Use memset to zero z_list

Using gprof I found the engine spending 10 - 20% of time in the
_render_canvas_item_tree function. The function profiles as using
about 0.09ms. Swapping the loop with two memset() calls reduces
the time spent in this function a lot, and the time per call to
about 0.02ms.

Likewise the render_canvas function was using ~10% of time, replacing
the loop there dropped per-call time from 0.22ms to 0.18ms.
This commit is contained in:
Hein-Pieter van Braam 2017-08-27 02:40:04 +02:00
parent a6e37ae2bf
commit 27c142a57b

View file

@ -37,10 +37,8 @@ void VisualServerCanvas::_render_canvas_item_tree(Item *p_canvas_item, const Tra
RasterizerCanvas::Item *z_list[z_range];
RasterizerCanvas::Item *z_last_list[z_range];
for (int i = 0; i < z_range; i++) {
z_list[i] = NULL;
z_last_list[i] = NULL;
}
memset(z_list, 0, z_range * sizeof(RasterizerCanvas::Item *));
memset(z_last_list, 0, z_range * sizeof(RasterizerCanvas::Item *));
_render_canvas_item(p_canvas_item, p_transform, p_clip_rect, Color(1, 1, 1, 1), 0, z_list, z_last_list, NULL, NULL);
@ -200,10 +198,9 @@ void VisualServerCanvas::render_canvas(Canvas *p_canvas, const Transform2D &p_tr
RasterizerCanvas::Item *z_list[z_range];
RasterizerCanvas::Item *z_last_list[z_range];
for (int i = 0; i < z_range; i++) {
z_list[i] = NULL;
z_last_list[i] = NULL;
}
memset(z_list, 0, z_range * sizeof(RasterizerCanvas::Item *));
memset(z_last_list, 0, z_range * sizeof(RasterizerCanvas::Item *));
for (int i = 0; i < l; i++) {
_render_canvas_item(ci[i].item, p_transform, p_clip_rect, Color(1, 1, 1, 1), 0, z_list, z_last_list, NULL, NULL);
}