Initial community commit

Src/external_dependencies/openmpt-trunk/include/ancient/src/CBR0Decompressor.cpp

@@ -0,0 +1,64 @@
+/* Copyright (C) Teemu Suutari */
+
+#include "CBR0Decompressor.hpp"
+#include "InputStream.hpp"
+#include "OutputStream.hpp"
+#include "common/Common.hpp"
+
+
+namespace ancient::internal
+{
+
+bool CBR0Decompressor::detectHeaderXPK(uint32_t hdr) noexcept
+{
+	// CBR1 is practical joke: it is the same as CBR0 but with ID changed
+	return hdr==FourCC("CBR0") || hdr==FourCC("CBR1");
+}
+
+std::shared_ptr<XPKDecompressor> CBR0Decompressor::create(uint32_t hdr,uint32_t recursionLevel,const Buffer &packedData,std::shared_ptr<XPKDecompressor::State> &state,bool verify)
+{
+	return std::make_shared<CBR0Decompressor>(hdr,recursionLevel,packedData,state,verify);
+}
+
+CBR0Decompressor::CBR0Decompressor(uint32_t hdr,uint32_t recursionLevel,const Buffer &packedData,std::shared_ptr<XPKDecompressor::State> &state,bool verify) :
+	XPKDecompressor(recursionLevel),
+	_packedData(packedData),
+	_isCBR0(hdr==FourCC("CBR0"))
+{
+	if (!detectHeaderXPK(hdr)) throw Decompressor::InvalidFormatError();
+}
+
+CBR0Decompressor::~CBR0Decompressor()
+{
+	// nothing needed
+}
+
+const std::string &CBR0Decompressor::getSubName() const noexcept
+{
+	static std::string nameCBR0="XPK-CBR0: RLE-compressor";
+	static std::string nameCBR1="XPK-CBR1: RLE-compressor";
+	return (_isCBR0)?nameCBR0:nameCBR1;
+}
+
+void CBR0Decompressor::decompressImpl(Buffer &rawData,const Buffer &previousData,bool verify)
+{
+	ForwardInputStream inputStream(_packedData,0,_packedData.size());
+	ForwardOutputStream outputStream(rawData,0,rawData.size());
+
+	// barely different than RLEN, however the count is well defined here.
+	while (!outputStream.eof())
+	{
+		uint32_t count=inputStream.readByte();
+		if (count<128)
+		{
+			count++;
+			for (uint32_t i=0;i<count;i++) outputStream.writeByte(inputStream.readByte());
+		} else {
+			count=257-count;
+			uint8_t ch=inputStream.readByte();
+			for (uint32_t i=0;i<count;i++) outputStream.writeByte(ch);
+		}
+	}
+}
+
+}