Initial commit

Bringing a lot of stuff over from my maze-reader project in an attempt
to split the image reading code off into a library.

1 files changed, 110 insertions, 0 deletions

diff --git a/src/reader.cpp b/src/reader.cpp
new file mode 100644
index 0000000..59b30c0
--- /dev/null
+++ b/src/reader.cpp
@@ -0,0 +1,110 @@
+#include "reader.h"
+
+#include "debug.h"
+
+#include <algorithm>
+#include <cstddef>
+#include <cstdint>
+#include <cstring>
+#include <iostream>
+
+Reader::Reader(std::string filename)
+{
+	file = fopen(filename.c_str(), "rb");
+	refreshBuffer();
+	ready = true;
+}
+Reader::~Reader()
+{
+	if(ready)
+		fclose(file);
+}
+
+char Reader::readByte()
+{
+	if(pos == BUFFER_SIZE)
+		refreshBuffer();
+	return buffer[pos++];
+}
+
+void Reader::refreshBuffer()
+{
+		fread(buffer, sizeof(buffer), 1, file);
+		pos = 0;
+}
+
+template<> uint8_t Reader::readData<uint8_t>()
+{
+	return readByte();
+}
+
+template<> uint16_t Reader::readData<uint16_t>()
+{
+	uint16_t num = 0;
+	for(int i = 0; i < 2; i++)
+	{
+		num += readByte() << (8 * (1-i));
+	}
+	return num;
+}
+
+template<> uint32_t Reader::readData<uint32_t>()
+{
+	uint32_t num = 0;
+	for(int i = 0; i < 4; i++)
+	{
+		uint8_t byte = readByte();
+		DEBUG(std::cout << std::hex << 0+byte << " ");
+		num += byte << (8 * (3-i));
+	}
+	DEBUG(std::cout << std::dec << std::endl);
+	return num;
+}
+
+template<> uint64_t Reader::readData<uint64_t>()
+{
+	uint64_t num = 0;
+	for(int i = 0; i < 8; i++)
+	{
+		num += readByte() << (8 * (7-i));
+	}
+	return num;
+}
+
+void Reader::readBytes(char* out, size_t len)
+{
+	while(len > 0)
+	{
+		size_t bytesToRead = std::min(len, BUFFER_SIZE - pos);
+		if(bytesToRead == 0)
+		{
+			refreshBuffer();
+			continue;
+		}
+		memcpy(out, buffer + pos, bytesToRead);
+		out += bytesToRead;
+		len -= bytesToRead;
+		pos += bytesToRead;
+	}
+}
+
+void Reader::skipBytes(size_t len)
+{
+	while(len > 0)
+	{
+		size_t bytesToRead = std::min(len, BUFFER_SIZE - pos);
+		if(bytesToRead == 0)
+		{
+			refreshBuffer();
+			continue;
+		}
+		len -= bytesToRead;
+		pos += bytesToRead;
+	}
+}
+
+void Reader::close()
+{
+	fclose(file);
+	ready = false;
+}