From 2450451a53d0a3650ce859de27855c8ece5279b9 Mon Sep 17 00:00:00 2001
From: Pete Favelle <pete@fsquared.co.uk>
Date: Mon, 12 Sep 2022 13:45:39 +0100
Subject: [PATCH 1/3] Initialise newly allocated buffer_t data to zero, to
 clear up display corruption

---
 libraries/utility.cpp | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/libraries/utility.cpp b/libraries/utility.cpp
index 7a9848a..b951f4d 100644
--- a/libraries/utility.cpp
+++ b/libraries/utility.cpp
@@ -60,7 +60,7 @@ namespace picosystem {
     buffer_t *b = new buffer_t();
     b->w = w;
     b->h = h;
-    b->data = data ? (color_t *)data : new color_t[w * h];
+    b->data = data ? (color_t *)data : new color_t[w * h]{};
     return b;
   }
 
@@ -111,4 +111,4 @@ namespace picosystem {
     return _fsin_lut[uint8_t((v * _2PI_LUTS) + 64)];
   }
 
-}
\ No newline at end of file
+}

From edeea558c6f36fe80dd092a738fd691dd452986a Mon Sep 17 00:00:00 2001
From: Pete Favelle <pete@fsquared.co.uk>
Date: Mon, 12 Sep 2022 14:08:26 +0100
Subject: [PATCH 2/3] Track when we allocate data in buffer_t, and delete it in
 destructor

---
 libraries/picosystem.hpp |  5 +++++
 libraries/utility.cpp    | 11 ++++++++++-
 2 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/libraries/picosystem.hpp b/libraries/picosystem.hpp
index edbc1cd..c0cbf05 100644
--- a/libraries/picosystem.hpp
+++ b/libraries/picosystem.hpp
@@ -34,10 +34,15 @@ namespace picosystem {
   struct buffer_t {
     int32_t w, h;
     color_t *data;
+    bool alloc;
 
     color_t *p(int32_t x, int32_t y) {
       return data + (x + y * w);
     }
+
+    ~buffer_t() {
+      if (alloc) delete data;
+    }
   };
 
   struct voice_t {
diff --git a/libraries/utility.cpp b/libraries/utility.cpp
index b951f4d..aa17092 100644
--- a/libraries/utility.cpp
+++ b/libraries/utility.cpp
@@ -60,7 +60,16 @@ namespace picosystem {
     buffer_t *b = new buffer_t();
     b->w = w;
     b->h = h;
-    b->data = data ? (color_t *)data : new color_t[w * h]{};
+    if (data)
+    {
+      b->data = (color_t *)data;
+      b->alloc = false;
+    }
+    else
+    {
+      b->data = new color_t[w * h]{};
+      b->alloc = true;
+    }
     return b;
   }
 

From eb7e4cc024b9fe8d1b16800450cf5d85a9f46eb6 Mon Sep 17 00:00:00 2001
From: Pete Favelle <pete@fsquared.co.uk>
Date: Mon, 12 Sep 2022 14:14:13 +0100
Subject: [PATCH 3/3] Python lint fixes, from @Gadgetoid

---
 micropython/examples/picosystem/text.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/micropython/examples/picosystem/text.py b/micropython/examples/picosystem/text.py
index 8f09c0b..24a1623 100644
--- a/micropython/examples/picosystem/text.py
+++ b/micropython/examples/picosystem/text.py
@@ -10,10 +10,10 @@
 def update(tick):
     global view
 
-    if(pressed(RIGHT)):
+    if pressed(RIGHT):
         view += 1
 
-    if(pressed(LEFT)):
+    if pressed(LEFT):
         view -= 1
 
     view %= view_count