Adding modding folder with a hacked build.

2026-09-26 08:53:08 +02:00
parent cdb960dc71
commit c91080aba7
755 changed files with 50424 additions and 0 deletions
@@ -0,0 +1,123 @@
+package compression
+
+// FrameDecoder is for decoding compressed frames with the help of data streams.
+// A new instance of a decoder is created with a FrameDecoderBuilder.
+type FrameDecoder struct {
+	horizontalTiles int
+	verticalTiles   int
+
+	colorer TileColorFunction
+
+	paletteLookupList []byte
+	controlWords      []ControlWord
+}
+
+func newFrameDecoder(builder *FrameDecoderBuilder) *FrameDecoder {
+	listLen := len(builder.paletteLookupList)
+	decoder := &FrameDecoder{
+		horizontalTiles:   builder.width / TileSideLength,
+		verticalTiles:     builder.height / TileSideLength,
+		colorer:           builder.colorer,
+		paletteLookupList: make([]byte, listLen+16),
+		controlWords:      builder.controlWords,
+	}
+
+	copy(decoder.paletteLookupList[:listLen], builder.paletteLookupList)
+
+	return decoder
+}
+
+// Decode reads the provided streams to paint a frame.
+func (decoder *FrameDecoder) Decode(bitstreamData []byte, maskstreamData []byte) error {
+	bitstream := NewBitstreamReader(bitstreamData)
+	maskstream := NewMaskstreamReader(maskstreamData)
+
+	for vTile := 0; vTile < decoder.verticalTiles && !bitstream.Exhausted(); vTile++ {
+		lastControl := ControlWordOf(0, CtrlUnknown, 0)
+		for hTile := 0; hTile < decoder.horizontalTiles && !bitstream.Exhausted(); hTile++ {
+			control, err := decoder.readNextControlWord(bitstream)
+			if err != nil {
+				return err
+			}
+
+			if control.Type() == CtrlRepeatPrevious {
+				if hTile == 0 {
+					return errCannotRepeatWordOnFirstTileOfRow
+				}
+				control = lastControl
+			}
+			if control.Type() == CtrlUnknown {
+				return errUnknownControl
+			}
+
+			if control.Type() == CtrlSkip {
+				skipCount := bitstream.Read(5)
+				bitstream.Advance(5)
+				if skipCount == 0x1F {
+					hTile = decoder.horizontalTiles
+				} else {
+					hTile += int(skipCount)
+				}
+			} else {
+				decoder.colorTile(hTile, vTile, control, maskstream)
+			}
+
+			lastControl = control
+		}
+	}
+	return nil
+}
+
+func (decoder *FrameDecoder) readNextControlWord(bitstream *BitstreamReader) (ControlWord, error) {
+	availableWords := uint32(len(decoder.controlWords))
+	controlIndex := bitstream.Read(12)
+	if controlIndex > availableWords {
+		return ControlWordOf(0, CtrlUnknown, 0),
+			wordIndexOutOfRangeError{
+				Index:     controlIndex,
+				Available: availableWords,
+			}
+	}
+
+	control := decoder.controlWords[controlIndex]
+	if control.IsLongOffset() {
+		longOffsetCount := 0
+		bitstream.Advance(8)
+		for control.IsLongOffset() {
+			longOffsetCount++
+			if longOffsetCount > 100 {
+				return ControlWordOf(0, CtrlUnknown, 0), errTooManyLongOffsets
+			}
+			bitstream.Advance(4)
+			offset := bitstream.Read(4)
+			controlIndex = control.LongOffset() + offset
+			if controlIndex > availableWords {
+				return ControlWordOf(0, CtrlUnknown, 0),
+					wordIndexOutOfRangeError{
+						Index:     controlIndex,
+						Available: availableWords,
+					}
+			}
+			control = decoder.controlWords[controlIndex]
+		}
+	}
+	bitstream.Advance(control.Count())
+	return control, nil
+}
+
+func (decoder *FrameDecoder) colorTile(hTile, vTile int, control ControlWord, maskstream *MaskstreamReader) {
+	param := control.Parameter()
+
+	switch control.Type() {
+	case CtrlColorTile2ColorsStatic:
+		decoder.colorer(hTile, vTile, []byte{byte(param & 0xFF), byte(param >> 8 & 0xFF)}, 0xAAAA, 1)
+	case CtrlColorTile2ColorsMasked:
+		decoder.colorer(hTile, vTile, []byte{byte(param & 0xFF), byte(param >> 8 & 0xFF)}, maskstream.Read(2), 1)
+	case CtrlColorTile4ColorsMasked:
+		decoder.colorer(hTile, vTile, decoder.paletteLookupList[param:param+4], maskstream.Read(4), 2)
+	case CtrlColorTile8ColorsMasked:
+		decoder.colorer(hTile, vTile, decoder.paletteLookupList[param:param+8], maskstream.Read(6), 3)
+	case CtrlColorTile16ColorsMasked:
+		decoder.colorer(hTile, vTile, decoder.paletteLookupList[param:param+16], maskstream.Read(8), 4)
+	}
+}