Merge pull request #214 from oakmound/feature/entities-with-explicit-…

…children

Feature/entities with explicit children

alg/floatgeom/polygon_test.go

@@ -171,3 +171,13 @@ func BenchmarkPolygonConvexContains(b *testing.B) {
 		benchContains = poly.ConvexContains(x, y)
 	}
 }
+
+func Test_orient(t *testing.T) {
+	t.Parallel()
+	t.Run("3 empty points", func(t *testing.T) {
+		v := orient(Point2{}, Point2{}, Point2{})
+		if v != 0 {
+			t.Fatal("expected orient to return 0 for 3 empty points")
+		}
+	})
+}

alg/floatgeom/rect.go

@@ -1,5 +1,11 @@
 package floatgeom
 
+import (
+	"math/rand"
+
+	"github.com/oakmound/oak/v4/alg/span"
+)
+
 // A Rect2 represents a span from one point in 2D space to another.
 // If Min is less than max on any axis, it will return undefined results
 // for methods.
@@ -349,3 +355,93 @@ func (r Rect3) ProjectZ() Rect2 {
 		Max: r.Max.ProjectZ(),
 	}
 }
+
+// MulConst multiplies the boundary points of this rectangle by i.
+func (r Rect2) MulConst(i float64) Rect2 {
+	return Rect2{
+		r.Min.MulConst(i),
+		r.Max.MulConst(i),
+	}
+}
+
+// Poll returns a pseudorandom point from within this rectangle
+func (r Rect2) Poll() Point2 {
+	return Point2{
+		r.Min.X() + rand.Float64()*float64(r.W()),
+		r.Min.Y() + rand.Float64()*float64(r.H()),
+	}
+}
+
+// Clamp returns a version of the provided point such that it is contained within r. If it was already contained in
+// r, it will not be changed.
+func (r Rect2) Clamp(pt Point2) Point2 {
+	for i := 0; i < r.MaxDimensions(); i++ {
+		if pt[i] < r.Min[i] {
+			pt[i] = r.Min[i]
+		} else if pt[i] > r.Max[i] {
+			pt[i] = r.Max[i]
+		}
+	}
+	return pt
+}
+
+// Percentile returns a point within this rectangle along the vector from the top left to the bottom right of the
+// rectangle, where for example, 0.0 will be r.Min, 1.0 will be r.Max, and 2.0 will be project the vector beyond r
+// and return r.Min + {r.W()*2, r.H()*2}
+func (r Rect2) Percentile(f float64) Point2 {
+	return Point2{
+		r.Min.X() + f*float64(r.W()),
+		r.Min.Y() + f*float64(r.H()),
+	}
+}
+
+// MulSpan returns this rectangle as a Point2 Span after multiplying the boundary points of the rectangle by f.
+func (r Rect2) MulSpan(f float64) span.Span[Point2] {
+	return r.MulConst(f)
+}
+
+// MulConst multiplies the boundary points of this rectangle by i.
+func (r Rect3) MulConst(i float64) Rect3 {
+	return Rect3{
+		r.Min.MulConst(i),
+		r.Max.MulConst(i),
+	}
+}
+
+// Poll returns a pseudorandom point from within this rectangle
+func (r Rect3) Poll() Point3 {
+	return Point3{
+		r.Min.X() + (rand.Float64() * float64(r.W())),
+		r.Min.Y() + (rand.Float64() * float64(r.H())),
+		r.Min.Z() + (rand.Float64() * float64(r.D())),
+	}
+}
+
+// Clamp returns a version of the provided point such that it is contained within r. If it was already contained in
+// r, it will not be changed.
+func (r Rect3) Clamp(pt Point3) Point3 {
+	for i := 0; i < r.MaxDimensions(); i++ {
+		if pt[i] < r.Min[i] {
+			pt[i] = r.Min[i]
+		} else if pt[i] > r.Max[i] {
+			pt[i] = r.Max[i]
+		}
+	}
+	return pt
+}
+
+// Percentile returns a point within this rectangle along the vector from the top left to the bottom right of the
+// rectangle, where for example, 0.0 will be r.Min, 1.0 will be r.Max, and 2.0 will be project the vector beyond r
+// and return r.Min + {r.W()*2, r.H()*2, r.D()*2}
+func (r Rect3) Percentile(f float64) Point3 {
+	return Point3{
+		r.Min.X() + (f * float64(r.W())),
+		r.Min.Y() + (f * float64(r.H())),
+		r.Min.Z() + (f * float64(r.D())),
+	}
+}
+
+// MulConst multiplies the boundary points of this rectangle by i.
+func (r Rect3) MulSpan(f float64) span.Span[Point3] {
+	return r.MulConst(f)
+}

