cmd/skill/surface.go - master - ah.samir/basic-go

cmd/skill/surface.go
83 строки2 KB
Samir
нерфы
27 июн 2026, 15:18
27 июн 2026, 15:180918d2c
package main

import (
	"fmt"
	"io"
	"math"
	"net/http"
	"strconv"
)

var (
	width, height float64 = 600, 320
	//cells         = 100
	xyrange float64 = 30.0
	xyscale float64 = width / 2 / xyrange
	zscale  float64 = height * 0.4
	angle   float64 = math.Pi / 6
)

var sin30, cos30 = math.Sin(angle), math.Cos(angle)

func surfaceHandler(w http.ResponseWriter, r *http.Request) {
	r.ParseForm()
	cellsStr := r.Form.Get("cells")
	cells, cellsErr := strconv.Atoi(cellsStr)
	if cellsErr != nil {
		cells = 100
	}
	widthStr := r.Form.Get("width")
	var widthErr error
	width, widthErr = strconv.ParseFloat(widthStr, 10)
	if widthErr != nil {
		width = 600
	}
	heightStr := r.Form.Get("height")
	var heightErr error
	height, heightErr = strconv.ParseFloat(heightStr, 10)
	if heightErr != nil {
		height = 320
	}
	xyrange = 30.0
	xyscale = width / 2 / xyrange
	zscale = height * 0.4
	angle = math.Pi / 6
	w.Header().Set("Content-Type", "image/svg+xml")
	surface(w, cells)

}

func surface(w io.Writer, cells int) {
	fmt.Fprintf(w, "<svg xmlns='http://www.w3.org/2000/svg' "+
		"style='stroke: grey; fill: white; stroke-width: 0.7' "+
		"width='%d' height='%d'>", width, height)
	for i := 0; i < cells; i++ {
		for j := 0; j < cells; j++ {
			ax, ay := corner(i+1, j, cells)
			bx, by := corner(i, j, cells)
			cx, cy := corner(i, j+1, cells)
			dx, dy := corner(i+1, j+1, cells)
			fmt.Fprintf(w, "<polygon points='%g,%g %g,%g %g,%g %g,%g'/>\n",
				ax, ay, bx, by, cx, cy, dx, dy)
		}
	}
	fmt.Fprintf(w, "</svg>")

}

func corner(i, j, cells int) (float64, float64) {

	x := xyrange * (float64(i)/float64(cells) - 0.5)
	y := xyrange * (float64(j)/float64(cells) - 0.5)

	z := f(x, y)

	sx := width/2 + (x-y)*cos30*xyscale
	sy := height/2 + (x+y)*sin30*xyscale - z*zscale
	return sx, sy
}

func f(x, y float64) float64 {
	r := math.Hypot(x, y)
	return math.Sin(r) / r
}