Mega Code Archive
Double Buffering
<![CDATA[
[STAThreadAttribute]
int main(array<System::String ^> ^args)
{
Application::Run(gcnew Form1());
return 0;
}
using namespace System;
using namespace System::ComponentModel;
using namespace System::Collections;
using namespace System::Windows::Forms;
using namespace System::Data;
using namespace System::Drawing;
public ref class Form1 : public System::Windows::Forms::Form
{
public:
Form1(void)
{
InitializeComponent();
this->SetStyle(ControlStyles::Opaque, true);
dbBitmap = nullptr;
dbGraphics = nullptr;
X = -250; // Preset to be just left of window
Form1_Resize(nullptr, EventArgs::Empty);
}
System::Windows::Forms::Timer^ timer1;
Bitmap^ dbBitmap;
Graphics^ dbGraphics;
int X; // Actual x coordinate of Happy face
void InitializeComponent(void)
{
this->timer1 = (gcnew System::Windows::Forms::Timer());
this->SuspendLayout();
//
// timer1
//
this->timer1->Enabled = true;
this->timer1->Interval = 10;
this->timer1->Tick +=
gcnew System::EventHandler(this, &Form1::timer1_Tick);
//
// Form1
//
this->AutoScaleDimensions = System::Drawing::SizeF(6, 13);
this->AutoScaleMode = System::Windows::Forms::AutoScaleMode::Font;
this->ClientSize = System::Drawing::Size(500, 300);
this->Name = L"Form1";
this->Text = L"Sliding Happy Face";
this->Paint +=
gcnew System::Windows::Forms::PaintEventHandler(this,
&Form1::Form1_Paint);
this->Resize +=
gcnew System::EventHandler(this, &Form1::Form1_Resize);
this->ResumeLayout(false);
}
System::Void Form1_Paint(System::Object^ sender,
System::Windows::Forms::PaintEventArgs^ e)
{
// Move image at end of line start from beginning
if (X < ClientRectangle.Width)
{
X ++;
dbGraphics->TranslateTransform(1.0, 0.0);
}
else
{
X = -250;
dbGraphics->TranslateTransform(
(float)-(ClientRectangle.Width+250), 0.0);
}
// Clear background
dbGraphics->Clear(Color::White);
// redraw image from scratch
Pen^ b4pen = gcnew Pen(Color::Black, 4);
Drawing::Rectangle Head = Drawing::Rectangle(0, 0, 250, 250);
dbGraphics->FillEllipse(Brushes::Yellow, Head);
dbGraphics->DrawEllipse(b4pen, Head);
Drawing::Rectangle Mouth = Drawing::Rectangle(75, 150, 100, 50);
dbGraphics->FillPie(Brushes::White, Mouth,0,180);
dbGraphics->DrawPie(b4pen, Mouth, 0, 180);
Drawing::Rectangle LEye = Drawing::Rectangle(75, 75, 25, 25);
dbGraphics->FillEllipse(Brushes::White, LEye);
dbGraphics->DrawEllipse(b4pen, LEye);
Drawing::Rectangle REye = Drawing::Rectangle(150, 75, 25, 25);
dbGraphics->FillEllipse(Brushes::White, REye);
dbGraphics->DrawEllipse(b4pen, REye);
// Make the buffer visible
e->Graphics->DrawImageUnscaled(dbBitmap, 0, 0);
delete b4pen;
}
System::Void Form1_Resize(System::Object^ sender, System::EventArgs^ e)
{
// Get rid of old stuff
if (dbGraphics != nullptr)
{
delete dbGraphics;
}
if (dbBitmap != nullptr)
{
delete dbBitmap;
}
if (ClientRectangle.Width > 0 && ClientRectangle.Height > 0)
{
// Create a bitmap
dbBitmap = gcnew Bitmap(ClientRectangle.Width,
ClientRectangle.Height);
// Grab its Graphics
dbGraphics = Graphics::FromImage(dbBitmap);
// Set up initial translation after resize (also at start)
dbGraphics->TranslateTransform((float)X, 25.0);
}
}
System::Void timer1_Tick(System::Object^ sender, System::EventArgs^ e)
{
// Move the image
Invalidate();
}
};
]]>