GDI

Bird flying to the cursor's position

• Demonstration
• Functionality:
  • Create an application with 1 window:
    • No caption bar, no border
    • Topmost
    • Only the bird should be visible, the rest of the window should be transparent
    • The window moves to the mouse cursor's position
      • The speed of movement should be constant and independent on the direction
    • An animated bird is displayed in the window
      • The bird should be headed (in a proper way) to the cursor's position
      • Animation frames can be found in this file
        • Application can load them from files or resources
        • In all frames, the RGB(0, 255, 255) colour should be used as transparent
• Hints:
  • WS_EX_LAYERED, SetLayeredWindowAttributes()
  • SetTimer(), WM_TIMER
  • LoadBitmap(), LoadImage()
  • atan2(), sin(), cos()
  • SetGraphicsMode(), GM_ADVANCED, ModifyWorldTransform()
    • Translation:

      XFORM xform;
      xform.eM11 = 1.0f;
      xform.eM12 = 0.0f;
      xform.eM21 = 0.0f;
      xform.eM22 = 1.0f;
      xform.eDx = (float)dx;
      xform.eDy = (float)dy;
      

    • Rotation:

      XFORM xform;
      xform.eM11 = cosine;
      xform.eM12 = -sine;
      xform.eM21 = sine;
      xform.eM22 = cosine;
      xform.eDx = 0.0f;
      xform.eDy = 0.0f;
      

    • Vertical mirroring:

      XFORM xform;
      xform.eM11 = -1.0f;
      xform.eM12 = 0.0f;
      xform.eM21 = 0.0f;
      xform.eM22 = 1.0f;
      xform.eDx = 0.0f;
      xform.eDy = 0.0f;
      

• Approximate points:
  • Window's features: 2.0
  • Moving the window to the current cursor position: 3.0
  • Displaying an animated bird in the window: 3.5
  • Proper rotating and mirroring the bird: 1.5

• Links for uploading:
  • Solutions
  • Corrections