/**
* Constructor for the GuiImageData class.
*/
GuiImageData::GuiImageData(const u8 * i, int maxw, int maxh)
{
data = NULL;
width = 0;
height = 0;
if(i)
data = DecodePNG(i, &width, &height, data, maxw, maxh);
}
RasterMapTile *RasterMapManager::GetTile(const unsigned int zoom, const unsigned int x, const unsigned int y) {
if (m_Ready) {
// Compute what file our tile is in (as implemented, this is dependent on MGM_CACHE_TILES_PER_FILE == 32)
unsigned int absX = x >> 3, absY = y >> 2;
unsigned char relX = x - absX * 8, relY = y - absY * 4;
// Work out the file name
static char filenameBuf[1024];
if (snprintf(filenameBuf, sizeof(filenameBuf), "%s/%s_%d/%d_%d.mgm",
m_CachePrefix.c_str(), m_MapType.c_str(), zoom, absX, absY) == sizeof(filenameBuf)) {
LogPrintf("RasterMapManager: Could not work out what file the requested tile is in.\n");
return NULL;
}
// Get the file
FILE *mgmFile = fopen(filenameBuf, "rb");
if (!mgmFile) {
LogPrintf("RasterMapManager: Provided cache does not contain requested tile, ignoring\n");
return NULL;
}
// Read MGMaps header
static unsigned char mgmapsHeader[2 + 6 * MGM_CACHE_TILES_PER_FILE];
if (fread(mgmapsHeader, 1, sizeof(mgmapsHeader), mgmFile) != sizeof(mgmapsHeader)) {
LogPrintf("RasterMapsManager: could not read MGMaps tile cache file header\n");
return NULL;
}
// Parse MGMaps header, searching for desired tile
unsigned int nextOffset = sizeof(mgmapsHeader), offset = 0;
int numTiles = mgmapsHeader[0] << 8 | mgmapsHeader[1];
Assert(numTiles >= 1 && numTiles <= MGM_CACHE_TILES_PER_FILE, "wrong number of tiles in cache file");
for (int i = 0; i < numTiles; ++i) {
MGMHeaderChunk *tmp = (MGMHeaderChunk*)(&mgmapsHeader[2 + i * sizeof(MGMHeaderChunk)]);
offset = nextOffset;
nextOffset = CHUNK_NEXT_OFFSET(tmp);
if (tmp->relX == relX && tmp->relY == relY) {
unsigned int length = nextOffset - offset;
// Check that the computed length is sane
fseek(mgmFile, 0, SEEK_END);
if (ftell(mgmFile) < nextOffset) {
LogPrintf("RasterMapsManager: error parsing MGMaps header (bad size)\n");
return NULL;
}
// Check read buffer is big enough to hold tile
if (length >= READ_BUFFER_SIZE) {
LogPrintf("RasterMapManager: can't read JPEG longer than read buffer; probable malformed cache.\n");
return NULL;
}
// Get the tile from the cachefile
fseek(mgmFile, offset, SEEK_SET);
if (length != fread(m_ReadBuffer, 1, length, mgmFile)) {
LogPrintf("RasterMapManager: end of file reached before JPEG was completely read, malformed cache.\n");
return NULL;
}
fclose(mgmFile);
// Decode the tile
unsigned int width = 0, height = 0;
unsigned char *img = DecodePNG(m_ReadBuffer, length, width, height);
return img ? new RasterMapTile(img, width, height) : NULL;
}
}
fclose(mgmFile);
}
LogPrintf("RasterMapsManager: could not find requested file in tile cache\n");
return NULL;
}
