lab/tmemo_converter/main.go
2022-05-07 16:14:42 +09:00

72 lines
1.5 KiB
Go

package main
import (
"fmt"
"image"
"image/color"
"image/png"
"io/ioutil"
"os"
)
const (
bytesPerPixel = 2
width = 480
height = 320
toolbarHeight = 16
actualHeight = height - toolbarHeight
total = width * actualHeight * bytesPerPixel
)
func main() {
if len(os.Args) == 1 {
fmt.Printf("Usage: %s INPUT ...\n", os.Args[0])
fmt.Printf("Example: %s tmemo000.tmd tmemo001.tmd\n", os.Args[0])
os.Exit(0)
}
for _, a := range os.Args[1:] {
err := convert(a)
if err != nil {
fmt.Fprintf(os.Stderr, "failed to convert %s: %s\n", a, err)
os.Exit(1)
}
}
}
func convert(fn string) error {
raw, err := ioutil.ReadFile(fn)
if err != nil {
return fmt.Errorf("failed to read %s: %s", fn, err)
}
if len(raw) != total {
return fmt.Errorf("unexpected binary length: expect=%d, actual=%d", total, len(raw))
}
rgba := image.NewRGBA(image.Rect(0, 0, width, actualHeight))
for i := 0; i < width*actualHeight; i++ {
pixel := uint16(raw[i*2+1])<<8 + uint16(raw[i*2])
r := float64(pixel&0xf800>>11) * 255 / 31
g := float64(pixel&0x07e0>>5) * 255 / 63
b := float64(pixel&0x001f) * 255 / 31
rgba.SetRGBA(i%width, actualHeight-i/width, color.RGBA{R: uint8(r), G: uint8(g), B: uint8(b), A: 255})
}
newFn := fn + ".png"
out, err := os.Create(newFn)
if err != nil {
return fmt.Errorf("failed to create a file %s: %s", newFn, err)
}
defer out.Close()
err = png.Encode(out, rgba)
if err != nil {
return fmt.Errorf("failed to compress the image into PNG: %s", err)
}
return nil
}