minecraft - maps/maker.go

     1  package maps
     2  
     3  import (
     4  	"image"
     5  	"image/color"
     6  
     7  	"vimagination.zapto.org/minecraft"
     8  )
     9  
    10  // Image represents a Minecraft Map
    11  type Image struct {
    12  	level         *minecraft.Level
    13  	bounds        image.Rectangle
    14  	scale         uint8
    15  	y             int32
    16  	width, height int
    17  	colour        func(minecraft.Block) color.Color
    18  }
    19  
    20  // ColorModel returns the palette for the map
    21  func (Image) ColorModel() color.Model {
    22  	return palette
    23  }
    24  
    25  // Bounds returns the dimensions of the map
    26  func (i Image) Bounds() image.Rectangle {
    27  	return image.Rectangle{
    28  		Min: image.Point{},
    29  		Max: image.Point{i.width, i.height},
    30  	}
    31  }
    32  
    33  // At returns the colour at the specified coords
    34  func (i Image) At(x, z int) color.Color {
    35  	var y int32
    36  	if i.y < 0 {
    37  		var err error
    38  		y, err = i.level.GetHeight(int32(x), int32(z))
    39  		if err != nil {
    40  			return color.Transparent
    41  		}
    42  	} else {
    43  		y = i.y
    44  	}
    45  	b, err := i.level.GetBlock(int32(x), y, int32(z))
    46  	if err != nil {
    47  		return color.Transparent
    48  	}
    49  	return i.colour(b)
    50  }
    51  
    52  // BlockColor is the standard block-to-colour func
    53  func BlockColor(b minecraft.Block) color.Color {
    54  	if c, ok := colours[uint32(b.ID)<<16|uint32(b.Data)]; ok {
    55  		return palette[c]
    56  	}
    57  	if c, ok := colours[uint32(b.ID)]; ok {
    58  		return palette[c]
    59  	}
    60  	return color.Transparent
    61  }
    62  
    63  // Option represents a optional parameter for a map type
    64  type Option func(*Image)
    65  
    66  // FixedY is an options to fix the Y-coord of the blocks to be read. By default
    67  // the highest, non-transparent block is usedd.
    68  func FixedY(y int32) Option {
    69  	return func(i *Image) {
    70  		i.y = y
    71  	}
    72  }
    73  
    74  // Scale sets the scale the map is to be rendered at.
    75  func Scale(s uint8) Option {
    76  	return func(i *Image) {
    77  		i.scale = s
    78  	}
    79  }
    80  
    81  // ColorFunc is an option for NewMap that specifies what colour blocks are
    82  // painted as.
    83  func ColorFunc(c func(minecraft.Block) color.Color) Option {
    84  	return func(i *Image) {
    85  		i.colour = c
    86  	}
    87  }
    88  
    89  // NewMap creates an image from a Minecraft level.
    90  func NewMap(l *minecraft.Level, bounds image.Rectangle, options ...Option) Image {
    91  	i := Image{
    92  		level:  l,
    93  		bounds: bounds,
    94  		scale:  3,
    95  		y:      -1,
    96  		colour: BlockColor,
    97  	}
    98  	for _, o := range options {
    99  		o(&i)
   100  	}
   101  	i.width = bounds.Dx() >> i.scale
   102  	i.height = bounds.Dy() >> i.scale
   103  	return i
   104  }
   105  
   106  var colours = map[uint32]uint8{}
   107