internal/graphicsdriver: refactoring: choose the graphics driver at this package

internal/graphicscommand/command.go

@@ -26,20 +26,6 @@ import (
 	"github.com/hajimehoshi/ebiten/v2/internal/shaderir"
 )
 
-var theGraphicsDriver graphicsdriver.Graphics
-
-func SetGraphicsDriver(driver graphicsdriver.Graphics) {
-	theGraphicsDriver = driver
-}
-
-func NeedsInvertY() bool {
-	return theGraphicsDriver.FramebufferYDirection() != theGraphicsDriver.NDCYDirection()
-}
-
-func NeedsRestoring() bool {
-	return theGraphicsDriver.NeedsRestoring()
-}
-
 // command represents a drawing command.
 //
 // A command for drawing that is created when Image functions are called like DrawTriangles,
@@ -245,7 +231,7 @@ func (q *commandQueue) flush() error {
 	vs := q.vertices
 	debug.Logf("Graphics commands:\n")
 
-	if theGraphicsDriver.HasHighPrecisionFloat() {
+	if graphicsDriver().HasHighPrecisionFloat() {
 		n := q.nvertices / graphics.VertexFloatNum
 		for i := 0; i < n; i++ {
 			s := q.srcSizes[i]
@@ -296,7 +282,7 @@ func (q *commandQueue) flush() error {
 		}
 	}
 
-	theGraphicsDriver.Begin()
+	graphicsDriver().Begin()
 	var present bool
 	cs := q.commands
 	for len(cs) > 0 {
@@ -320,7 +306,7 @@ func (q *commandQueue) flush() error {
 			nc++
 		}
 		if 0 < ne {
-			theGraphicsDriver.SetVertices(vs[:nv], es[:ne])
+			graphicsDriver().SetVertices(vs[:nv], es[:ne])
 			es = es[ne:]
 			vs = vs[nv:]
 		}
@@ -339,7 +325,7 @@ func (q *commandQueue) flush() error {
 		}
 		cs = cs[nc:]
 	}
-	theGraphicsDriver.End(present)
+	graphicsDriver().End(present)
 
 	// Release the commands explicitly (#1803).
 	// Apparently, the part of a slice between len and cap-1 still holds references.
@@ -488,7 +474,7 @@ func (c *drawTrianglesCommand) Exec(indexOffset int) error {
 		imgs[0] = c.srcs[0].image.ID()
 	}
 
-	return theGraphicsDriver.DrawTriangles(c.dst.image.ID(), imgs, c.offsets, shaderID, c.nindices, indexOffset, c.mode, c.color, c.filter, c.address, c.dstRegion, c.srcRegion, c.uniforms, c.evenOdd)
+	return graphicsDriver().DrawTriangles(c.dst.image.ID(), imgs, c.offsets, shaderID, c.nindices, indexOffset, c.mode, c.color, c.filter, c.address, c.dstRegion, c.srcRegion, c.uniforms, c.evenOdd)
 }
 
 func (c *drawTrianglesCommand) numVertices() int {
@@ -662,7 +648,7 @@ func (c *newImageCommand) String() string {
 
 // Exec executes a newImageCommand.
 func (c *newImageCommand) Exec(indexOffset int) error {
-	i, err := theGraphicsDriver.NewImage(c.width, c.height)
+	i, err := graphicsDriver().NewImage(c.width, c.height)
 	if err != nil {
 		return err
 	}
@@ -684,7 +670,7 @@ func (c *newScreenFramebufferImageCommand) String() string {
 // Exec executes a newScreenFramebufferImageCommand.
 func (c *newScreenFramebufferImageCommand) Exec(indexOffset int) error {
 	var err error
-	c.result.image, err = theGraphicsDriver.NewScreenFramebufferImage(c.width, c.height)
+	c.result.image, err = graphicsDriver().NewScreenFramebufferImage(c.width, c.height)
 	return err
 }
 
@@ -701,14 +687,14 @@ func (c *newShaderCommand) String() string {
 // Exec executes a newShaderCommand.
 func (c *newShaderCommand) Exec(indexOffset int) error {
 	var err error
-	c.result.shader, err = theGraphicsDriver.NewShader(c.ir)
+	c.result.shader, err = graphicsDriver().NewShader(c.ir)
 	return err
 }
 
