// Copyright Terence J. Boldt (c)2021-2024 // Use of this source code is governed by an MIT // license that can be found in the LICENSE file. // This file provides access to read, write and delete // files on a ProDOS drive image package prodos import ( "bytes" "fmt" "image" "image/color" // force import jpeg support by init only _ "image/jpeg" // force import png support by init only _ "image/png" "golang.org/x/image/draw" ) // 10 PRINT CHR$ (4)"open offsets" // 20 PRINT CHR$ (4)"write offsets" // 30 PRINT "offsets := [192]int{"; // 40 FOR Y = 0 TO 191 // 50 HPLOT 0,Y // 60 PRINT ( PEEK (39) * 256 + PEEK (38)) - 8192; // 70 IF Y < 191 THEN PRINT ", "; // 80 NEXT // 90 PRINT "}" // 100 PRINT CHR$ (4)"close offsets" var offsets = []int{0, 1024, 2048, 3072, 4096, 5120, 6144, 7168, 128, 1152, 2176, 3200, 4224, 5248, 6272, 7296, 256, 1280, 2304, 3328, 4352, 5376, 6400, 7424, 384, 1408, 2432, 3456, 4480, 5504, 6528, 7552, 512, 1536, 2560, 3584, 4608, 5632, 6656, 7680, 640, 1664, 2688, 3712, 4736, 5760, 6784, 7808, 768, 1792, 2816, 3840, 4864, 5888, 6912, 7936, 896, 1920, 2944, 3968, 4992, 6016, 7040, 8064, 40, 1064, 2088, 3112, 4136, 5160, 6184, 7208, 168, 1192, 2216, 3240, 4264, 5288, 6312, 7336, 296, 1320, 2344, 3368, 4392, 5416, 6440, 7464, 424, 1448, 2472, 3496, 4520, 5544, 6568, 7592, 552, 1576, 2600, 3624, 4648, 5672, 6696, 7720, 680, 1704, 2728, 3752, 4776, 5800, 6824, 7848, 808, 1832, 2856, 3880, 4904, 5928, 6952, 7976, 936, 1960, 2984, 4008, 5032, 6056, 7080, 8104, 80, 1104, 2128, 3152, 4176, 5200, 6224, 7248, 208, 1232, 2256, 3280, 4304, 5328, 6352, 7376, 336, 1360, 2384, 3408, 4432, 5456, 6480, 7504, 464, 1488, 2512, 3536, 4560, 5584, 6608, 7632, 592, 1616, 2640, 3664, 4688, 5712, 6736, 7760, 720, 1744, 2768, 3792, 4816, 5840, 6864, 7888, 848, 1872, 2896, 3920, 4944, 5968, 6992, 8016, 976, 2000, 3024, 4048, 5072, 6096, 7120, 8144} var pixel = []byte{1, 2, 4, 8, 16, 32, 64} // ConvertImageToHiResMonochrome converts jpeg and png images to Apple II hi-res monochrome func ConvertImageToHiResMonochrome(imageBytes []byte) []byte { img, _, err := image.Decode(bytes.NewReader(imageBytes)) if err != nil { fmt.Printf("%s\n", err) return nil } a2imgSize := image.Rect(0, 0, 280, 192) a2img := image.NewPaletted(a2imgSize, []color.Color{ color.Black, color.White, }) a2monoImgSize := image.Rect(0, 0, 280, 192) scaledImg := image.NewRGBA(a2monoImgSize) draw.BiLinear.Scale(scaledImg, a2monoImgSize, img, img.Bounds(), draw.Over, nil) draw.FloydSteinberg.Draw(a2img, a2monoImgSize, scaledImg, image.Point{}) hires := make([]byte, 8192) for y := a2img.Bounds().Min.Y; y < a2img.Bounds().Max.Y; y++ { for x := a2img.Bounds().Min.X; x < a2img.Bounds().Max.X; x++ { if a2img.At(x, y) == color.White { hires[offsets[y]+x/7] |= pixel[x%7] | 128 } } } return hires } // ConvertImageToHiResColour converts jpeg and png images to Apple II hi-res colour func ConvertImageToHiResColour(imageBytes []byte) []byte { img, _, err := image.Decode(bytes.NewReader(imageBytes)) if err != nil { fmt.Printf("%s\n", err) return nil } a2colourImgSize := image.Rect(0, 0, 140, 192) black := color.NRGBA{0, 0, 0, 255} green := color.NRGBA{20, 245, 60, 255} purple := color.NRGBA{255, 68, 253, 255} white := color.NRGBA{255, 