graphics: Refactoring: easier way to clear framebuffer

graphicscontext.go

@@ -57,8 +57,8 @@ func (c *graphicsContext) SetSize(screenWidth, screenHeight int, screenScale flo
 
 	w := int(float64(screenWidth) * screenScale)
 	h := int(float64(screenHeight) * screenScale)
-	px0, py0, px1, py1 := ui.ScreenPadding()
-	c.screen = newImageWithScreenFramebuffer(w, h, px0, py0, px1, py1)
+	px0, py0, _, _ := ui.ScreenPadding()
+	c.screen = newImageWithScreenFramebuffer(w, h)
 	_ = c.screen.Clear()
 
 	c.offscreen = offscreen

image.go

@@ -421,9 +421,9 @@ func NewImageFromImage(source image.Image, filter Filter) (*Image, error) {
 	return i, nil
 }
 
-func newImageWithScreenFramebuffer(width, height int, paddingX0, paddingY0, paddingX1, paddingY1 float64) *Image {
+func newImageWithScreenFramebuffer(width, height int) *Image {
 	checkSize(width, height)
-	r := restorable.NewScreenFramebufferImage(width, height, paddingX0, paddingY0, paddingX1, paddingY1)
+	r := restorable.NewScreenFramebufferImage(width, height)
 	i := &Image{
 		restorable: r,
 		filter:     FilterDefault,

internal/graphics/image.go

@@ -111,3 +111,7 @@ func (i *Image) createFramebufferIfNeeded() (*framebuffer, error) {
 	i.framebuffer = f
 	return i.framebuffer, nil
 }
+
+func (i *Image) ViewportSize() (int, int) {
+	return i.framebuffer.viewportSize()
+}

internal/restorable/image.go

@@ -17,7 +17,6 @@ package restorable
 import (
 	"errors"
 	"image/color"
-	"math"
 	"runtime"
 
 	"github.com/hajimehoshi/ebiten/internal/affine"
@@ -74,11 +73,6 @@ type Image struct {
 
 	// screen indicates whether the image is used as an actual screen.
 	screen bool
-
-	paddingX0 float64
-	paddingY0 float64
-	paddingX1 float64
-	paddingY1 float64
 }
 
 // NewImage creates an empty image with the given size.
@@ -93,15 +87,11 @@ func NewImage(width, height int, volatile bool) *Image {
 }
 
 // NewScreenFramebufferImage creates a special image that framebuffer is one for the screen.
-func NewScreenFramebufferImage(width, height int, paddingX0, paddingY0, paddingX1, paddingY1 float64) *Image {
+func NewScreenFramebufferImage(width, height int) *Image {
 	i := &Image{
-		image:     graphics.NewScreenFramebufferImage(width, height),
-		volatile:  true,
-		screen:    true,
-		paddingX0: paddingX0,
-		paddingY0: paddingY0,
-		paddingX1: paddingX1,
-		paddingY1: paddingY1,
+		image:    graphics.NewScreenFramebufferImage(width, height),
+		volatile: true,
+		screen:   true,
 	}
 	theImages.add(i)
 	runtime.SetFinalizer(i, (*Image).Dispose)
@@ -146,11 +136,11 @@ func (i *Image) clearIfVolatile() {
 		panic("not reached")
 	}
 
-	w, h := i.image.Size()
+	w, h := i.image.ViewportSize()
 	x0 := float32(0)
 	y0 := float32(0)
-	x1 := float32(w + int(math.Ceil(i.paddingX0+i.paddingX1)))
-	y1 := float32(h + int(math.Ceil(i.paddingY0+i.paddingY1)))
+	x1 := float32(w)
+	y1 := float32(h)
 	// For the rule of values, see vertices.go.
 	clearVertices := []float32{
 		x0, y0, 0, 0, 1, 1,