From 0f6732bcf99786a13a8ba4a54d055d4eb19fa551 Mon Sep 17 00:00:00 2001
From: surdeus <surdeus@gmail.com>
Date: Thu, 11 Jan 2024 06:39:57 +0300
Subject: [PATCH] feat: implemented layering for DrawableTriangles.

---
 cmd/test/debug.go    |  9 +++---
 cmd/test/player.go   | 20 ++----------
 cmd/test/trianlge.go |  6 ++--
 engine.go            | 75 ++++++++++++++++++++++++++++++++++----------
 object.go            |  4 +--
 polygon.go           |  8 ++---
 rect.go              | 31 +++++++-----------
 sprite.go            | 11 ++++---
 triangle.go          | 60 ++++++++---------------------------
 9 files changed, 103 insertions(+), 121 deletions(-)

diff --git a/cmd/test/debug.go b/cmd/test/debug.go
index dd8d16e..f869971 100644
--- a/cmd/test/debug.go
+++ b/cmd/test/debug.go
@@ -11,17 +11,17 @@ type Debug struct {
 	gg.Object
 }
 
-func (d *Debug) Draw(c *Context) {
+func (d *Debug) Draw(c *Context) []gg.EVertex {
 	e := c.Engine
 	keyStrs := []string{}
 	keyStrs = append(keyStrs, fmt.Sprintf(
 		"counter: %d", counter,
 	))
 	keyStrs = append(keyStrs, fmt.Sprintf(
-		"tps: %d", int(c.TPS()),
+		"tps: %d", int(c.Tps()),
 	))
 	keyStrs = append(keyStrs, fmt.Sprintf(
-		"fps: %d", int(c.FPS()),
+		"fps: %d", int(c.Fps()),
 	))
 	keyStrs = append(keyStrs, fmt.Sprintf(
 		"relPlayerPos: %v", player.Position,
@@ -74,7 +74,8 @@ func (d *Debug) Draw(c *Context) {
 
 	e.DebugPrint(c.Image,
 		strings.Join(keyStrs, "\n"))
-
+	
+	return nil
 }
 
 func (d *Debug) IsVisible() bool { return true }
diff --git a/cmd/test/player.go b/cmd/test/player.go
index 7df7c27..25b59c1 100644
--- a/cmd/test/player.go
+++ b/cmd/test/player.go
@@ -36,27 +36,11 @@ func NewPlayer() *Player {
 func (p *Player) Start(c *Context) {
 }
 
-// Custom drawing function.
-func (p *Player) Draw(c *Context) {
-	p.Sprite.Draw(c)
-	return
-	t := p.Transform
-	t.Scale.X *= 4.
-	t.Scale.Y *= 4.
-
-	r := &gg.DrawableRectangle{}
-	r.Color = gg.Rgba(0, 0, 1, 1)
-	r.Rectangle = gg.Rectangle{
-		Transform: t,
-	}
-	r.Draw(c)
-}
-
 func (p *Player) Update(c *Context) {
 	if p.Spawned {
 		return
 	}
-	dt := c.DT()
+	dt := c.Dt()
 	cam := c.Camera
 	keys := c.Keys()
 
@@ -140,7 +124,7 @@ func (p *Player) Update(c *Context) {
 		c.Camera.Position = pos.Sub(ec.Abs)
 	case *gg.WheelChange:
 		c.Camera.Scale = c.Camera.Scale.Add(gg.V2(
-			ec.Offset.Y * c.DT() * p.ScaleSpeed * 40,
+			ec.Offset.Y * c.Dt() * p.ScaleSpeed * 40,
 		))
 	}}
 }
diff --git a/cmd/test/trianlge.go b/cmd/test/trianlge.go
index 72df453..323611d 100644
--- a/cmd/test/trianlge.go
+++ b/cmd/test/trianlge.go
@@ -32,7 +32,7 @@ func NewTri() *Tri {
 }
 
