animesh wrote:
> Hi All,
> I am using DirectFB 1.0.1, and trying to run the following code.
> This code is the df_palette.c code that comes with the DirectFB
> Examples, which i have modified a bit for seeing the use of SetColorIndex.
>
> Can anyone tell me what is wrong in this code, and if nothing is
> wrong then why i am getting the error.
> "SetColorIndex not supported."
>
> What is the use of SetColorIndex?
> How can this code be modified to use SetColorIndex.
SetColorIndex() saves finding the index by comparing each palette entry with
the given color.
Only surfaces with DSPF_*LUT* formats support it.
From looking at your I think this should work.
>
> #include <stdio.h>
> #include <stdlib.h>
> #include <string.h>
> #include <unistd.h>
> #include <directfb.h>
>
> /* the super interface */
> static IDirectFB *dfb;
>
> /* the primary surface (surface of primary layer) */
> static IDirectFBSurface *primary;
> static IDirectFBPalette *palette;
>
> /* Input interfaces: device and its buffer */
> static IDirectFBEventBuffer *events;
>
> static int screen_width, screen_height;
>
> /* macro for a safe call to DirectFB functions */
> #define DFBCHECK(x...) \
>
> { \
> err =
> x; \
> if (err != DFB_OK)
> { \
> fprintf( stderr, "%s <%d>:\n\t", __FILE__, __LINE__
> ); \
> DirectFBErrorFatal( #x, err
> ); \
>
> } \
> }
>
> static void
> generate_palette()
> {
> int i;
> DFBResult err;
> DFBColor colors[256];
>
>
> for (i=0; i<256; i++) {
> colors[i].a = 0xff;
> colors[i].r = i + 85;
> colors[i].g = i;
> colors[i].b = i + 171;
> }
>
> DFBCHECK(palette->SetEntries( palette, colors, 256, 0 ));
> }
>
> static void
> rotate_palette()
> {
> DFBResult err;
> DFBColor colors[256];
>
> DFBCHECK(palette->GetEntries( palette, colors, 256, 0 ));
>
> DFBCHECK(palette->SetEntries( palette, colors + 1, 255, 0 ));
>
> colors[0].r += 17;
> colors[0].g += 31;
> colors[0].b += 29;
> DFBCHECK(palette->SetEntries( palette, colors, 1, 255 ));
> }
>
> static void
> fill_surface( IDirectFBSurface *surface )
> {
> DFBResult err;
> int x;
> int y;
> void *ptr;
> int pitch;
> u8 *dst;
>
> DFBCHECK(surface->Lock( surface, DSLF_WRITE, &ptr, &pitch ));
>
> for (y=0; y<screen_height; y++) {
> dst = ptr + y * pitch;
>
> for (x=0; x<screen_width; x++)
> dst[x] = (x*x + y) / (y+1);
> }
>
> DFBCHECK(surface->Unlock( surface ));
> }
> int
> main( int argc, char *argv[] )
> {
> int quit = 0;
> DFBResult err;
> DFBSurfaceDescription sdsc;
> DFBColor colors[256];
> int i;
>
> colors[0].a = 0xff;
> colors[0].r = 0xff;
> colors[0].g = 0xff;
> colors[0].b = 0x00;
>
> for (i=1; i<256; i++) {
> colors[i].a = 0xff;
> colors[i].r = i + 85;
> colors[i].g = i;
> colors[i].b = i + 171;
> }
>
> DFBCHECK(DirectFBInit( &argc, &argv ));
>
> /* create the super interface */
> DFBCHECK(DirectFBCreate( &dfb ));
>
> /* create an event buffer for all devices */
> DFBCHECK(dfb->CreateInputEventBuffer( dfb, DICAPS_ALL,
> DFB_FALSE, &events ));
>
> /* set our cooperative level to DFSCL_FULLSCREEN
> for exclusive access to the primary layer */
> dfb->SetCooperativeLevel( dfb, DFSCL_FULLSCREEN );
>
> /* get the primary surface, i.e. the surface of the
> primary layer we have exclusive access to */
> sdsc.flags = DSDESC_CAPS | DSDESC_PIXELFORMAT | DSDESC_PALETTE;
> sdsc.caps = DSCAPS_PRIMARY;
> sdsc.pixelformat = DSPF_LUT8;
> sdsc.palette.entries = colors;
> sdsc.palette.size = 256;
>
> DFBCHECK(dfb->CreateSurface( dfb, &sdsc, &primary ));
> primary->Clear( primary, 0, 0, 0, 0 );
>
> primary->GetSize( primary, &screen_width, &screen_height );
>
> /* get access to the palette */
> DFBCHECK(primary->GetPalette( primary, &palette ));
>
> generate_palette();
> fill_surface( primary );
>
> DFBCHECK(primary->SetColorIndex(primary, 0));
> primary->FillRectangle (primary, 10, 10, 240, 320);
>
> primary->Flip (primary, NULL, 0);
>
> while (!quit) {
> DFBInputEvent evt;
>
> while (events->GetEvent( events, DFB_EVENT(&evt) ) == DFB_OK) {
> switch (evt.type) {
> case DIET_KEYPRESS:
> switch (evt.key_symbol) {
> case DIKS_ESCAPE:
> quit = 1;
> break;
> default:
> ;
> }
> default:
> ;
> }
> }
> }
>
> /* release our interfaces to shutdown DirectFB */
> palette->Release( palette );
> primary->Release( primary );
> events->Release( events );
> dfb->Release( dfb );
>
> return 0;
> }
>
> And one more doubt, In the documentation given in the following link.
>
> http://www.directfb.org/docs/DirectFB_Reference/types.html#DFBSurfaceDescription
>
>
> The DFBSurfaceDescription, structure is having the following field, but
> in the actual code,
> const DFBColor *entries;
> unsigned int size ;
> are part of the palette structure as you can seen in the above code:
> sdsc.palette.entries = colors;
> sdsc.palette.size = 256;
>
> Why is this ambiguity?
The documentation generator needs to be fixed to handle nested structs.
--
Best regards,
Denis Oliver Kropp
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| DirectFB - Hardware accelerated graphics |
| http://www.directfb.org/ |
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