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@Adron

Adron/main.go

Created Mar 10, 2019
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Rendering an SVG and more maths!
package main
import (
"fmt"
"io/ioutil"
"math"
"strconv"
)
const (
width, height = 600, 600
cells = 100
xyrange = 30.0
xyscale = width / 2 / xyrange
zscale = height * 0.4
angle = math.Pi / 6
)
var sin30, cos30 = math.Sin(angle), math.Cos(angle)
func main() {
var outputResult string
outputResult = "<svg xmlns='http://www.w3.org/2000/svg' " +
"style='stroke: blue; fill: white; stroke-width: 0.7' " +
"width='" + strconv.Itoa(width) + "' height='" + strconv.Itoa(height) + "'>"
for i := 0; i < cells; i++ {
for j := 0; j < cells; j++ {
ax, ay := corner(i+1, j)
bx, by := corner(i, j)
cx, cy := corner(i, j+1)
dx, dy := corner(i+1, j+1)
outputResult = outputResult + "<polygon points='" +
ax + "," + ay +
bx + "," + by +
cx + "," + cy +
dx + "," + dy +
"'/>\n"
}
}
outputResult = outputResult + "</svg>"
fmt.Printf(outputResult)
err := ioutil.WriteFile("surface-plot.svg", []byte(outputResult), 0644)
if err != nil {
fmt.Printf("Error: %s", err)
}
}
func corner(i, j int) (string, string) {
x := xyrange * (float64(i)/cells - 0.5)
y := xyrange * (float64(j)/cells - 0.5)
z := f(x, y)
sx := width/2 + (x-y)*cos30*xyscale
sy := height/2 + (x+y)*sin30*xyscale - z*zscale
xResult := strconv.FormatFloat(sx, 'f', -1, 64)
yResult := strconv.FormatFloat(sy, 'f', -1, 64)
return xResult, yResult
}
func f(x, y float64) float64 {
r := math.Hypot(x, y)
return math.Sin(r)
}
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