filter: changed embedded struct to a field within struct

filter/basic.go

@@ -40,34 +40,30 @@ type pixel struct{ r, g, b uint32 }
 // Basic is a filter that provides basic motion detection via a difference
 // method.
 type Basic struct {
-	debugFile
+	debugging debugFile
-	dst    io.WriteCloser
+	dst       io.WriteCloser
-	img    image.Image
+	img       image.Image
-	bg     [][]pixel
+	bg        [][]pixel
-	thresh int
+	thresh    int
-	pix    int
+	pix       int
-	w      int
+	w         int
-	h      int
+	h         int
-	motion int
+	motion    int
 }
 
 // NewBasic returns a pointer to a new Basic filter struct.
 func NewBasic(dst io.WriteCloser, t, p int) *Basic {
-	bf := &Basic{
+	return &Basic{
-		dst:    dst,
+		dst:       dst,
-		thresh: t,
+		thresh:    t,
-		pix:    p,
+		pix:       p,
+		debugging: newDebugFile(),
 	}
-	err := bf.newDebugFile()
-	if err != nil {
-		panic(fmt.Sprintf("could not create debug file: %w", err))
-	}
-	return bf
 }
 
 // Implements io.Closer.
 func (bf *Basic) Close() error {
-	return bf.closeDebugFile()
+	return bf.debugging.close()
 }
 
 // Implements io.Writer.
@@ -87,7 +83,7 @@ func (bf *Basic) Write(f []byte) (int, error) {
 		bf.w = bounds.Max.X
 		bf.h = bounds.Max.Y
 
-		bf.resetDebugFileFrame(bf.w, bf.h)
+		bf.debugging.resetFrame(bf.w, bf.h)
 
 		bf.bg = make([][]pixel, bf.h)
 		for j, _ := range bf.bg {
@@ -119,7 +115,7 @@ func (bf *Basic) Write(f []byte) (int, error) {
 	}
 
 	// Will save a video of where motion is detected in motion.mjpeg (in the current folder).
-	err = bf.saveFrame(bf.motion, bf.pix)
+	err = bf.debugging.saveFrame(bf.motion, bf.pix)
 	if err != nil {
 		return len(f), fmt.Errorf("image can't be encoded for debug video: %w", err)
 	}
@@ -148,9 +144,9 @@ func (bf *Basic) process(j int, wg *sync.WaitGroup) {
 
 		if diff > bf.thresh {
 			bf.motion++
-			bf.drawToDebugFile(i, j, 0xff)
+			bf.debugging.draw(i, j, 0xff)
 		} else {
-			bf.drawToDebugFile(i, j, 0x00)
+			bf.debugging.draw(i, j, 0x00)
 		}
 
 		// Update backgound image.

filter/debug.go

@@ -47,16 +47,22 @@ type debugFile struct {
 }
 
 // newDebugFile creates a file for saving debugging frames to.
-func (d *debugFile) newDebugFile() error {
+func newDebugFile() debugFile {
 	const debugfile = "motion.mjpeg"
-	d.bwImg = image.NewRGBA(image.Rect(0, 0, 0, 0))
+
-	var err error
+	file, err := os.Create(debugfile)
-	d.file, err = os.Create(debugfile)
+	if err != nil {
-	return err
+		panic(fmt.Sprintf("could not create debug file: %w", err))
+	}
+
+	return debugFile{
+		bwImg: image.NewRGBA(image.Rect(0, 0, 0, 0)),
+		file:  file,
+	}
 }
 
-// closeDebugFile closes files used for debugging purposes.
+// close closes files used for debugging purposes.
-func (d *debugFile) closeDebugFile() error {
+func (d *debugFile) close() error {
 	err := d.file.Close()
 	if err != nil {
 		return fmt.Errorf("file cannot be closed: %w", err)
@@ -64,8 +70,8 @@ func (d *debugFile) closeDebugFile() error {
 	return nil
 }
 
-// drawToDebugFile draws debugging information to a frame.
+// draw draws debugging information to a frame.
-func (d *debugFile) drawToDebugFile(i, j int, val uint8) {
+func (d *debugFile) draw(i, j int, val uint8) {
 	d.bwImg.SetRGBA(i, j, color.RGBA{val, val, val, 0xff})
 }
 
