feat: add Number Connect game with ABC spatial optimization and auto-pagination

pkg/learnnumber/logic/writing.go

@@ -0,0 +1,179 @@
+package logic
+
+import (
+	"bytes"
+	"math"
+	"math/rand"
+	"strconv"
+	"toolbox/pkg/learnnumber/data"
+
+	"github.com/signintech/gopdf"
+)
+
+type WritingRequest struct {
+	StartNum  int    `json:"start_num"`
+	EndNum    int    `json:"end_num"`
+	PaperSize string `json:"paper_size"`
+}
+
+type WritingNode struct {
+	X, Y, R float64
+	AngleA, AngleB float64
+	BulgeR, Dist   float64
+	Number         int
+}
+
+func GenerateWritingPDF(req WritingRequest) ([]byte, error) {
+	pdf := &gopdf.GoPdf{}
+	rect := gopdf.Rect{W: 595.28, H: 841.89}
+	if req.PaperSize == "Letter" { rect = gopdf.Rect{W: 612, H: 792} }
+	pdf.Start(gopdf.Config{PageSize: rect})
+
+	err := pdf.AddTTFFontData("basic", data.FontContent)
+	if err != nil { return nil, err }
+
+	currentNum := req.StartNum
+	// 只要还没达到 EndNum，就继续生成“整页”内容
+	for currentNum <= req.EndNum {
+		pdf.AddPage()
+		lastPlaced := drawOneFullPage(pdf, currentNum, rect.W, rect.H)
+		currentNum = lastPlaced + 1
+	}
+
+	var buf bytes.Buffer
+	_, err = pdf.WriteTo(&buf)
+	return buf.Bytes(), err
+}
+
+// 核心改变：不再受限于 end 参数，而是尝试填满整页
+func drawOneFullPage(pdf *gopdf.GoPdf, start int, pW, pH float64) int {
+	margin := 80.0
+	boxW, boxH := pW-2*margin, pH-160.0
+	xBase, yBase := margin, 100.0
+
+	nodeR := 28.0
+	bulgeR := nodeR * 0.32
+	dist := nodeR + bulgeR + 18.0
+	checkR := nodeR * 1.3 
+
+	var nodes []WritingNode
+	num := start
+
+	// 无限循环，直到页面塞不下为止
+	for {
+		placed := false
+		for retry := 0; retry < 1000; retry++ {
+			rx := xBase + dist + 20 + rand.Float64()*(boxW - 2*dist - 40)
+			ry := yBase + dist + 20 + rand.Float64()*(boxH - 2*dist - 40)
+			
+			if isColliding(rx, ry, checkR, nodes) { continue }
+			
+			angleA := rand.Float64() * 2 * math.Pi
+			angleB := angleA + math.Pi + (rand.Float64()-0.5)*1.5
+			nodes = append(nodes, WritingNode{X: rx, Y: ry, R: nodeR, AngleA: angleA, AngleB: angleB, BulgeR: bulgeR, Dist: dist, Number: num})
+			placed = true
+			break
+		}
+
+		if !placed {
+			// 页面已满
+			break
+		}
+		num++
+	}
+
+	// 空间优化
+	optimizeSpace(nodes, xBase, yBase, boxW, boxH, dist, checkR)
+
+	// 绘制
+	for _, n := range nodes {
+		drawFullNode(pdf, n)
+	}
+
+	// 返回本页最后一个数字
+	if len(nodes) > 0 {
+		return nodes[len(nodes)-1].Number
+	}
+	return start
+}
+
+func optimizeSpace(nodes []WritingNode, xBase, yBase, boxW, boxH, dist, checkR float64) {
+	if len(nodes) < 2 { return }
+	for iter := 0; iter < 120; iter++ {
+		for i := range nodes {
+			bestX, bestY := nodes[i].X, nodes[i].Y
+			maxMinDist := calcMinDist(bestX, bestY, i, nodes)
+			for k := 0; k < 8; k++ {
+				moveAngle := rand.Float64() * 2 * math.Pi
+				nx := nodes[i].X + math.Cos(moveAngle)*5.0
+				ny := nodes[i].Y + math.Sin(moveAngle)*5.0
