[directfb-users] error(Invalid argument!) about for create surface with preallocated memory if the "dsc.preallocated[0].pitch < 0"

[jojo]

Hi,
I want to use directfb to Blit/StretchBlit with my preallocated memory, my preallocated memory's stride is negative (src_stride < 0) and the address "src_data"

is end of source data.

It return error from "CreateSurface", my steps and environment is following:

DFB version : 1.4.0

DFBSurfaceDescription dsc = {0};
dsc.flags = DSDESC_WIDTH | DSDESC_HEIGHT | DSDESC_PIXELFORMAT | DSDESC_PREALLOCATED | DSDESC_CAPS;
dsc.pixelformat = DSPF_RGB32;
dsc.caps = DSCAPS_SYSTEMONLY;

dsc.width = src_width;
dsc.height = src_height;
dsc.preallocated[0].data = src_data;
dsc.preallocated[0].pitch = src_stride;

ret = dfb->CreateSurface(dfb, &dsc, &src );
if (ret != DFB_OK) {
printf("CreateSurface(src) error(%s)\n", DirectResultString(ret));
return;
}


Anyone have ideas about for this ?

Thanks,

- Jojo