https://stackoverflow.com/questions/14364535
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RussianCan you try this because I have no such version right now.
dsc.caps = DFBSurfaceCapabilities(DSCAPS_PRIMARY | DSCAPS_FLIPPING);
...
primary->Flip(primary, NULL, DFBSurfaceFlipFlags(0));
How to execute this DirectFB sample?
質問
I got the following directFB example code form the tutorials:
#include <stdio.h>
#include <unistd.h>
#include <directfb/directfb.h>
static IDirectFB *dfb = NULL;
static IDirectFBSurface *primary = NULL;
static int screen_width = 0;
static int screen_height = 0;
#define DFBCHECK(x...) \
{ \
DFBResult err = x; \
\
if (err != DFB_OK) \
{ \
fprintf( stderr, "%s <%d>:\n\t", __FILE__, __LINE__ ); \
DirectFBErrorFatal( #x, err ); \
} \
}
int main(int argc, char **argv) {
DFBSurfaceDescription dsc;
DFBCHECK(DirectFBInit (&argc, &argv));
DFBCHECK(DirectFBCreate (&dfb));
DFBCHECK(dfb->SetCooperativeLevel (dfb, DFSCL_FULLSCREEN));
dsc.flags = DSDESC_CAPS;
dsc.caps = DSCAPS_PRIMARY | DSCAPS_FLIPPING;
DFBCHECK(dfb->CreateSurface( dfb, &dsc, &primary ));
DFBCHECK(primary->GetSize (primary, &screen_width, &screen_height));
DFBCHECK(primary->FillRectangle (primary, 0, 0, screen_width, screen_height));
DFBCHECK(primary->SetColor (primary, 0x80, 0x80, 0xff, 0xff));
DFBCHECK(primary->DrawLine (primary, 0, screen_height / 2, screen_width - 1, screen_height / 2));
DFBCHECK(primary->Flip (primary, NULL, 0));
sleep(5);
primary->Release(primary);
dfb->Release(dfb);
return 23;
}
And I'm trying to compile and got the error (from a gnome-terminal):
$ g++ Test01HorizontalLine.cpp -I /usr/local/include/directfb/
Test01HorizontalLine.cpp: In function ‘int main(int, char**)’:
Test01HorizontalLine.cpp:27: error: invalid conversion from ‘int’ to ‘DFBSurfaceCapabilities’
Test01HorizontalLine.cpp:33: error: invalid conversion from ‘int’ to ‘DFBSurfaceFlipFlags’
I'm using DFB 1.4.11 (I can't update for my current project). How can I make this sample run? (newbie)
--update
After update the lines (as stated by @jclin):
dsc.caps = DFBSurfaceCapabilities(DSCAPS_PRIMARY | DSCAPS_FLIPPING);
...
primary->Flip(primary, NULL, DFBSurfaceFlipFlags(0));
the result is:
$ g++ Test01HorizontalLine.cpp -I /usr/local/include/directfb/
/tmp/cc6iUS1W.o: In function `main':
Test01HorizontalLine.cpp:(.text+0x1c): undefined reference to `DirectFBInit'
Test01HorizontalLine.cpp:(.text+0x61): undefined reference to `DirectFBErrorFatal'
Test01HorizontalLine.cpp:(.text+0x6d): undefined reference to `DirectFBCreate'
Test01HorizontalLine.cpp:(.text+0xb2): undefined reference to `DirectFBErrorFatal'
Test01HorizontalLine.cpp:(.text+0x111): undefined reference to `DirectFBErrorFatal'
Test01HorizontalLine.cpp:(.text+0x188): undefined reference to `DirectFBErrorFatal'
Test01HorizontalLine.cpp:(.text+0x1ef): undefined reference to `DirectFBErrorFatal'
Test01HorizontalLine.cpp:(.text+0x26d): undefined reference to `DirectFBErrorFatal'
/tmp/cc6iUS1W.o:Test01HorizontalLine.cpp:(.text+0x2e4): more undefined references to `DirectFBErrorFatal' follow
collect2: ld returned 1 exit status
解決 2
他のヒント
Below code works on my test ubuntu12, I may have different directfb with yous but should be similar:
#include <stdio.h>
#include <unistd.h>
#include <directfb/directfb.h>
static IDirectFB *dfb = NULL;
static IDirectFBSurface *primary = NULL;
static int screen_width = 0;
static int screen_height = 0;
#define DFBCHECK(x...) \
{ \
DFBResult err = x; \
\
if (err != DFB_OK) \
{ \
fprintf( stderr, "%s <%d>:\n\t", __FILE__, __LINE__ ); \
DirectFBErrorFatal( #x, err ); \
} \
}
int main(int argc, char **argv) {
DFBSurfaceDescription dsc;
DFBCHECK(DirectFBInit (&argc, &argv));
DFBCHECK(DirectFBCreate (&dfb));
DFBCHECK(dfb->SetCooperativeLevel (dfb, DFSCL_FULLSCREEN));
dsc.flags = DSDESC_CAPS;
dsc.caps = DFBSurfaceCapabilities(DSCAPS_PRIMARY | DSCAPS_FLIPPING);
DFBCHECK(dfb->CreateSurface( dfb, &dsc, &primary ));
DFBCHECK(primary->GetSize (primary, &screen_width, &screen_height));
DFBCHECK(primary->FillRectangle (primary, 0, 0, screen_width, screen_height));
DFBCHECK(primary->SetColor (primary, 0x80, 0x80, 0xff, 0xff));
DFBCHECK(primary->DrawLine (primary, 0, screen_height / 2, screen_width - 1, screen_height / 2));
primary->Flip(primary, NULL, DFBSurfaceFlipFlags(0));
sleep(5);
primary->Release(primary);
dfb->Release(dfb);
return 23;
}
Build with below command line:
g++ -o testHorizonLine Test01HorizontalLine.cpp -I/usr/include \
-I/usr/include/directfb -L/usr/lib/i386-linux-gnu -ldirectfb
To find where libdirectfb.so is located, you could use linux find command, then add -L option to g++ command to include library path and add -ldirectfb to link libdirectfb.so file.
$ find /usr/lib -name libdirectfb.so
Run testhorizonLine output:
~~~~~~~~~~~~~~~~~~~~~~~~~~| DirectFB 1.2.10 |~~~~~~~~~~~~~~~~~~~~~~~~~~
(c) 2001-2008 The world wide DirectFB Open Source Community
(c) 2000-2004 Convergence (integrated media) GmbH
----------------------------------------------------------------
(*) DirectFB/Core: Single Application Core. (2012-05-21 06:43)
(!) Direct/Util: opening '/dev/fb0' failed
--> Permission denied
(!) DirectFB/FBDev: Error opening framebuffer device!
(!) DirectFB/FBDev: Use 'fbdev' option or set FRAMEBUFFER environment variable.
(!) DirectFB/Core: Could not initialize 'system_core' core!
--> Initialization error!
Test01HorizontalLine.cpp <24>:
(#) DirectFBError [DirectFBCreate (&dfb)]: Initialization error!
In case you use libraries in your project, including headers is only half of the work. You must also show where the actual library (libdirectfb.so in your case) is located so it can be linked to your code. Do this by passing -L and -l options (also note that neither prefix lib- nor externsion .so are required):
g++ your_source_file.cpp -I /path/to/include -L/path/to/lib -ldirectfb
There are great deal of topics on how to use libraries in your projects i.e. you might want to start here and here
P.S. It is always a good idea to use -Wall option to see more information on what's happening.
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