 // InitializeGraphicsDriverState initialize the current graphics driver state.
 func InitializeGraphicsDriverState() (err error) {
 	runOnRenderingThread(func() {
-		err = theGraphicsDriver.Initialize()
+		err = graphicsDriver().Initialize()
 	})
 	return
 }
@@ -716,7 +702,7 @@ func InitializeGraphicsDriverState() (err error) {
 // ResetGraphicsDriverState resets the current graphics driver state.
 // If the graphics driver doesn't have an API to reset, ResetGraphicsDriverState does nothing.
 func ResetGraphicsDriverState() (err error) {
-	if r, ok := theGraphicsDriver.(interface{ Reset() error }); ok {
+	if r, ok := graphicsDriver().(interface{ Reset() error }); ok {
 		runOnRenderingThread(func() {
 			err = r.Reset()
 		})
@@ -728,7 +714,7 @@ func ResetGraphicsDriverState() (err error) {
 func MaxImageSize() int {
 	var size int
 	runOnRenderingThread(func() {
-		size = theGraphicsDriver.MaxImageSize()
+		size = graphicsDriver().MaxImageSize()
 	})
 	return size
 }

internal/graphicscommand/graphics.go

@@ -0,0 +1,59 @@
+// Copyright 2022 The Ebiten Authors
+//
+// 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 graphicscommand
+
+import (
+	"github.com/hajimehoshi/ebiten/v2/internal/graphicsdriver"
+)
+
+type Drawer interface {
+	Draw(screenScale float64, offsetX, offsetY float64, needsClearingScreen bool, framebufferYDirection graphicsdriver.YDirection, screenClearedEveryFrame, filterEnabled bool) error
+}
+
+func Draw(drawer Drawer, screenScale float64, offsetX, offsetY float64, screenClearedEveryFrame, filterEnabled bool) error {
+	return drawer.Draw(screenScale, offsetX, offsetY, graphicsDriver().NeedsClearingScreen(), graphicsDriver().FramebufferYDirection(), screenClearedEveryFrame, filterEnabled)
+}
+
+// TODO: Reduce these 'getter' global functions if possible.
+
+func NeedsInvertY() bool {
+	return graphicsDriver().FramebufferYDirection() != graphicsDriver().NDCYDirection()
+}
+
+func NeedsRestoring() bool {
+	return graphicsDriver().NeedsRestoring()
+}
+
+func IsGL() bool {
+	return graphicsDriver().IsGL()
+}
+
+func SetVsyncEnabled(enabled bool) {
+	graphicsDriver().SetVsyncEnabled(enabled)
+}
+
+func SetTransparent(transparent bool) {
+	graphicsDriver().SetTransparent(transparent)
+}
+
+func SetFullscreen(fullscreen bool) {
+	graphicsDriver().SetFullscreen(fullscreen)
+}
+
+func SetWindow(window uintptr) {
+	if g, ok := graphicsDriver().(interface{ SetWindow(uintptr) }); ok {
+		g.SetWindow(window)
+	}
+}

internal/graphicscommand/graphics_darwin.go

@@ -15,7 +15,7 @@
 //go:build !ios && !ebitengl && !ebitencbackend
 // +build !ios,!ebitengl,!ebitencbackend
 
-package ui
+package graphicscommand
 
 // #cgo CFLAGS: -x objective-c
 // #cgo LDFLAGS: -framework Foundation
@@ -55,7 +55,7 @@ func supportsMetal() bool {
 
 var graphicsOnce sync.Once
 
-func graphics() graphicsdriver.Graphics {
+func graphicsDriver() graphicsdriver.Graphics {
 	graphicsOnce.Do(func() {
 		if supportsMetal() {
 			theGraphics = metal.Get()

internal/graphicscommand/graphics_ios_amd64.go

@@ -15,14 +15,14 @@
 //go:build ios && !ebitengl && !ebitencbackend
 // +build ios,!ebitengl,!ebitencbackend
 
-package ui
+package graphicscommand
 
 import (
 	"github.com/hajimehoshi/ebiten/v2/internal/graphicsdriver"
 	"github.com/hajimehoshi/ebiten/v2/internal/graphicsdriver/opengl"
 )
 
-func graphics() graphicsdriver.Graphics {
+func graphicsDriver() graphicsdriver.Graphics {
 	// Metal might not be supported on emulators on Intel machines.
 	return opengl.Get()
 }

internal/graphicscommand/graphics_ios_arm64.go

@@ -15,14 +15,14 @@
 //go:build ios && !ebitengl && !ebitencbackend
 // +build ios,!ebitengl,!ebitencbackend
 
-package ui
+package graphicscommand
 
 import (
 	"github.com/hajimehoshi/ebiten/v2/internal/graphicsdriver"
 	"github.com/hajimehoshi/ebiten/v2/internal/graphicsdriver/metal"
 )
 
-func graphics() graphicsdriver.Graphics {
+func graphicsDriver() graphicsdriver.Graphics {
 	g := metal.Get()
 	if g == nil {
 		panic("ui: Metal is not available on this iOS device")

internal/graphicscommand/graphics_mobile.go

@@ -1,4 +1,4 @@
-// Copyright 2020 The Ebiten Authors
+// Copyright 2022 The Ebiten Authors
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
@@ -12,13 +12,17 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package ui
+//go:build android || ios
+// +build android ios
+
+package graphicscommand
 
 import (
-	"github.com/hajimehoshi/ebiten/v2/internal/graphicscommand"
+	"golang.org/x/mobile/gl"
+
+	"github.com/hajimehoshi/ebiten/v2/internal/graphicsdriver/opengl"
 )
 
