18/8/21 9:23 PM

builtInComponentsAndSystems/rectangleRenderer.go

@@ -0,0 +1,38 @@
+package builtInComponentsAndSystems
+
+
+import (
+	"github.com/hajimehoshi/ebiten/v2"
+	"github.com/hajimehoshi/ebiten/v2/ebitenutil"
+
+	"github.com/eboatwright/pearl"
+
+	"image/color"
+)
+
+
+type RectangleRenderer struct {
+	Color color.RGBA
+}
+func (rr *RectangleRenderer) ID() string { return "rectangleRenderer" }
+
+
+type RectangleRendererSystem struct {}
+
+func (rrs *RectangleRendererSystem) Update(entity *pearl.Entity, scene *pearl.Scene) {}
+
+func (rrs *RectangleRendererSystem) Draw(entity *pearl.Entity, scene *pearl.Scene, screen *ebiten.Image, options *ebiten.DrawImageOptions) {
+	t := entity.GetComponent("transform").(*Transform)
+	rr := entity.GetComponent("rectangleRenderer").(*RectangleRenderer)
+
+	ebitenutil.DrawRect(
+		screen,
+		t.Position.X, t.Position.Y,
+		t.Scale.X, t.Scale.Y,
+		rr.Color,
+	)
+}
+
+func (rrs *RectangleRendererSystem) GetRequirements() []string {
+	return []string { "transform", "rectangleRenderer" }
+}

examples/2-rectangle/main.go

@@ -0,0 +1,34 @@
+package main
+
+
+import (
+	"github.com/eboatwright/pearl"
+	bicas "github.com/eboatwright/pearl/builtInComponentsAndSystems"
+)
+
+
+func main() {
+	pearl.Start(960, 600, 3, "Rectangle Rendering", pearl.RGBA(0, 0, 0, 255), func() {
+		gameScene := &pearl.Scene { ID: "game" }
+		pearl.LoadScene(gameScene)
+
+		rect := &pearl.Entity { ID: "rect" }
+		rect.AddComponents([]pearl.IComponent {
+			&bicas.Transform {
+				Position: pearl.Vector2 { 5, 5 },
+				Scale:    pearl.Vector2 { 10, 10 },
+			},
+			&bicas.RectangleRenderer {
+				Color: pearl.RGBA(255, 255, 255, 255),
+			},
+		})
+
+		gameScene.AddEntities([]*pearl.Entity {
+			rect,
+		})
+
+		gameScene.AddSystems([]pearl.ISystem {
+			&bicas.RectangleRendererSystem {  },
+		})
+	})
+}