internal/graphicscommand: better calculation for callers

internal/debug/caller.go

@@ -0,0 +1,67 @@
+// 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 debug
+
+import (
+	"fmt"
+	"os/exec"
+	"path"
+	"path/filepath"
+	"runtime"
+	"strings"
+	"sync"
+)
+
+var (
+	ebitengineFileDir     string
+	ebitengineFileDirOnce sync.Once
+)
+
+// FirstCaller returns the file and line number of the first caller outside of Ebitengine.
+func FirstCaller() (file string, line int, ok bool) {
+	ebitengineFileDirOnce.Do(func() {
+		cmd := exec.Command("go", "list", "-f", "{{.Dir}}", "github.com/hajimehoshi/ebiten/v2")
+		out, err := cmd.Output()
+		if err != nil {
+			panic(fmt.Sprintf("debug: go list -f {{.Dir}} failed: %v", err))
+		}
+		ebitengineFileDir = filepath.ToSlash(strings.TrimSpace(string(out)))
+	})
+
+	// Relying on a caller stacktrace is very fragile, but this is fine as this is only for debugging.
+	var ebitenPackageReached bool
+	for i := 0; ; i++ {
+		_, file, line, ok := runtime.Caller(i)
+		if !ok {
+			break
+		}
+		// The file should be with a slash, but just in case, convert it.
+		file = filepath.ToSlash(file)
+
+		if !ebitenPackageReached {
+			if path.Dir(file) == ebitengineFileDir {
+				ebitenPackageReached = true
+			}
+			continue
+		}
+
+		if path.Dir(file) == ebitengineFileDir || path.Dir(file) == ebitengineFileDir+"/colorm" || path.Dir(file) == ebitengineFileDir+"/text" || path.Dir(file) == ebitengineFileDir+"/text/v2" {
+			continue
+		}
+		return file, line, true
+	}
+
+	return "", 0, false
+}

internal/graphicscommand/commandqueue.go

@@ -18,7 +18,6 @@ import (
 	"fmt"
 	"image"
 	"math"
-	"runtime"
 	"strings"
 	"sync"
 	"sync/atomic"
@@ -165,20 +164,10 @@ func (q *commandQueue) EnqueueDrawTrianglesCommand(dst *Image, srcs [graphics.Sh
 	c.uniforms = uniforms
 	c.fillRule = fillRule
 	if debug.IsDebug {
-		// Get the root caller of this function.
-		// Relying on a caller stacktrace is very fragile, but this is fine as this is only for debugging.
-		for i := 0; ; i++ {
-			_, file, _, ok := runtime.Caller(i)
-			if !ok {
-				break
-			}
-			if !strings.HasSuffix(file, "/ebiten/image.go") {
-				continue
-			}
-			if _, file, line, ok := runtime.Caller(i + 1); ok {
-				c.firstCaller = fmt.Sprintf("%s:%d", file, line)
-			}
-			break
+		if file, line, ok := debug.FirstCaller(); ok {
+			c.firstCaller = fmt.Sprintf("%s:%d", file, line)
+		} else {
+			c.firstCaller = "(internal)"
 		}
 	}
 	q.commands = append(q.commands, c)