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package structs
import (
"log"
"github.com/fogleman/gg"
)
func initializePlot(imageWidth int, imageHeight int) *gg.Context {
// define an new context using the given image width and height
context := gg.NewContext(imageWidth, imageHeight)
// set the background color to black
context.SetRGB(0, 0, 0)
context.Clear()
context.SetRGB(1, 1, 1)
// translate the coordinate origin to the midpoint of the image
context.Translate(float64(imageWidth/2), float64(imageHeight/2))
return context
}
// drawQuadtree draws a given quadtree and the stars in it recursively to the given canvas
func drawQuadtree(context *gg.Context, q Quadtree) {
// find out if the node is a leaf find out if the node is a leaf find out if the node is a leaf find out if the node is a leaf
var draw bool = false
for i := 0; i < 4; i++ {
if q.Quadrants[i] == nil {
draw = true
}
}
// draw the bounding box and the star if the node is a leaf
if draw == true {
// Don't draw nonexistent stars
if q.Star != (Star2D{}) {
// define the current star
x := q.Star.C.X
y := q.Star.C.Y
starsize := 2
// set the color of the stars to green
context.SetRGB(0, 1, 1)
context.DrawPoint(x, y, float64(starsize))
context.Fill()
// context.DrawString(fmt.Sprintf("(%f, %f)", x, y), x, y)
context.Stroke()
log.Printf("[***] Drawing Star (%f, %f)", x, y)
}
// define the bounding box
boundingx := q.Boundary.Center.X
boundingy := q.Boundary.Center.Y
boundingw := q.Boundary.Width
// bottom left corner
contextx := boundingx - (boundingw / 2)
contexty := boundingy - (boundingw / 2)
// draw the rectangle
context.SetRGB(1, 1, 1)
context.DrawRectangle(contextx, contexty, boundingw, boundingw)
context.Stroke()
log.Printf("[***] Drawing Box ((%f, %f), %f)", contextx, contexty, boundingw)
}
// draw all the other trees recursively...
for i := 0; i < 4; i++ {
// ... but only if they exist
if q.Quadrants[i] != nil {
drawQuadtree(context, *q.Quadrants[i])
}
}
}
// saveImage saves the given context to the given path as a png
func saveImage(context *gg.Context, outpath string) {
savePngError := context.SavePNG(outpath)
if savePngError != nil {
panic(savePngError)
}
}
// Draw draws the given quadtree to the given output path
func (q Quadtree) Draw(outpath string) {
log.Printf("Drawing the quadtree to %s", outpath)
// define the image dimensions
imageWidth := 1024 * 8
imageHeight := 1024 * 8
// define a new context to draw on
context := initializePlot(imageWidth, imageHeight)
// first recursive call of drawQuadtree
drawQuadtree(context, q)
// save the context to the given output path
saveImage(context, outpath)
}
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