ProDOS-Utilities/prodos/image.go
2023-01-22 12:25:11 -05:00

225 lines
6.8 KiB
Go

// Copyright Terence J. Boldt (c)2021-2023
// 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
}