From 08b1a94dcd8a50bfcd9e256c74910010888a6056 Mon Sep 17 00:00:00 2001
From: JetSetIlly <stephen.t.illingworth@gmail.com>
Date: Mon, 9 Sep 2024 19:50:42 +0100
Subject: [PATCH] simplified RunForFrameCount()

---
 hardware/run.go                   | 32 +++++++++++++++++--------------
 hardware/television/television.go |  4 ++++
 preview/preview.go                |  2 +-
 regression/log.go                 |  3 ++-
 regression/video.go               |  3 ++-
 5 files changed, 27 insertions(+), 17 deletions(-)

diff --git a/hardware/run.go b/hardware/run.go
index 87cfb67a0..beee6b61f 100644
--- a/hardware/run.go
+++ b/hardware/run.go
@@ -100,32 +100,36 @@ func (vcs *VCS) Run(continueCheck func() (govern.State, error)) error {
 // RunForFrameCount sets emulator running for the specified number of frames.
 // Useful for FPS and regression tests. Not used by the debugger because traps
 // (and volatile traps) are more flexible.
-func (vcs *VCS) RunForFrameCount(numFrames int, continueCheck func(frame int) (govern.State, error)) error {
+//
+// continueCheck can be used to instruct the emulation to end before the
+// specified number of frames has elapsed.
+func (vcs *VCS) RunForFrameCount(numFrames int, continueCheck func() (govern.State, error)) error {
 	if continueCheck == nil {
-		continueCheck = func(frame int) (govern.State, error) { return govern.Running, nil }
+		continueCheck = func() (govern.State, error) { return govern.Running, nil }
 	}
 
-	frameNum := vcs.TV.GetCoords().Frame
-	targetFrame := frameNum + numFrames
+	targetFrame := vcs.TV.GetCoords().Frame + numFrames
 
 	state := govern.Running
-	for frameNum != targetFrame && state != govern.Ending {
+	for state != govern.Ending {
 		// check if CPU has been killed. emulation will run forever if we don't
 		// check for this
 		if vcs.CPU.Killed {
 			return nil
 		}
 
-		err := vcs.Step(nil)
-		if err != nil {
-			return err
-		}
-
-		frameNum = vcs.TV.GetCoords().Frame
+		if vcs.TV.IsFrameNum(targetFrame) {
+			state = govern.Ending
+		} else {
+			err := vcs.Step(nil)
+			if err != nil {
+				return err
+			}
 
-		state, err = continueCheck(frameNum)
-		if err != nil {
-			return err
+			state, err = continueCheck()
+			if err != nil {
+				return err
+			}
 		}
 	}
 
diff --git a/hardware/television/television.go b/hardware/television/television.go
index ff60e6d1a..9889b476d 100644
--- a/hardware/television/television.go
+++ b/hardware/television/television.go
@@ -1063,6 +1063,10 @@ func (tv *Television) GetCoords() coords.TelevisionCoords {
 	return tv.state.GetCoords()
 }
 
+func (tv *Television) IsFrameNum(frame int) bool {
+	return tv.state.frameNum == frame
+}
+
 // SetRotation instructs the television to a different orientation. In truth,
 // the television just forwards the request to the pixel renderers.
 func (tv *Television) SetRotation(rotation specification.Rotation) {
diff --git a/preview/preview.go b/preview/preview.go
index a1f8000d9..0803519f1 100644
--- a/preview/preview.go
+++ b/preview/preview.go
@@ -63,7 +63,7 @@ func (em *Emulation) RunN(loader cartridgeloader.Loader, N int) error {
 		return fmt.Errorf("preview: %w", err)
 	}
 
-	err = em.vcs.RunForFrameCount(N, func(_ int) (govern.State, error) {
+	err = em.vcs.RunForFrameCount(N, func() (govern.State, error) {
 		select {
 		case <-timeout:
 			return govern.Ending, nil
diff --git a/regression/log.go b/regression/log.go
index fa65f3e5c..7706c4d43 100644
--- a/regression/log.go
+++ b/regression/log.go
@@ -165,7 +165,7 @@ func (reg *LogRegression) regress(newRegression bool, output io.Writer, msg stri
 	logOutput := &strings.Builder{}
 
 	// run emulation
-	err = vcs.RunForFrameCount(reg.NumFrames, func(frame int) (govern.State, error) {
+	err = vcs.RunForFrameCount(reg.NumFrames, func() (govern.State, error) {
 		// if the CPU is in the KIL state then the test will never end normally
 		if vcs.CPU.Killed {
 			return govern.Ending, fmt.Errorf("CPU in KIL state")
@@ -174,6 +174,7 @@ func (reg *LogRegression) regress(newRegression bool, output io.Writer, msg stri
 		// display progress meter every 1 second
 		select {
 		case <-tck.C:
+			frame := vcs.TV.GetCoords().Frame
 			output.Write([]byte(fmt.Sprintf("\r%s [%d/%d (%.1f%%)]", msg, frame, reg.NumFrames, 100*(float64(frame)/float64(reg.NumFrames)))))
 		default:
 		}
diff --git a/regression/video.go b/regression/video.go
index 487673f63..d6a1373c3 100644
--- a/regression/video.go
+++ b/regression/video.go
@@ -239,7 +239,7 @@ func (reg *VideoRegression) regress(newRegression bool, output io.Writer, msg st
 	tck := time.NewTicker(dur)
 
 	// run emulation
-	err = vcs.RunForFrameCount(reg.NumFrames, func(frame int) (govern.State, error) {
+	err = vcs.RunForFrameCount(reg.NumFrames, func() (govern.State, error) {
 		// if the CPU is in the KIL state then the test will never end normally
 		if vcs.CPU.Killed {
 			return govern.Ending, fmt.Errorf("CPU in KIL state")
@@ -248,6 +248,7 @@ func (reg *VideoRegression) regress(newRegression bool, output io.Writer, msg st
 		// display progress meter every 1 second
 		select {
 		case <-tck.C:
+			frame := vcs.TV.GetCoords().Frame
 			output.Write([]byte(fmt.Sprintf("\r%s [%d/%d (%.1f%%)]", msg, frame, reg.NumFrames, 100*(float64(frame)/float64(reg.NumFrames)))))
 		default:
 		}