ebiten/gameforui.go
2022-02-23 02:54:14 +09:00

122 lines
3.4 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"
"github.com/hajimehoshi/ebiten/v2/internal/graphicsdriver"
)
type gameForUI struct {
game Game
offscreen *Image
screen *Image
}
func newGameForUI(game Game) *gameForUI {
return &gameForUI{
game: game,
}
}
func (c *gameForUI) Layout(outsideWidth, outsideHeight float64, deviceScaleFactor float64) (int, int) {
ow, oh := c.game.Layout(int(outsideWidth), int(outsideHeight))
if ow <= 0 || oh <= 0 {
panic("ebiten: Layout must return positive numbers")
}
sw, sh := int(outsideWidth*deviceScaleFactor), int(outsideHeight*deviceScaleFactor)
if c.screen != nil {
if w, h := c.screen.Size(); w != sw || h != sh {
c.screen.Dispose()
c.screen = nil
}
}
if c.screen == nil {
c.screen = newScreenFramebufferImage(sw, sh)
}
if c.offscreen != nil {
if w, h := c.offscreen.Size(); w != ow || h != oh {
c.offscreen.Dispose()
c.offscreen = nil
}
}
if c.offscreen == nil {
c.offscreen = NewImage(ow, oh)
// Keep the offscreen an independent image from an atlas (#1938).
// The shader program for the screen is special and doesn't work well with an image on an atlas.
// An image on an atlas is surrounded by a transparent edge,
// and the shader program unexpectedly picks the pixel on the edges.
c.offscreen.mipmap.SetIndependent(true)
}
return ow, oh
}
func (c *gameForUI) Update() error {
return c.game.Update()
}
func (c *gameForUI) Draw(screenScale float64, offsetX, offsetY float64, needsClearingScreen bool, framebufferYDirection graphicsdriver.YDirection, clearScreenEveryFrame bool) error {
c.offscreen.mipmap.SetVolatile(clearScreenEveryFrame)
// 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 clearScreenEveryFrame {
c.offscreen.Clear()
}
c.game.Draw(c.offscreen)
if needsClearingScreen {
// This clear is needed for fullscreen mode or some mobile platforms (#622).
c.screen.Clear()
}
op := &DrawImageOptions{}
s := screenScale
switch framebufferYDirection {
case graphicsdriver.Upward:
op.GeoM.Scale(s, -s)
_, h := c.offscreen.Size()
op.GeoM.Translate(0, float64(h)*s)
case graphicsdriver.Downward:
op.GeoM.Scale(s, s)
default:
panic(fmt.Sprintf("ebiten: invalid v-direction: %d", framebufferYDirection))
}
op.GeoM.Translate(offsetX, offsetY)
op.CompositeMode = CompositeModeCopy
switch {
case math.Floor(s) == s:
op.Filter = FilterNearest
case s > 1:
op.Filter = filterScreen
default:
// filterScreen works with >=1 scale, but does not well with <1 scale.
// Use regular FilterLinear instead so far (#669).
op.Filter = FilterLinear
}
c.screen.DrawImage(c.offscreen, op)
return nil
}