ebiten/examples/shader/main.go
2020-06-22 00:47:53 +09:00

116 lines
2.5 KiB
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.
// +build example jsgo
package main
import (
"log"
"github.com/hajimehoshi/ebiten"
)
const (
screenWidth = 640
screenHeight = 480
)
const shaderSrc = `package main
var Time float
var Mouse vec2
// viewportSize is a predefined function.
func Vertex(position vec2, texCoord vec2, color vec4) vec4 {
return mat4(
2/viewportSize().x, 0, 0, 0,
0, 2/viewportSize().y, 0, 0,
0, 0, 1, 0,
-1, -1, 0, 1,
) * vec4(position, 0, 1)
}
func Fragment(position vec4) vec4 {
pos := position.xy / viewportSize() + Mouse / viewportSize() / 4
color := 0.0
color += sin(pos.x * cos(Time / 15) * 80) + cos(pos.y * cos(Time / 15) * 10)
color += sin(pos.y * sin(Time / 10) * 40) + cos(pos.x * sin(Time / 25) * 40)
color += sin(pos.x * sin(Time / 5) * 10) + sin(pos.y * sin(Time / 35) * 80)
color *= sin(Time / 10) * 0.5
return vec4(color, color * 0.5, sin(color + Time / 3 ) * 0.75, 1)
}`
type Game struct {
shader *ebiten.Shader
time int
}
func (g *Game) Update(screen *ebiten.Image) error {
g.time++
if g.shader == nil {
var err error
g.shader, err = ebiten.NewShader([]byte(shaderSrc))
if err != nil {
return err
}
}
return nil
}
func (g *Game) Draw(screen *ebiten.Image) {
w, h := screen.Size()
vs := []ebiten.Vertex{
{
DstX: 0,
DstY: 0,
},
{
DstX: float32(w),
DstY: 0,
},
{
DstX: 0,
DstY: float32(h),
},
{
DstX: float32(w),
DstY: float32(h),
},
}
is := []uint16{0, 1, 2, 1, 2, 3}
cx, cy := ebiten.CursorPosition()
op := &ebiten.DrawTrianglesWithShaderOptions{}
op.Uniforms = []interface{}{
float32(g.time) / 60, // time
[]float32{float32(cx), float32(cy)}, // cursor
}
screen.DrawTrianglesWithShader(vs, is, g.shader, op)
}
func (g *Game) Layout(outsideWidth, outsideHeight int) (int, int) {
return screenWidth, screenHeight
}
func main() {
ebiten.SetWindowSize(screenWidth, screenHeight)
ebiten.SetWindowTitle("Shader (Ebiten Demo)")
if err := ebiten.RunGame(&Game{}); err != nil {
log.Fatal(err)
}
}