forked from hajimehoshi/ebiten
-
Notifications
You must be signed in to change notification settings - Fork 0
/
run.go
262 lines (237 loc) · 6.87 KB
/
run.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
// 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 (
"errors"
"sync"
"time"
"github.com/hajimehoshi/ebiten/internal/ui"
)
type runContext struct {
isRunning bool
fps float64
newScreenWidth int
newScreenHeight int
newScreenScale int
isRunningSlowly bool
m sync.RWMutex
}
var currentRunContext runContext
func (c *runContext) startRunning() {
c.m.Lock()
defer c.m.Unlock()
c.isRunning = true
}
func (c *runContext) endRunning() {
c.m.Lock()
defer c.m.Unlock()
c.isRunning = false
}
func (c *runContext) FPS() float64 {
c.m.RLock()
defer c.m.RUnlock()
if !c.isRunning {
// TODO: Should panic here?
return 0
}
return c.fps
}
func (c *runContext) updateFPS(fps float64) {
c.m.Lock()
defer c.m.Unlock()
c.fps = fps
}
func (c *runContext) IsRunningSlowly() bool {
c.m.RLock()
defer c.m.RUnlock()
if !c.isRunning {
// TODO: Should panic here?
return false
}
return c.isRunningSlowly
}
func (c *runContext) setRunningSlowly(isRunningSlowly bool) {
c.m.Lock()
defer c.m.Unlock()
c.isRunningSlowly = isRunningSlowly
}
func (c *runContext) updateScreenSize(g *graphicsContext) error {
c.m.Lock()
defer c.m.Unlock()
if c.newScreenWidth == 0 && c.newScreenHeight == 0 && c.newScreenScale == 0 {
return nil
}
changed := false
if 0 < c.newScreenWidth || 0 < c.newScreenHeight {
c := ui.CurrentUI().SetScreenSize(c.newScreenWidth, c.newScreenHeight)
changed = changed || c
}
if 0 < c.newScreenScale {
c := ui.CurrentUI().SetScreenScale(c.newScreenScale)
changed = changed || c
}
if changed {
w, h := c.newScreenWidth, c.newScreenHeight
if err := g.setSize(w, h, ui.CurrentUI().ActualScreenScale()); err != nil {
return err
}
}
c.newScreenWidth = 0
c.newScreenHeight = 0
c.newScreenScale = 0
return nil
}
func (c *runContext) SetScreenSize(width, height int) error {
c.m.Lock()
defer c.m.Unlock()
if !c.isRunning {
return errors.New("ebiten: SetScreenSize must be called during Run")
}
if width <= 0 || height <= 0 {
return errors.New("ebiten: width and height must be positive")
}
c.newScreenWidth = width
c.newScreenHeight = height
return nil
}
func (c *runContext) SetScreenScale(scale int) error {
c.m.Lock()
defer c.m.Unlock()
if !c.isRunning {
return errors.New("ebiten: SetScreenScale must be called during Run")
}
if scale <= 0 {
return errors.New("ebiten: scale must be positive")
}
c.newScreenScale = scale
return nil
}
// FPS represents how many times game updating happens in a second.
const FPS = 60
// 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 currentRunContext.FPS()
}
// 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 currentRunContext.IsRunningSlowly()
}
// 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.
//
// This function 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.
func Run(f func(*Image) error, width, height, scale int, title string) error {
currentRunContext.startRunning()
defer currentRunContext.endRunning()
if err := ui.CurrentUI().Start(width, height, scale, title); err != nil {
return err
}
defer ui.CurrentUI().Terminate()
graphicsContext, err := newGraphicsContext(width, height, ui.CurrentUI().ActualScreenScale())
if err != nil {
return err
}
frames := 0
n := ui.Now()
beforeForUpdate := n
beforeForFPS := n
for {
// TODO: setSize should be called after swapping buffers?
if err := currentRunContext.updateScreenSize(graphicsContext); err != nil {
return err
}
if err := ui.CurrentUI().DoEvents(); err != nil {
return err
}
if ui.CurrentUI().IsClosed() {
return nil
}
now := ui.Now()
// If beforeForUpdate is too old, we assume that screen is not shown.
if int64(5*time.Second/FPS) < now-beforeForUpdate {
currentRunContext.setRunningSlowly(false)
beforeForUpdate = now
} else {
// Note that generally t is a little different from 1/60[sec].
t := now - beforeForUpdate
currentRunContext.setRunningSlowly(t*FPS >= int64(time.Second*5/2))
tt := int(t * FPS / int64(time.Second))
// As t is not accurate 1/60[sec], errors are accumulated.
// To make the FPS stable, set tt 1 if t is a little less than 1/60[sec].
if tt == 0 && (int64(time.Second)/FPS-int64(5*time.Millisecond)) < t {
tt = 1
}
for i := 0; i < tt; i++ {
if err := ui.CurrentUI().DoEvents(); err != nil {
return err
}
if ui.CurrentUI().IsClosed() {
return nil
}
if err := graphicsContext.update(f); err != nil {
return err
}
}
ui.CurrentUI().SwapBuffers()
beforeForUpdate += int64(tt) * int64(time.Second) / FPS
frames++
}
// Calc the current FPS.
if time.Second <= time.Duration(now-beforeForFPS) {
currentRunContext.updateFPS(float64(frames) * float64(time.Second) / float64(now-beforeForFPS))
beforeForFPS = now
frames = 0
}
}
}
// SetScreenSize changes the (logical) size of the screen.
// This doesn't affect the current scale of the screen.
//
// This function is concurrent-safe.
func SetScreenSize(width, height int) {
if err := currentRunContext.SetScreenSize(width, height); err != nil {
panic(err)
}
}
// SetScreenSize changes the scale of the screen.
//
// This function is concurrent-safe.
func SetScreenScale(scale int) {
if err := currentRunContext.SetScreenScale(scale); err != nil {
panic(err)
}
}
// ScreenScale returns the current screen scale.
//
// This function is concurrent-safe.
func ScreenScale() int {
return ui.CurrentUI().ScreenScale()
}