ebiten/internal/ui/ui_js.go

296 lines
7.2 KiB
Go

// Copyright 2015 Hajime Hoshi
//
// 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 js
package ui
import (
"strconv"
"github.com/gopherjs/gopherjs/js"
"github.com/hajimehoshi/ebiten/internal/graphics"
"github.com/hajimehoshi/ebiten/internal/graphics/opengl"
)
func (u *UserInterface) SetScreenSize(width, height int) bool {
return u.setScreenSize(width, height, u.scale)
}
func (u *UserInterface) SetScreenScale(scale int) bool {
width, height := u.size()
return u.setScreenSize(width, height, scale)
}
func (u *UserInterface) ScreenScale() int {
return u.scale
}
func (u *UserInterface) ActualScreenScale() int {
return u.scale * int(u.deviceScale)
}
var canvas *js.Object
type UserInterface struct {
scale int
deviceScale float64
sizeChanged bool
}
var currentUI = &UserInterface{
sizeChanged: true,
}
func CurrentUI() *UserInterface {
return currentUI
}
// NOTE: This returns true even when the browser is not active.
func shown() bool {
return !js.Global.Get("document").Get("hidden").Bool()
}
func vsync() {
ch := make(chan struct{})
n := 1
var l func()
l = func() {
if 0 < n {
n--
// TODO: In iOS8, this is called at every 1/30[sec] frame.
// Can we use DOMHighResTimeStamp?
js.Global.Get("window").Call("requestAnimationFrame", l)
return
}
close(ch)
}
l()
<-ch
}
func (u *UserInterface) Update() (interface{}, error) {
currentInput.UpdateGamepads()
if u.sizeChanged {
u.sizeChanged = false
w, h := u.size()
e := ScreenSizeEvent{
Width: w,
Height: h,
Scale: u.ScreenScale(),
ActualScale: u.ActualScreenScale(),
}
return e, nil
}
return RenderEvent{}, nil
}
func (u *UserInterface) Terminate() {
// Do nothing.
}
func (u *UserInterface) SwapBuffers() {
vsync()
for !shown() {
vsync()
}
}
func initialize() (*opengl.Context, error) {
// Do nothing in node.js.
if js.Global.Get("require") != js.Undefined {
c, err := opengl.NewContext()
if err != nil {
return nil, err
}
if err := graphics.Initialize(c); err != nil {
return nil, err
}
return c, nil
}
doc := js.Global.Get("document")
window := js.Global.Get("window")
if doc.Get("body") == nil {
ch := make(chan struct{})
window.Call("addEventListener", "load", func() {
close(ch)
})
<-ch
}
canvas = doc.Call("createElement", "canvas")
canvas.Set("width", 16)
canvas.Set("height", 16)
doc.Get("body").Call("appendChild", canvas)
htmlStyle := doc.Get("documentElement").Get("style")
htmlStyle.Set("height", "100%")
htmlStyle.Set("margin", "0")
htmlStyle.Set("padding", "0")
bodyStyle := doc.Get("body").Get("style")
bodyStyle.Set("backgroundColor", "#000")
bodyStyle.Set("position", "relative")
bodyStyle.Set("height", "100%")
bodyStyle.Set("margin", "0")
bodyStyle.Set("padding", "0")
// TODO: This is OK as long as the game is in an independent iframe.
// What if the canvas is embedded in a HTML directly?
doc.Get("body").Call("addEventListener", "click", func() {
canvas.Call("focus")
})
canvasStyle := canvas.Get("style")
canvasStyle.Set("position", "absolute")
// Make the canvas focusable.
