step2 - implement rotation

src/README.md

@@ -27,4 +27,12 @@ If the image file is not detected peroperly:
 ffmpeg -i IMG_8491.MOV -an -c copy IMG_8491.m4a
 ```
 
-CGO_LDFLAGS="-L/usr/local/Cellar/ffmpeg/3.3/lib" CGO_CFLAGS="-I/usr/local/Cellar/ffmpeg/3.3/include" gb build
+CGO_LDFLAGS="-L/usr/local/Cellar/ffmpeg/3.3/lib" CGO_CFLAGS="-I/usr/local/Cellar/ffmpeg/3.3/include" gb build
+
+
+# Image libraries
+
+> https://github.com/bamiaux/rez Image resizing in pure Go and SIMD
+http://www.imagemagick.org/Usage/distorts/
+https://godoc.org/github.com/rainycape/magick
+https://godoc.org/gopkg.in/gographics/imagick.v3/imagick#DistortImageMethod

src/cmd/open_speed_data/open_speed_data.go

@@ -12,6 +12,8 @@ import (
 	"strconv"
 	"strings"
 	"time"
+
+	"gopkg.in/gographics/imagick.v3/imagick"
 )
 
 type FrameAnalysis struct {
@@ -50,6 +52,8 @@ func OpenInBrowser(l net.Listener) error {
 }
 
 func main() {
+	imagick.Initialize()
+	defer imagick.Terminate()
 	log.SetFlags(log.Ldate | log.Ltime | log.Lmicroseconds | log.Llongfile)
 	fileName := flag.String("file", "", "")
 	httpAddress := flag.String("http-address", ":53001", "http address")

src/cmd/open_speed_data/points.go

@@ -62,6 +62,13 @@ func ParsePoint(s string) (p Point) {
 
 const SkipRotate = 0.00001
 
+func RadiansToDegrees(rad float64) (deg float64) {
+	deg = rad * 180.0 / math.Pi
+	return
+}
+
+const rightAngelRadians = 1.570796 // 90 degrees
+
 func Radians(a, b Point) float64 {
 	if a.Y == b.Y {
 		return SkipRotate
@@ -71,12 +78,12 @@ func Radians(a, b Point) float64 {
 	opposite := math.Max(a.Y, b.Y) - math.Min(a.Y, b.Y)
 	radians := math.Atan(adjacent / opposite)
 	log.Printf("adjacent: %v opposite %v radians %v", adjacent, opposite, radians)
-	if a.Y < b.Y {
-		adjusted := (-1 * radians) + 1.570796
+	if a.Y > b.Y {
+		adjusted := (-1 * radians) + rightAngelRadians
 		log.Printf("adjusting to %v because %v < %v", adjusted, a, b)
 		return adjusted
 	}
-	adjusted := radians - 1.570796
+	adjusted := radians - rightAngelRadians
 	log.Printf("adjusting to %v because %v > %v", adjusted, a, b)
 	return adjusted
 }

src/cmd/open_speed_data/project.go

@@ -4,8 +4,10 @@ package main
 // #cgo CGO_CFLAGS="-I/usr/local/Cellar/ffmpeg/3.3/include"
 
 import (
+	"bytes"
 	"fmt"
 	"html/template"
+	"image/png"
 	"io"
 	"log"
 	"time"
@@ -16,6 +18,7 @@ import (
 	"github.com/nareix/joy4/format"
 	"github.com/nfnt/resize"
 	// "github.com/nareix/joy4/format/mp4"
+	"gopkg.in/gographics/imagick.v3/imagick"
 )
 
 func init() {
@@ -27,7 +30,7 @@ type Project struct {
 	Filename string `json:"filename"`
 
 	// User Inputs
-	Rotate       float64        `json:"rotate,omitempty"`
+	Rotate       float64        `json:"rotate,omitempty"` // radians
 	BBox         *BBox          `json:"bbox,omitempty"`
 	Masks        []Mask         `json:"masks,omitempty"`
 	Tolerance    float64        `json:"tolerance"`
@@ -137,6 +140,20 @@ func (p *Project) Run() error {
 			if p.Step == 2 {
 				p.Response.Step2Img, err = dataImg(&vf.Image)
 			}
+			if p.Step == 3 {
+				// apply rotation
+				mw := imagick.NewMagickWand()
+				background := imagick.NewPixelWand()
+				background.SetColor("#000000")
+				out := new(bytes.Buffer)
+				png.Encode(out, &vf.Image)
+				mw.ReadImageBlob(out.Bytes())
+				mw.RotateImage(background, RadiansToDegrees(p.Rotate))
+				mw.SetImageFormat("PNG")
+				imgBytes := mw.GetImageBlob()
+				p.Response.Step3Img = dataImgFromBytes(imgBytes)
+			}
+
 		}
 		p.Duration = pkt.Time
 		p.Frames = int64(frame)

src/cmd/open_speed_data/templates.go

@@ -18,15 +18,18 @@ func dataImg(img image.Image) (template.URL, error) {
 	if err != nil {
 		return "", err
 	}
+	return dataImgFromBytes(out.Bytes()), nil
+}
 
+func dataImgFromBytes(b []byte) template.URL {
 	// This now takes a []byte of the buffer and base64 encodes it to a string
 	// Never needing to create the image file all done in memory
-	base64Img := base64.StdEncoding.EncodeToString(out.Bytes())
+	base64Img := base64.StdEncoding.EncodeToString(b)
 
 	//And now you can see the magic happen.
 	// Go ahead and run it then take the output and copy/paste it in your
 	// browser's URL bar, and you'll see your image.
-	return template.URL("data:image/png;base64," + base64Img), nil
+	return template.URL("data:image/png;base64," + base64Img)
 }
 
 func init() {

vendor.sh

@@ -1,3 +1,4 @@
 gb vendor fetch  github.com/nareix/joy4
 gb vendor fetch github.com/3d0c/gmf
-gb vendor fetch github.com/nfnt/resize
+gb vendor fetch github.com/nfnt/resize
+gb vendor fetch gopkg.in/gographics/imagick.v3