internal/graphicsdriver/opengl: refactoring: separate graphcis_*.go

Updates #2714

internal/graphicsdriver/opengl/graphics_linbsd.go

@@ -12,17 +12,14 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-//go:build !android && !darwin && !js && !nintendosdk && !playstation5
+//go:build (freebsd || linux || netbsd || openbsd) && !android && !nintendosdk && !playstation5
 
 package opengl
 
 import (
-	"fmt"
-
 	"github.com/hajimehoshi/ebiten/v2/internal/glfw"
 	"github.com/hajimehoshi/ebiten/v2/internal/graphicsdriver"
 	"github.com/hajimehoshi/ebiten/v2/internal/graphicsdriver/opengl/gl"
-	"github.com/hajimehoshi/ebiten/v2/internal/microsoftgdk"
 )
 
 type graphicsPlatform struct {
@@ -32,10 +29,6 @@ type graphicsPlatform struct {
 // NewGraphics creates an implementation of graphicsdriver.Graphics for OpenGL.
 // The returned graphics value is nil iff the error is not nil.
 func NewGraphics() (graphicsdriver.Graphics, error) {
-	if microsoftgdk.IsXbox() {
-		return nil, fmt.Errorf("opengl: OpenGL is not supported on Xbox")
-	}
-
 	ctx, err := gl.NewDefaultContext()
 	if err != nil {
 		return nil, err

internal/graphicsdriver/opengl/graphics_windows.go

@@ -0,0 +1,84 @@
+// Copyright 2024 The Ebitengine 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 opengl
+
+import (
+	"fmt"
+
+	"github.com/hajimehoshi/ebiten/v2/internal/glfw"
+	"github.com/hajimehoshi/ebiten/v2/internal/graphicsdriver"
+	"github.com/hajimehoshi/ebiten/v2/internal/graphicsdriver/opengl/gl"
+	"github.com/hajimehoshi/ebiten/v2/internal/microsoftgdk"
+)
+
+type graphicsPlatform struct {
+	window *glfw.Window
+}
+
+// NewGraphics creates an implementation of graphicsdriver.Graphics for OpenGL.
+// The returned graphics value is nil iff the error is not nil.
+func NewGraphics() (graphicsdriver.Graphics, error) {
+	if microsoftgdk.IsXbox() {
+		return nil, fmt.Errorf("opengl: OpenGL is not supported on Xbox")
+	}
+
+	ctx, err := gl.NewDefaultContext()
+	if err != nil {
+		return nil, err
+	}
+
+	if err := glfw.WindowHint(glfw.ClientAPI, glfw.OpenGLAPI); err != nil {
+		return nil, err
+	}
+	if err := glfw.WindowHint(glfw.ContextVersionMajor, 3); err != nil {
+		return nil, err
+	}
+	if err := glfw.WindowHint(glfw.ContextVersionMinor, 2); err != nil {
+		return nil, err
+	}
+
+	return newGraphics(ctx), nil
+}
+
+func (g *Graphics) SetGLFWWindow(window *glfw.Window) {
+	g.window = window
+}
+
+func (g *Graphics) makeContextCurrent() error {
+	return g.window.MakeContextCurrent()
+}
+
+func (g *Graphics) swapBuffers() error {
+	// Call SwapIntervals even though vsync is not changed.
+	// When toggling to fullscreen, vsync state might be reset unexpectedly (#1787).
+
+	// 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).
+	if g.vsync {
+		if err := glfw.SwapInterval(1); err != nil {
+			return err
+		}
+	} else {
+		if err := glfw.SwapInterval(0); err != nil {
+			return err
+		}
+	}
+
+	if err := g.window.SwapBuffers(); err != nil {
+		return err
+	}
+	return nil
+}