@@ -90,7 +96,7 @@ func (d *debugFile) saveFrame(motion, pix int) error {
 	return jpeg.Encode(d.file, d.bwImg, nil)
 }
 
-// resetDebugFileFrame makes an image of given dimensions.
+// resetFrame makes an image of given dimensions.
-func (d *debugFile) resetDebugFileFrame(w, h int) {
+func (d *debugFile) resetFrame(w, h int) {
 	d.bwImg = image.NewRGBA(image.Rect(0, 0, w, h))
 }

filter/debug_nocircleci.go

@@ -39,20 +39,25 @@ type debugWindows struct {
 	windows []*gocv.Window
 }
 
-// closeWindows frees resources used by gocv.
+// close frees resources used by gocv.
-func (d *debugWindows) closeWindows() {
+func (d *debugWindows) close() {
 	for _, window := range d.windows {
 		window.Close()
 	}
 }
 
 // newWindows creates debugging windows for the motion filter.
-func (d *debugWindows) newWindows(name string) {
+func newWindows(name string) debugWindows {
-	d.windows = []*gocv.Window{gocv.NewWindow(name + ": Bounding boxes"), gocv.NewWindow(name + ": Motion")}
+	return debugWindows{
+		windows: []*gocv.Window{
+			gocv.NewWindow(name + ": Bounding boxes"),
+			gocv.NewWindow(name + ": Motion"),
+		},
+	}
 }
 
-// showDebug displays debug information for the motion filters.
+// show displays debug information for the motion filters.
-func (d *debugWindows) showDebug(img, imgDelta gocv.Mat, motion bool, contours ...[][]image.Point) {
+func (d *debugWindows) show(img, imgDelta gocv.Mat, motion bool, contours ...[][]image.Point) {
 	if len(contours) > 0 {
 		for _, c := range contours[0] {
 			rect := gocv.BoundingRect(c)

filter/difference.go

@@ -39,21 +39,20 @@ import (
 // the absolute difference for each pixel between two frames, then finds the mean. If
 // the mean is above a given threshold, then it is considered motion.
 type Difference struct {
-	debugWindows
+	debugging debugWindows
-	dst    io.WriteCloser
+	dst       io.WriteCloser
-	thresh float64
+	thresh    float64
-	prev   gocv.Mat
+	prev      gocv.Mat
 }
 
 // NewDifference returns a pointer to a new Difference struct.
 func NewDifference(dst io.WriteCloser, threshold float64) *Difference {
-	d := &Difference{
+	return &Difference{
-		dst:    dst,
+		dst:       dst,
-		thresh: threshold,
+		thresh:    threshold,
-		prev:   gocv.NewMat(),
+		prev:      gocv.NewMat(),
+		debugging: newWindows("DIFF"),
 	}
-	d.newWindows("DIFF")
-	return d
 }
 
 // Implements io.Closer.
@@ -61,7 +60,7 @@ func NewDifference(dst io.WriteCloser, threshold float64) *Difference {
 // it using c-go.
 func (d *Difference) Close() error {
 	d.prev.Close()
-	d.closeWindows()
+	d.debugging.close()
 	return nil
 }
 
@@ -97,7 +96,7 @@ func (d *Difference) Write(f []byte) (int, error) {
 	d.prev = img.Clone()
 
 	// Draw debug information.
-	d.showDebug(img, imgDelta, mean > d.thresh)
+	d.debugging.show(img, imgDelta, mean > d.thresh)
 