255, 255, 255} orange := color.NRGBA{255, 106, 60, 255} blue := color.NRGBA{20, 207, 253, 255} a2img := image.NewPaletted(a2colourImgSize, []color.Color{ black, green, purple, white, orange, blue, }) scaledImg := image.NewRGBA(a2colourImgSize) draw.BiLinear.Scale(scaledImg, a2colourImgSize, img, img.Bounds(), draw.Over, nil) draw.FloydSteinberg.Draw(a2img, a2colourImgSize, scaledImg, image.Point{}) hires := make([]byte, 8192) for y := a2img.Bounds().Min.Y; y < a2img.Bounds().Max.Y; y++ { for x7 := a2img.Bounds().Min.X; x7 < a2img.Bounds().Max.X; x7 += 7 { switch a2img.At(x7, y) { case green: hires[offsets[y]+x7*2/7] = 2 case purple: hires[offsets[y]+x7*2/7] = 1 case orange: hires[offsets[y]+x7*2/7] = 2 hires[offsets[y]+x7*2/7] |= 0x80 case blue: hires[offsets[y]+x7*2/7] = 1 hires[offsets[y]+x7*2/7] |= 0x80 case white: hires[offsets[y]+x7*2/7] = 3 } switch a2img.At(x7+1, y) { case green: hires[offsets[y]+x7*2/7] |= 8 hires[offsets[y]+x7*2/7] &= 0x7F case purple: hires[offsets[y]+x7*2/7] |= 4 hires[offsets[y]+x7*2/7] &= 0x7F case orange: hires[offsets[y]+x7*2/7] |= 8 hires[offsets[y]+x7*2/7] |= 0x80 case blue: hires[offsets[y]+x7*2/7] |= 4 hires[offsets[y]+x7*2/7] |= 0x80 case white: hires[offsets[y]+x7*2/7] |= 12 } switch a2img.At(x7+2, y) { case green: hires[offsets[y]+x7*2/7] |= 32 hires[offsets[y]+x7*2/7] &= 0x7F case purple: hires[offsets[y]+x7*2/7] |= 16 hires[offsets[y]+x7*2/7] &= 0x7F case orange: hires[offsets[y]+x7*2/7] |= 32 hires[offsets[y]+x7*2/7] |= 0x80 case blue: hires[offsets[y]+x7*2/7] |= 16 hires[offsets[y]+x7*2/7] |= 0x80 case white: hires[offsets[y]+x7*2/7] |= 48 } switch a2img.At(x7+3, y) { case green: hires[offsets[y]+x7*2/7+1] |= 1 hires[offsets[y]+x7*2/7+1] &= 0x7F case purple: hires[offsets[y]+x7*2/7] |= 64 hires[offsets[y]+x7*2/7] &= 0x7F case orange: hires[offsets[y]+x7*2/7+1] |= 1 hires[offsets[y]+x7*2/7+1] |= 0x80 case blue: hires[offsets[y]+x7*2/7] |= 64 hires[offsets[y]+x7*2/7] |= 0x80 case white: hires[offsets[y]+x7*2/7] |= 64 hires[offsets[y]+x7*2/7+1] |= 1 } switch a2img.At(x7+4, y) { case green: hires[offsets[y]+x7*2/7+1] |= 4 hires[offsets[y]+x7*2/7+1] &= 0x7F case purple: hires[offsets[y]+x7*2/7+1] |= 2 hires[offsets[y]+x7*2/7+1] &= 0x7F case orange: hires[offsets[y]+x7*2/7+1] |= 4 hires[offsets[y]+x7*2/7+1] |= 0x80 case blue: hires[offsets[y]+x7*2/7+1] |= 2 hires[offsets[y]+x7*2/7+1] |= 0x80 case white: hires[offsets[y]+x7*2/7+1] |= 6 } switch a2img.At(x7+5, y) { case green: hires[offsets[y]+x7*2/7+1] |= 16 hires[offsets[y]+x7*2/7+1] &= 0x7F case purple: hires[offsets[y]+x7*2/7+1] |= 8 hires[offsets[y]+x7*2/7+1] &= 0x7F case orange: hires[offsets[y]+x7*2/7+1] |= 16 hires[offsets[y]+x7*2/7+1] |= 0x80 case blue: hires[offsets[y]+x7*2/7+1] |= 8 hires[offsets[y]+x7*2/7+1] |= 0x80 case white: hires[offsets[y]+x7*2/7+1] |= 24 } switch a2img.At(x7+6, y) { case green: hires[offsets[y]+x7*2/7+1] |= 64 hires[offsets[y]+x7*2/7+1] &= 0x7F case purple: hires[offsets[y]+x7*2/7+1] |= 32 hires[offsets[y]+x7*2/7+1] &= 0x7F case orange: hires[offsets[y]+x7*2/7+1] |= 64 hires[offsets[y]+x7*2/7+1] |= 0x80 case blue: hires[offsets[y]+x7*2/7+1] |= 32 hires[offsets[y]+x7*2/7+1] |= 0x80 case white: hires[offsets[y]+x7*2/7+1] |= 96 } } } return hires }