+				if nx-dist < xBase || nx+dist > xBase+boxW || ny-dist < yBase || ny+dist > yBase+boxH { continue }
+				if isColliding(nx, ny, checkR, nodes[:i]) || isColliding(nx, ny, checkR, nodes[i+1:]) { continue }
+				newMinDist := calcMinDist(nx, ny, i, nodes)
+				if newMinDist > maxMinDist {
+					maxMinDist = newMinDist; bestX, bestY = nx, ny
+				}
+			}
+			nodes[i].X, nodes[i].Y = bestX, bestY
+		}
+	}
+}
+
+func isColliding(x, y, r float64, existing []WritingNode) bool {
+	for _, e := range existing {
+		d := math.Sqrt(math.Pow(x-e.X, 2) + math.Pow(y-e.Y, 2))
+		if d < (r + e.R*1.3 + 30.0) { return true } 
+	}
+	return false
+}
+
+func calcMinDist(x, y float64, idx int, nodes []WritingNode) float64 {
+	minD := 10000.0
+	for i, n := range nodes {
+		if i == idx { continue }
+		d := math.Sqrt(math.Pow(x-n.X, 2) + math.Pow(y-n.Y, 2))
+		if d < minD { minD = d }
+	}
+	return minD
+}
+
+func getEdgePoint(x, y, r, angle float64, isCircle bool) (float64, float64) {
+	gap := 2.0 
+	er := r + gap
+	if isCircle { return x + math.Cos(angle)*er, y + math.Sin(angle)*er }
+	absCos, absSin := math.Abs(math.Cos(angle)), math.Abs(math.Sin(angle))
+	var d float64
+	if absCos > absSin { d = er / absCos } else { d = er / absSin }
+	return x + math.Cos(angle)*d, y + math.Sin(angle)*d
+}
+
+func drawCenteredText(pdf *gopdf.GoPdf, cx, cy float64, text string, fontSize float64) {
+	pdf.SetFont("basic", "", fontSize)
+	tw, _ := pdf.MeasureTextWidth(text)
+	pdf.SetXY(cx - tw/2, cy + fontSize*0.38)
+	pdf.Text(text)
+}
+
+func drawFullNode(pdf *gopdf.GoPdf, n WritingNode) {
+	isOdd := n.Number%2 != 0
+	pdf.SetStrokeColor(0, 0, 0); pdf.SetLineWidth(1.8)
+	if isOdd { pdf.Oval(n.X-n.R, n.Y-n.R, n.X+n.R, n.Y+n.R) } else { pdf.RectFromUpperLeft(n.X-n.R, n.Y-n.R, n.R*2, n.R*2) }
+	pdf.SetTextColor(220, 220, 220)
+	drawCenteredText(pdf, n.X, n.Y, strconv.Itoa(n.Number), n.R*1.35)
+
+	pdf.SetStrokeColor(180, 180, 180); pdf.SetLineWidth(1.0)
+	ax, ay := n.X + math.Cos(n.AngleA)*n.Dist, n.Y + math.Sin(n.AngleA)*n.Dist
+	lx1, ly1 := getEdgePoint(n.X, n.Y, n.R, n.AngleA, isOdd)
+	lx2, ly2 := getEdgePoint(ax, ay, n.BulgeR, n.AngleA+math.Pi, !isOdd)
+	pdf.Line(lx1, ly1, lx2, ly2)
+	if isOdd { pdf.RectFromUpperLeft(ax-n.BulgeR, ay-n.BulgeR, n.BulgeR*2, n.BulgeR*2) } else { pdf.Oval(ax-n.BulgeR, ay-n.BulgeR, ax+n.BulgeR, ay+n.BulgeR) }
+
+	bx, by := n.X + math.Cos(n.AngleB)*n.Dist, n.Y + math.Sin(n.AngleB)*n.Dist
+	lx3, ly3 := getEdgePoint(n.X, n.Y, n.R, n.AngleB, isOdd)
+	lx4, ly4 := getEdgePoint(bx, by, n.BulgeR, n.AngleB+math.Pi, !isOdd)
+	pdf.Line(lx3, ly3, lx4, ly4)
+	if isOdd { pdf.RectFromUpperLeft(bx-n.BulgeR, by-n.BulgeR, n.BulgeR*2, n.BulgeR*2) } else { pdf.Oval(bx-n.BulgeR, by-n.BulgeR, bx+n.BulgeR, by+n.BulgeR) }
+	
+	pdf.SetTextColor(120, 120, 120)
+	drawCenteredText(pdf, bx, by, strconv.Itoa(n.Number+1), math.Max(7, n.BulgeR*1.2))
+}