package izapple2 import ( "fmt" "image" "image/color" "strings" "time" ) const ( charWidth = 7 charHeight = 8 text40Columns = 40 textLines = 24 textPage1Address = uint16(0x0400) textPage2Address = uint16(0x0800) textPageSize = uint16(0x0400) ) func snapshotText40Mode(a *Apple2, isSecondPage bool, light color.Color) *image.RGBA { text := getTextFromMemory(a.mmu.getVideoRAM(false), isSecondPage) return renderTextMode(a, text, nil /*colorMap*/, light) } func snapshotText80Mode(a *Apple2, isSecondPage bool, light color.Color) *image.RGBA { text := getText80FromMemory(a, isSecondPage) return renderTextMode(a, text, nil /*colorMap*/, light) } func snapshotText40RGBMode(a *Apple2, isSecondPage bool) *image.RGBA { text := getTextFromMemory(a.mmu.getVideoRAM(false), isSecondPage) colorMap := getTextFromMemory(a.mmu.getVideoRAM(true), isSecondPage) return renderTextMode(a, text, colorMap, nil) } func snapshotText40RGBModeColors(a *Apple2, isSecondPage bool) *image.RGBA { colorMap := getTextFromMemory(a.mmu.getVideoRAM(true), isSecondPage) return renderTextMode(a, nil /*text*/, colorMap, nil) } func getTextCharOffset(col int, line int) uint16 { // See "Understanding the Apple II", page 5-10 // http://www.applelogic.org/files/UNDERSTANDINGTHEAII.pdf section := line / 8 // Top, middle and bottom eighth := line % 8 return uint16(section*40 + eighth*0x80 + col) } func getText80FromMemory(a *Apple2, isSecondPage bool) []uint8 { text40Columns := getTextFromMemory(a.mmu.getVideoRAM(false), isSecondPage) text40ColumnsAlt := getTextFromMemory(a.mmu.getVideoRAM(true), isSecondPage) // Merge the two 40 cols to return 80 cols text80Columns := make([]uint8, 2*len(text40Columns)) for i := 0; i < len(text40Columns); i++ { text80Columns[2*i] = text40ColumnsAlt[i] text80Columns[2*i+1] = text40Columns[i] } return text80Columns } func getTextFromMemory(mem *memoryRange, isSecondPage bool) []uint8 { addressStart := textPage1Address if isSecondPage { addressStart = textPage2Address } addressEnd := addressStart + textPageSize data := mem.subRange(addressStart, addressEnd) text := make([]uint8, textLines*text40Columns) for l := 0; l < textLines; l++ { for c := 0; c < text40Columns; c++ { char := data[getTextCharOffset(c, l)] text[text40Columns*l+c] = char } } return text } func getRGBTextColor(pixel bool, colorKey uint8) color.Color { if pixel { colorKey >>= 4 } colorKey &= 0x0f return ntscColorMap[colorKey] } func renderTextMode(a *Apple2, text []uint8, colorMap []uint8, light color.Color) *image.RGBA { // Flash mode is 2Hz (host time) isFlashedFrame := time.Now().Nanosecond() > (1 * 1000 * 1000 * 1000 / 2) isAltText := a.io.isSoftSwitchActive(ioFlagAltChar) columns := len(text) / textLines if text == nil { columns = text40Columns } width := columns * charWidth height := textLines * charHeight size := image.Rect(0, 0, 2*hiResWidth, hiResHeight) img := image.NewRGBA(size) for x := 0; x < width; x++ { for y := 0; y < height; y++ { line := y / charHeight col := x / charWidth rowInChar := y % charHeight colInChar := x % charWidth charIndex := line*columns + col var char uint8 if text != nil { char = text[charIndex] } else { char = 79 + 128 // Debug screen filed with O } var pixel bool if a.isApple2e { vid6 := (char & 0x40) != 0 vid7 := (char & 0x80) != 0 char := char & 0x3f if vid6 && (vid7 || isAltText) { char += 0x40 } if vid7 || (vid6 && isFlashedFrame && !isAltText) { char += 0x80 } pixel = !a.cg.getPixel(char, rowInChar, colInChar) } else { pixel = a.cg.getPixel(char, rowInChar, colInChar) topBits := char >> 6 isInverse := topBits == 0 isFlash := topBits == 1 pixel = pixel != (isInverse || (isFlash && isFlashedFrame)) } var colour color.Color if colorMap != nil { colour = getRGBTextColor(pixel, colorMap[charIndex]) } else if pixel { colour = light } else { colour = color.Black } if columns == text40Columns { img.Set(x*2, y, colour) img.Set(x*2+1, y, colour) } else { img.Set(x, y, colour) } } } return img } // DumpTextModeAnsi returns the text mode contents using ANSI escape codes // for reverse and flash func DumpTextModeAnsi(a *Apple2) string { is80Columns := a.io.isSoftSwitchActive(ioFlag80Col) isSecondPage := a.io.isSoftSwitchActive(ioFlagSecondPage) && !a.mmu.store80Active isAltText := a.isApple2e && a.io.isSoftSwitchActive(ioFlagAltChar) var text []uint8 if is80Columns { text = getText80FromMemory(a, isSecondPage) } else { text = getTextFromMemory(a.mmu.getVideoRAM(false), isSecondPage) } columns := len(text) / textLines content := "\n" content += fmt.Sprintln(strings.Repeat("#", columns+4)) for l := 0; l < textLines; l++ { line := "" for c := 0; c < columns; c++ { char := text[l*columns+c] line += textMemoryByteToString(char, isAltText) } content += fmt.Sprintf("# %v #\n", line) } content += fmt.Sprintln(strings.Repeat("#", columns+4)) return content } func textMemoryByteToString(value uint8, isAltCharSet bool) string { // See https://en.wikipedia.org/wiki/Apple_II_character_set // Supports the new lowercase characters in the Apple2e // Only ascii from 0x20 to 0x5F is visible topBits := value >> 6 isInverse := topBits == 0 isFlash := topBits == 1 if isFlash && isAltCharSet { // On the Apple2e with lowercase chars there is not flash mode. isFlash = false isInverse = true } if isAltCharSet { value = value & 0x7F } else { value = value & 0x3F } if value < 0x20 { value += 0x40 } if value == 0x7f { // DEL is full box value = '_' } if isFlash { if value == ' ' { // Flashing space in Apple is the full box. It can't be done with ANSI codes value = '_' } return fmt.Sprintf("\033[5m%v\033[0m", string(value)) } else if isInverse { return fmt.Sprintf("\033[7m%v\033[0m", string(value)) } else { return string(value) } }