 func (t *Tri) Update(c *Context) {
-	dt := c.DT()
+	dt := c.Dt()
 	if t.ContainsPoint(c.AbsCursorPosition()) {
 		t.Color = gg.Rgba(0, 1, 0, 1)
 	} else {
@@ -53,12 +53,12 @@ func (t *Tri) Update(c *Context) {
 	case gg.KeyM:
 		absPos := t.AbsPosition()
 		t.SetAbsPosition(
-			absPos.Add(gg.V(0, 100*c.DT()*d)),
+			absPos.Add(gg.V(0, 100*c.Dt()*d)),
 		)
 	case gg.KeyN:
 		absPos := t.AbsPosition()
 		t.SetAbsPosition(
-			absPos.Add(gg.V(100*c.DT()*d, 0)),
+			absPos.Add(gg.V(100*c.Dt()*d, 0)),
 		)
 	case gg.KeyV:
 			t.Rotation += d * gg.Pi * 0.3 * dt
diff --git a/engine.go b/engine.go
index 372bcd7..5b1c82c 100644
--- a/engine.go
+++ b/engine.go
@@ -11,7 +11,7 @@ import (
 )
 
 const (
-	LayerBufSize = 0
+	MaxVertices = 1 << 16
 )
 
 type GraphicsLibrary = ebiten.GraphicsLibrary
@@ -64,7 +64,7 @@ type Engine struct {
 	// The same delta time for all frames
 	// and all objects.
 	lastTime time.Time
-	dt Float
+	dt, fdt Float
 
 	// Temporary stuff 
 	keys, prevKeys []Key
@@ -75,8 +75,8 @@ type Engine struct {
 	wg sync.WaitGroup
 
 	//bufs [LayerBufSize]*Image
-	vertices []ebiten.Vertex
-	vindices []uint16
+	vertices map[Layer] []ebiten.Vertex
+	//vindices []uint16
 }
 
 type engine Engine
@@ -297,9 +297,22 @@ func (e *engine) Update() error {
 	return nil
 }
 
-func (e *engine) Draw(i *ebiten.Image) {
-	e.vindices = []uint16{}
-	e.vertices = []ebiten.Vertex{}
+var (
+	fullPageIndexes = func() [MaxVertices]uint16 {
+		ret := [MaxVertices]uint16{}
+		for i:=0 ; i<len(ret) ; i++ {
+			ret[i] = uint16(i)
+		}
+		return ret
+	}()
+	defaultPageImg = func() *Image {
+		img := NewImage(1, 1)
+		img.Set(0, 0, Rgba(1, 1, 1, 1))
+		return img
+	}()
+	defaultTriOptions = &ebiten.DrawTrianglesOptions{}
+)
+func (e *engine) Draw(img *ebiten.Image) {
 	e.dt = time.Since(e.lastTime).Seconds()
 	eng := (*Engine)(e)
 	m := map[Layer][]Drawer{}
@@ -319,17 +332,39 @@ func (e *engine) Draw(i *ebiten.Image) {
 		m[l] = append(layer, object)
 	}
 
-	// Drawing layers.
+	// Drawing layers via the sparse array.
+	// First drawing via the inside function
+	// and then the returned []EVertex.
 	layers := maps.NewSparse[Layer, []Drawer](nil, m)
-	c := &Context{Engine: eng, typ: drawContext, Image: i}
+	c := &Context{Engine: eng, typ: drawContext, Image: img}
 	for layer := range layers.Chan() {
+		vertices := []EVertex{}
 		for _, drawer := range layer {
-			drawer.Draw(c)
+			vs := drawer.Draw(c)
+			if vs != nil {
+				vertices = append(vertices, vs...)
+			}
 		}
+		pn := len(vertices) / MaxVertices
+		mod := len(vertices) % MaxVertices
+		for i := 0 ; i<pn ; i++ {
+			cur := i*MaxVertices
+			img.DrawTriangles(
+				vertices[cur:cur+MaxVertices],
+				fullPageIndexes[:],
+				defaultPageImg,
+				defaultTriOptions,
+			)
+		}
+		st := pn*MaxVertices
+		img.DrawTriangles(
+			vertices[st:],
+			fullPageIndexes[:mod],
+			defaultPageImg,
+			defaultTriOptions,
+		)
 	}
-	img := NewImage(1, 1)
-	img.Set(0, 0, Rgba(1, 1, 1, 1))
-	i.DrawTriangles(e.vertices, e.vindices, img, &ebiten.DrawTrianglesOptions{})
+
 
 	// Empty the buff to generate it again.
 	eng.Camera.buffered = false
@@ -344,15 +379,21 @@ func (e *engine) Layout(ow, oh int) (int, int) {
 	return ow, oh
 }
 
-// Return the delta time duration value.
-func (e *Engine) DT() Float {
+// Return the delta time.
+func (e *Engine) Dt() Float {
 	return e.dt
 }
-func (e *Engine) FPS() float64 {
+
+// Return the current fixed delta time.
+func (e *Engine) Fdt() Float {
+	return 1/60
+}
+
+func (e *Engine) Fps() float64 {
 	return ebiten.ActualFPS()
 }
 
