Include lava

- volcanic areas now include regions of lava (well, they did anyways,
but it's now extended)
- add alpha tool to facilitate transparentifying things

cmd/alpha/main.go

@@ -0,0 +1,101 @@
+package main
+
+import (
+	"bytes"
+	"fmt"
+	"image"
+	"image/color"
+	_ "image/gif"
+	_ "image/jpeg"
+	"image/png"
+	"io/ioutil"
+	"os"
+
+	"github.com/alecthomas/kong"
+)
+
+const desc = `Alpha tool takes some input image & a region (x0,y0)->(x1,y1).
+
+All colours in the given region are made fully transparent across the image.
+`
+
+var cli struct {
+	//
+	Input string `arg short:"i" type:"existingfile" help:"input image"`
+
+	AlphaX0 int `arg long:"alpha-x0" help:"x0 of region designating colours to alpha"`
+	AlphaY0 int `arg long:"alpha-y0" help:"y0 of region designating colours to alpha"`
+	AlphaX1 int `arg long:"alpha-x1" help:"x1 of region designating colours to alpha"`
+	AlphaY1 int `arg long:"alpha-y1" help:"y1 of region designating colours to alpha"`
+
+	//
+	Output string `short:"o" default:"out.png" help:"output name"`
+}
+
+func main() {
+	kong.Parse(
+		&cli,
+		kong.Name("alpha"),
+		kong.Description(desc),
+	)
+	fmt.Println("args", cli)
+
+	f, err := os.Open(cli.Input)
+	if err != nil {
+		panic(err)
+	}
+
+	im, _, err := image.Decode(f)
+	if err != nil {
+		panic(err)
+	}
+
+	toalpha := coloursInRegion(im, cli.AlphaX0, cli.AlphaY0, cli.AlphaX1, cli.AlphaY1)
+	fmt.Printf("colors to remove: %d\n", len(toalpha))
+	if len(toalpha) < 1 {
+		panic(fmt.Errorf("region must contain at least one colour"))
+	}
+
+	bnds := im.Bounds()
+	out := image.NewRGBA(bnds)
+
+	for dy := bnds.Min.Y; dy < bnds.Max.Y; dy++ {
+		for dx := bnds.Min.X; dx < bnds.Max.X; dx++ {
+			c := im.At(dx, dy)
+			_, ok := toalpha[c]
+			if ok {
+				out.Set(dx, dy, color.RGBA{255, 255, 255, 0})
+			} else {
+				out.Set(dx, dy, c)
+			}
+		}
+	}
+
+	err = savePng(cli.Output, out)
+	if err != nil {
+		panic(err)
+	}
+}
+
+// coloursInRegion returns a map of colours found in the given region
+func coloursInRegion(im image.Image, x0, y0, x1, y1 int) map[color.Color]bool {
+	cs := map[color.Color]bool{}
+
+	for dy := y0; dy <= y1; dy++ {
+		for dx := x0; dx <= x1; dx++ {
+			cs[im.At(dx, dy)] = true
+		}
+	}
+
+	return cs
+}
+
+// savePng to disk
+func savePng(fpath string, in image.Image) error {
+	buff := new(bytes.Buffer)
+	err := png.Encode(buff, in)
+	if err != nil {
+		return err
+	}
+	return ioutil.WriteFile(fpath, buff.Bytes(), 0644)
+}

pkg/landscape/area.go

@@ -8,12 +8,14 @@ type Area struct {
 	Temperature uint8 // in degress c, offset so 100 => 0 degrees cel
 	Volcanism   uint8
 
-	// if the square contains fresh/salt water
-	Sea       bool
-	River     bool
-	Lake      bool // lake implies river
-	Swamp     bool // swamp water
-	Swampland bool // water ridden land
+	// if the square contains fresh/salt water/lava
+	Sea   bool
+	River bool
+	Lake  bool // lake implies river
+	Swamp bool // swamp water
+	Lava  bool
+
+	BiomeSwamp bool
 
 	// if river, we set a river ID else 0
 	RiverID int

pkg/landscape/config.go

@@ -27,6 +27,9 @@ type volcSettings struct {
 
 	// min dist volcanoes must have from each other
 	OriginMinDist float64
+
+	// at or over this value we consider volanic land lava
+	LavaOver uint8
 }
 
 type swampSettings struct {
@@ -115,6 +118,7 @@ func DefaultConfig() *Config {
 			Radius:        30,
 			Variance:      0.7,
 			OriginMinDist: 10,
+			LavaOver:      180,
 		},
 		Swamp: &swampSettings{
 			Number:      8,

pkg/landscape/geography.go

@@ -109,14 +109,20 @@ func determineGeothermal(hmap *MapImage, vs *volcSettings) (*MapImage, []*POI) {
 
 	for _, volcano := range origins {
 		pois = append(pois, &POI{X: volcano.X(), Y: volcano.Y(), Type: Volcano})
-		vmap.SetValue(volcano.X(), volcano.Y(), 255)
+
+		lavamap := &MapImage{im: perlin.Perlin(x, y, vs.Variance*1.5)}
 
 		// describe square around origin
 		for dy := volcano.Y() - int(vs.Radius)/2; dy < volcano.Y()+int(vs.Radius)/2; dy++ {
 			for dx := volcano.X() - int(vs.Radius)/2; dx < volcano.X()+int(vs.Radius)/2; dx++ {
 				current := vmap.Value(dx, dy)
 
 				pv := pmap.Value(dx, dy)
+				if lavamap.Value(dx, dy) > vs.LavaOver {
+					pv = 255
+					hmap.SetValue(dx, dy, decrement(hmap.Value(dx, dy), 5))
+				}
+
 				dist := math.Sqrt(
 					math.Pow(float64(volcano.X())-float64(dx), 2) + math.Pow(float64(volcano.Y())-float64(dy), 2),
 				)
@@ -126,9 +132,9 @@ func determineGeothermal(hmap *MapImage, vs *volcSettings) (*MapImage, []*POI) {
 					continue
 				} else if dist > vs.Radius/2 {
 					pv /= 6
-				} else if dist > vs.Radius/3 {
+				} else if dist > vs.Radius/3 && pv != 255 {
 					pv /= 4
-				} else if dist > vs.Radius/4 {
+				} else if dist > vs.Radius/4 && pv != 255 {
 					pv /= 2
 				}
 

pkg/landscape/land.go

@@ -72,8 +72,9 @@ func (l *Landscape) At(x, y int) *Area {
 		River:       l.rivers.Value(x, y) == 255,
 		Temperature: l.temperature.Value(x, y),
 		Swamp:       l.swamp.Value(x, y) == 255,
-		Swampland:   l.swamp.Value(x, y) == 120,
+		BiomeSwamp:  l.swamp.Value(x, y) != 0,
 		Volcanism:   l.volcanic.Value(x, y),
+		Lava:        l.volcanic.Value(x, y) == 255,
 	}
 	if !a.River {
 		return a