VisualStudio write UNIX style linefeeds using StreamWriter/WriteLine
Like so:
StreamWriter^ sw = gcnew StreamWriter("filename");
sw->NewLine = "\n";
sw->WriteLine("Line data");
Serial IO in VisualStudio 2011 / C++
I needed to hack together a quick windows application to read data over a serial port and write it to a file. Unfortunately I think VisualStudio is probably still the best way of writing Win32 GUI apps. However I’ve not really used VisualStudio since the VisualStudio.net beta, and most of the stuff I did before that was on VisualStudio 6.
Man Microsoft have really murdered C++… are these proprietary garbage collection extensions all over the place? I couldn’t see a way of writing a pure C++, unmanaged GUI app in VS 2011…
Anyway, to get Serial IO working in a GUI application I needed to add the following methods, these were all added to the Form itself, like I say this was a quick hack:
public:
// members
String^ comport;
String^ dump_filepath;
String^ current_filename;
SerialPort^ serialn;
// initalise serial port
void init_acquire() {
int baudRate=9600;
serialn = gcnew SerialPort(comport, baudRate);
serialn->ReadTimeout = 50;
serialn->Open();
}
// Read from serial port
String^ acquire() {;
String^ s;
try {
s = serialn->ReadLine();
}
catch (TimeoutException ^) { }
return s;
}
// Button handler, starts thread
private: System::Void button1_Click(System::Object^ sender, System::EventArgs^ e) {
dumped_lines = 0;
dumped_file_count = 0;
dump_filepath = this->drop_location_textbox->Text;
current_filename = dump_filepath + dumped_file_count + ".txt";
comport = comport_textbox->Text;
ThreadStart ^myThreadDelegate = gcnew ThreadStart(this, &Form1::repeat);
trd = gcnew Thread(myThreadDelegate);
trd->IsBackground = true;
trd->Start();
dumped_lines = 0;
}
// Thread code
delegate void DelegateThreadTask();
private: void ThreadTask() {
// This weirdness is required because setting the TextBox text is not thread safe.
if (data_textbox->InvokeRequired == false) {
String ^data = acquire();
this->data_textbox->Text = this->data_textbox->Text + data;
//current_filename
StreamWriter^ sw = gcnew StreamWriter(current_filename,true);
sw->WriteLine(data);
sw->Close();
} else {
DelegateThreadTask ^myThreadDelegate = gcnew DelegateThreadTask(this,&Form1::ThreadTask);
this->Invoke(myThreadDelegate);
}
}
// Thread loop (reads from serial, dumps to file/textbox.
private: void repeat() {
init_acquire();
while(true) {
ThreadTask();
Thread::Sleep(100);
}
}
You’ll also need to add the following headers:
using namespace System::IO::Ports; using namespace System::Threading; using namespace System::IO;
SDL_BlitSurface causes memory leak on MacOS X
When I use SDL_BlitSurface on Mac OS X it seems to cause a memory leak, it’s probably in some way related to the way I’m using Blit but anyway I needed a quick hack to get round the problem, performance is not really an issue so I just wrote a function to write the points to the screen one by one:
There are a bunch of things this version doesn’t do that SDL_BlitSurface does, so beware. It ignores src_rec (just like SDL_BlitSurface would if it were NULL), and it does no conversion to insure source and dest are the same format (so you’ll have to convert the surfaces first).
void SlowBlitSurface(SDL_Surface *source,SDL_Rect *src_rec,SDL_Surface *dest,SDL_Rect *dest_rec) {
int sbpp = source->format->BytesPerPixel;
int dbpp = dest->format->BytesPerPixel;
for(size_t x=0;x<source->w;x++) {
for(size_t y=0;y<source->h;y++) {
Uint8 *p = (Uint8 *)source->pixels + (((y * source->w) + x) * sbpp);
Uint32 pval = *(Uint32 *) p;
Uint8 *d = (Uint8 *)dest->pixels + ((((dest_rec->y+y) * (dest->w)) + (dest_rec->x+x)) * dbpp);
*((Uint32 *) d) = pval;
}
}
}
HTML Canvas simple example
<html>
<head>
<script type="text/javascript">
function draw_rect(x,y) {
var canvas = document.getElementById("m_canvas");
if(canvas.getContext) {
var ctx = canvas.getContext("2d");
ctx.fillStyle = "rgb(200,0,0)";
ctx.fillRect(x,y,5,5);
}
}
function onMouseMove(evt) {
draw_rect(evt.pageX,evt.pageY);
}
window.onmousemove = onMouseMove;
</script>
</head>
<canvas id="m_canvas" width="800" height="600">You need a better web browser.</canvas>
</body>
</html>
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