Process Logging Process (arrow implementation, refresh screen)

3. Arrow implementation.

/////////////////////
// Draw arrows to encapsulate and call function implementation
Void cbuttontestdlg: arrowto (
CDC * PDC, // painter
Cpoint point, // The end Coordinate
Int npenstyle, // line style
Int npenwidth, // line width
Colorref color, // color
Int nwidth, // triangle bottom side width
Float ftheta, // triangle top angle
Bool bfill // whether to fill the color
)
{
Cpen * poldpen;
Cpen pen (npenstyle, npenwidth, color );
Poldpen = PDC-> SelectObject (& pen );

Cbrush Br, * pbrold;
BR. createsolidbrush (color );
Pbrold = PDC-> SelectObject (& Br );

// Start plotting
Point pfrom;
Point pbase;
Point aptpoly [3];
Float vecline [2];
Float vecleft [2];
Float flength;
Float th;
Float ta;

// Get from point
Movetoex (* PDC, 0, 0, & pfrom );

// Set to Point
Aptpoly [0]. x = point. X;
Aptpoly [0]. Y = point. Y;

// Build the line vector
Vecline [0] = (float) aptpoly [0]. X-pfrom. X;
Vecline [1] = (float) aptpoly [0]. Y-pfrom. Y;

// Build the arrow base vector-normal to the line
Vecleft [0] =-vecline [1];
Vecleft [1] = vecline [0];

// Setup length parameters
Flength = (float) SQRT (vecline [0] * vecline [0] + vecline [1] * vecline [1]);
If (flength <0.1)
{
Flength = 0.1f;
}
Th = nwidth/(2.0f * flength );
Ta = nwidth/(2.0f * (TANF (ftheta)/2.0f) * flength );

// Find the base of the arrow
Pbase. x = (INT) (aptpoly [0]. x +-TA * vecline [0]);
Pbase. Y = (INT) (aptpoly [0]. Y +-TA * vecline [1]);

// Build the points on the sides of the arrow
Aptpoly [1]. x = (INT) (pbase. x + Th * vecleft [0]);
Aptpoly [1]. Y = (INT) (pbase. Y + Th * vecleft [1]);
Aptpoly [2]. x = (INT) (pbase. x +-th * vecleft [0]);
Aptpoly [2]. Y = (INT) (pbase. Y +-th * vecleft [1]);

Movetoex (* PDC, pfrom. X, pfrom. Y, null );

// Draw we're fillin '...
If (bfill ){
Lineto (* PDC, aptpoly [0]. X, aptpoly [0]. y );
Polygon (* PDC, aptpoly, 3); // draw an entity triangle
}
//... Or even Jes chillin '...
Else
{
Lineto (* PDC, pbase. X, pbase. y );
Lineto (* PDC, aptpoly [1]. X, aptpoly [1]. y );
Lineto (* PDC, aptpoly [0]. X, aptpoly [0]. y );
Lineto (* PDC, aptpoly [2]. X, aptpoly [2]. y );
Lineto (* PDC, pbase. X, pbase. y );
Movetoex (* PDC, aptpoly [0]. X, aptpoly [0]. Y, null );
}
// End the drawing

PDC-> SelectObject (poldpen );
PDC-> SelectObject (pbrold );
}

/// // Call:
DC. moveTo (points [0]. X, points [0]. y );
Arrowto (& DC, points [1], ps_solid, 1, RGB (0, 0), 10, 45, false );

2. Refresh the screen.

Dialog attribute: Set clip children to true. This indicates editing the subwindow when creating a dialog box,
That is, when invalidate (); is called, The Child window is not repainted. It can be ensured that the interface will not flash when invalidate.

Void cbuttontestdlg: onpaint ()
{
If (isiconic ())
{
///....
}
Else
{
Invalidate (); // The value must be invalidate, followed by cpaintdc DC (this );
Cpaintdc DC (this); // device context used for plotting

Cpoint points [2];
Getlinepoints (rfmsstepbutton *) getdlgitem (124), (rfmsstepbutton *) getdlgitem (125), points );

DC. moveTo (points [0]. X, points [0]. y );
Arrowto (& DC, points [1], ps_solid, 1, RGB (0, 0), 10, 45, false );

Getlinepoints (rfmsstepbutton *) getdlgitem (123), (rfmsstepbutton *) getdlgitem (125), points );
DC. moveTo (points [0]. X, points [0]. y );
Arrowto (& DC, points [1], ps_solid, 1, RGB (0, 0), 10, 45, true );

Cdialog: onpaint ();
}
}