Fuzz atomic and msaa PLS modes

Diffs=
3191f5e38 Fuzz atomic and msaa PLS modes (#7236)

Co-authored-by: Chris Dalton <99840794+csmartdalton@users.noreply.github.com>

.rive_head

diff --git a/.rive_head b/.rive_head
index 89472af..89189b0 100644
--- a/.rive_head
+++ b/.rive_head
@@ -1 +1 @@
-cd35e613d258ba2e0e8698ce7a1b826977a13ec7
+3191f5e384df0016a4e82bf113b70b253a06ec35

renderer/intersection_board.cpp

diff --git a/renderer/intersection_board.cpp b/renderer/intersection_board.cpp
index 4d62dce..a58318b 100644
--- a/renderer/intersection_board.cpp
+++ b/renderer/intersection_board.cpp
@@ -211,6 +211,10 @@
         return 0;
     }
 
+    // Clamp ltrb to the viewport to avoid integer overflows.
+    ltrb.xy = simd::max(ltrb.xy, int2(0));
+    ltrb.zw = simd::min(ltrb.zw, m_viewportSize);
+
     // Find the tiled row and column that each corner of the rectangle falls on.
     int4 span = (ltrb - int4{0, 0, 1, 1}) / 255;
     span = simd::clamp(span, int4(0), int4{m_cols, m_rows, m_cols, m_rows} - 1);

renderer/pls_render_context.cpp

diff --git a/renderer/pls_render_context.cpp b/renderer/pls_render_context.cpp
index b5a4a1f..9f17286 100644
--- a/renderer/pls_render_context.cpp
+++ b/renderer/pls_render_context.cpp
@@ -880,10 +880,15 @@
         {
             PLSDraw* draw = m_plsDraws[i].get();
 
+            int4 drawBounds = simd::load4i(&m_plsDraws[i]->pixelBounds());
+
             // Add one extra pixel of padding to the draw bounds to make absolutely certain we get
             // no overlapping pixels, which destroy the atomic shader.
-            int4 drawBounds = simd::load4i(&m_plsDraws[i]->pixelBounds());
-            drawBounds += int4{-1, -1, 1, 1};
+            const int32_t kMax32i = std::numeric_limits<int32_t>::max();
+            const int32_t kMin32i = std::numeric_limits<int32_t>::min();
+            drawBounds = simd::if_then_else(drawBounds != int4{kMin32i, kMin32i, kMax32i, kMax32i},
+                                            drawBounds + int4{-1, -1, 1, 1},
+                                            drawBounds);
 
             // Our top priority in re-ordering is to group non-overlapping draws together, in order
             // to maximize batching while preserving correctness.