-func init() {
+func SetGomobileGLContext(ctx gl.Context) {
-	// TODO: Should graphics() be moved to the graphicscommand package?
+	graphicsDriver().(*opengl.Graphics).SetGomobileGLContext(ctx)
-	graphicscommand.SetGraphicsDriver(graphics())
 }

internal/graphicscommand/graphics_opengl.go

@@ -15,13 +15,13 @@
 //go:build !darwin || ebitencbackend || ebitengl
 // +build !darwin ebitencbackend ebitengl
 
-package ui
+package graphicscommand
 
 import (
 	"github.com/hajimehoshi/ebiten/v2/internal/graphicsdriver"
 	"github.com/hajimehoshi/ebiten/v2/internal/graphicsdriver/opengl"
 )
 
-func graphics() graphicsdriver.Graphics {
+func graphicsDriver() graphicsdriver.Graphics {
 	return opengl.Get()
 }

internal/ui/context.go

@@ -23,6 +23,7 @@ import (
 	"github.com/hajimehoshi/ebiten/v2/internal/clock"
 	"github.com/hajimehoshi/ebiten/v2/internal/debug"
 	graphicspkg "github.com/hajimehoshi/ebiten/v2/internal/graphics"
+	"github.com/hajimehoshi/ebiten/v2/internal/graphicscommand"
 	"github.com/hajimehoshi/ebiten/v2/internal/graphicsdriver"
 	"github.com/hajimehoshi/ebiten/v2/internal/hooks"
 )
@@ -106,7 +107,7 @@ func (c *contextImpl) updateFrameImpl(updateCount int, outsideWidth, outsideHeig
 
 	// Draw the game.
 	screenScale, offsetX, offsetY := c.screenScaleAndOffsets(deviceScaleFactor)
-	if err := c.game.Draw(screenScale, offsetX, offsetY, graphics().NeedsClearingScreen(), graphics().FramebufferYDirection(), theGlobalState.isScreenClearedEveryFrame(), theGlobalState.isScreenFilterEnabled()); err != nil {
+	if err := graphicscommand.Draw(c.game, screenScale, offsetX, offsetY, theGlobalState.isScreenClearedEveryFrame(), theGlobalState.isScreenFilterEnabled()); err != nil {
 		return err
 	}
 

internal/ui/ui_glfw.go

@@ -28,6 +28,7 @@ import (
 
 	"github.com/hajimehoshi/ebiten/v2/internal/devicescale"
 	"github.com/hajimehoshi/ebiten/v2/internal/glfw"
+	"github.com/hajimehoshi/ebiten/v2/internal/graphicscommand"
 	"github.com/hajimehoshi/ebiten/v2/internal/hooks"
 	"github.com/hajimehoshi/ebiten/v2/internal/thread"
 )
@@ -667,7 +668,7 @@ func (u *UserInterface) createWindow(width, height int) error {
 	// Ensure to consume this callback.
 	u.waitForFramebufferSizeCallback(u.window, nil)
 
-	if graphics().IsGL() {
+	if graphicscommand.IsGL() {
 		u.window.MakeContextCurrent()
 	}
 
@@ -721,7 +722,7 @@ func (u *UserInterface) registerWindowSetSizeCallback() {
 				u.err = err
 			}
 
-			if graphics().IsGL() {
+			if graphicscommand.IsGL() {
 				u.swapBuffers()
 			}
 		})
@@ -815,7 +816,7 @@ event:
 }
 
 func (u *UserInterface) init() error {
-	if graphics().IsGL() {
+	if graphicscommand.IsGL() {
 		glfw.WindowHint(glfw.ClientAPI, glfw.OpenGLAPI)
 		glfw.WindowHint(glfw.ContextVersionMajor, 2)
 		glfw.WindowHint(glfw.ContextVersionMinor, 1)
@@ -836,7 +837,7 @@ func (u *UserInterface) init() error {
 		transparent = glfw.True
 	}
 	glfw.WindowHint(glfw.TransparentFramebuffer, transparent)
-	graphics().SetTransparent(u.isInitScreenTransparent())
+	graphicscommand.SetTransparent(u.isInitScreenTransparent())
 
 	// Before creating a window, set it unresizable no matter what u.isInitWindowResizable() is (#1987).
 	// Making the window resizable here doesn't work correctly when switching to enable resizing.
@@ -888,9 +889,7 @@ func (u *UserInterface) init() error {
 
 	u.window.Show()
 
