From 6bda8c29038649f4bd4c54ce011473b1344bb291 Mon Sep 17 00:00:00 2001 From: Dana Jansens Date: Mon, 11 Feb 2008 01:15:06 -0500 Subject: [PATCH] speed up the pyramid gradient using memcpy's. also make it not crash for 1px high textures. here are some sample profiling results. pyramid2 is the new code % cumulative self self total time seconds seconds calls ms/call ms/call name 58.78 1.54 1.54 255 6.04 6.04 gradient_pyramid1 40.46 2.60 1.06 255 4.16 4.16 gradient_pyramid2 54.88 2.25 2.25 504 4.46 4.46 gradient_pyramid1 44.88 4.09 1.84 504 3.65 3.65 gradient_pyramid2 --- render/gradient.c | 87 ++++++++++++++++++++++++++++++------------------------- 1 file changed, 48 insertions(+), 39 deletions(-) diff --git a/render/gradient.c b/render/gradient.c index d7401a9..fc75047 100644 --- a/render/gradient.c +++ b/render/gradient.c @@ -754,14 +754,13 @@ static void gradient_crossdiagonal(RrSurface *sf, gint w, gint h) *data = COLOR(x); } -static void gradient_pyramid(RrSurface *sf, gint inw, gint inh) +static void gradient_pyramid(RrSurface *sf, gint w, gint h) { - gint x, y, w = (inw >> 1) + 1, h = (inh >> 1) + 1; - RrPixel32 *data = sf->pixel_data; - RrPixel32 *end = data + inw*inh - 1; - RrPixel32 current; + RrPixel32 *ldata, *rdata; + RrPixel32 *cp; RrColor left, right; RrColor extracorner; + gint x, y, halfw, halfh, midx, midy; VARS(lefty); VARS(righty); @@ -771,54 +770,64 @@ static void gradient_pyramid(RrSurface *sf, gint inw, gint inh) extracorner.g = (sf->primary->g + sf->secondary->g) / 2; extracorner.b = (sf->primary->b + sf->secondary->b) / 2; - SETUP(lefty, (&extracorner), sf->secondary, h); - SETUP(righty, sf->primary, (&extracorner), h); + halfw = w >> 1; + halfh = h >> 1; + midx = w - halfw - halfw; /* 0 or 1, depending if w is even or odd */ + midy = h - halfh - halfh; /* 0 or 1, depending if h is even or odd */ + + SETUP(lefty, sf->primary, (&extracorner), halfh + midy); + SETUP(righty, (&extracorner), sf->secondary, halfh + midy); + + /* draw the top half + + it is faster to draw both top quarters together than to draw one and + then copy it over to the other side. + */ + + ldata = sf->pixel_data; + rdata = ldata + w - 1; + for (y = halfh + midy; y > 0; --y) { /* 0 -> (h+1)/2 */ + RrPixel32 c; - for (y = h - 1; y > 0; --y) { /* 0 -> h-1 */ COLOR_RR(lefty, (&left)); COLOR_RR(righty, (&right)); - SETUP(x, (&left), (&right), w); + SETUP(x, (&left), (&right), halfw + midx); - for (x = w - 1; x > 0; --x) { /* 0 -> w-1 */ - current = COLOR(x); - *(data+x) = current; - *(data+inw-x) = current; - *(end-x) = current; - *(end-(inw-x)) = current; + for (x = halfw + midx - 1; x > 0; --x) { /* 0 -> (w+1)/2 */ + c = COLOR(x); + *(ldata++) = *(rdata--) = c; NEXT(x); } - current = COLOR(x); - *(data+x) = current; - *(data+inw-x) = current; - *(end-x) = current; - *(end-(inw-x)) = current; - - data+=inw; - end-=inw; + c = COLOR(x); + *ldata = *rdata = c; + ldata += halfw + 1; + rdata += halfw - 1 + midx + w; NEXT(lefty); NEXT(righty); } - COLOR_RR(lefty, (&left)); - COLOR_RR(righty, (&right)); - SETUP(x, (&left), (&right), w); + /* copy the top half into the bottom half, mirroring it, so we can only + copy one row at a time - for (x = w - 1; x > 0; --x) { /* 0 -> w-1 */ - current = COLOR(x); - *(data+x) = current; - *(data+inw-x) = current; - *(end-x) = current; - *(end-(inw-x)) = current; + it is faster, to move the writing pointer forward, and the reading + pointer backward - NEXT(x); + this is the current code, moving the write pointer forward and read + pointer backward + 41.78 4.26 1.78 504 3.53 3.53 gradient_pyramid2 + this is the opposite, moving the read pointer forward and the write + pointer backward + 42.27 4.40 1.86 504 3.69 3.69 gradient_pyramid2 + + */ + ldata = sf->pixel_data + (halfh - 1) * w; + cp = ldata + (midy + 1) * w; + for (y = halfh; y > 0; --y) { + memcpy(cp, ldata, w * sizeof(RrPixel32)); + ldata -= w; + cp += w; } - current = COLOR(x); - *(data+x) = current; - *(data+inw-x) = current; - *(end-x) = current; - *(end-(inw-x)) = current; } - -- 1.9.1