/r/place. generate pixel data from file

// This example demonstrates decoding a JPEG image and examining its pixels.
package main

import (
    // "encoding/base64"
    "fmt"
    "image"
    // "image/color"
    "log"
    "os"
    // "strings"

    // Package image/jpeg is not used explicitly in the code below,
    // but is imported for its initialization side-effect, which allows
    // image.Decode to understand JPEG formatted images. Uncomment these
    // two lines to also understand GIF and PNG images:
    // _ "image/gif"
    _ "image/jpeg"
    _ "image/png"
)

type rep struct {
    R, G, B, A uint32
}

var cMap = map[rep]int{
    rep{0, 0, 0, 65535}:             3, // black
    rep{65535, 65535, 65535, 65535}: 0, // white
    rep{65535, 0, 0, 65535}:         5, // red
}

func main() {
    // Decode the JPEG data. If reading from file, create a reader with
    //
    reader, err := os.Open(os.Args[1])
    if err != nil {
        log.Fatal(err)
    }
    defer reader.Close()

    m, _, err := image.Decode(reader)
    if err != nil {
        log.Fatal(err)
    }
    bounds := m.Bounds()

    fmt.Print("[")
    for y := bounds.Min.Y; y < bounds.Max.Y; y++ {
        fmt.Print("[")
        for x := bounds.Min.X; x < bounds.Max.X; x++ {
            r, g, b, a := m.At(x, y).RGBA()

            if a == 0 {
                fmt.Print("-1,")
                continue
            }

            c := rep{r, g, b, a}

            found := false
            for col, i := range cMap {
                // fmt.Println("%x %x", col, c)
                // return
                if col == c {
                    fmt.Printf("%d,", i)
                    found = true
                    break
                }
            }

            if found {
                continue
            }

            fmt.Printf("(%d, %d, %d, %d @ %d,%d) ", r, g, b, a, x, y)

        }
        fmt.Print("],\n")
    }
    fmt.Print("];\n")
}