ebiten/mobile/ebitenmobileview/funcs.go

81 lines
2.3 KiB
Go

// Copyright 2016 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.
// Package ebitenmobileview offers functions for OpenGL/Metal view of mobiles.
//
// The functions are not intended for public usages.
// There is no guarantee of backward compatibility.
package ebitenmobileview
import (
"math"
"runtime"
"github.com/hajimehoshi/ebiten"
)
type ViewRectSetter interface {
SetViewRect(x, y, width, height int)
}
func Layout(viewWidth, viewHeight int, viewRectSetter ViewRectSetter) {
theState.m.Lock()
defer theState.m.Unlock()
layout(viewWidth, viewHeight, viewRectSetter)
}
func layout(viewWidth, viewHeight int, viewRectSetter ViewRectSetter) {
if theState.game == nil {
// It is fine to override the existing function since only the last layout result matters.
theState.delayedLayout = func() {
layout(viewWidth, viewHeight, viewRectSetter)
}
return
}
w, h := theState.game.Layout(int(viewWidth), int(viewHeight))
scaleX := float64(viewWidth) / float64(w)
scaleY := float64(viewHeight) / float64(h)
scale := math.Min(scaleX, scaleY)
// To convert a logical offscreen size to the actual screen size, use Math.floor to use smaller and safer
// values, or glitches can appear (#956).
width := int(math.Floor(float64(w) * scale))
height := int(math.Floor(float64(h) * scale))
x := (viewWidth - width) / 2
y := (viewHeight - height) / 2
if theState.isRunning() {
ebiten.SetScreenSize(w, h)
ebiten.SetScreenScale(scale)
} else {
// The last argument 'title' is not used on mobile platforms, so just pass an empty string.
theState.errorCh = ebiten.RunWithoutMainLoop(theState.game.Update, w, h, scale, "")
}
if viewRectSetter != nil {
viewRectSetter.SetViewRect(x, y, width, height)
}
}
func Update() error {
runtime.LockOSThread()
defer runtime.UnlockOSThread()
theState.m.Lock()
defer theState.m.Unlock()
return update()
}