ebiten/internal/ui/ui_js.go

335 lines
8.5 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"
"strings"
"github.com/gopherjs/gopherjs/js"
"github.com/hajimehoshi/ebiten/internal/opengl"
)
var canvas *js.Object
type userInterface struct {
scale float64
deviceScale float64
sizeChanged bool
contextRestored bool
windowFocus bool
}
var currentUI = &userInterface{
sizeChanged: true,
contextRestored: true,
windowFocus: true,
}
// NOTE: This returns true even when the browser is not active.
func shown() bool {
return !js.Global.Get("document").Get("hidden").Bool()
}
func SetScreenSize(width, height int) (bool, error) {
return currentUI.setScreenSize(width, height, currentUI.scale), nil
}
func SetScreenScale(scale float64) (bool, error) {
width, height := currentUI.size()
return currentUI.setScreenSize(width, height, scale), nil
}
func ScreenScale() float64 {
return currentUI.scale
}
func SetCursorVisibility(visibility bool) {
if visibility {
canvas.Get("style").Set("cursor", "auto")
} else {
canvas.Get("style").Set("cursor", "none")
}
}
func (u *userInterface) actualScreenScale() float64 {
return u.scale * u.deviceScale
}
func (u *userInterface) update(g GraphicsContext) error {
if !u.windowFocus {
return nil
}
if !u.contextRestored {
return nil
}
currentInput.updateGamepads()
if u.sizeChanged {
u.sizeChanged = false
w, h := u.size()
if err := g.SetSize(w, h, u.actualScreenScale()); err != nil {
return err
}
return nil
}
if err := g.Update(); err != nil {
return err
}
return nil
}
func (u *userInterface) loop(g GraphicsContext) error {
ch := make(chan error)
var f func()
f = func() {
go func() {
if err := u.update(g); err != nil {
ch <- err
close(ch)
return
}
js.Global.Get("window").Call("requestAnimationFrame", f)
}()
}
f()
return <-ch
}
func touchEventToTouches(e *js.Object) []touch {
scale := currentUI.scale
j := e.Get("targetTouches")
rect := canvas.Call("getBoundingClientRect")
left, top := rect.Get("left").Int(), rect.Get("top").Int()
t := make([]touch, j.Get("length").Int())
for i := 0; i < len(t); i++ {
jj := j.Call("item", i)
t[i].id = jj.Get("identifier").Int()
t[i].x = int(float64(jj.Get("clientX").Int()-left) / scale)
t[i].y = int(float64(jj.Get("clientY").Int()-top) / scale)
}
return t
}
func init() {
if err := initialize(); err != nil {
panic(err)
}
}
func initialize() error {
// Do nothing in node.js.
if js.Global.Get("require") != js.Undefined {
return 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
}
window.Call("addEventListener", "focus", func() {
currentUI.windowFocus = true
})
window.Call("addEventListener", "blur", func() {
currentUI.windowFocus = false
})
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
canvas.Call("addEventListener", "touchstart", func(e *js.Object) {
e.Call("preventDefault")
currentInput.updateTouches(touchEventToTouches(e))
})
canvas.Call("addEventListener", "touchend", func(e *js.Object) {
e.Call("preventDefault")
currentInput.updateTouches(touchEventToTouches(e))
})
canvas.Call("addEventListener", "touchmove", func(e *js.Object) {
e.Call("preventDefault")
currentInput.updateTouches(touchEventToTouches(e))
})
// Gamepad
window.Call("addEventListener", "gamepadconnected", func(e *js.Object) {
// Do nothing.
})
canvas.Call("addEventListener", "webglcontextlost", func(e *js.Object) {
e.Call("preventDefault")
currentUI.contextRestored = false
})
canvas.Call("addEventListener", "webglcontextrestored", func(e *js.Object) {
// TODO: Call preventDefault?
currentUI.contextRestored = true
})
return 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(int(float64(x)/scale), int(float64(y)/scale))
}
func devicePixelRatio() float64 {
ratio := js.Global.Get("window").Get("devicePixelRatio").Float()
if ratio == 0 {
ratio = 1
}
return ratio
}
func RunMainThreadLoop(ch <-chan error) error {
return <-ch
}
func Run(width, height int, scale float64, title string, g GraphicsContext) error {
u := currentUI
doc := js.Global.Get("document")
doc.Set("title", title)
u.setScreenSize(width, height, scale)
canvas.Call("focus")
var err error
glContext, err = opengl.NewContext()
if err != nil {
return err
}
return u.loop(g)
}
func (u *userInterface) size() (width, height int) {
a := u.actualScreenScale()
if a == 0 {
// a == 0 only on the initial state.
return
}
width = int(canvas.Get("width").Float() / a)
height = int(canvas.Get("height").Float() / a)
return
}
func isSafari() bool {
ua := js.Global.Get("navigator").Get("userAgent").String()
if !strings.Contains(ua, "Safari") {
return false
}
if strings.Contains(ua, "Chrome") {
return false
}
return true
}
func (u *userInterface) setScreenSize(width, height int, scale float64) bool {
w, h := u.size()
s := u.scale
if w == width && h == height && s == scale {
return false
}
u.scale = scale
// When the scale is an integer, let's rely on CSS crisp-edge/pixelated effect.
// Note that pixelated effect doesn't work for canvas on Safari.
if scale == float64(int64(scale)) && !isSafari() {
u.deviceScale = 1
} else {
u.deviceScale = devicePixelRatio()
}
canvas.Set("width", int(float64(width)*u.actualScreenScale()))
canvas.Set("height", int(float64(height)*u.actualScreenScale()))
canvasStyle := canvas.Get("style")
cssWidth := int(float64(width) * scale)
cssHeight := int(float64(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)")
canvasStyle.Set("imageRendering", "-moz-crisp-edges")
canvasStyle.Set("imageRendering", "pixelated")
// TODO: Set `-ms-interpolation-mode: nearest-neighbor;` for IE.
u.sizeChanged = true
return true
}