#SNG: from ftbgn2c16.png
IHDR {
    width: 32; height: 32; bitdepth: 16;
    using color;
}
gAMA {1.0000}
bKGD {red: 0;  green: 65535;  blue: 0;}
tRNS {
    red: 65535; green: 65535; blue: 65535;
}
IMAGE {
    pixels hex

#SNG: from ftbbn2c16.png
IHDR {
    width: 32; height: 32; bitdepth: 16;
    using color;
}
gAMA {1.0000}
bKGD {red: 0;  green: 0;  blue: 65535;}
tRNS {
    red: 65535; green: 65535; blue: 65535;
}
IMAGE {
    pixels hex

#SNG: from ftbwn0g16.png
IHDR {
    width: 32; height: 32; bitdepth: 16;
    using grayscale;
}
gAMA {1.0000}
bKGD {gray: 65535;}
tRNS {
    gray: 65535;
}
IMAGE {
    pixels hex
ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff 

    ( 45, 45, 84)     # rgb = (0x2d,0x2d,0x54)
    ( 10, 10, 96)     # rgb = (0x0a,0x0a,0x60)
    (  0,  0,255)     # rgb = (0x00,0x00,0xff) blue1
    (191,125,125)     # rgb = (0xbf,0x7d,0x7d)
}
bKGD {index: 0}
tRNS {
 0}
IMAGE {
    pixels hex
0000000000000000000000000000000000000000000000000000000000000000
0000000000000000000000000000000000000000000000000000000000000000

    (  0,  0,255)     # rgb = (0x00,0x00,0xff) blue1
    (191,125,125)     # rgb = (0xbf,0x7d,0x7d)
    (  0,  0,  0)     # rgb = (0x00,0x00,0x00) grey0
}
bKGD {index: 245}
tRNS {
 0}
IMAGE {
    pixels hex
0000000000000000000000000000000000000000000000000000000000000000
0000000000000000000000000000000000000000000000000000000000000000

    ( 10, 10, 96)     # rgb = (0x0a,0x0a,0x60)
    (  0,  0,255)     # rgb = (0x00,0x00,0xff) blue1
    (191,125,125)     # rgb = (0xbf,0x7d,0x7d)
    (170,170,170)     # rgb = (0xaa,0xaa,0xaa)
}
bKGD {index: 245}
tRNS {
 0}
IMAGE {
    pixels hex
0000000000000000000000000000000000000000000000000000000000000000
0000000000000000000000000000000000000000000000000000000000000000

    (  0,  0,255)     # rgb = (0x00,0x00,0xff) blue1
    (191,125,125)     # rgb = (0xbf,0x7d,0x7d)
    (255,255,  0)     # rgb = (0xff,0xff,0x00) yellow1
}
bKGD {index: 245}
tRNS {
 0}
IMAGE {
    pixels hex
0000000000000000000000000000000000000000000000000000000000000000
0000000000000000000000000000000000000000000000000000000000000000

		e.tmp[3*i+2] = c1.B
		if c1.A != 0xff {
			last = i
		}
		e.tmp[3*256+i] = c1.A
	}
	e.writeChunk(e.tmp[:3*len(p)], "PLTE")
	if last != -1 {
		e.writeChunk(e.tmp[3*256:3*256+1+last], "tRNS")
	}
}

// An encoder is an io.Writer that satisfies writes by writing PNG IDAT chunks,
// including an 8-byte header and 4-byte CRC checksum per Write call. Such calls