refactor: plotter bitmap

pkg/bitmap/bitmap.go

@@ -1,8 +1,10 @@
 package bitmap
 
 import (
+	"errors"
 	"fmt"
 	"math"
+	"math/bits"
 )
 
 const intSize = 32
@@ -35,14 +37,61 @@ func (p bitmap) isSet(number uint32) bool {
 	return p.bitVector[number/intSize]&(0b1<<(number%intSize)) > 0
 }
 
-func (p bitmap) Circle(x, y int, r float64) {
+func (p bitmap) FreeCount() (result int) {
+	result = int(p.width) * int(p.height)
+	for i := range p.bitVector {
+		result -= bits.OnesCount32(p.bitVector[i])
+	}
+	return
+}
+
+func (p bitmap) GetFreeN(number int) (int, int, error) {
+	if p.FreeCount() == 0 {
+		return 0, 0, errors.New("no free pixels left")
+	}
+	fc := 0
+	n := 0
+	for ; n < int(p.width)*int(p.height); n++ {
+		if p.isSet(uint32(n)) {
+			continue
+		}
+		if fc == number {
+			y := n / int(p.height)
+			x := n - int(p.height)*y
+			return x, y, nil
+		}
+		fc++
+	}
+	return 0, 0, fmt.Errorf("get free pixel: no such number=%d, max=%d", number, n)
+}
+
+func (p bitmap) SetFreeN(number int) error {
+	if p.FreeCount() == 0 {
+		return errors.New("no free pixels left")
+	}
+	fc := 0
+	n := 0
+	for ; n < int(p.width)*int(p.height); n++ {
+		if p.isSet(uint32(n)) {
+			continue
+		}
+		if fc == number {
+			p.set(uint32(n))
+			return nil
+		}
+		fc++
+	}
+	return fmt.Errorf("set free pixel: no such number=%d, max=%d", number, n)
+}
+
+func (p bitmap) Circle(x, y int, r float64, fill bool) {
 	plotX := 0
 	plotY := int(math.Ceil(r))
 	delta := 3 - 2*plotY
 	lastY := plotY
 	for plotX <= plotY {
 		p.octant(x, y, plotX, plotY)
-		if plotY < lastY {
+		if fill && plotY < lastY {
 			for lineX := 0; lineX < plotX; lineX++ {
 				p.octant(x, y, lineX, plotY)
 			}
@@ -56,6 +105,9 @@ func (p bitmap) Circle(x, y int, r float64) {
 		}
 		plotX += 1
 	}
+	if !fill {
+		return
+	}
 	for fillX := 0; fillX < plotX; fillX++ {
 		for fillY := 0; fillY <= fillX; fillY++ {
 			p.octant(x, y, fillX, fillY)
@@ -63,7 +115,7 @@ func (p bitmap) Circle(x, y int, r float64) {
 	}
 }
 
-func (p bitmap) CircleAdjacent(x, y int, r float64) {
+func (p bitmap) circleAdjacent(x, y int, r float64) {
 	plotX := 0
 	plotY := int(math.Ceil(r))
 	delta := 1 - 2*plotY
@@ -110,7 +162,7 @@ func (p bitmap) String() string {
 	cnt := 0
 	for i := 0; i < len(p.bitVector); i++ {
 		for bit := 0; bit < intSize && cnt < int(p.width*p.height); bit++ {
-			result += fmt.Sprintf("%s", px[p.bitVector[i]&(0b1<<bit) > 0])
+			result += px[p.bitVector[i]&(0b1<<bit) > 0]
 			cnt++
 			if cnt%int(p.width) == 0 {
 				result += "\n"