gradient_painter

gradient_painter lets you draw a linear gradient. You can set start- and end-colors and the angle in which the gradient is drawn.

namespace win32 { namespace gui {

     class gradient_painter : public painter_base
     {
     public:
          typedef std::pair<COLORREF, COLORREF> GradientColors;       // first: start color, second: end color
          typedef const GradientColors& param0;   
          typedef unsigned param1;

          // c'tor
          gradient_painter(const GradientColors& colors, unsigned angle = 0);   

          // virtual functions of painter_base
          gradient_painter* clone() const;
          void draw(HDC hDC, int cx, int cy);     
          bool is_opaque(int cx, int cy) const;
               
          // own functions
          void gradient_colors(const GradientColors& colors);
          GradientColors gradient_colors() const;
          void angle(unsigned angle);
          unsigned angle() const;
          static GradientColors make_gradient_colors(COLORREF crStart, COLORREF crEnd);   
     };

} }  // namespace win32::gui

Note:

• gradient_colors() returns the start- and end-colors of the gradient
  
  

• angle() returns the angle of the gradient

Example:

unsigned angle = ...;
COLORREF cr_blue = RGB(0, 0, 150);
COLORREF cr_black = RGB(0, 0, 0);
add_painter<gradient_painter> ( gradient_painter::make_gradient_colors(cr_blue, cr_black), angle );

The result is as follows

angle = 0	angle = 90	angle = 180	angle = 270