png2c: rewrite to GoLang for efficiency

tools/png2c/.gitignore

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+png2c
+png2c.exe

tools/png2c/MakeFile

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+TOPDIR := $(realpath ../..)
+
+include $(TOPDIR)/build/go.mk

tools/png2c/main.go

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+package main
+
+import (
+	"flag"
+	"image"
+	"log"
+	"os"
+
+	"../misc"
+)
+
+var printHelp bool
+var palParams PaletteParams
+
+func init() {
+	flag.BoolVar(&printHelp, "help", false,
+		"print help message and exit")
+	flag.Var(&palParams, "palette", "Output Amiga palette 'name,color'")
+}
+
+func main() {
+	flag.Parse()
+
+	if len(flag.Args()) < 1 || printHelp {
+		flag.PrintDefaults()
+		os.Exit(1)
+	}
+
+	img, ok := misc.LoadPNG(flag.Arg(0)).(*image.Paletted)
+	if !ok {
+		log.Fatal("Only 8-bit images with palette supported.")
+	}
+	if (PaletteParams{}) != palParams {
+		DoPalette(img, palParams)
+	}
+}

tools/png2c/palette.go

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+package main
+
+import (
+	"../misc"
+	"image"
+	"image/color"
+	"log"
+)
+
+func DoPalette(img *image.Paletted, params PaletteParams) {
+	palette := misc.Palette{}
+	colorsCount := len(img.Palette)
+
+	for _, col := range img.Palette {
+		r, g, b, a := col.RGBA()
+		palette = append(palette, color.RGBA{R: uint8(r), G: uint8(g), B: uint8(b), A: uint8(a)})
+	}
+
+	if colorsCount == 0 {
+		log.Fatal("Image has no palette!")
+	}
+	if params.Colors > colorsCount {
+		log.Fatalf("Image has %d colors, expected at most %d!", len(palette), params.Colors)
+	}
+	if params.StoreUnused {
+		if params.Colors < colorsCount {
+			params.Colors = colorsCount
+		}
+	}
+	err := palette.Export(params.Name)
+	if err != nil {
+		log.Fatal("Could not export palette to C source.")
+	}
+	return
+}

tools/png2c/params.go

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+package main
+
+import (
+	"errors"
+	"fmt"
+	"strconv"
+	"strings"
+)
+
+type PaletteParams struct {
+	Name        string
+	Colors      int
+	StoreUnused bool
+}
+
+func (pp *PaletteParams) String() string {
+	return fmt.Sprintf("%s,%d,%t", pp.Name, pp.Colors, pp.StoreUnused)
+}
+
+func (pp *PaletteParams) Set(value string) error {
+	params := strings.Split(value, ",")
+	if len(params) < 2 {
+		return errors.New("not enough comma separated parameters")
+	}
+	colors, err := strconv.Atoi(params[1])
+	if err != nil {
+		return errors.New("could not parse colors parameter to integer")
+	}
+	storeUnused := false
+	if len(params) == 3 {
+		storeUnused, err = strconv.ParseBool(params[2])
+		if err != nil {
+			return errors.New("could not parse store-unused param to boolean")
+		}
+	}
+	*pp = PaletteParams{
+		Name:        params[0],
+		Colors:      colors,
+		StoreUnused: storeUnused,
+	}
+	return nil
+}