tinyfontgen: Added support for generating fonts from ttf

[sago35]

This PR adds the ability to create tinyfont from ttf-font.

For example, it can be generated and used with the following command.

$ go run ./cmd/tinyfontgen-ttf --size 32 --package rubikmoonrocks --fontname RubikMoonrocks ./_fonts/RubikMoonrocks-Regular.ttf --output rubikmoonrocks/font.go

$ tinygo flash --target wioterminal --size short ./examples/ttf
   code    data     bss |   flash     ram
  36052     228    6240 |   36280    6468

file : ./examples/ttf

package main

import (
    "image/color"

    "tinygo.org/x/drivers/ili9341"
    "tinygo.org/x/tinyfont"
    "tinygo.org/x/tinyfont/examples/initdisplay"
    "tinygo.org/x/tinyfont/rubikmoonrocks"
)

var (
    font = &rubikmoonrocks.RubikMoonrocks
)

func main() {
    display := initdisplay.InitDisplay()
    dev := display.(*ili9341.Device)
    dev.SetRotation(ili9341.Rotation270)

    tinyfont.WriteLine(display, font, 5, 50, "tinyfont", color.RGBA{0x00, 0x00, 0x00, 0xFF})
    tinyfont.WriteLine(display, font, 5, 100, font.Name, color.RGBA{0x00, 0x00, 0x00, 0xFF})

    select {}
}

font : https://fonts.google.com/specimen/Rubik+Moonrocks?query=rub

[sago35]

Since most of the font data is stored in ROM, it is easier to use even higher resolution fonts than before. Currently, only the combination of white background and black text color is supported. In the future, it should be possible to create them in a variety of colors.

[sago35]

font : https://fonts.google.com/specimen/Rubik+Moonrocks?query=rub

font : https://fonts.google.com/noto/specimen/Noto+Sans+JP (japanese)

[sago35]

Thanks for the review. Merged.