From 4a2806829574c6661c342e60e9430edb6d8b49dd Mon Sep 17 00:00:00 2001
From: RSDuck <RSDuck@users.noreply.github.com>
Date: Tue, 26 Jan 2021 19:05:21 +0100
Subject: [PATCH] the rasteriser doesn't have to be done on line 144 thanks to
 the VRAM cache

---
 src/GPU.cpp | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/src/GPU.cpp b/src/GPU.cpp
index 40334de7..e31b2392 100644
--- a/src/GPU.cpp
+++ b/src/GPU.cpp
@@ -1124,6 +1124,14 @@ void StartScanline(u32 line)
     {
         if (VCount == 192)
         {
+            // in reality rendering already finishes at line 144
+            // and games might already start to modify texture memory.
+            // That doesn't matter for us because we cache the entire
+            // texture memory anyway and only update it before the start
+            //of the next frame.
+            // So we can give the rasteriser a bit more headroom
+            GPU3D::VCount144();
+
             // VBlank
             DispStat[0] |= (1<<0);
             DispStat[1] |= (1<<0);
@@ -1144,10 +1152,6 @@ void StartScanline(u32 line)
             if (Accelerated) GLCompositor::RenderFrame();
 #endif
         }
-        else if (VCount == 144)
-        {
-            GPU3D::VCount144();
-        }
     }
 
     NDS::ScheduleEvent(NDS::Event_LCD, true, HBLANK_CYCLES, StartHBlank, line);