 	// Don't write to destination if there is no motion.
 	if mean < d.thresh {

filter/knn.go

@@ -39,32 +39,31 @@ import (
 // KNN is a filter that provides basic motion detection. KNN is short for
 // K-Nearest Neighbours method.
 type KNN struct {
-	debugWindows
+	debugging debugWindows
-	dst     io.WriteCloser                // Destination to which motion containing frames go.
+	dst       io.WriteCloser                // Destination to which motion containing frames go.
-	area    float64                       // The minimum area that a contour can be found in.
+	area      float64                       // The minimum area that a contour can be found in.
-	bs      *gocv.BackgroundSubtractorKNN // Uses the KNN algorithm to find the difference between the current and background frame.
+	bs        *gocv.BackgroundSubtractorKNN // Uses the KNN algorithm to find the difference between the current and background frame.
-	knl     gocv.Mat                      // Matrix that is used for calculations.
+	knl       gocv.Mat                      // Matrix that is used for calculations.
-	hold    [][]byte                      // Will hold all frames up to hf (so only every hf frame is motion detected).
+	hold      [][]byte                      // Will hold all frames up to hf (so only every hf frame is motion detected).
-	hf      int                           // The number of frames to be held.
+	hf        int                           // The number of frames to be held.
-	hfCount int                           // Counter for the hold array.
+	hfCount   int                           // Counter for the hold array.
-	scale   float64                       // The factor that frames will be downscaled by for motion detection.
+	scale     float64                       // The factor that frames will be downscaled by for motion detection.
 }
 
 // NewKNN returns a pointer to a new KNN filter struct.
 func NewKNN(dst io.WriteCloser, area, threshold float64, history, kernelSize int, hf int, scaleFactor int) *KNN {
 	bs := gocv.NewBackgroundSubtractorKNNWithParams(history, threshold, false)
 	k := gocv.GetStructuringElement(gocv.MorphRect, image.Pt(kernelSize, kernelSize))
-	m := &KNN{
+	return &KNN{
-		dst:   dst,
+		dst:       dst,
-		area:  area,
+		area:      area,
-		bs:    &bs,
+		bs:        &bs,
-		knl:   k,
+		knl:       k,
-		hold:  make([][]byte, hf-1),
+		hold:      make([][]byte, hf-1),
-		hf:    hf,
+		hf:        hf,
-		scale: 1 / float64(scaleFactor),
+		scale:     1 / float64(scaleFactor),
+		debugging: newWindows("KNN"),
 	}
-	m.newWindows("KNN")
-	return m
 }
 
 // Implements io.Closer.
@@ -73,7 +72,7 @@ func NewKNN(dst io.WriteCloser, area, threshold float64, history, kernelSize int
 func (m *KNN) Close() error {
 	m.bs.Close()
 	m.knl.Close()
-	m.closeWindows()
+	m.debugging.close()
 	return nil
 }
 
@@ -124,7 +123,7 @@ func (m *KNN) Write(f []byte) (int, error) {
 	}
 
 	// Draw debug information.
-	m.showDebug(img, imgDelta, len(contours) > 0, contours)
+	m.debugging.show(img, imgDelta, len(contours) > 0, contours)
 
 	// Don't write to destination if there is no motion.
 	if len(contours) == 0 {

filter/mog.go

@@ -39,32 +39,31 @@ import (
 // MOG is a filter that provides basic motion detection. MoG is short for
 // Mixture of Gaussians method.
 type MOG struct {
-	debugWindows
+	debugging debugWindows
-	dst     io.WriteCloser                 // Destination to which motion containing frames go.
+	dst       io.WriteCloser                 // Destination to which motion containing frames go.
-	area    float64                        // The minimum area that a contour can be found in.
+	area      float64                        // The minimum area that a contour can be found in.
-	bs      *gocv.BackgroundSubtractorMOG2 // Uses the MOG algorithm to find the difference between the current and background frame.
+	bs        *gocv.BackgroundSubtractorMOG2 // Uses the MOG algorithm to find the difference between the current and background frame.
-	knl     gocv.Mat                       // Matrix that is used for calculations.
+	knl       gocv.Mat                       // Matrix that is used for calculations.
-	hold    [][]byte                       // Will hold all frames up to hf (so only every hf frame is motion detected).
+	hold      [][]byte                       // Will hold all frames up to hf (so only every hf frame is motion detected).
-	hf      int                            // The number of frames to be held.
+	hf        int                            // The number of frames to be held.
-	hfCount int                            // Counter for the hold array.
+	hfCount   int                            // Counter for the hold array.
-	scale   float64                        // The factor that frames will be downscaled by for motion detection.
+	scale     float64                        // The factor that frames will be downscaled by for motion detection.
 }
 