alg/floatgeom/rect_test.go

@@ -269,3 +269,67 @@ func projectZHolds(x1, y1, z1, x2, y2, z2 float64) bool {
 	projected := r.ProjectZ()
 	return expected == projected
 }
+
+func TestRect2Span(t *testing.T) {
+	t.Run("Basic", func(t *testing.T) {
+		r := NewRect2WH(1, 1, 9, 9)
+		p1 := r.Percentile(1.0)
+		if p1 != r.Max {
+			t.Errorf("Percentile(1.0) did not return max point: got %v expected %v", p1, r.Max)
+		}
+		p2 := r.Percentile(0.0)
+		if p2 != r.Min {
+			t.Errorf("Percentile(0.0) did not return min point: got %v expected %v", p2, r.Min)
+		}
+		const pollTries = 100
+		for i := 0; i < pollTries; i++ {
+			if !r.Contains(r.Poll()) {
+				t.Fatalf("polled point did not lie within the creating rectangle")
+			}
+		}
+		p3 := r.Clamp(Point2{0, 5})
+		if p3 != (Point2{1, 5}) {
+			t.Errorf("Clamp(0,5) did not return {1,5}: got %v", p3)
+		}
+		p4 := r.Clamp(Point2{2, 11})
+		if p4 != (Point2{2, 10}) {
+			t.Errorf("Clamp(2,11) did not return {2,10}: got %v", p4)
+		}
+		r2 := r.MulSpan(4)
+		if r2 != NewRect2(4, 4, 40, 40) {
+			t.Errorf("MulSpan did not return {4,4,40,40}: got %v", r2)
+		}
+	})
+}
+
+func TestRect3Span(t *testing.T) {
+	t.Run("Basic", func(t *testing.T) {
+		r := NewRect3WH(1, 1, 1, 9, 9, 9)
+		p1 := r.Percentile(1.0)
+		if p1 != r.Max {
+			t.Errorf("Percentile(1.0) did not return max point: got %v expected %v", p1, r.Max)
+		}
+		p2 := r.Percentile(0.0)
+		if p2 != r.Min {
+			t.Errorf("Percentile(0.0) did not return min point: got %v expected %v", p2, r.Min)
+		}
+		const pollTries = 100
+		for i := 0; i < pollTries; i++ {
+			if !r.Contains(r.Poll()) {
+				t.Fatalf("polled point did not lie within the creating rectangle")
+			}
+		}
+		p3 := r.Clamp(Point3{0, -1, 5})
+		if p3 != (Point3{1, 1, 5}) {
+			t.Errorf("Clamp(0,-1,5) did not return {1,1,5}: got %v", p3)
+		}
+		p4 := r.Clamp(Point3{20, 2, 11})
+		if p4 != (Point3{10, 2, 10}) {
+			t.Errorf("Clamp(20, 2,11) did not return {10,2,10}: got %v", p4)
+		}
+		r2 := r.MulSpan(4)
+		if r2 != NewRect3(4, 4, 4, 40, 40, 40) {
+			t.Errorf("MulSpan did not return {4,4,4,40,40,40}: got %v", r2)
+		}
+	})
+}

entities/entity.go

@@ -31,7 +31,8 @@ type Generator struct {
 	UseMouseTree     bool
 	WithoutCollision bool
 
-	Children [][]Option
+	Children         [][]Option
+	ExplicitChildren []*Entity
 }
 
 func And(opts ...Option) Option {
@@ -50,6 +51,13 @@ func WithChild(opts ...Option) Option {
 	}
 }
 
+func WithExplicitChild(e *Entity) Option {
+	return func(s Generator) Generator {
+		s.ExplicitChildren = append(s.ExplicitChildren, e)
+		return s
+	}
+}
+
 func WithRect(v floatgeom.Rect2) Option {
 	return func(s Generator) Generator {
 		s.Position = v.Min
@@ -135,6 +143,9 @@ func (e *Entity) Shift(delta floatgeom.Point2) {
 			e.X(), e.Y(), e.W(), e.H(), e.Space,
 		)
 	}
+	for _, c := range e.Children {
+		c.Shift(delta)
+	}
 }
 
 func (e *Entity) SetX(x float64) {
@@ -153,6 +164,9 @@ func (e *Entity) ShiftX(x float64) {
 			e.X(), e.Y(), e.W(), e.H(), e.Space,
 		)
 	}
+	for _, c := range e.Children {
+		c.ShiftX(x)
+	}
 }
 
 func (e *Entity) ShiftY(y float64) {
@@ -163,23 +177,17 @@ func (e *Entity) ShiftY(y float64) {
 			e.X(), e.Y(), e.W(), e.H(), e.Space,
 		)
 	}
+	for _, c := range e.Children {
+		c.ShiftY(y)
+	}
 }
 
 func (e *Entity) SetPos(p floatgeom.Point2) {
-	w, h := e.W(), e.H()
-	e.Rect = floatgeom.NewRect2WH(p.X(), p.Y(), w, h)
-	e.Renderable.SetPos(p.X(), p.Y())
-	if e.Tree != nil {
-		e.Tree.UpdateSpace(
-			e.X(), e.Y(), e.W(), e.H(), e.Space,
-		)
-	}
+	e.Shift(p.Sub(e.Rect.Min))
 }
 
