How To Draw Rectangle In Dev C%2b%2b
How do I used glBegin(what goes here) to draw a rectangle using this? Edit 2: We are using OpenGL 2.6 or 2.7 for my class so can't use stuff from 3.0+. Also using C on windows. Edit: Why does this now draw 4 vertices? I know this function is supposed to work because it is from an example. So i have this code which makes a box, but want to make the corners +, the lengths , and the widths -. Also want to input a number so you can draw them like cout<<'enter the length number'.
Drawing in windows applications by using plain GDI involves acquainting with DC, BITMAP, PEN, BRUSH, FONT objects and WM_PAINT-ing messages and system functions operating on the objects. Each time application window should be redrawed it receives following messages:
- WM_PAINT – when should be redrawed client area of the window,
- WM_NCPAINT – when should be redrawed non-client (NC) area of the window.
Client area of the window is the inner part of its: all area excluding windows caption, border frames and optional menu component. Non client area includes border frames and window caption. It is depicted below:
To draw something on a window we should handle WM_PAINT message. It can be done as below: http://frannabtatent1975.tilda.ws/page14686153.html.
As we see, before start drawing we obtain a HDC value (a handle to Device Context object). Using GDI, all drawing operations are done just on DC objects. Device context is a structure that defines a set of graphics objects (such as PEN, BRUSH, FONT, BITMAP) and device drawing capabilities (which varies between devices – another capabilities has a Screen and another has a Printer). PEN object is used to draw shapes (Rectangles, Squares, Circles, Ellipses, custom Polylines). BRUSH is used for filling the shapes with specified color or pattern. FONT allows for drawing texts and BITMAP is an optional object that – if assigned to DC – holds drawings done. When we call function BeginPaint we receive a HDC which represents client area of the window. This handle can be used in following GDI functions for creating basic primitives:
Here is demonstration of how to draw Rectangle of specified border and background color.
After finishing painting EndPaint function should be called. Having client area DC of the winow we cannot draw allover the window. We can check it thanks to following function:
Result of the code can looks like this:
window client area drawing
Trying to draw outside the client rect does not affected neither NC window nor menu area. So if we want to draw custom lookandfill rectangular window we have to obtain window DC and do drawing also in WM_NCPAINT:
How To Draw Rectangle In Dev C++ Free
Now in CustomDraw and CustomNCDraw functions we have access to allover window area. After painting it we must release handle to DC by calling ReleaseDC system function.