nanogui: Performance hints?
Subject:
Performance hints?
From:
"Richard Copeman" ####@####.####
Date:
26 Nov 2007 12:04:14 +0000
Message-Id: <008401c83024$76d18e60$642aa8c0@Buffy>
Hi,
I am using 16 bit frame buffer driver and am getting killed on performance. I have hooked up a JTAG debugger and run some profiling on the code and it is spending about 35% of the cpu time in a small loop copying memory in linear16_drawhorzline().
It is here:
_addr/line________|source
|linear16_drawhorzline(PSD psd, MWCOORD x1, MWCOORD x2, MWCOOR
82 |{
83 | ADDR16 addr = psd->addr;
|
85 | assert (addr != 0);
86 | assert (x1 >= 0 && x1 < psd->xres);
87 | assert (x2 >= 0 && x2 < psd->xres);
88 | assert (x2 >= x1);
89 | assert (y >= 0 && y < psd->yres);
90 | assert (c < psd->ncolors);
|
92 | DRAWON;
93 | addr += x1 + y * psd->linelen;
94 | if(gr_mode == MWMODE_COPY) {
| /* FIXME: memsetw(dst, c, x2-x1+1)*/
=========>>>>> | while(x1++_<=_x2)
97 | *addr++ = c;
| } else {
| while (x1++ <= x2) {
100 | applyOp(gr_mode, c, addr, ADDR16);
101 | ++addr;
| }
| }
104 | DRAWOFF;
Can somebody tell me why the memsetw() function has been commented out with a FIXME? Surely, that would have been a faster approach.
Maybe I am expecting too much of Nano-X. If so, can somebody please confirm or deny this for me? I am trying to draw to an off screen buffer (640x640x16bpp) and then flush it to screen using GrArea(). Maybe there is a better way of doing it?
If I am barking up the wrong tree here, can some kind soul point me at a direct fb library I can use?
Thanks,
Richard.
