github.com/df-mc/dragonfly@v0.9.13/server/player/skin/cape.go (about)

     1  package skin
     2  
     3  import (
     4  	"image"
     5  	"image/color"
     6  )
     7  
     8  // Cape represents the cape that a skin may additionally have. A skin is of a fixed size (always 32x64 bytes)
     9  // and may be either empty or of that size.
    10  type Cape struct {
    11  	w, h int
    12  
    13  	// Pix holds the colour data of the cape in an RGBA byte array, similarly to the way that the pixels of
    14  	// a Skin are stored.
    15  	// The size of Pix is always 32 * 64 * 4 bytes.
    16  	Pix []uint8
    17  }
    18  
    19  // NewCape initialises a new Cape using the width and height passed. The pixels are pre-allocated so that the
    20  // Cape may be used immediately.
    21  func NewCape(width, height int) Cape {
    22  	return Cape{w: width, h: height, Pix: make([]uint8, width*height*4)}
    23  }
    24  
    25  // ColorModel ...
    26  func (c Cape) ColorModel() color.Model {
    27  	return color.RGBAModel
    28  }
    29  
    30  // Bounds returns the bounds of the cape, which is always 32x64 or 0x0, depending on if the cape has any data
    31  // in it.
    32  func (c Cape) Bounds() image.Rectangle {
    33  	return image.Rectangle{
    34  		Max: image.Point{X: c.w, Y: c.h},
    35  	}
    36  }
    37  
    38  // At returns the colour at a given position in the cape, provided the X and Y are within the bounds of the
    39  // cape passed during construction.
    40  // The concrete type returned by At is a color.RGBA value.
    41  func (c Cape) At(x, y int) color.Color {
    42  	if x < 0 || y < 0 || x >= c.w || y >= c.h {
    43  		panic("pixel coordinates out of bounds")
    44  	}
    45  	offset := x*4 + c.w*y*4
    46  	return color.RGBA{
    47  		R: c.Pix[offset],
    48  		G: c.Pix[offset+1],
    49  		B: c.Pix[offset+2],
    50  		A: c.Pix[offset+3],
    51  	}
    52  }