ArgusMaker

Hi there.

I would like to optimize the double buffer rendering system I made in win32 c++ programming with gdi+.

So far I created an offscreen static bitmap surface and a global Graphics object to draw onto it.
The problem is, every time I want to update the HDC of my window i need to create a new Graphic object and destroy it at the end of the event, like this:

...
case WM_PAINT:
    hdc = BeginPaint(hWnd,&ps);
    graphics = Graphics(hdc);
    graphics.DrawImage(backbuffer,0,0,width,height);
    EndPaint(hWnd,&ps);
    break;
...
//graphics gets destroyed at the end of WndProc

Since this operation is repeated almost 40 times per second, i was wondering wether creating and destroying every time that object would somehow slow down my program.
Maybe this solution would be better:

- using a new compatible HDC as the backbuffer instead of the BMP
- inside WM_PAINT, copy that with BitBlt instead of creating a Graphics object

What do you think?

GLuint VBuffer;
GLuint CBuffer;
GLfloat Vertices[] = {
0.0f,0.0f, //0,0
100.0f,100.0f, //100,100
2.0f,2.0f,
3.0f,3.0f
};
// the line will be rendered using the first two vertices
GLfloat Colors[] = {
1.0f,0.0f,0.0f,1.0f, //red
0.0f,0.0f,1.0f,1.0f, //blue
1.0f,0.0f,0.0f,1.0f,
1.0f,0.0f,0.0f,1.0f
};
//the line will be rendered using the first two colors


glGenBuffers(1,&VBuffer);
glBindBuffer(GL_ARRAY_BUFFER,VBuffer);
glBufferData(GL_ARRAY_BUFFER,sizeof(GLfloat)*8,Vertices,GL_DYNAMIC_DRAW);


glGenBuffers(1,&CBuffer);
glBindBuffer(GL_COLOR_BUFFER_BIT,CBuffer);
glBufferData(GL_COLOR_BUFFER_BIT,sizeof(GLfloat)*16,Colors,GL_DYNAMIC_DRAW);

glBindBuffer(GL_ARRAY_BUFFER,VBuffer);
glVertexPointer(2,GL_FLOAT,0,BUFFER_OFFSET(0));

glBindBuffer(GL_COLOR_BUFFER_BIT,CBuffer);
glColorPointer(4,GL_FLOAT,0,BUFFER_OFFSET(0));

glEnableClientState(GL_VERTEX_ARRAY);
glEnableClientState(GL_COLOR_BUFFER_BIT);
glDrawArrays(GL_LINES,0,2);
glDisableClientState(GL_COLOR_BUFFER_BIT);
glDisableClientState(GL_VERTEX_ARRAY);