ebiten/run.go
2017-09-23 17:40:09 +09:00

273 lines
7.8 KiB
Go

// Copyright 2014 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 ebiten
import (
"image"
"sync/atomic"
"github.com/hajimehoshi/ebiten/internal/clock"
"github.com/hajimehoshi/ebiten/internal/ui"
)
// FPS represents how many times game updating happens in a second (60).
const FPS = clock.FPS
// CurrentFPS returns the current number of frames per second of rendering.
//
// This function is concurrent-safe.
//
// This value represents how many times rendering happens in 1/60 second and
// NOT how many times logical game updating (a passed function to Run) happens.
// Note that logical game updating is assured to happen 60 times in a second
// as long as the screen is active.
func CurrentFPS() float64 {
return clock.CurrentFPS()
}
var (
isRunningSlowly = int32(0)
)
func setRunningSlowly(slow bool) {
v := int32(0)
if slow {
v = 1
}
atomic.StoreInt32(&isRunningSlowly, v)
}
// IsRunningSlowly returns true if the game is running too slowly to keep 60 FPS of rendering.
// The game screen is not updated when IsRunningSlowly is true.
// It is recommended to skip heavy processing, especially drawing, when IsRunningSlowly is true.
//
// This function is concurrent-safe.
func IsRunningSlowly() bool {
return atomic.LoadInt32(&isRunningSlowly) != 0
}
var theGraphicsContext atomic.Value
func run(width, height int, scale float64, title string, g *graphicsContext) error {
if err := ui.Run(width, height, scale, title, &updater{g}); err != nil {
if _, ok := err.(*ui.RegularTermination); ok {
return nil
}
return err
}
return nil
}
type updater struct {
g *graphicsContext
}
func (u *updater) SetSize(width, height int, scale float64) {
u.g.SetSize(width, height, scale)
}
func (u *updater) Update() error {
n := clock.Update()
if err := u.g.Update(n); err != nil {
return err
}
return nil
}
func (u *updater) Invalidate() {
u.g.Invalidate()
}
// Run runs the game.
// f is a function which is called at every frame.
// The argument (*Image) is the render target that represents the screen.
//
// Run must be called from the main thread.
// Note that ebiten bounds the main goroutine to the main OS thread by runtime.LockOSThread.
//
// The given function f is guaranteed to be called 60 times a second
// even if a rendering frame is skipped.
// f is not called when the screen is not shown.
//
// The given scale is ignored on fullscreen mode.
//
// Run returns error when 1) OpenGL error happens, or 2) f returns error.
// In the case of 2), Run returns the same error.
//
// The size unit is device-independent pixel.
func Run(f func(*Image) error, width, height int, scale float64, title string) error {
ch := make(chan error)
go func() {
defer close(ch)
g := newGraphicsContext(f)
theGraphicsContext.Store(g)
if err := run(width, height, scale, title, g); err != nil {
ch <- err
return
}
}()
// TODO: Use context in Go 1.7?
if err := ui.RunMainThreadLoop(ch); err != nil {
return err
}
return nil
}
// RunWithoutMainLoop runs the game, but don't call the loop on the main (UI) thread.
// Different from Run, this function returns immediately.
//
// Typically, Ebiten users don't have to call this directly.
// Instead, functions in github.com/hajimehoshi/ebiten/mobile module call this.
//
// The size unit is device-independent pixel.
func RunWithoutMainLoop(f func(*Image) error, width, height int, scale float64, title string) <-chan error {
ch := make(chan error)
go func() {
defer close(ch)
g := newGraphicsContext(f)
theGraphicsContext.Store(g)
if err := run(width, height, scale, title, g); err != nil {
ch <- err
return
}
}()
return ch
}
// SetScreenSize changes the (logical) size of the screen.
// This doesn't affect the current scale of the screen.
//
// Unit is device-independent pixel.
//
// This function is concurrent-safe.
func SetScreenSize(width, height int) {
if width <= 0 || height <= 0 {
panic("ebiten: width and height must be positive")
}
ui.SetScreenSize(width, height)
}
// SetScreenScale changes the scale of the screen.
//
// This function is concurrent-safe.
func SetScreenScale(scale float64) {
if scale <= 0 {
panic("ebiten: scale must be positive")
}
ui.SetScreenScale(scale)
}
// ScreenScale returns the current screen scale.
//
// If Run is not called, this returns 0.
//
// This function is concurrent-safe.
func ScreenScale() float64 {
return ui.ScreenScale()
}
// IsCursorVisible returns a boolean value indicating whether
// the cursor is visible or not.
//
// IsCursorVisible always returns false on mobiles.
//
// This function is concurrent-safe.
func IsCursorVisible() bool {
return ui.IsCursorVisible()
}
// SetCursorVisibility changes the state of cursor visiblity.
//
// SetCursorVisibility does nothing on mobiles.
//
// This function is concurrent-safe.
func SetCursorVisibility(visible bool) {
ui.SetCursorVisibility(visible)
}
// IsFullscreen returns a boolean value indicating whether
// the current mode is fullscreen or not.
//
// This function is concurrent-safe.
func IsFullscreen() bool {
return ui.IsFullscreen()
}
// SetFullscreen changes the current mode to fullscreen or not.
//
// On fullscreen mode, the game screen is automatically enlarged
// to fit with the monitor. The current scale value is ignored.
//
// On desktops, Ebiten uses 'windowed' fullscreen mode, which doesn't change
// your monitor's resolution.
//
// On browsers, the game screen is resized to fit with the body element (client) size.
// Additionally, the game screen is automatically resized when the body element is resized.
//
// SetFullscreen does nothing on mobiles.
//
// This function is concurrent-safe.
func SetFullscreen(fullscreen bool) {
ui.SetFullscreen(fullscreen)
}
// IsRunnableInBackground returns a boolean value indicating whether the game runs even in background.
//
// This function is concurrent-safe.
func IsRunnableInBackground() bool {
return ui.IsRunnableInBackground()
}
// SetRunnableInBackground sets the state if the game runs even in background.
//
// If the given value is true, the game runs in background e.g. when losing focus.
// The initial state is false.
//
// Known issue: On browsers, even if the state is on, the game doesn't run in background tabs.
// This is because browsers throttles background tabs not to often update.
//
// SetRunnableInBackground does nothing on mobiles so far.
//
// This function is concurrent-safe.
func SetRunnableInBackground(runnableInBackground bool) {
ui.SetRunnableInBackground(runnableInBackground)
}
// SetWindowIcon sets the icon of the game window.
//
// If len(iconImages) is 0, SetWindowIcon reverts the icon to the default one.
//
// For desktops, see the document of glfwSetWindowIcon of GLFW 3.2:
//
// This function sets the icon of the specified window.
// If passed an array of candidate images, those of or closest to the sizes
// desired by the system are selected.
// If no images are specified, the window reverts to its default icon.
//
// The desired image sizes varies depending on platform and system settings.
// The selected images will be rescaled as needed.
// Good sizes include 16x16, 32x32 and 48x48.
//
// As macOS windows don't have icons, SetWindowIcon doesn't work on macOS.
//
// SetWindowIcon doesn't work on browsers or mobiles.
//
// This function is concurrent-safe.
func SetWindowIcon(iconImages []image.Image) {
ui.SetWindowIcon(iconImages)
}