	// Width and height.
-	W, H Float
-	
 }
 
 // The type describes rectangle that can be drawn.
@@ -40,10 +38,13 @@ func (r Rectangle) Corners() []Point {
 // Get 2 triangles that the rectangle consists of.
 func (r Rectangle) Triangles() Triangles {
 	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)
+	
+	p1 := V(0, 0).Apply(&m)
+	p2 := V(1, 0).Apply(&m)
+	p3 := V(1, -1).Apply(&m)
+	p4 := V(0, -1).Apply(&m)
+	
+	//fmt.Println("in:", p1, p2, p3, p4)
 	
 	return Triangles{
 		Triangle{p1, p2, p3},
@@ -72,9 +73,6 @@ func (r *DrawableRectangle) Draw(
 		img := NewImage(1, 1)
 		img.Set(0, 0, r.Color)
 		
-		t.S.X *= r.W
-		t.S.Y *= r.H
-		
 		m := t.Matrix()
 		rm := e.Camera().RealMatrix(e)
 		
@@ -89,21 +87,21 @@ func (r *DrawableRectangle) Draw(
 	
 	
 	// Use the Color as base image if no is provided.
-	var did bool
+	//var did bool
 	if r.Images[0] == nil {
 		r.Images[0] = NewImage(1, 1)
 		r.Images[0].Set(0, 0, r.Color)
-		did = true
+		//did = true
 	} 
 	
 	w, h := r.Images[0].Size()
-	if !did {
+	/*if !did {
 		t.S.X /= Float(w)
 		t.S.Y /= Float(h)
 		
 		t.S.X *= r.W
 		t.S.Y *= r.H
-	}
+	}*/
 	
 	
 	rm := e.Camera().RealMatrix(e)

src/gx/transform.go

@@ -21,14 +21,14 @@ func T() Transform {
 }
 
 // Returns the GeoM with corresponding
-// to the transfrom transformation 
+// to the transfrom transformation.
 func (t Transform)Matrix() Matrix {
 	g := &Matrix{}
 
 	g.Scale(t.S.X, t.S.Y)
 	g.Translate(-t.RA.X, -t.RA.Y)
 	g.Rotate(t.R)
-	g.Translate(t.P.X, -t.P.Y)
+	g.Translate(t.P.X, t.P.Y)
 
 	return *g
 }