From bffa77f98cdb8971c10090c47e63a58492a20fa4 Mon Sep 17 00:00:00 2001
From: Tim Sylvester <tim@wetdogweather.com>
Date: Wed, 7 Jun 2023 14:11:14 -0700
Subject: [PATCH] Drawable Renderer (#1570), Fix stencil IDs on tiles passed to
 `renderTileClippingMasks` more than once during a frame

---
 src/mbgl/renderer/paint_parameters.cpp | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/src/mbgl/renderer/paint_parameters.cpp b/src/mbgl/renderer/paint_parameters.cpp
index 3fffbe93a..63eac29ca 100644
--- a/src/mbgl/renderer/paint_parameters.cpp
+++ b/src/mbgl/renderer/paint_parameters.cpp
@@ -149,8 +149,15 @@ void PaintParameters::renderTileClippingMasks(TIter beg, TIter end, GetTileIDFun
     for (auto i = beg; i != end; ++i) {
         const auto& tileID = f(*i);
 
-        const int32_t stencilID = nextStencilID++;
-        tileClippingMaskIDs.emplace(tileID, stencilID);
+        const int32_t stencilID = nextStencilID + 1;
+        const auto result = tileClippingMaskIDs.insert(std::make_pair(tileID, stencilID));
+        if (result.second) {
+            // inserted
+            nextStencilID++;
+        } else {
+            // already present
+            continue;
+        }
 
         program->draw(context,
                       *renderPass,