-func (e *Engine) TPS() float64 {
+func (e *Engine) Tps() float64 {
 	return ebiten.ActualTPS()
 }
 
diff --git a/object.go b/object.go
index c053b7a..d3c428b 100644
--- a/object.go
+++ b/object.go
@@ -40,7 +40,7 @@ type Colority struct {
 // drawn. It will be drew corresponding to
 // the layers order so the layer must be returned.
 type Drawer interface {
-	Draw(*Context)
+	Draw(*Context) []EVertex
 	GetLayer() Layer
 	IsVisible() bool
 }
@@ -66,6 +66,6 @@ func (o *Object) Input() chan *Context { return o.input }
 
 func (o *Object) Start(c *Context) {}
 func (o *Object) Update(c *Context) {}
-func (o *Object) Draw(c *Context) {}
+func (o *Object) Draw(c *Context) []EVertex { return nil}
 func (o *Object) Delete(c *Context) {}
 
diff --git a/polygon.go b/polygon.go
index 11d7eac..bf4b15f 100644
--- a/polygon.go
+++ b/polygon.go
@@ -37,12 +37,10 @@ func (p Polygon) MakeTriangles() Triangles {
 	return ret
 }
 
-func (p *DrawablePolygon) Draw(c *Context) {
-	(&DrawableTriangles{
-		Visibility: p.Visibility,
+func (p *DrawablePolygon) Draw(c *Context) []EVertex {
+	return (&DrawableTriangles{
 		Colority: p.Colority,
-		ShaderOptions: p.ShaderOptions,
 		Triangles: p.MakeTriangles(),
-	}).Draw(c)
+	}).MakeEVertices(c)
 }
 
diff --git a/rect.go b/rect.go
index 3392601..ba644a4 100644
--- a/rect.go
+++ b/rect.go
@@ -1,7 +1,7 @@
 package gg
 
 import (
-	"github.com/hajimehoshi/ebiten/v2"
+	//"github.com/hajimehoshi/ebiten/v2"
 	//"github.com/hajimehoshi/ebiten/v2/vector"
 	//"fmt"
 	//"image"
@@ -48,7 +48,7 @@ func (r Rectangle) Edges() Edges {
 }
 
 // Get 2 triangles that the rectangle consists of.
-func (r Rectangle) Triangles() Triangles {
+func (r Rectangle) MakeTriangles() Triangles {
 	pts := r.Vertices()
 	p1 := pts[0]
 	p2 := pts[1]
@@ -63,7 +63,7 @@ func (r Rectangle) Triangles() Triangles {
 
 // Check whether the rectangle contains the point.
 func (r Rectangle) ContainsPoint(p Point) bool {
-	return r.Triangles().ContainsPoint(p)
+	return r.MakeTriangles().ContainsPoint(p)
 }
 
 // Check whether the drawable rectangle should be drawn.
@@ -71,23 +71,13 @@ func (r *DrawableRectangle) IsVisible() bool {
 	return r.Visible
 }
 
-func (r *DrawableRectangle) Draw(c *Context) {
-	m := r.Matrix()
-	rm := c.Camera.RealMatrix()
-	m.Concat(rm)
-	// Draw solid color if no shader.
-	if r.Shader == nil {
-		img := NewImage(1, 1)
-		img.Set(0, 0, r.Color)
-		
-		c.DrawImage(img, &ebiten.DrawImageOptions{
-			GeoM: m,
-		})
-		return
-	}
+func (r *DrawableRectangle) Draw(c *Context) []EVertex {
+	return (&DrawableTriangles{
+		Colority: r.Colority,
+		Triangles: r.MakeTriangles(),
+	}).MakeEVertices(c)
 	
-	
-	// Use the Color as base image if no is provided.
+	/*// Use the Color as base image if no is provided.
 	//var did bool
 	if r.Images[0] == nil {
 		r.Images[0] = NewImage(1, 1)
@@ -101,6 +91,7 @@ func (r *DrawableRectangle) Draw(c *Context) {
 		GeoM: m,
 		Images: r.Images,
 		Uniforms: r.Uniforms,
-	})
+	})*/
+	return nil
 }
 
diff --git a/sprite.go b/sprite.go
index 7039ac3..26733f9 100644
--- a/sprite.go
+++ b/sprite.go
@@ -17,10 +17,10 @@ var (
 	//spritesOp DrawImageOptions
 )
 
