From a4849d40b34de4433e0a512b1efde5f7d572be96 Mon Sep 17 00:00:00 2001
From: Hermet Park <hermet@lottiefiles.com>
Date: Sat, 21 Jun 2025 12:14:55 +0900
Subject: [PATCH] sw_engine: small optimization with a fast-clipping region
 access

Now the engine can access intermidate rle sections
with a specific y ranges, It doesn't need full iterations.
---
 src/renderer/sw_engine/tvgSwRle.cpp | 21 ++++++++++++++-------
 1 file changed, 14 insertions(+), 7 deletions(-)

diff --git a/src/renderer/sw_engine/tvgSwRle.cpp b/src/renderer/sw_engine/tvgSwRle.cpp
index 58ebffa2..a902aac4 100644
--- a/src/renderer/sw_engine/tvgSwRle.cpp
+++ b/src/renderer/sw_engine/tvgSwRle.cpp
@@ -881,12 +881,18 @@ bool rleClip(SwRle *rle, const SwRle *clip)
     Array<SwSpan> out;
     out.reserve(std::max(rle->spans.count, clip->spans.count));
 
-    auto spans = rle->data();
-    auto end = rle->spans.end();
-    auto cspans = clip->data();
-    auto cend = clip->spans.end();
+    const SwSpan *end;
+    auto spans = rle->fetch(clip->spans.first().y, clip->spans.last().y, &end);
 
-    while(spans < end && cspans < cend) {
+    if (spans >= end) {
+        rle->spans.clear();
+        return false;
+    }
+
+    const SwSpan *cend;
+    auto cspans = clip->fetch(spans->y, (end - 1)->y, &cend);
+
+    while (spans < end && cspans < cend) {
         //align y-coordinates.
         if (cspans->y > spans->y) {
             ++spans;
@@ -928,9 +934,10 @@ bool rleClip(SwRle *rle, const RenderRegion* clip)
     Array<SwSpan> out;
     out.reserve(rle->spans.count);
     auto data = out.data;
+    const SwSpan* end;
     uint16_t x, len;
 
-    ARRAY_FOREACH(p, rle->spans) {
+    for (auto p = rle->fetch(*clip, &end); p < end; ++p) {
         if (p->y >= max.y) break;
         if (p->y < min.y || p->x >= max.x || (p->x + p->len) <= min.x) continue;
         if (p->x < min.x) {
@@ -948,4 +955,4 @@ bool rleClip(SwRle *rle, const RenderRegion* clip)
     }
     out.move(rle->spans);
     return true;
-}
\ No newline at end of file
+}