ebiten/internal/ui/context.go
2022-03-26 20:09:34 +09:00

288 lines
8.1 KiB
Go

// Copyright 2022 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.
package ui
import (
"math"
"sync"
"sync/atomic"
"github.com/hajimehoshi/ebiten/v2/internal/buffered"
"github.com/hajimehoshi/ebiten/v2/internal/clock"
"github.com/hajimehoshi/ebiten/v2/internal/debug"
graphicspkg "github.com/hajimehoshi/ebiten/v2/internal/graphics"
"github.com/hajimehoshi/ebiten/v2/internal/graphicsdriver"
"github.com/hajimehoshi/ebiten/v2/internal/hooks"
)
const DefaultTPS = 60
type Game interface {
Layout(outsideWidth, outsideHeight float64, deviceScaleFactor float64) (int, int)
Update() error
Draw(screenScale float64, offsetX, offsetY float64, needsClearingScreen bool, framebufferYDirection graphicsdriver.YDirection, screenClearedEveryFrame, filterEnabled bool) error
}
type contextImpl struct {
game Game
updateCalled bool
// The following members must be protected by the mutex m.
outsideWidth float64
outsideHeight float64
screenWidth int
screenHeight int
m sync.Mutex
}
func newContextImpl(game Game) *contextImpl {
return &contextImpl{
game: game,
}
}
func (c *contextImpl) updateFrame(graphicsDriver graphicsdriver.Graphics, outsideWidth, outsideHeight float64, deviceScaleFactor float64) error {
// TODO: If updateCount is 0 and vsync is disabled, swapping buffers can be skipped.
return c.updateFrameImpl(graphicsDriver, clock.Update(theGlobalState.maxTPS()), outsideWidth, outsideHeight, deviceScaleFactor)
}
func (c *contextImpl) forceUpdateFrame(graphicsDriver graphicsdriver.Graphics, outsideWidth, outsideHeight float64, deviceScaleFactor float64) error {
n := 1
if graphicsDriver.IsDirectX() {
// On DirectX, both framebuffers in the swap chain should be updated.
// Or, the rendering result becomes unexpected when the window is resized.
n = 2
}
for i := 0; i < n; i++ {
if err := c.updateFrameImpl(graphicsDriver, 1, outsideWidth, outsideHeight, deviceScaleFactor); err != nil {
return err
}
}
return nil
}
func (c *contextImpl) updateFrameImpl(graphicsDriver graphicsdriver.Graphics, updateCount int, outsideWidth, outsideHeight float64, deviceScaleFactor float64) error {
if err := theGlobalState.error(); err != nil {
return err
}
// The given outside size can be 0 e.g. just after restoring from the fullscreen mode on Windows (#1589)
// Just ignore such cases. Otherwise, creating a zero-sized framebuffer causes a panic.
if outsideWidth == 0 || outsideHeight == 0 {
return nil
}
// ForceUpdate can be invoked even if the context is not initialized yet (#1591).
if w, h := c.layoutGame(outsideWidth, outsideHeight, deviceScaleFactor); w == 0 || h == 0 {
return nil
}
debug.Logf("----\n")
if err := buffered.BeginFrame(graphicsDriver); err != nil {
return err
}
// Ensure that Update is called once before Draw so that Update can be used for initialization.
if !c.updateCalled && updateCount == 0 {
updateCount = 1
c.updateCalled = true
}
debug.Logf("Update count per frame: %d\n", updateCount)
// Update the game.
for i := 0; i < updateCount; i++ {
if err := hooks.RunBeforeUpdateHooks(); err != nil {
return err
}
if err := c.game.Update(); err != nil {
return err
}
// Catch the error that happened at (*Image).At.
if err := theGlobalState.error(); err != nil {
return err
}
Get().resetForTick()
}
// Draw the game.
screenScale, offsetX, offsetY := c.screenScaleAndOffsets(deviceScaleFactor)
if err := c.game.Draw(screenScale, offsetX, offsetY, graphicsDriver.NeedsClearingScreen(), graphicsDriver.FramebufferYDirection(), theGlobalState.isScreenClearedEveryFrame(), theGlobalState.isScreenFilterEnabled()); err != nil {
return err
}
// All the vertices data are consumed at the end of the frame, and the data backend can be
// available after that. Until then, lock the vertices backend.
return graphicspkg.LockAndResetVertices(func() error {
if err := buffered.EndFrame(graphicsDriver); err != nil {
return err
}
return nil
})
}
func (c *contextImpl) layoutGame(outsideWidth, outsideHeight float64, deviceScaleFactor float64) (int, int) {
c.m.Lock()
defer c.m.Unlock()
c.outsideWidth = outsideWidth
c.outsideHeight = outsideHeight
w, h := c.game.Layout(outsideWidth, outsideHeight, deviceScaleFactor)
c.screenWidth = w
c.screenHeight = h
return w, h
}
func (c *contextImpl) adjustPosition(x, y float64, deviceScaleFactor float64) (float64, float64) {
s, ox, oy := c.screenScaleAndOffsets(deviceScaleFactor)
// The scale 0 indicates that the screen is not initialized yet.
