ebiten/examples/shader/chromaticaberration.go

// Copyright 2020 The Ebiten Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

//go:build ignore

//kage:unit pixels

package main

var Time float
var Cursor vec2

func Fragment(dstPos vec4, srcPos vec2, color vec4) vec4 {
	center := imageDstSize() / 2
	amount := (center - Cursor) / 10
	var clr vec3
	clr.r = imageSrc2At(srcPos + amount).r
	clr.g = imageSrc2UnsafeAt(srcPos).g
	clr.b = imageSrc2At(srcPos - amount).b
	return vec4(clr, 1)
}