将结构变成2048年的大块

Question

我试图从一个文件中读取一个结构，到2048年的块中。但我不明白该怎么做，我自己累了，但它只读了一个块，我该怎么办？实现它？

我有这个：

int chunks = ceil(lasHeader.Legacy_Number_of_Point_Records / 2048);

for (unsigned long i = 0; i < chunks; i++)
{
    LASPOINT * pts = new LASPOINT[2048];
    fread(pts, sizeof LASPOINT, 2048, of);

    for (int j = 0; j < 2048; j++)
    {
        LASPOINT pt = *pts;

        pt.X = pt.X * lasHeader.X_Scale_Factor + lasHeader.X_Offset;
        pt.Y = pt.Y * lasHeader.Y_Scale_Factor + lasHeader.Y_Offset;
        pt.Z = pt.Z * lasHeader.Z_Scale_Factor + lasHeader.Z_Offset;

        pt.X = (pt.X - scalex) / 1.0;
        pt.Y = (pt.Y - scaley) / 1.0;
        pt.Z = (pt.Z - 0.0) / 1.0;

        ret.points.push_back(pt.X);
        ret.points.push_back(pt.Z);
        ret.points.push_back(pt.Y);

        pts++;
    }
}

这是我的完整代码：

#define LAS_1_4
#include "LasLoader.h"

const char* file_mode = "r";
LASHEADER lasHeader;

LasData LoadQuickData(const char* file)
{
    LasData ret;
    FILE* of;
    int size_p = sizeof(lasHeader);

    __asm
    {
        push ebp
        push    file_mode
        push    file
        call    fopen
        mov of, eax

        mov esi, esp
        mov eax, DWORD PTR of
        push eax
        push 1
        push size_p

        lea ecx, DWORD PTR lasHeader
        push ecx

        call DWORD PTR fread
    }

    ///////////////////////////THIS WORKS ///////////////////////////////////////////////
    //LASPOINT * pts = new LASPOINT[lasHeader.Legacy_Number_of_Point_Records];
    //fseek(of, lasHeader.Offset_To_Point_Data, 0);
    //fread(pts, (int)lasHeader.Legacy_Number_of_Point_Records, sizeof LASPOINT, of);
    //////////////////////////////////////////////////////////////////////////////////////.









    //THIS DOES NOT WORK:
    //---------------------------------------------------------------------------------
    float scalex = (float)lasHeader.Min_X;
    float scaley = (float)(lasHeader.Min_Y + (lasHeader.Max_Y - lasHeader.Min_Y));

    int chunks = ceil(lasHeader.Legacy_Number_of_Point_Records / 2048);
    long offset = lasHeader.Offset_To_Point_Data;

    fseek(of, lasHeader.Offset_To_Point_Data, 0);

    for (unsigned long i = 0; i < chunks; i++)
    {
        LASPOINT * pts = new LASPOINT[2048];
        long size = fread(pts, sizeof LASPOINT, 2048, of);

        cout << size << endl;

        for (int j = 0; j < 2048; j++)
        {
            LASPOINT pt = *pts;

            pt.X = pt.X * lasHeader.X_Scale_Factor + lasHeader.X_Offset;
            pt.Y = pt.Y * lasHeader.Y_Scale_Factor + lasHeader.Y_Offset;
            pt.Z = pt.Z * lasHeader.Z_Scale_Factor + lasHeader.Z_Offset;

            pt.X = (pt.X - scalex) / 1.0;
            pt.Y = (pt.Y - scaley) / 1.0;
            pt.Z = (pt.Z - 0.0) / 1.0;

            ret.points.push_back(pt.X);
            ret.points.push_back(pt.Z);
            ret.points.push_back(pt.Y);

            pts++;
        }

        fseek(of, offset += 2048, 0);
    }

    __asm
    {
        mov eax, of
        push eax
        call fclose

        add esp, 28
        pop ebp
    }


    cout << file << endl;
    cout << "-----------------------------------------" << endl;
    cout << lasHeader.Legacy_Number_of_Point_Records << " Points Loaded." << endl;
    cout << lasHeader.Generating_Software << endl;


    ret.Header = lasHeader;

    return ret;
}