// As any cursor values don't make sense, just return NaN.
if s == 0 {
return math.NaN(), math.NaN()
}
return (x*deviceScaleFactor - ox) / s, (y*deviceScaleFactor - oy) / s
}
func (c *contextImpl) screenScaleAndOffsets(deviceScaleFactor float64) (float64, float64, float64) {
c.m.Lock()
defer c.m.Unlock()
if c.screenWidth == 0 || c.screenHeight == 0 {
return 0, 0, 0
}
scaleX := c.outsideWidth / float64(c.screenWidth) * deviceScaleFactor
scaleY := c.outsideHeight / float64(c.screenHeight) * deviceScaleFactor
scale := math.Min(scaleX, scaleY)
width := float64(c.screenWidth) * scale
height := float64(c.screenHeight) * scale
x := (c.outsideWidth*deviceScaleFactor - width) / 2
y := (c.outsideHeight*deviceScaleFactor - height) / 2
return scale, x, y
}
var theGlobalState = globalState{
maxTPS_: DefaultTPS,
isScreenClearedEveryFrame_: 1,
screenFilterEnabled_: 1,
}
// globalState represents a global state in this package.
// This is available even before the game loop starts.
type globalState struct {
err_ error
errM sync.Mutex
fpsMode_ int32
maxTPS_ int32
isScreenClearedEveryFrame_ int32
screenFilterEnabled_ int32
}
func (g *globalState) error() error {
g.errM.Lock()
defer g.errM.Unlock()
return g.err_
}
func (g *globalState) setError(err error) {
g.errM.Lock()
defer g.errM.Unlock()
if g.err_ == nil {
g.err_ = err
}
}
func (g *globalState) fpsMode() FPSModeType {
return FPSModeType(atomic.LoadInt32(&g.fpsMode_))
}
func (g *globalState) setFPSMode(fpsMode FPSModeType) {
atomic.StoreInt32(&g.fpsMode_, int32(fpsMode))
}
func (g *globalState) maxTPS() int {
if g.fpsMode() == FPSModeVsyncOffMinimum {
return clock.SyncWithFPS
}
return int(atomic.LoadInt32(&g.maxTPS_))
}
func (g *globalState) setMaxTPS(tps int) {
if tps < 0 && tps != clock.SyncWithFPS {
panic("ebiten: tps must be >= 0 or SyncWithFPS")
}
atomic.StoreInt32(&g.maxTPS_, int32(tps))
}
func (g *globalState) isScreenClearedEveryFrame() bool {
return atomic.LoadInt32(&g.isScreenClearedEveryFrame_) != 0
}
func (g *globalState) setScreenClearedEveryFrame(cleared bool) {
v := int32(0)
if cleared {
v = 1
}
atomic.StoreInt32(&g.isScreenClearedEveryFrame_, v)
}
func (g *globalState) isScreenFilterEnabled() bool {
return graphicsdriver.Filter(atomic.LoadInt32(&g.screenFilterEnabled_)) != 0
}
func (g *globalState) setScreenFilterEnabled(enabled bool) {
v := int32(0)
if enabled {
v = 1
}
atomic.StoreInt32(&g.screenFilterEnabled_, v)
}
func FPSMode() FPSModeType {
return theGlobalState.fpsMode()
}
func SetFPSMode(fpsMode FPSModeType) {
theGlobalState.setFPSMode(fpsMode)
Get().SetFPSMode(fpsMode)
}
func MaxTPS() int {
return theGlobalState.maxTPS()
}
func SetMaxTPS(tps int) {
theGlobalState.setMaxTPS(tps)
}
func IsScreenClearedEveryFrame() bool {
return theGlobalState.isScreenClearedEveryFrame()
}
func SetScreenClearedEveryFrame(cleared bool) {
theGlobalState.setScreenClearedEveryFrame(cleared)
}
func IsScreenFilterEnabled() bool {
return theGlobalState.isScreenFilterEnabled()
}
func SetScreenFilterEnabled(enabled bool) {
theGlobalState.setScreenFilterEnabled(enabled)
}