for detailed information about the changes, see https://git.darknebu.la/GalaxySimulator/Source/pulls/1

1 files changed, 54 insertions, 63 deletions

diff --git a/forces/forces.go b/forces/forces.go
index 7763f87..a994334 100644
--- a/forces/forces.go
+++ b/forces/forces.go
@@ -1,87 +1,81 @@
 package forces
 
 import (
-	"../llog"
 	"../structs"
 	"fmt"
+	"git.darknebu.la/bit/logplus"
 	"gopkg.in/cheggaaa/pb.v1"
 	"math"
 )
 
 // forces_acting calculates the force inbetween the two given stars s1 and s2
 // The function return the force
-func forceActing(s1 structs.Star2D, s2 structs.Star2D) structs.Force {
+func accelerationActing(s1 structs.Star2D, s2 structs.Star2D) structs.Vec2 {
+
 	// Gravitational constant
-	var G float64 = 6.674e-11
+	var G = 6.674E-11
 
-	// Distance between the stars
-	var r21 = math.Sqrt(math.Pow(s2.C.X-s1.C.X, 2) + math.Pow(s2.C.Y-s1.C.Y, 2))
+	// the vector from star s1 to star s2
+	var r12 = s2.C.Subtract(s1.C)
 
-	// Unit vector pointing from s1 to s2
-	rhat := structs.Force{s2.C.X - s1.C.X, s2.C.Y - s1.C.Y}
+	// the distance between the stars
+	var deltaR = r12.GetLength()
 
-	// Calculate how strong the star is affected
-	var FScalar = G * (s1.Mass * s2.Mass) / math.Pow(math.Abs(r21), 2)
+	// the scalar acceleration of star s1 by star s2
+	scalarA := G * (s2.M) / math.Pow(deltaR, 2)
 
-	// Calculate the overall force by combining the scalar and the vector
-	var Fx = FScalar * rhat.X
-	var Fy = FScalar * rhat.Y
+	// calculate the direction vector of the vector from s1 to s2
+	directionVectorA := r12.GetDirVector()
 
-	// Pack the forces in a force structur
-	F := structs.Force{Fx, Fy}
+	// the vector acceleration of scalarA
+	A := directionVectorA.Multiply(scalarA)
 
-	return F
+	return A
 }
 
-// forces calculates the forces acting in between a given star and all the other stars in a given array.
-func forces(stars_arr []structs.Star2D, nr int) structs.Force {
+// accelerations calculates the acceleration acting in between a given star and all the other stars in a given array.
+func accelerations(stars_arr []structs.Star2D, nr int) structs.Vec2 {
 
-	var force structs.Force
+	var a = /*acceleration*/ structs.Vec2{}
 	// Iterate over all the stars in the stars_arr
 	for index := range stars_arr {
 
 		// If the current star is not the star itself
 		if index != nr {
 
-			// generate a new force and add it to the overall force of the star
-			fa := forceActing(stars_arr[nr], stars_arr[index])
-			stars_arr[nr].F.X += fa.X
-			stars_arr[nr].F.Y += fa.Y
+			// calculate the acceleration and add it to the overall acceleration of the star
+			aa := accelerationActing(stars_arr[nr], stars_arr[index])
+			a = a.Add(aa)
 
-			force.X += fa.X
-			force.Y += fa.Y
 		}
 	}
 
-	return force
+	return a
 }
 
-// forcesThread calculates the forces acting on a given amount of stars in a given range for a given slice of stars
+// accelerationThread calculates the acceleration acting on a given amount of stars in a given range for a given slice of stars
 // as a go-routine
-func forcesThread(starSlice []structs.Star2D, localRangeStar2Dt int, localRangeEnd int, channel chan structs.Star2D) {
+func accelerationThread(starSlice []structs.Star2D, localRangeStart int, localRangeEnd int, channel chan structs.Star2D) {
 
 	// iterate over the given range
-	for index := localRangeStar2Dt; index < localRangeEnd; index++ {
+	for index := localRangeStart; index < localRangeEnd; index++ {
 
-		// Calculate the force acting inbetween the given star and all other stars
-		var force = forces(starSlice, index)
+		// Calculate the acceleration acting inbetween the given star and all other stars
+		var a = accelerations(starSlice, index)
 
 		// create a new star
-		newStar2D := structs.Star2D{
-			structs.Coord{starSlice[index].C.X, starSlice[index].C.Y},
-			structs.Force{force.X, force.Y},
-			starSlice[index].Mass,
-		}
+		newStar := starSlice[index].Copy()
+		newStar.AccelerateVelocity(a, 1)
 
-		// push the new Star2D into the channel
-		channel <- newStar2D
+		// push the new Star into the channel
+		channel <- newStar
 	}
 }
 