-func (s *Sprite) Draw(c *Context) {
+func (s *Sprite) Draw(c *Context) []EVertex {
 	// Nothing to draw.
 	if s.Images[0] == nil {
-		return
+		return nil
 	}
 	
 	t := s.Rectangle().Transform
@@ -34,7 +34,7 @@ func (s *Sprite) Draw(c *Context) {
 		c.DrawImage(s.Images[0], &ebiten.DrawImageOptions{
 			GeoM: m,
 		})
-		return
+		return nil
 	}
 	
 	w, h := s.Images[0].Size()
@@ -44,6 +44,7 @@ func (s *Sprite) Draw(c *Context) {
 		Uniforms: s.Uniforms,
 		GeoM: m,
 	})
+	return nil
 }
 
 // Return the rectangle that contains the sprite.
@@ -64,7 +65,7 @@ func (s *Sprite) Rectangle() Rectangle {
 
 // Get triangles of the rectangle that contains the sprite
 // and has the same widght and height.
-func (s *Sprite) Triangles() Triangles {
-	return s.Rectangle().Triangles()
+func (s *Sprite) MakeTriangles() Triangles {
+	return s.Rectangle().MakeTriangles()
 }
 
diff --git a/triangle.go b/triangle.go
index aa47417..72d8daf 100644
--- a/triangle.go
+++ b/triangle.go
@@ -5,6 +5,8 @@ import (
 	"github.com/hajimehoshi/ebiten/v2"
 )
 
+type EVertex = ebiten.Vertex
+
 // Ebitens vector in better abstractions like Vectors.
 type Vertex struct {
 	Dst Vector
@@ -16,14 +18,11 @@ type Triangle [3]Vector
 type Triangles []Triangle
 type DrawableTriangles struct {
 	Triangles
-	Visibility
 	Colority
-	ShaderOptions
-	ebiten.DrawTrianglesOptions
 }
 
-func (v Vertex) Ebiten() ebiten.Vertex {
-	return ebiten.Vertex {
+func (v Vertex) Ebiten() EVertex {
+	return EVertex {
 		DstX: float32(v.Dst.X),
 		DstY: float32(v.Dst.Y),
 		SrcX: float32(v.Src.X),
@@ -88,50 +87,17 @@ func (ts Triangles) ContainsPoint(p Point) bool {
 	return false
 }
 
-func (r *DrawableTriangles) Draw(c *Context) {
+func (r *DrawableTriangles) MakeEVertices(c *Context) []EVertex {
 	m := c.Camera.RealMatrix()
-	
-	// Draw solid color if no shader.
-	if r.Shader == nil {
-		vs := make([]ebiten.Vertex, len(r.Triangles) * 3)
-		var buf Vertex
-		buf.Color = r.Color
-		for i := range r.Triangles {
-			for j := range r.Triangles[i] {
-				buf.Dst = r.Triangles[i][j].Apply(m)
-				vs[i*3 + j] = buf.Ebiten()
-			}
+	vs := make([]ebiten.Vertex, len(r.Triangles) * 3)
+	var buf Vertex
+	buf.Color = r.Color
+	for i := range r.Triangles {
+		for j := range r.Triangles[i] {
+			buf.Dst = r.Triangles[i][j].Apply(m)
+			vs[i*3 + j] = buf.Ebiten()
 		}
-		
-		is := make([]uint16, len(r.Triangles) * 3)
-		start := len(c.Engine.vindices)
-		for i := 0 ; i < len(is) ; i++ {
-			is[i] = uint16(start + i)
-		}
-
-		c.Engine.vertices = append(c.Engine.vertices, vs...)
-		c.Engine.vindices = append(c.Engine.vindices, is...)
-		
-		
-		return
-		//c.DrawTriangles(vs, is, img, &r.DrawTrianglesOptions)
-		return
 	}
-	
-	// Use the Color as base image if no is provided.
-	/*if r.Images[0] == nil {
-		r.Images[0] = NewImage(1, 1)
-		r.Images[0].Set(0, 0, r.Color)
-	} 
-	
-	w, h := r.Images[0].Size()
-	
-	// Drawing with shader.
-	opts := &ebiten.DrawRectShaderOptions{
-		GeoM: m,
-		Images: r.Images,
-		Uniforms: r.Uniforms,
-	}
-	i.DrawRectShader(w, h, r.Shader, opts)*/
+	return vs
 }