Update ebiten -> ebitengine

Also update to latest version. Unfortunately the audio is broken,
so I raised hajimehoshi/ebiten#2970.

Author: johanbrandhorst

Makefile

@@ -50,10 +50,10 @@ tinygo-canvas: clean
 	cp ./canvas/index.html ./html/index.html
 	cp ./canvas/main.go ./html/main.go
 
-.PHONY: ebiten
-ebiten: clean
-	GOOS=js GOARCH=wasm go build -o ./html/ebiten.wasm ./ebiten/main.go
-	cp ./ebiten/index.html ./html/index.html
+.PHONY: ebitengine
+ebitengine: clean
+	GOOS=js GOARCH=wasm go build -o ./html/ebitengine.wasm ./ebitengine/main.go
+	cp ./ebitengine/index.html ./html/index.html
 	cp $$(go env GOROOT)/misc/wasm/wasm_exec.js ./html/wasm_exec.js
 
 .PHONY: vugu

README.md

@@ -90,10 +90,10 @@ send a HTTP request, parse the result and write it to the DOM.
 An updated version of the [repulsion](https://stdiopt.github.io/gowasm-experiments/repulsion)
 demo by [Luis Figuerido](https://github.com/stdiopt).
 
-### Ebiten
+### Ebitengine
 
-A short demo of using the [Ebiten game engine](https://github.com/hajimehoshi/ebiten)
-to create a WebGL based flappy bird clone. Copied from the Ebiten examples.
+A short demo of using the [Ebitengine game engine](https://github.com/hajimehoshi/ebiten)
+to create a WebGL based flappy bird clone. Copied from the Ebitengine examples.
 
 ### Vugu
 

ebiten/LICENSE renamed to ebitengine/LICENSE

@@ -0,0 +1,30 @@
+//go:build ignore
+
+//kage:unit pixels
+
+// Reference: a public domain CRT effect
+// https://github.com/libretro/glsl-shaders/blob/master/crt/shaders/crt-lottes.glsl
+
+package main
+
+func Warp(pos vec2) vec2 {
+	const (
+		warpX = 0.031
+		warpY = 0.041
+	)
+	pos = pos*2 - 1
+	pos *= vec2(1+(pos.y*pos.y)*warpX, 1+(pos.x*pos.x)*warpY)
+	return pos/2 + 0.5
+}
+
+func Fragment(dstPos vec4, srcPos vec2, color vec4) vec4 {
+	// Adjust the texture position to [0, 1].
+	origin := imageSrc0Origin()
+	size := imageSrc0Size()
+	pos := srcPos
+	pos -= origin
+	pos /= size
+
+	pos = Warp(pos)
+	return imageSrc0At(pos*size + origin)
+}

ebitengine/crt.go

@@ -10,7 +10,7 @@
     }
 
     const go = new Go();
-    WebAssembly.instantiateStreaming(fetch("ebiten.wasm"), go.importObject).then(result => {
+    WebAssembly.instantiateStreaming(fetch("ebitengine.wasm"), go.importObject).then(result => {
         go.run(result.instance);
     });
 </script>