-// TODO: take a point, not floats
 func (e *Entity) ShiftPos(x, y float64) {
-	p := e.Rect.Min
-	e.SetPos(p.Add(floatgeom.Point2{x, y}))
+	e.Shift(floatgeom.Point2{x, y})
 }
 
 func (e *Entity) HitLabel(label collision.Label) *collision.Space {
@@ -214,11 +222,16 @@ func New(ctx *scene.Context, opts ...Option) *Entity {
 		g = o(g)
 	}
 
-	children := make([]*Entity, len(g.Children))
+	children := make([]*Entity, len(g.Children)+len(g.ExplicitChildren))
 	for i, childOpts := range g.Children {
 		childOpts = append(childOpts, WithOffset(g.Position))
 		children[i] = New(ctx, childOpts...)
 	}
+	for i, explicitChild := range g.ExplicitChildren {
+		child := explicitChild
+		child.ShiftPos(g.Position.X(), g.Position.Y())
+		children[i+len(g.Children)] = child
+	}
 
 	e := &Entity{
 		ctx: ctx,
@@ -240,8 +253,9 @@ func New(ctx *scene.Context, opts ...Option) *Entity {
 	if m, isMod := e.Renderable.(render.Modifiable); g.Mod != nil && isMod {
 		e.Renderable = m.Modify(g.Mod)
 	}
-
-	e.Renderable.SetPos(e.X(), e.Y())
+	if e.Renderable != nil {
+		e.Renderable.SetPos(e.X(), e.Y())
+	}
 
 	if g.Parent == nil {
 		cid := ctx.CallerMap.Register(e)
@@ -265,7 +279,7 @@ func New(ctx *scene.Context, opts ...Option) *Entity {
 		e.Tree.Add(e.Space)
 	}
 
-	if len(g.DrawLayers) != 0 {
+	if len(g.DrawLayers) != 0 && e.Renderable != nil {
 		ctx.Draw(e.Renderable, g.DrawLayers...)
 	}
 

render/particle/generator.go

@@ -5,6 +5,7 @@ import (
 
 	"github.com/oakmound/oak/v4/alg/span"
 	"github.com/oakmound/oak/v4/physics"
+	"github.com/oakmound/oak/v4/render"
 )
 
 var (
@@ -29,6 +30,7 @@ type Generator interface {
 // Modeled after Parcycle
 type BaseGenerator struct {
 	physics.Vector
+	DrawStack *render.DrawStack
 	// This float is currently forced to an integer
 	// at new particle rotation. This should be changed
 	// to something along the lines of 'new per 30 frames',
@@ -68,6 +70,7 @@ func (bg *BaseGenerator) GetBaseGenerator() *BaseGenerator {
 func (bg *BaseGenerator) setDefaults() {
 	*bg = BaseGenerator{
 		Vector:      physics.NewVector(0, 0),
+		DrawStack:   nil,
 		NewPerFrame: span.NewConstant(1.0),
 		LifeSpan:    span.NewConstant(60.0),
 		Angle:       span.NewConstant(0.0),

render/particle/options.go

@@ -6,6 +6,7 @@ import (
 	"github.com/oakmound/oak/v4/alg"
 	"github.com/oakmound/oak/v4/alg/span"
 	"github.com/oakmound/oak/v4/physics"
+	"github.com/oakmound/oak/v4/render"
 )
 
 // And chains together particle options into a single option
@@ -116,3 +117,10 @@ func Limit(limit int) func(Generator) {
 		g.GetBaseGenerator().ParticleLimit = limit
 	}
 }
+
+// DrawStack sets the current drawstack so that we dont use the globaldrawstack
+func DrawStack(drawStack *render.DrawStack) func(Generator) {
+	return func(g Generator) {
+		g.GetBaseGenerator().DrawStack = drawStack
+	}
+}

render/particle/source.go

@@ -177,7 +177,11 @@ func (ps *Source) addParticles() {
 		ps.particles[ps.nextPID] = p
 		ps.nextPID++
 		p.SetLayer(ps.Layer(bp.GetPos()))
-		render.Draw(p, ps.stackLevel)
+		if pg.DrawStack == nil {
+			render.Draw(p, ps.stackLevel)
+		} else {
+			pg.DrawStack.Draw(p, ps.stackLevel)
+		}
 	}
 
 }