From 25ae96db89474d3cb7046ee6d2a522bd30bd8e59 Mon Sep 17 00:00:00 2001
From: Hajime Hoshi <hajimehoshi@gmail.com>
Date: Fri, 14 Oct 2022 01:58:03 +0900
Subject: [PATCH] internal/ui: move screenScaleAndOffsets to the ebiten package

Updates #2046
---
 gameforui.go           | 20 +++++++++++++++++++-
 internal/ui/context.go | 22 ++++------------------
 2 files changed, 23 insertions(+), 19 deletions(-)

diff --git a/gameforui.go b/gameforui.go
index a3509b605..f43ed0fce 100644
--- a/gameforui.go
+++ b/gameforui.go
@@ -136,7 +136,8 @@ func (g *gameForUI) DrawOffscreen() {
 	g.game.Draw(g.offscreen)
 }
 
-func (g *gameForUI) DrawScreen(scale, offsetX, offsetY float64) {
+func (g *gameForUI) DrawScreen() {
+	scale, offsetX, offsetY := g.ScreenScaleAndOffsets()
 	switch {
 	case !isScreenFilterEnabled(), math.Floor(scale) == scale:
 		op := &DrawImageOptions{}
@@ -158,3 +159,20 @@ func (g *gameForUI) DrawScreen(scale, offsetX, offsetY float64) {
 		g.screen.DrawRectShader(w, h, g.screenShader, op)
 	}
 }
+
+func (g *gameForUI) ScreenScaleAndOffsets() (scale, offsetX, offsetY float64) {
+	if g.screen == nil {
+		return
+	}
+
+	sw, sh := g.screen.Size()
+	ow, oh := g.offscreen.Size()
+	scaleX := float64(sw) / float64(ow)
+	scaleY := float64(sh) / float64(oh)
+	scale = math.Min(scaleX, scaleY)
+	width := float64(ow) * scale
+	height := float64(oh) * scale
+	offsetX = (float64(sw) - width) / 2
+	offsetY = (float64(sh) - height) / 2
+	return
+}
diff --git a/internal/ui/context.go b/internal/ui/context.go
index 12842a88a..708552a99 100644
--- a/internal/ui/context.go
+++ b/internal/ui/context.go
@@ -39,7 +39,8 @@ type Game interface {
 	Layout(outsideWidth, outsideHeight int) (int, int)
 	Update() error
 	DrawOffscreen()
-	DrawScreen(scale, offsetX, offsteY float64)
+	DrawScreen()
+	ScreenScaleAndOffsets() (scale, offsetX, offsetY float64)
 }
 
 type context struct {
@@ -169,7 +170,7 @@ func (c *context) drawGame(graphicsDriver graphicsdriver.Graphics) {
 		c.screen.clear()
 	}
 
-	c.game.DrawScreen(c.screenScaleAndOffsets())
+	c.game.DrawScreen()
 }
 
 func (c *context) layoutGame(outsideWidth, outsideHeight float64, deviceScaleFactor float64) (int, int) {
@@ -215,7 +216,7 @@ func (c *context) layoutGame(outsideWidth, outsideHeight float64, deviceScaleFac
 }
 
 func (c *context) adjustPosition(x, y float64, deviceScaleFactor float64) (float64, float64) {
-	s, ox, oy := c.screenScaleAndOffsets()
+	s, ox, oy := c.game.ScreenScaleAndOffsets()
 	// 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 {
@@ -224,21 +225,6 @@ func (c *context) adjustPosition(x, y float64, deviceScaleFactor float64) (float
 	return (x*deviceScaleFactor - ox) / s, (y*deviceScaleFactor - oy) / s
 }
 
-func (c *context) screenScaleAndOffsets() (float64, float64, float64) {
-	if c.screen == nil {
-		return 0, 0, 0
-	}
-
-	scaleX := float64(c.screen.width) / float64(c.offscreen.width)
-	scaleY := float64(c.screen.height) / float64(c.offscreen.height)
-	scale := math.Min(scaleX, scaleY)
-	width := float64(c.offscreen.width) * scale
-	height := float64(c.offscreen.height) * scale
-	x := (float64(c.screen.width) - width) / 2
-	y := (float64(c.screen.height) - height) / 2
-	return scale, x, y
-}
-
 var theGlobalState = globalState{
 	isScreenClearedEveryFrame_: 1,
 }