diff options
Diffstat (limited to 'draw/draw.go')
| -rw-r--r-- | draw/draw.go | 69 |
1 files changed, 35 insertions, 34 deletions
diff --git a/draw/draw.go b/draw/draw.go index 1823493..a5d5f0d 100644 --- a/draw/draw.go +++ b/draw/draw.go @@ -33,41 +33,32 @@ func saveImage(dc *gg.Context, path string) { dc.SavePNG(path) } -// drawStar2D draws the given stars to the given context -func drawStar2D(dc *gg.Context, star structs.Star2D) { - // the radius can be any value inbetween 1e4 and 1e5 - - // Define the default star radius as 1 and change it according to the stars mass - radius := 1 - switch { - case star.Mass < 10000: - radius = 1 - case star.Mass < 50000 && star.Mass > 10000: - radius = 2 - case star.Mass < 100000 && star.Mass > 50000: - radius = 3 +// drawStar draws the given stars to the given context +func drawStar(dc *gg.Context, star structs.Star2D) { + + // set radius of the star to 2 + R := 2.0 + + // if the star has a greater mass than the default 5E4, it's radius is increased to 5 + if star.M > 5E4 { + R = 5 } - // Draw the star - dc.DrawPoint(star.C.X/50, star.C.Y/50, float64(radius)) + // draw the star / point + dc.DrawPoint(star.C.X/50, star.C.Y/50, R) dc.Fill() dc.Stroke() } -// vectorLength calculates the length of the given vector -func vectorLength(force structs.Force) float64 { - return math.Sqrt(math.Pow(force.X, 2) + math.Pow(force.Y, 2)) -} - -func drawForce(dc *gg.Context, star structs.Star2D) { - // controll the length of the vector +func drawVelocity(dc *gg.Context, star structs.Star2D) { + // scaling factor for a better view of the velocity difference var scalingFactor float64 = 15 // Move the "cursor" to the start position of the vector dc.MoveTo(star.C.X/50, star.C.Y/50) // calculate the length of the vector - vecLength := vectorLength(star.F) + vecLength := star.V.GetLength() // Use a sigmoid function to generate useful values for coloring the vectors according to their // strength @@ -76,31 +67,31 @@ func drawForce(dc *gg.Context, star structs.Star2D) { // Set the color to a blue / red dc.SetRGB(val, 0, 1-val) - // trace the Vector - FxUnit := star.F.X / math.Abs(vecLength) - FyUnit := star.F.Y / math.Abs(vecLength) + // calculate the direction vector + FUnit := (&star.V).Divide(vecLength) - dc.LineTo(star.C.X/50+(FxUnit*scalingFactor), star.C.Y/50+(FyUnit*scalingFactor)) + // set end-position of the vector line + dc.LineTo(star.C.X/50+(FUnit.X*scalingFactor), star.C.Y/50+(FUnit.Y*scalingFactor)) - // css + // set line width dc.SetLineWidth(3) // And finally: DRAW (stroke) the vector dc.Stroke() } -// drawStar2Ds draws all the stars in the given slice to the given context -func drawStars2D(dc *gg.Context, slice []structs.Star2D) { - // draw all the forces in the given slice +// drawStars draws all the stars in the given slice to the given context +func drawStars(dc *gg.Context, slice []structs.Star2D) { + // draw all the velocity in the given slice for _, star := range slice { - drawForce(dc, star) + drawVelocity(dc, star) } dc.SetRGB(1, 1, 1) // draw all the stars in the given slice for _, star := range slice { - drawStar2D(dc, star) + drawStar(dc, star) } } @@ -111,7 +102,17 @@ func Slice(slice []structs.Star2D, path string) { dc := initializePlot() // draw all the stars in the given slice - drawStars2D(dc, slice) + drawStars(dc, slice) + + dc.SetRGB(1, 1, 1) + + // drawing the 4 big stars as bigger white dots + //dc.DrawCircle(600, 600, 5) + //dc.DrawCircle(-600, 600, 5) + //dc.DrawCircle(-600, 0, 5) + //dc.DrawCircle(600, -600, 5) + + dc.Fill() // save the plot to the given path saveImage(dc, path) |
