ebiten/uicontext.go
2021-08-05 01:48:56 +09:00

244 lines
6.5 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 (
"fmt"
"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"
"github.com/hajimehoshi/ebiten/v2/internal/driver"
"github.com/hajimehoshi/ebiten/v2/internal/graphics"
"github.com/hajimehoshi/ebiten/v2/internal/hooks"
)
type uiContext struct {
game Game
offscreen *Image
screen *Image
updateCalled bool
outsideSizeUpdated bool
outsideWidth float64
outsideHeight float64
err atomic.Value
m sync.Mutex
}
var theUIContext = &uiContext{}
func (c *uiContext) set(game Game) {
c.m.Lock()
defer c.m.Unlock()
c.game = game
}
func (c *uiContext) setError(err error) {
c.err.Store(err)
}
func (c *uiContext) Layout(outsideWidth, outsideHeight float64) {
// 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
}
c.outsideSizeUpdated = true
c.outsideWidth = outsideWidth
c.outsideHeight = outsideHeight
}
func (c *uiContext) updateOffscreen() {
sw, sh := c.game.Layout(int(c.outsideWidth), int(c.outsideHeight))
if sw <= 0 || sh <= 0 {
panic("ebiten: Layout must return positive numbers")
}
if c.offscreen != nil && !c.outsideSizeUpdated {
if w, h := c.offscreen.Size(); w == sw && h == sh {
return
}
}
c.outsideSizeUpdated = false
if c.screen != nil {
c.screen.Dispose()
c.screen = nil
}
if c.offscreen != nil {
if w, h := c.offscreen.Size(); w != sw || h != sh {
c.offscreen.Dispose()
c.offscreen = nil
}
}
if c.offscreen == nil {
c.offscreen = NewImage(sw, sh)
c.offscreen.mipmap.SetVolatile(IsScreenClearedEveryFrame())
}
// TODO: This is duplicated with mobile/ebitenmobileview/funcs.go. Refactor this.
d := uiDriver().DeviceScaleFactor()
c.screen = newScreenFramebufferImage(int(c.outsideWidth*d), int(c.outsideHeight*d))
}
func (c *uiContext) setScreenClearedEveryFrame(cleared bool) {
c.m.Lock()
defer c.m.Unlock()
if c.offscreen != nil {
c.offscreen.mipmap.SetVolatile(cleared)
}
}
func (c *uiContext) screenScale(deviceScaleFactor float64) float64 {
if c.offscreen == nil {
return 0
}
sw, sh := c.offscreen.Size()
scaleX := c.outsideWidth / float64(sw) * deviceScaleFactor
scaleY := c.outsideHeight / float64(sh) * deviceScaleFactor
return math.Min(scaleX, scaleY)
}
func (c *uiContext) offsets(deviceScaleFactor float64) (float64, float64) {
if c.offscreen == nil {
return 0, 0
}
sw, sh := c.offscreen.Size()
s := c.screenScale(deviceScaleFactor)
width := float64(sw) * s
height := float64(sh) * s
x := (c.outsideWidth*deviceScaleFactor - width) / 2
y := (c.outsideHeight*deviceScaleFactor - height) / 2
return x, y
}
func (c *uiContext) UpdateFrame() error {
// TODO: If updateCount is 0 and vsync is disabled, swapping buffers can be skipped.
return c.updateFrame(clock.Update(MaxTPS()))
}
func (c *uiContext) ForceUpdateFrame() error {
// ForceUpdate can be invoked even if uiContext it not initialized yet (#1591).
if c.outsideWidth == 0 || c.outsideHeight == 0 {
return nil
}
return c.updateFrame(1)
}
func (c *uiContext) updateFrame(updateCount int) error {
if err, ok := c.err.Load().(error); ok && err != nil {
return err
}
debug.Logf("----\n")
if err := buffered.BeginFrame(); err != nil {
return err
}
if err := c.updateFrameImpl(updateCount); 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 graphics.LockAndResetVertices(func() error {
if err := buffered.EndFrame(); err != nil {
return err
}
return nil
})
}
func (c *uiContext) updateFrameImpl(updateCount int) error {
c.updateOffscreen()
// 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)
for i := 0; i < updateCount; i++ {
if err := hooks.RunBeforeUpdateHooks(); err != nil {
return err
}
if err := c.game.Update(); err != nil {
return err
}
uiDriver().ResetForFrame()
}
// Even though updateCount == 0, the offscreen is cleared and Draw is called.
// Draw should not update the game state and then the screen should not be updated without Update, but
// users might want to process something at Draw with the time intervals of FPS.
if IsScreenClearedEveryFrame() {
c.offscreen.Clear()
}
c.game.Draw(c.offscreen)
if uiDriver().Graphics().NeedsClearingScreen() {
// This clear is needed for fullscreen mode or some mobile platforms (#622).
c.screen.Clear()
}
op := &DrawImageOptions{}
s := c.screenScale(uiDriver().DeviceScaleFactor())
switch vd := uiDriver().Graphics().FramebufferYDirection(); vd {
case driver.Upward:
op.GeoM.Scale(s, -s)
_, h := c.offscreen.Size()
op.GeoM.Translate(0, float64(h)*s)
case driver.Downward:
op.GeoM.Scale(s, s)
default:
panic(fmt.Sprintf("ebiten: invalid v-direction: %d", vd))
}
op.GeoM.Translate(c.offsets(uiDriver().DeviceScaleFactor()))
op.CompositeMode = CompositeModeCopy
// filterScreen works with >=1 scale, but does not well with <1 scale.
// Use regular FilterLinear instead so far (#669).
if s >= 1 {
op.Filter = filterScreen
} else {
op.Filter = FilterLinear
}
c.screen.DrawImage(c.offscreen, op)
return nil
}
func (c *uiContext) AdjustPosition(x, y float64, deviceScaleFactor float64) (float64, float64) {
ox, oy := c.offsets(deviceScaleFactor)
s := c.screenScale(deviceScaleFactor)
// The scale 0 indicates that the offscreen 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
}