From 3dc34ef835783cb522cb39ac3eb56ee13cfd5653 Mon Sep 17 00:00:00 2001
From: YariKartoshe4ka <yaroslav.kikel.06@inbox.ru>
Date: Wed, 11 Jan 2023 22:06:30 +0300
Subject: [PATCH 1/2] Optimize Arduboy2Base::drawFastVLine

---
 src/Arduboy2.cpp | 24 ++++++++++++++++++++----
 1 file changed, 20 insertions(+), 4 deletions(-)

diff --git a/src/Arduboy2.cpp b/src/Arduboy2.cpp
index 552828d..fc00431 100644
--- a/src/Arduboy2.cpp
+++ b/src/Arduboy2.cpp
@@ -547,12 +547,28 @@ void Arduboy2Base::drawRect
 void Arduboy2Base::drawFastVLine
 (int16_t x, int16_t y, uint8_t h, uint8_t color)
 {
-  int end = y+h;
-  for (int a = max(0,y); a < min(end,HEIGHT); a++)
+  if (x < 0 || x >= WIDTH || y >= HEIGHT) return;
+
+  color = (color == WHITE ? ~0 : 0);
+
+  if (y < 0)
   {
-    drawPixel(x,a,color);
+    h += y;
+    y = 0;
   }
-}
+
+  int16_t end = y + h;
+
+  sBuffer[(y & 0xf8) * WIDTH / 8 + x] = color << (y - (y & 0xf8));
+
+  for (uint8_t i = max(y + 7, 0); i < min(end, HEIGHT); i += 8)
+  {
+    sBuffer[(i & 0xf8) * WIDTH / 8 + x] = color;
+  }
+
+  sBuffer[(min(end, HEIGHT - 1) & 0xf8) * WIDTH / 8 + x] = color >> (8 - (min(end, HEIGHT - 1) & 7));
+};
+
 
 void Arduboy2Base::drawFastHLine
 (int16_t x, int16_t y, uint8_t w, uint8_t color)

From 8db5f35a4eb88ce631ccfeb12898d4fd0967c293 Mon Sep 17 00:00:00 2001
From: YariKartoshe4ka <yaroslav.kikel.06@inbox.ru>
Date: Thu, 12 Jan 2023 15:22:07 +0300
Subject: [PATCH 2/2] Fix bug with overwriting

---
 src/Arduboy2.cpp | 14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)

diff --git a/src/Arduboy2.cpp b/src/Arduboy2.cpp
index fc00431..0f77e4c 100644
--- a/src/Arduboy2.cpp
+++ b/src/Arduboy2.cpp
@@ -558,15 +558,21 @@ void Arduboy2Base::drawFastVLine
   }
 
   int16_t end = y + h;
+  uint8_t data, colorUp = 0xff << (y - (y & 0xf8)),
+          colorDown = 0xff >> (8 - (min(end, HEIGHT - 1) & 7));
 
-  sBuffer[(y & 0xf8) * WIDTH / 8 + x] = color << (y - (y & 0xf8));
+  data = sBuffer[(y & 0xf8) * WIDTH / 8 + x] | colorUp;
+  if (!color) data ^= colorUp;
+  sBuffer[(y & 0xf8) * WIDTH / 8 + x] = data;
 
-  for (uint8_t i = max(y + 7, 0); i < min(end, HEIGHT); i += 8)
+  for (uint8_t i = max(y + 7, 0) & 0xf8; i <= min(end, HEIGHT - 1) - 7; i += 8)
   {
-    sBuffer[(i & 0xf8) * WIDTH / 8 + x] = color;
+    sBuffer[i * WIDTH / 8 + x] = color;
   }
 
-  sBuffer[(min(end, HEIGHT - 1) & 0xf8) * WIDTH / 8 + x] = color >> (8 - (min(end, HEIGHT - 1) & 7));
+  data = sBuffer[(min(end, HEIGHT - 1) & 0xf8) * WIDTH / 8 + x] | colorDown;
+  if (!color) data ^= colorDown;
+  sBuffer[(min(end, HEIGHT - 1) & 0xf8) * WIDTH / 8 + x] = data;
 };