Files
DarkflameServer/dNavigation/dTerrain/RawChunk.cpp
Aaron Kimbrell 746919b3d2 fix: skip raw terrain chunk data with 64 bit relative seeks
Each skip computed an absolute offset as a 32 bit tellg plus a size
product in 32 bit math (colorMapSize * colorMapSize * 4 and friends),
which wraps for large values and can seek backwards. The skips are now
relative to the current position with the size promoted to
std::streamoff first. Offsets are unchanged for every real terrain file,
so this only removes the overflow the TODO asked about.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
2026-09-28 22:30:47 -05:00

94 lines
2.7 KiB
C++

#include "RawChunk.h"
#include "BinaryIO.h"
#include "RawMesh.h"
#include "RawHeightMap.h"
RawChunk::RawChunk(std::ifstream& stream) {
// Read the chunk index and info
BinaryIO::BinaryRead(stream, m_ChunkIndex);
BinaryIO::BinaryRead(stream, m_Width);
BinaryIO::BinaryRead(stream, m_Height);
BinaryIO::BinaryRead(stream, m_X);
BinaryIO::BinaryRead(stream, m_Z);
m_HeightMap = new RawHeightMap(stream, m_Height, m_Width);
// We can just skip the rest of the data so we can read the next chunks, we don't need anymore data
// Skips are relative and done in 64 bit math so large sizes can't wrap around and seek backwards.
uint32_t colorMapSize;
BinaryIO::BinaryRead(stream, colorMapSize);
stream.seekg(static_cast<std::streamoff>(colorMapSize) * colorMapSize * 4, std::ios::cur);
uint32_t lightmapSize;
BinaryIO::BinaryRead(stream, lightmapSize);
stream.seekg(static_cast<std::streamoff>(lightmapSize), std::ios::cur);
uint32_t colorMapSize2;
BinaryIO::BinaryRead(stream, colorMapSize2);
stream.seekg(static_cast<std::streamoff>(colorMapSize2) * colorMapSize2 * 4, std::ios::cur);
uint8_t unknown;
BinaryIO::BinaryRead(stream, unknown);
uint32_t blendmapSize;
BinaryIO::BinaryRead(stream, blendmapSize);
stream.seekg(static_cast<std::streamoff>(blendmapSize), std::ios::cur);
uint32_t pointSize;
BinaryIO::BinaryRead(stream, pointSize);
stream.seekg(static_cast<std::streamoff>(pointSize) * 9 * 4, std::ios::cur);
stream.seekg(static_cast<std::streamoff>(colorMapSize) * colorMapSize, std::ios::cur);
uint32_t endCounter;
BinaryIO::BinaryRead(stream, endCounter);
stream.seekg(static_cast<std::streamoff>(endCounter) * 2, std::ios::cur);
if (endCounter != 0) {
stream.seekg(32, std::ios::cur);
for (int i = 0; i < 0x10; i++) {
uint16_t finalCountdown;
BinaryIO::BinaryRead(stream, finalCountdown);
stream.seekg(static_cast<std::streamoff>(finalCountdown) * 2, std::ios::cur);
}
}
// Generate our mesh/geo data for this chunk
this->GenerateMesh();
}
RawChunk::~RawChunk() {
if (m_Mesh) delete m_Mesh;
if (m_HeightMap) delete m_HeightMap;
}
void RawChunk::GenerateMesh() {
RawMesh* meshData = new RawMesh();
for (int i = 0; i < m_Width; ++i) {
for (int j = 0; j < m_Height; ++j) {
float y = *std::next(m_HeightMap->m_FloatMap.begin(), m_Width * i + j);
meshData->m_Vertices.push_back(NiPoint3(i, y, j));
if (i == 0 || j == 0) continue;
meshData->m_Triangles.push_back(m_Width * i + j);
meshData->m_Triangles.push_back(m_Width * i + j - 1);
meshData->m_Triangles.push_back(m_Width * (i - 1) + j - 1);
meshData->m_Triangles.push_back(m_Width * (i - 1) + j - 1);
meshData->m_Triangles.push_back(m_Width * (i - 1) + j);
meshData->m_Triangles.push_back(m_Width * i + j);
}
}
m_Mesh = meshData;
}