[directfb-dev] Some font flags are "sticky" when they shouldn't be - DirectFB 1.0.1

[Poole, Bryce]

I just ran into a problem on DirectFB 1.0.1.  I setup a layer surface, called 
DrawString with no problem.  I set the surface's Destination Color Key drawing 
flag.  I then called DrawString and observed that the resulting blits for 
drawing the glyphs of the font utilized the surface's Dest Color Key flag.  I 
then disabled the flag by setting it to NOFX and called DrawString again.  But 
this time, the font continued to use Dest Color Key flag even though the 
surface's flag had been cleared.

I followed the code down and it appears that when DrawString is called the 
surface's CardState is intelligently copied into the font's CardState in the 
function: setup_font_state:gfxcard.c.  The offending code is:

          if (state->drawingflags & DSDRAW_DST_COLORKEY) {
               flags |= DSBLIT_DST_COLORKEY;
               dfb_state_set_dst_colorkey( &font->state, state->dst_colorkey );
          }

As can be seen, the flag is set conditionally, but never cleared.  I admit to 
being tempted to add the following:
            else
            {
              flags &= ~DSBLIT_DST_COLOR_KEY;
            }

but I am unaware if this is valid for other locations in the code.  Can anyone 
speak to this?  Incidentally, this seems true for the other flags such as 
DSDRAW_XOR and DSDRAW_BLEND.

For those that would like to see this in action, I have attached some sample 
code that demonstrates this:

#include <stdio.h>
#include <unistd.h>
#include <directfb.h>

int main (int argc, char **argv)
{
    IDirectFB *dfb = NULL;
    DirectFBInit (&argc, &argv);
    DirectFBCreate (&dfb);

    IDirectFBDisplayLayer *pLayer;
    dfb->GetDisplayLayer(dfb, DLID_PRIMARY, &pLayer);
    pLayer->SetCooperativeLevel(pLayer, DLSCL_EXCLUSIVE);

    DFBFontDescription desc;
    desc.height = 24;
    desc.flags  = DFDESC_HEIGHT;

    IDirectFBFont *pFont;
    dfb->CreateFont(dfb, "decker.ttf",&desc,&pFont);

    IDirectFBSurface *pSurface;
    pLayer->GetSurface(pLayer, &pSurface);

    pSurface->SetFont(pSurface, pFont);

    // Clear to Red
    pSurface->Clear(pSurface, 0xFF, 0x00, 0x00, 0xFF);

    // Draw Blue String
    pSurface->SetColor(pSurface, 0x00, 0x00, 0xFF, 0xFF);
    pSurface->DrawString(pSurface,
                         "Before Dest Color Key is set", -1,
                         100, 100, DSTF_LEFT);

    // Set Destination Color Key Flag
    pSurface->SetDrawingFlags(pSurface, DSDRAW_DST_COLORKEY);
    // Set the Dest Color Key to Red
    pSurface->SetDstColorKey(pSurface, 0xFF, 0x00, 0x00);
    pSurface->DrawString(pSurface,
                         "DestColorKey:SET ColorKey:RED String:VISIBLE", -1,
                         100, 120, DSTF_LEFT);

    // Set the Dest Color Key to something besides Red
    pSurface->SetDstColorKey(pSurface, 0x00, 0xFF, 0x00);
    pSurface->DrawString(pSurface,
                         "DestColorKey:SET ColorKey:GREEN String:NOT_VISIBLE", 
-1,
                         100, 120, DSTF_LEFT);

    // Clear Destination Color Key Flag
    pSurface->SetDrawingFlags(pSurface, DSDRAW_NOFX);
    pSurface->DrawString(pSurface,
                         "DestColorKey:CLEARED ColorKey:GREEN 
String:SHOULD_BE_VISIBLE(But isn't)",
                         -1, 100, 140, DSTF_LEFT);

    sleep(10);

    pFont->Release(pFont);
    pSurface->Release(pSurface);
    pLayer->Release(pLayer);
    dfb->Release( dfb );

    return 0;
}

Thanks to anyone that can help me confirm if this is a bug or if I have just 
done something wrong.

Bryce Poole

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