ebiten/examples/shader/water.go

43 lines
1.3 KiB
Go
Raw Normal View History

// 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.
// +build ignore
package main
var Time float
var Cursor vec2
var ScreenSize vec2
func Fragment(position vec4, texCoord vec2, color vec4) vec4 {
border := ScreenSize.y*0.6 + 4*cos(Time*3+texCoord.y*200)
if position.y < border {
return image2TextureAt(texCoord)
}
srcsize := imageSrcTextureSize()
rorigin, rsize := imageSrcTextureSourceRegion()
xoffset := (4 / srcsize.x) * cos(Time*3+texCoord.y*200)
yoffset := (20 / srcsize.y) * (1.0 + cos(Time*3+texCoord.y*50))
bordertex := border / srcsize.y
clr := image2TextureBoundsAt(vec2(
texCoord.x+xoffset,
-(texCoord.y+yoffset-rorigin.y)+bordertex*2+rorigin.y,
)).rgb
overlay := vec3(0.5, 1, 1)
return vec4(mix(clr, overlay, 0.25), 1)
}