bedrocktool/subcommands/world/chunk_render.go

package world

import (
	"image"
	"image/color"

	"github.com/bedrock-tool/bedrocktool/utils"

	"github.com/df-mc/dragonfly/server/block"
	"github.com/df-mc/dragonfly/server/block/cube"
	"github.com/df-mc/dragonfly/server/world"
	"github.com/df-mc/dragonfly/server/world/chunk"
)

func blockColorAt(c *chunk.Chunk, x uint8, y int16, z uint8) (blockColor color.RGBA) {
	blockColor = color.RGBA{255, 0, 255, 255}
	rid := c.Block(x, y, z, 0)
	if rid == 0 && y == 0 { // void
		blockColor = color.RGBA{0, 0, 0, 255}
	} else {
		b, found := world.BlockByRuntimeID(rid)
		if found {
			if d, ok := b.(block.LightDiffuser); ok && d.LightDiffusionLevel() == 0 && y > int16(c.Range().Min()) {
				return blockColorAt(c, x, y-1, z)
			}
			if _, ok := b.(block.Water); ok {
				y2 := c.HeightMap().At(x, z)
				depth := y - y2
				if depth > 0 {
					blockColor = blockColorAt(c, x, y2, z)
				}

				bw := (&block.Water{}).Color()
				bw.A = uint8(utils.Clamp(int(150+depth*7), 255))
				blockColor = utils.BlendColors(blockColor, bw)
				blockColor.R -= uint8(depth * 2)
				blockColor.G -= uint8(depth * 2)
				blockColor.B -= uint8(depth * 2)
			} else {
				blockColor = b.Color()
			}
		}
		/*
			if blockColor.R == 0 || blockColor.R == 255 && blockColor.B == 255 {
				name, nbt := b.EncodeBlock()
				fmt.Printf("unknown color %d  %s %s %s\n", rid, reflect.TypeOf(b), name, nbt)
				b.Color()
			}
		*/
	}
	return blockColor
}

func chunkGetColorAt(c *chunk.Chunk, x uint8, y int16, z uint8) color.RGBA {
	p := cube.Pos{int(x), int(y), int(z)}
	haveUp := false
	p.Side(cube.FaceUp).Neighbours(func(neighbour cube.Pos) {
		if neighbour.X() < 0 || neighbour.X() >= 16 || neighbour.Z() < 0 || neighbour.Z() >= 16 || neighbour.Y() > c.Range().Max() {
			return
		}
		if !haveUp {
			blockRid := c.Block(uint8(neighbour[0]), int16(neighbour[1]), uint8(neighbour[2]), 0)
			if blockRid > 0 {
				b, found := world.BlockByRuntimeID(blockRid)
				if found {
					if _, ok := b.(block.Air); !ok {
						haveUp = true
					}
				}
			}
		}
	}, cube.Range{int(y + 1), int(y + 1)})

	col := blockColorAt(c, x, y, z)

	if haveUp {
		if col.R > 10 {
			col.R -= 10
		}
		if col.G > 10 {
			col.G -= 10
		}
		if col.B > 10 {
			col.B -= 10
		}
	}
	return col
}

func Chunk2Img(c *chunk.Chunk) *image.RGBA {
	img := image.NewRGBA(image.Rect(0, 0, 16, 16))
	hm := c.HeightMapWithWater()

	for x := uint8(0); x < 16; x++ {
		for z := uint8(0); z < 16; z++ {
			height := hm.At(x, z)
			col := chunkGetColorAt(c, x, height, z)
			img.SetRGBA(int(x), int(z), col)
		}
	}
	return img
}