Hello, I'm programming in C++ using VisualC++ 2008 Express; no APIs or libraries aside from the standard C++ ones. I've been experimenting with bitmaps as a learning exercise for the past week. I coded a bitmap reader and copier using fstream. When it comes to writing to a bitmap created out of whole cloth, I come across a problem. Source code: -----Loader.h------------- #include "Preliminaries.h" //contains all //the major #includes (string, fstream, etc.) #ifndef _BITMAPLOADER #define _BITMAPLOADER #pragma pack(push, 1) using std::fstream; struct Bitmap { //data members short x, y; short h, w; string filename; fstream pic; struct Header { short type; int size; short reserved1, reserved2; int offset; }header; struct Info { int size; int width; int height; short planes; short depth; int compressn; int imgsize; int xbpm; int ypbm; int colors; int palette; }info; struct Color { unsigned char b; unsigned char g; unsigned char r; /*unsigned char misc;*/ }color; //member functions void Create(string,int, int); void Load(string f); inline void Load() { Load(filename);} //operators operator const fstream&() { return pic;} //constructors Bitmap(string f); Bitmap(); }; #pragma pack(pop) #endif --------Loader.cpp---------- <code> #include "Loader.h" using std::cout; using std::cin; using std::endl; using std::ios; void Bitmap::Create(string name, int h2, int w2) { h = h2; w = w2; filename = name; Header temp1 = {19778,sizeof(Color) *(w*h), 0, 0, 1078}; Info temp2 = {sizeof(Bitmap::Info), w, h, 1, sizeof(Color)*8, 0, header.size, 0, 0, 0, 0}; Color temp3 = {0,255,90}; header = temp1; info = temp2; color = temp3; pic.open(filename.c_str(), ios::out|ios::binary); pic.write(reinterpret_cast<char*>(&header), sizeof(header)); pic.write(reinterpret_cast<char*>(&info), sizeof(info)); for (int f = 0; f <= w*h; ++f) { pic.put((char)&color); cout<<(int)color.b<<","<<(int)color.g<<","<<(int)color.r<<"..."<<f<<endl; } cin.get(); } void Bitmap::Load(string f) { filename = f; pic.open(filename.c_str(), ios::in|ios::binary); pic.read(reinterpret_cast<char*>(&header), sizeof(Bitmap::Header)); pic.read(reinterpret_cast<char*>(&info), sizeof(Bitmap::Info)); h = info.height; w = info.width; } Bitmap::Bitmap(string f) : x(0), y(0), filename(f) { pic.open(filename.c_str(), ios::in|ios::binary);} Bitmap::Bitmap(){x = y = 0;} int main() { Bitmap a; a.Load("italianpretties.bmp"); Bitmap b; b.Create("new.bmp", 20, 20); return 0; } I was trying to write a bitmap with a solid color. I'm not quite sure what I'm doing wrong. While it compiles and runs just fine, but the outputted bitmap never comes out right--it's either all black, black and grey, or a random jumble of pixels. I hope someone can point me in the right direction!

Why re-inventing the wheel ?! Use win32 api, it's immediate (3 lines of code !)

lucas999: Why re-inventing the wheel ?! 'Cause he apparently didn't download the Win32 SDK. MH89: In Bitmap::Create(), you have: pic.put((char)&color); Change that to: pic.write(reinterpret_cast<char*>(&color), sizeof(color)); (Not writing enough per pixel.) In Bitmap::Create(), you have: Header temp1 = {19778,sizeof(Color) *(w*h), 0, 0, 1078}; Change that to: Header temp1 = {19778,sizeof(Color) *(w*h), 0, 0, sizeof(Bitmap::Header) + sizeof(Bitmap::Info)}; (Offset is incorrect.)

Thank you very much, I got it to work perfectly!