Abstracted some of the sprite dumper functionality out

1 files changed, 139 insertions, 0 deletions

@@ -0,0 +1,139 @@
+#ifndef COMMON_H_04DD2B2A
+#define COMMON_H_04DD2B2A
+
+#include <vector>
+#include <string_view>
+#include <fstream>
+#include <stdexcept>
+
+class BufferView {
+public:
+
+  BufferView(const std::vector<char>& buffer) : data_(&buffer) {}
+
+  int ReadNextByte() {
+    int o2r = offset_;
+    offset_++;
+    return ReadByte(o2r);
+  }
+
+  int ReadByte(int addr) const {
+    return static_cast<unsigned char>((*data_)[addr]);
+  }
+
+  int ReadNextTwoBytes() {
+    int o2r = offset_;
+    offset_+=2;
+    return ReadTwoBytes(o2r);
+  }
+
+  int ReadTwoBytes(int addr) const {
+    return static_cast<unsigned char>((*data_)[addr]) | (static_cast<unsigned char>((*data_)[addr + 1]) << 8);
+  }
+
+  int ReadNextFourBytes() {
+    int o2r = offset_;
+    offset_+=4;
+    return ReadFourBytes(o2r);
+  }
+
+  unsigned long ReadFourBytes(int addr) const {
+    return static_cast<unsigned char>((*data_)[addr]) | (static_cast<unsigned char>((*data_)[addr + 1]) << 8) | (static_cast<unsigned char>((*data_)[addr + 2]) << 16) | (static_cast<unsigned char>((*data_)[addr + 3]) << 24);
+  }
+
+  void Seek(int offset) {
+    offset_ = offset;
+  }
+
+  void SeekAdd(int delta) {
+    offset_ += delta;
+  }
+
+  std::vector<char> Decompress(int addr) {
+    int start = addr;
+    Seek(addr);
+    if (ReadNextByte() != 0x10) {
+      throw std::domain_error("No LZ77 signature");
+    }
+
+    int length = ReadNextByte();
+    length += (ReadNextByte() << 8);
+    length += (ReadNextByte() << 16);
+
+    std::vector<char> result(length, 0);
+
+    int bPos = 0;
+    while (bPos < length) {
+      unsigned char ch = ReadNextByte();
+      for (int i=0;i<8;i++) {
+        switch ((ch >> (7-i)) & 1) {
+          case 0: {
+            if (bPos >= length) break;
+            result[bPos++] = ReadNextByte();
+            break;
+          }
+          case 1: {
+            int t = (ReadNextByte() << 8);
+            t += ReadNextByte();
+            int n = ((t >> 12) & 0xF) + 3; // num of bytes to copy
+            int o = (t & 0xFFF);
+
+            memcpy(result.data() + bPos, result.data() + bPos - o - 1, n);
+            bPos += n;
+            break;
+          }
+          default: break;
+        }
+      }
+    }
+
+    return result;
+  }
+
+private:
+
+  const std::vector<char>* data_;
+  int offset_ = 0;
+};
+
+class Rom {
+public:
+
+  explicit Rom(std::string_view filename) {
+    std::ifstream romfile(filename.data(), std::ios::binary);
+    if (!romfile.is_open()) {
+      throw std::invalid_argument("Could not find ROM file: " + std::string(filename));
+    }
+
+    romfile.seekg(0, romfile.end);
+    int length = romfile.tellg();
+    romfile.seekg(0, romfile.beg);
+
+    if (length != 0x2000000) {
+      throw std::invalid_argument("Incorrect ROM length");
+    }
+
+    data_ = std::vector<char>(length, 0);
+    romfile.read(data_.data(), length);
+
+    const char header[] = {'M','O','T','H','E','R','3',0,0,0,0,0,'A','3','U','J'};
+    std::string headerTest;
+    for (int i = 0xA0; i < 0xB0; i++) {
+      if (data_.at(i) != header[i-0xA0]) {
+        std::cout << i << std::endl;
+
+        throw std::invalid_argument("Invalid ROM header");
+      }
+    }
+  }
+
+  const std::vector<char>& data() const { return data_; }
+
+  BufferView buffer() const { return {data_}; }
+
+private:
+
+  std::vector<char> data_;
+};
+
+#endif /* end of include guard: COMMON_H_04DD2B2A */