all: use Go 1.20 APIs

Closes #2746

audio/audio.go

@@ -188,14 +188,7 @@ func (c *Context) addPlayingPlayer(p *playerImpl) {
 	defer c.m.Unlock()
 	c.playingPlayers[p] = struct{}{}
 
-	// (reflect.Type).Comparable() is enough here, as reflect.TypeOf should always return a dynamic (non-interface) type.
-	// If reflect.TypeOf returned an interface type, this check would be meaningless.
-	// See these for more details:
-	// * https://pkg.go.dev/reflect#TypeOf
-	// * https://pkg.go.dev/reflect#Type.Comparable
-	//
-	// (*reflect.Value).Comparable() is more intuitive but this was introduced in Go 1.20.
-	if !reflect.TypeOf(p.sourceIdent()).Comparable() {
+	if !reflect.ValueOf(p.sourceIdent()).Comparable() {
 		return
 	}
 

audio/internal/convert/float32_test.go

@@ -69,15 +69,14 @@ func TestFloat32(t *testing.T) {
 					name = "seek"
 				}
 				t.Run(name, func(t *testing.T) {
-					// Note that unsafe.SliceData is available as of Go 1.20.
 					var in, out []byte
 					if len(c.In) > 0 {
 						outF32 := make([]float32, len(c.In))
 						for i := range c.In {
 							outF32[i] = float32(c.In[i]) / (1 << 15)
 						}
-						in = unsafe.Slice((*byte)(unsafe.Pointer(&c.In[0])), len(c.In)*2)
-						out = unsafe.Slice((*byte)(unsafe.Pointer(&outF32[0])), len(outF32)*4)
+						in = unsafe.Slice((*byte)(unsafe.Pointer(unsafe.SliceData(c.In))), len(c.In)*2)
+						out = unsafe.Slice((*byte)(unsafe.Pointer(unsafe.SliceData(outF32))), len(outF32)*4)
 					}
 					r := convert.NewFloat32BytesReaderFromInt16BytesReader(bytes.NewReader(in)).(io.ReadSeeker)
 					var got []byte

internal/glfw/context_windows.go

@@ -616,6 +616,5 @@ func bytePtrToString(p *byte) string {
 		ptr = unsafe.Add(ptr, 1)
 	}
 
-	// unsafe.String(p, n) is available as of Go 1.20.
-	return string(unsafe.Slice(p, n))
+	return unsafe.String(p, n)
 }

internal/graphicsdriver/opengl/gl/procaddr_darwin.go

@@ -38,8 +38,7 @@ func (c *defaultContext) init() error {
 		return nil
 	}
 
-	// TODO: Use multiple %w-s as of Go 1.20
-	return fmt.Errorf("gl: failed to load: OpenGL.framework: %v, OpenGLES.framework: %v", errGL, errGLES)
+	return fmt.Errorf("gl: failed to load: OpenGL.framework: %w, OpenGLES.framework: %w", errGL, errGLES)
 }
 
 func (c *defaultContext) getProcAddress(name string) (uintptr, error) {

internal/graphicsdriver/opengl/gl/procaddr_linbsd.go

@@ -17,8 +17,8 @@
 package gl
 
 import (
+	"errors"
 	"fmt"
-	"strings"
 
 	"github.com/ebitengine/purego"
 )
@@ -29,8 +29,7 @@ var (
 )
 
 func (c *defaultContext) init() error {
-	// TODO: Use multiple %w-s as of Go 1.20.
-	var errors []string
+	var errs []error
 
 	// Try OpenGL ES first. Some machines like Android and Raspberry Pi might work only with OpenGL ES.
 	for _, name := range []string{"libGLESv2.so", "libGLESv2.so.2", "libGLESv2.so.1", "libGLESv2.so.0"} {
@@ -40,7 +39,7 @@ func (c *defaultContext) init() error {
 			c.isES = true
 			return nil
 		}
-		errors = append(errors, fmt.Sprintf("%s: %v", name, err))
+		errs = append(errs, fmt.Errorf("gl: Dlopen failed: name: %s: %w", name, err))
 	}
 
 	// Try OpenGL next.
@@ -54,10 +53,11 @@ func (c *defaultContext) init() error {
 			libGL = lib
 			return nil
 		}
-		errors = append(errors, fmt.Sprintf("%s: %v", name, err))
+		errs = append(errs, fmt.Errorf("gl: Dlopen failed: name: %s: %w", name, err))
 	}
 
-	return fmt.Errorf("gl: failed to load libGL.so and libGLESv2.so: %s", strings.Join(errors, ", "))
+	errs = append([]error{fmt.Errorf("gl: failed to load libGL.so and libGLESv2.so: ")}, errs...)
+	return errors.Join(errs...)
 }
 
 func (c *defaultContext) getProcAddress(name string) (uintptr, error) {