Make draw_leaf pass uniformity analysis
It was in fact uniform, but required a little arithmetic to infer that. Refactor the math slightly so it's clear even to a simplistic analysis.
diff --git a/shader/draw_leaf.wgsl b/shader/draw_leaf.wgsl
index e041a51..2ef76db 100644
--- a/shader/draw_leaf.wgsl
+++ b/shader/draw_leaf.wgsl
@@ -80,9 +80,10 @@
let remainder = num_blocks_total % WG_SIZE;
let first_block = n_blocks_base * wg_id.x + min(wg_id.x, remainder);
let n_blocks = n_blocks_base + u32(wg_id.x < remainder);
- var ix = first_block * WG_SIZE + local_id.x;
- let ix_end = ix + n_blocks * WG_SIZE;
- while ix != ix_end {
+ var block_start = first_block * WG_SIZE;
+ let blocks_end = block_start + n_blocks * WG_SIZE;
+ while block_start != blocks_end {
+ let ix = block_start + local_id.x;
let tag_word = read_draw_tag_from_scene(ix);
agg = map_draw_tag(tag_word);
workgroupBarrier();
@@ -262,7 +263,7 @@
}
clip_inp[m.clip_ix] = ClipInp(ix, i32(path_ix));
}
- ix += WG_SIZE;
+ block_start += WG_SIZE;
// break here on end to save monoid aggregation?
prefix = combine_draw_monoid(prefix, sh_scratch[WG_SIZE - 1u]);
}
