[BUGFIX] splitting in parts

main.go

@@ -51,10 +51,15 @@ func main() {
 
 	// transform
 
-	pixelmatrix = getPart(pixelmatrix, partCount, partTotal, partBegin)
+	pixelmatrix, sx, sy := getPart(pixelmatrix, partCount, partTotal, partBegin)
+	startx += sx
+	starty += sy
 
 	for s := 0; s < socketCount; s++ {
-		conn := createSocket(getPart(pixelmatrix, 1, socketCount, s))
+		pm, sx, sy := getPart(pixelmatrix, 1, socketCount, s)
+		sx += startx
+		sy += starty
+		conn := createSocket(pm, sx, sy)
 		defer conn.Close()
 	}
 
@@ -66,7 +71,7 @@ func main() {
 
 }
 
-func createSocket(pixelmatrix [][][4]uint32) net.Conn {
+func createSocket(pixelmatrix [][][4]uint32, xstart, ystart int) net.Conn {
 	// connection(s)
 	conn, err := net.Dial("tcp", targetAddr)
 	if err != nil {
@@ -76,7 +81,7 @@ func createSocket(pixelmatrix [][][4]uint32) net.Conn {
 
 	// start painting
 	for s := 0; s < goProc; s++ {
-		go paint(conn, pixelmatrix, startx, starty)
+		go paint(conn, pixelmatrix, xstart, ystart)
 	}
 	return conn
 }

part.go

@@ -4,17 +4,18 @@ import (
 	log "github.com/sirupsen/logrus"
 )
 
-func getPart(pixelmatrix [][][4]uint32, partCount, partTotal, partBegin int) [][][4]uint32 {
+func getPart(pixelmatrix [][][4]uint32, partCount, partTotal, partBegin int) ([][][4]uint32, int, int) {
 	xLength := len(pixelmatrix)
 	if xLength < partTotal {
 		log.Fatal("more parts then rows not possible")
-		return nil
+		return nil, 0, 0
 	}
-	partSize := (xLength / partTotal)
+	partStep := (xLength / partTotal)
+	start := partBegin * partStep
 
 	// last part should return last rows
 	if partBegin + partCount == partTotal {
-		return pixelmatrix[ partBegin * partSize : ]
+		return pixelmatrix[start: ], start, 0
 	}
-	return pixelmatrix[ partBegin * partSize : (partBegin + partCount) * partSize]
+	return pixelmatrix[ start : (partBegin + partCount) * partStep], start, 0
 }