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// 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 Damaged int
const HP float = 0
func Fragment(_ vec4, texCoord vec2, _ vec4) vec4 {
wallpx := imageSrc0At(texCoord) // A pixel from the wall tile
mask := imageSrc1At(texCoord) // A pixel from the damage mask image
if Damaged == 1 && (wallpx.a != 0.0 && mask.a != 0.0) {
alpha := clamp(HP+(1.0-mask.a), 0.0, 1.0)
// Create a darker pixel if it's inside a damage mask.
return vec4(wallpx.r*alpha, wallpx.g*alpha, wallpx.b*alpha, wallpx.a)
}
return wallpx // Otherwise, leave a pixel color as is
}