From a1b3ace3866458706942d1fa7089ad37e7034486 Mon Sep 17 00:00:00 2001
From: Jaklyy <102590697+Jaklyy@users.noreply.github.com>
Date: Fri, 22 Dec 2023 15:07:57 -0500
Subject: [PATCH] fix 0px tall polygon aa

---
 src/GPU3D_Soft.cpp | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/src/GPU3D_Soft.cpp b/src/GPU3D_Soft.cpp
index c96464a6..1139d3b4 100644
--- a/src/GPU3D_Soft.cpp
+++ b/src/GPU3D_Soft.cpp
@@ -1036,6 +1036,14 @@ void SoftRenderer::RenderPolygonScanline(const GPU& gpu, RendererPolygon* rp, s3
         }
     }
 
+    // quick hack to fix a minor bug.
+    // for some reason 0 pixel tall polygons have broken aa.
+    if (polygon->YBottom == polygon->YTop)
+    {
+        l_edgecov = 0;
+        r_edgecov = 0;
+    }
+
     // interpolate attributes along Y
 
     s32 rl = interp_start->Interpolate(vlcur->FinalColor[0], vlnext->FinalColor[0]);