 // NewMOG returns a pointer to a new MOG filter struct.
 func NewMOG(dst io.WriteCloser, area, threshold float64, history int, hf int, scaleFactor int) *MOG {
 	bs := gocv.NewBackgroundSubtractorMOG2WithParams(history, threshold, false)
 	k := gocv.GetStructuringElement(gocv.MorphRect, image.Pt(3, 3))
-	m := &MOG{
+	return &MOG{
-		dst:   dst,
+		dst:       dst,
-		area:  area,
+		area:      area,
-		bs:    &bs,
+		bs:        &bs,
-		knl:   k,
+		knl:       k,
-		hold:  make([][]byte, hf-1),
+		hold:      make([][]byte, hf-1),
-		hf:    hf,
+		hf:        hf,
-		scale: 1 / float64(scaleFactor),
+		scale:     1 / float64(scaleFactor),
+		debugging: newWindows("MOG"),
 	}
-	m.newWindows("MOG")
-	return m
 }
 
 // Implements io.Closer.
@@ -73,7 +72,7 @@ func NewMOG(dst io.WriteCloser, area, threshold float64, history int, hf int, sc
 func (m *MOG) Close() error {
 	m.bs.Close()
 	m.knl.Close()
-	m.closeWindows()
+	m.debugging.close()
 	return nil
 }
 
@@ -124,7 +123,7 @@ func (m *MOG) Write(f []byte) (int, error) {
 	}
 
 	// Draw debug information.
-	m.showDebug(img, imgDelta, len(contours) > 0, contours)
+	m.debugging.show(img, imgDelta, len(contours) > 0, contours)
 
 	// Don't write to destination if there is no motion.
 	if len(contours) == 0 {

filter/release.go

@@ -2,7 +2,7 @@
 
 /*
 DESCRIPTION
-  Displays debug information for the motion filters.
+  Doesn't display debug information for the motion filters.
 
 AUTHORS
   Scott Barnard <scott@ausocean.org>
@@ -30,16 +30,16 @@ package filter
 type debugFile struct{}
 
 // newDebugFile creates a file for saving debugging frames to.
-func (d *debugFile) newDebugFile() error { return nil }
+func newDebugFile() debugFile { return debugFile{} }
 
-// closeDebugFile closes files used for debugging purposes.
+// close closes files used for debugging purposes.
-func (d *debugFile) closeDebugFile() error { return nil }
+func (d *debugFile) close() error { return nil }
 
-// drawToDebugFile draws debugging information to a frame.
+// draw draws debugging information to a frame.
-func (d *debugFile) drawToDebugFile(i, j int, val uint8) {}
+func (d *debugFile) draw(i, j int, val uint8) {}
 
 // saveFrame writes a frame showing motion to a file.
 func (d *debugFile) saveFrame(motion, pix int) error { return nil }
 
-// resetDebugFileFrame makes an image of given dimensions.
+// resetFrame makes an image of given dimensions.
-func (d *debugFile) resetDebugFileFrame(w, h int) {}
+func (d *debugFile) resetFrame(w, h int) {}

filter/release_nocircleci.go

@@ -3,7 +3,7 @@
 
 /*
 DESCRIPTION
-  Displays debug information for the motion filters.
+  Doesn't display debug information for the motion filters.
 
 AUTHORS
   Scott Barnard <scott@ausocean.org>
@@ -36,11 +36,11 @@ import (
 // debugWindows is used for displaying debug information for the motion filters.
 type debugWindows struct{}
 
-// closeWindows frees resources used by gocv.
+// close frees resources used by gocv.
-func (d *debugWindows) closeWindows() {}
+func (d *debugWindows) close() {}
 
 // newWindows creates debugging windows for the motion filter.
-func (d *debugWindows) newWindows(name string) {}
+func newWindows(name string) debugWindows { return debugWindows{} }
 
-// showDebug displays debug information for the motion filters.
+// show displays debug information for the motion filters.
-func (d *debugWindows) showDebug(img, imgDelta gocv.Mat, motion bool, contours ...[][]image.Point) {}
+func (d *debugWindows) show(img, imgDelta gocv.Mat, motion bool, contours ...[][]image.Point) {}