-	if g, ok := graphics().(interface{ SetWindow(uintptr) }); ok {
+	graphicscommand.SetWindow(u.nativeWindow())
-		g.SetWindow(u.nativeWindow())
-	}
 
 	return nil
 }
@@ -1067,7 +1066,7 @@ func (u *UserInterface) loop() error {
 		// swapBuffers also checks IsGL, so this condition is redundant.
 		// However, (*thread).Call is not good for performance due to channels.
 		// Let's avoid this whenever possible (#1367).
-		if graphics().IsGL() {
+		if graphicscommand.IsGL() {
 			u.t.Call(u.swapBuffers)
 		}
 
@@ -1089,7 +1088,7 @@ func (u *UserInterface) loop() error {
 
 // swapBuffers must be called from the main thread.
 func (u *UserInterface) swapBuffers() {
-	if graphics().IsGL() {
+	if graphicscommand.IsGL() {
 		u.window.SwapBuffers()
 	}
 }
@@ -1146,7 +1145,7 @@ func (u *UserInterface) adjustWindowSizeBasedOnSizeLimitsInDIP(width, height int
 func (u *UserInterface) setWindowSizeInDIP(width, height int, fullscreen bool) {
 	width, height = u.adjustWindowSizeBasedOnSizeLimitsInDIP(width, height)
 
-	graphics().SetFullscreen(fullscreen)
+	graphicscommand.SetFullscreen(fullscreen)
 
 	scale := u.deviceScaleFactor(u.currentMonitor())
 	if u.windowWidthInDIP == width && u.windowHeightInDIP == height && u.isFullscreen() == fullscreen && u.lastDeviceScaleFactor == scale {
@@ -1220,7 +1219,7 @@ func (u *UserInterface) setWindowSizeInDIPImpl(width, height int, fullscreen boo
 
 			// Swapping buffer is necesary to prevent the image lag (#1004).
 			// TODO: This might not work when vsync is disabled.
-			if graphics().IsGL() {
+			if graphicscommand.IsGL() {
 				glfw.PollEvents()
 				u.swapBuffers()
 			}
@@ -1267,7 +1266,7 @@ func (u *UserInterface) setWindowSizeInDIPImpl(width, height int, fullscreen boo
 
 // updateVsync must be called on the main thread.
 func (u *UserInterface) updateVsync() {
-	if graphics().IsGL() {
+	if graphicscommand.IsGL() {
 		// SwapInterval is affected by the current monitor of the window.
 		// This needs to be called at least after SetMonitor.
 		// Without SwapInterval after SetMonitor, vsynch doesn't work (#375).
@@ -1281,7 +1280,7 @@ func (u *UserInterface) updateVsync() {
 			glfw.SwapInterval(0)
 		}
 	}
-	graphics().SetVsyncEnabled(u.fpsMode == FPSModeVsyncOn)
+	graphicscommand.SetVsyncEnabled(u.fpsMode == FPSModeVsyncOn)
 }
 
 // currentMonitor returns the current active monitor.

internal/ui/ui_glfw_darwin.go

@@ -227,6 +227,7 @@ import "C"
 
 import (
 	"github.com/hajimehoshi/ebiten/v2/internal/glfw"
+	"github.com/hajimehoshi/ebiten/v2/internal/graphicscommand"
 )
 
 // clearVideoModeScaleCache must be called from the main thread.
@@ -316,7 +317,7 @@ func (u *UserInterface) setNativeFullscreen(fullscreen bool) {
 }
 
 func (u *UserInterface) adjustViewSize() {
-	if graphics().IsGL() {
+	if graphicscommand.IsGL() {
 		return
 	}
 	C.adjustViewSize(C.uintptr_t(u.window.GetCocoaWindow()))

internal/ui/ui_mobile.go

@@ -36,7 +36,6 @@ import (
 	"github.com/hajimehoshi/ebiten/v2/internal/devicescale"
 	"github.com/hajimehoshi/ebiten/v2/internal/gamepad"
 	"github.com/hajimehoshi/ebiten/v2/internal/graphicscommand"
-	"github.com/hajimehoshi/ebiten/v2/internal/graphicsdriver/opengl"
 	"github.com/hajimehoshi/ebiten/v2/internal/hooks"
 	"github.com/hajimehoshi/ebiten/v2/internal/restorable"
 	"github.com/hajimehoshi/ebiten/v2/internal/thread"
@@ -277,7 +276,7 @@ func (u *UserInterface) run(game Game, mainloop bool) (err error) {
 		// When mainloop is true, gomobile-build is used. In this case, GL functions must be called via
 		// gl.Context so that they are called on the appropriate thread.
 		ctx := <-glContextCh
-		graphics().(*opengl.Graphics).SetGomobileGLContext(ctx)
+		graphicscommand.SetGomobileGLContext(ctx)
 	} else {
 		u.t = thread.NewOSThread()
 		graphicscommand.SetRenderingThread(u.t)