-// CalcAllForces calculates all the forces acting inbetween all the stars in the given starSlice slice and
-// returns a "new" slice contaning the forces
-func CalcAllForces(starSlice []structs.Star2D, threads int) []structs.Star2D {
-	// create a channel for bundling the stars generaten in the go-routines
+// CalcAllAccelerations calculates all the accelerations acting in between all the stars in the given starSlice slice and
+// returns a "new" slice containing the stars with their new velocities
+func CalcAllAccelerations(starSlice []structs.Star2D, threads int) []structs.Star2D {
+	// create a channel for bundling the stars generated in the go-routines
 	channel := make(chan structs.Star2D, 1000)
 
 	sliceLength := len(starSlice)
@@ -93,43 +87,47 @@ func CalcAllForces(starSlice []structs.Star2D, threads int) []structs.Star2D {
 	// generate a new slice for storing the stars
 	var newSlice []structs.Star2D
 
-	llog.Good(fmt.Sprintf("Starting %d workers, each processing %d stars", threads, localRangeLen))
+	logplus.LogNeutral(fmt.Sprintf("Starting %d workers, each processing %d stars", threads, localRangeLen))
 
 	// start n go threads
 	for i := 0; i < threads; i++ {
 
 		// define the local range
-		localRangeStar2Dt := i * localRangeLen
+		localRangeStart := i * localRangeLen
 		localRangeEnd := (i * localRangeLen) + localRangeLen
 
-		// calculate the forces for all the stars in the given slice in the given range and return them using the
+		// fmt.Printf("starting worker nr. %d, processing %d stars\n", i, localRangeEnd-localRangeStart)
+
+		// calculate the accelerations for all the stars in the given slice in the given range and return them using the
 		// given channel
-		go forcesThread(starSlice, localRangeStar2Dt, localRangeEnd, channel)
+		go accelerationThread(starSlice, localRangeStart, localRangeEnd, channel)
 	}
 
 	// Handle errors (10004 stars, but 1250 stars per thread, so 4 stars are not calculate and block the queue)
 	if sliceLength > localRangeLen {
 
 		// Calculate the amount of stars and their range
-		remainingStar2Ds := sliceLength - (localRangeLen * threads)
+		remainingStars := sliceLength - (localRangeLen * threads)
 		localRangeEnd := ((threads - 1) * localRangeLen) + localRangeLen
 
 		// Run the Thread
-		// go forcesThread(starSlice, localRangeEnd, localRangeEnd+remainingStar2Ds, channel)
-		forcesThread(starSlice, localRangeEnd, localRangeEnd+remainingStar2Ds, channel)
+		// go accelerationThread(starSlice, localRangeEnd, localRangeEnd+remainingStars, channel)
+		accelerationThread(starSlice, localRangeEnd, localRangeEnd+remainingStars, channel)
 	}
 
 	// Initialize a new progress bar
-	bar := pb.New(len(starSlice)).Prefix("Star2Ds: ")
+	bar := pb.New(len(starSlice)).Prefix("Stars: ")
+
+	bar.Start()
 
 	// iterate over the amount of stars
 	for i := 0; i < sliceLength; i++ {
 
 		// block until a star is finisehd
-		var newStar2D structs.Star2D = <-channel
+		var newStar = <-channel
 
 		// append the star from the channel to the newSlice for returning in the end
-		newSlice = append(newSlice, newStar2D)
+		newSlice = append(newSlice, newStar)
 
 		// increment the progress bar and the counter
 		bar.Increment()
@@ -141,26 +139,19 @@ func CalcAllForces(starSlice []structs.Star2D, threads int) []structs.Star2D {
 }
 
 // Calculate the new positions of the stars using the
-func NextTimestep(starSlice []structs.Star2D, deltat int) []structs.Star2D {
+func NextTimestep(starSlice []structs.Star2D, deltat float64) []structs.Star2D {
 	// create a new slice for storing the "new" stars
 	var newSlice []structs.Star2D
 
 	// iterate over all the stars in the old slice
 	for index := range starSlice {
 
-		// calculate the new position
-		newX := starSlice[index].C.X + starSlice[index].F.X*float64(deltat)
-		newY := starSlice[index].C.Y + starSlice[index].F.Y*float64(deltat)
-
-		// assemble the new star
-		newStar2D := structs.Star2D{
-			C:    structs.Coord{X: newX, Y: newY},
-			F:    structs.Force{},
-			Mass: starSlice[index].Mass,
-		}
+		// move the star with it's velocity for time deltat
+		newStar := starSlice[index].Copy()
+		newStar.Move(deltat)
 
 		// append the new star to the newSlice
-		newSlice = append(newSlice, newStar2D)
+		newSlice = append(newSlice, newStar)
 	}
 
 	return newSlice