| How can I set up a SCR_RECT structure?

Previous | Graphics and Display | Next

Q: | How I can setup properly a SCR_RECT structure? For example, the FillTriangle function requires the parameter of SCR_RECT type. How to put coordinates into it, so that I can change the clipping area for the screen?
A: | If all coordinates of clip area are known in advance (for example 5, 5, 90, 70), do this:
    FillTriangle (10, 10, 10, 50, 50, 50, &(SCR_RECT){{5, 5, 90, 70}}, A_NORMAL);
or, using "standard" C (i.e. without GNU extensions):
    SCR_RECT area = {{5, 5, 90, 70}};  // somewhere in the declaration part
    ...
    FillTriangle (10, 10, 10, 50, 50, 50, &area, A_NORMAL);
Note that double braces are necessary because SCR_RECT is an union. If coordinates are not known in advance, for examples if they are in integer variables a, b, c and d, you can do this:
    SCR_RECT area;
    ...
    area.xy.x0 = a;
    area.xy.y0 = b;
    area.xy.x1 = c;
    area.xy.y1 = d;
    FillTriangle (10, 10, 10, 50, 50, 50, &area, A_NORMAL);
or, much simpler, using GNU C extensions:
    FillTriangle (10, 10, 10, 50, 50, 50, &(SCR_RECT){{a, b, c, d}}, A_NORMAL);