From 3a6248361216294cc2a3492f2455ab6bcf1af96c Mon Sep 17 00:00:00 2001
From: ch4nsuk3 <chansuke@gmail.com>
Date: Fri, 26 Jul 2024 18:19:56 -0500
Subject: [PATCH 1/5] Initial Testing

Initial testing of the transparency block.
---
 adafruit_imageload/png.py | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/adafruit_imageload/png.py b/adafruit_imageload/png.py
index 34b32f0..93d0e21 100644
--- a/adafruit_imageload/png.py
+++ b/adafruit_imageload/png.py
@@ -61,6 +61,10 @@ def load(
     height = 0
     while True:
         size, chunk = struct.unpack(">I4s", file.read(8))
+        print("==================")
+        print(size)
+        print(chunk)
+        print('====================')
         if chunk == b"IHDR":
             (
                 width,
@@ -86,6 +90,9 @@ def load(
                 pal = palette(pal_size)
                 for i in range(pal_size):
                     pal[i] = file.read(3)
+        elif chunk == b"tRNS":
+            transparent = file.read(size)
+            print(transparent)
         elif chunk == b"IDAT":
             data.extend(file.read(size))
         elif chunk == b"IEND":

From 0aed0e9c1ccd84085e3f6fa545ad82112064dd52 Mon Sep 17 00:00:00 2001
From: ch4nsuk3 <134003603+ch4nsuk3@users.noreply.github.com>
Date: Wed, 31 Jul 2024 15:02:30 -0500
Subject: [PATCH 2/5] Initial Implementation

Transparency checking works, but there still may be efficient methods.
---
 adafruit_imageload/png.py | 10 ++++------
 1 file changed, 4 insertions(+), 6 deletions(-)

diff --git a/adafruit_imageload/png.py b/adafruit_imageload/png.py
index 93d0e21..130579c 100644
--- a/adafruit_imageload/png.py
+++ b/adafruit_imageload/png.py
@@ -61,10 +61,6 @@ def load(
     height = 0
     while True:
         size, chunk = struct.unpack(">I4s", file.read(8))
-        print("==================")
-        print(size)
-        print(chunk)
-        print('====================')
         if chunk == b"IHDR":
             (
                 width,
@@ -91,8 +87,10 @@ def load(
                 for i in range(pal_size):
                     pal[i] = file.read(3)
         elif chunk == b"tRNS":
-            transparent = file.read(size)
-            print(transparent)
+            trns_list = list(file.read(size))
+            indices = [i for i, x in enumerate(trns_list) if x == 0]
+            for index in indices:
+                pal.make_transparent(index)
         elif chunk == b"IDAT":
             data.extend(file.read(size))
         elif chunk == b"IEND":

From ce523ff41fe4446f0d2926815a55391b2c424570 Mon Sep 17 00:00:00 2001
From: ch4nsuk3 <chansuke@gmail.com>
Date: Thu, 1 Aug 2024 15:41:56 -0500
Subject: [PATCH 3/5] Final Implementation

Various testing shows using a for loop is the quickest method, beating enumeration and list comprehension.
---
 adafruit_imageload/png.py | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/adafruit_imageload/png.py b/adafruit_imageload/png.py
index 130579c..8e0d481 100644
--- a/adafruit_imageload/png.py
+++ b/adafruit_imageload/png.py
@@ -48,7 +48,7 @@ def load(
     :param object palette: Type to store the palette. Must have API similar to
       `displayio.Palette`. Will be skipped if None.
     """
-    # pylint: disable=too-many-locals,too-many-branches
+    # pylint: disable=too-many-locals,too-many-branches, consider-using-enumerate, too-many-statements
     header = file.read(8)
     if header != b"\x89PNG\r\n\x1a\n":
         raise ValueError("Not a PNG file")
@@ -87,10 +87,12 @@ def load(
                 for i in range(pal_size):
                     pal[i] = file.read(3)
         elif chunk == b"tRNS":
-            trns_list = list(file.read(size))
-            indices = [i for i, x in enumerate(trns_list) if x == 0]
-            for index in indices:
-                pal.make_transparent(index)
+            if size > len(pal):
+                raise ValueError("More transparency entries than palette entries")
+            trns_data = file.read(size)
+            for i in range(len(trns_data)):
+                if trns_data[i] == 0:
+                    pal.make_transparent(i)
         elif chunk == b"IDAT":
             data.extend(file.read(size))
         elif chunk == b"IEND":

From a8809b03a6f40a2f96402d5ec9d864edddc5f27e Mon Sep 17 00:00:00 2001
From: ch4nsuk3 <chansuke@gmail.com>
Date: Thu, 1 Aug 2024 15:44:40 -0500
Subject: [PATCH 4/5] Updated author info

---
 adafruit_imageload/png.py | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/adafruit_imageload/png.py b/adafruit_imageload/png.py
index 8e0d481..870313c 100644
--- a/adafruit_imageload/png.py
+++ b/adafruit_imageload/png.py
@@ -1,5 +1,6 @@
 # SPDX-FileCopyrightText: 2022 Radomir Dopieralski
 # SPDX-FileCopyrightText: 2023 Matt Land
+# SPDX-FileCopyrightText: 2024 Channing Ramos
 #
 # SPDX-License-Identifier: MIT
 
@@ -10,7 +11,7 @@
 Load pixel values (indices or colors) into a bitmap and colors into a palette
 from a PNG file.
 
-* Author(s): Radomir Dopieralski, Matt Land
+* Author(s): Radomir Dopieralski, Matt Land, Channing Ramos
 
 """
 

From a7ac0db3a7f5c39808718afe165b7a2f1a985dbb Mon Sep 17 00:00:00 2001
From: ch4nsuk3 <chansuke@gmail.com>
Date: Fri, 2 Aug 2024 16:24:59 -0500
Subject: [PATCH 5/5] Del trans_data

Deletes the trans_data list after its no longer needed.
---
 adafruit_imageload/png.py | 1 +
 1 file changed, 1 insertion(+)

diff --git a/adafruit_imageload/png.py b/adafruit_imageload/png.py
index 870313c..dbc0abf 100644
--- a/adafruit_imageload/png.py
+++ b/adafruit_imageload/png.py
@@ -94,6 +94,7 @@ def load(
             for i in range(len(trns_data)):
                 if trns_data[i] == 0:
                     pal.make_transparent(i)
+            del trns_data
         elif chunk == b"IDAT":
             data.extend(file.read(size))
         elif chunk == b"IEND":