canvas.Call("setAttribute", "tabindex", 1)
canvas.Get("style").Set("outline", "none")
// Keyboard
canvas.Call("addEventListener", "keydown", func(e *js.Object) {
e.Call("preventDefault")
code := e.Get("keyCode").Int()
currentInput.KeyDown(code)
})
canvas.Call("addEventListener", "keyup", func(e *js.Object) {
e.Call("preventDefault")
code := e.Get("keyCode").Int()
currentInput.KeyUp(code)
})
// Mouse
canvas.Call("addEventListener", "mousedown", func(e *js.Object) {
e.Call("preventDefault")
button := e.Get("button").Int()
currentInput.MouseDown(button)
setMouseCursorFromEvent(e)
})
canvas.Call("addEventListener", "mouseup", func(e *js.Object) {
e.Call("preventDefault")
button := e.Get("button").Int()
currentInput.MouseUp(button)
setMouseCursorFromEvent(e)
})
canvas.Call("addEventListener", "mousemove", func(e *js.Object) {
e.Call("preventDefault")
setMouseCursorFromEvent(e)
})
canvas.Call("addEventListener", "contextmenu", func(e *js.Object) {
e.Call("preventDefault")
})
// Touch (emulating mouse events)
// TODO: Create indimendent touch functions
canvas.Call("addEventListener", "touchstart", func(e *js.Object) {
e.Call("preventDefault")
currentInput.MouseDown(0)
touches := e.Get("changedTouches")
touch := touches.Index(0)
setMouseCursorFromEvent(touch)
})
canvas.Call("addEventListener", "touchend", func(e *js.Object) {
e.Call("preventDefault")
currentInput.MouseUp(0)
touches := e.Get("changedTouches")
touch := touches.Index(0)
setMouseCursorFromEvent(touch)
})
canvas.Call("addEventListener", "touchmove", func(e *js.Object) {
e.Call("preventDefault")
touches := e.Get("changedTouches")
touch := touches.Index(0)
setMouseCursorFromEvent(touch)
})
// Gamepad
window.Call("addEventListener", "gamepadconnected", func(e *js.Object) {
// Do nothing.
})
c, err := opengl.NewContext()
if err != nil {
return nil, err
}
if err := graphics.Initialize(c); err != nil {
return nil, err
}
return c, nil
}
func setMouseCursorFromEvent(e *js.Object) {
scale := currentUI.scale
rect := canvas.Call("getBoundingClientRect")
x, y := e.Get("clientX").Int(), e.Get("clientY").Int()
x -= rect.Get("left").Int()
y -= rect.Get("top").Int()
currentInput.SetMouseCursor(x/scale, y/scale)
}
func devicePixelRatio() float64 {
ratio := js.Global.Get("window").Get("devicePixelRatio").Float()
if ratio == 0 {
ratio = 1
}
return ratio
}
func Main() error {
// Do nothing
return nil
}
func (u *UserInterface) Start(width, height, scale int, title string) error {
doc := js.Global.Get("document")
doc.Set("title", title)
u.setScreenSize(width, height, scale)
canvas.Call("focus")
return nil
}
func (u *UserInterface) size() (width, height int) {
a := int(u.ActualScreenScale())
if a == 0 {
// a == 0 only on the initial state.
return
}
width = canvas.Get("width").Int() / a
height = canvas.Get("height").Int() / a
return
}
func (u *UserInterface) setScreenSize(width, height, scale int) bool {
w, h := u.size()
s := u.scale
if w == width && h == height && s == scale {
return false
}
u.scale = scale
u.deviceScale = devicePixelRatio()
canvas.Set("width", width*u.ActualScreenScale())
canvas.Set("height", height*u.ActualScreenScale())
canvasStyle := canvas.Get("style")
cssWidth := width * scale
cssHeight := height * scale
canvasStyle.Set("width", strconv.Itoa(cssWidth)+"px")
canvasStyle.Set("height", strconv.Itoa(cssHeight)+"px")
// CSS calc requires space chars.
canvasStyle.Set("left", "calc((100% - "+strconv.Itoa(cssWidth)+"px) / 2)")
canvasStyle.Set("top", "calc((100% - "+strconv.Itoa(cssHeight)+"px) / 2)")
u.sizeChanged = true
return true
}