From f8fc3518ddf7707963405124a94cb559e63a0320 Mon Sep 17 00:00:00 2001
From: Josh Holtrop <jholtrop@gmail.com>
Date: Tue, 10 Oct 2023 19:25:24 -0400
Subject: [PATCH] Update write_png() to take a Color array

---
 src/fart/png.d | 25 +++++++++++++++++++------
 1 file changed, 19 insertions(+), 6 deletions(-)

diff --git a/src/fart/png.d b/src/fart/png.d
index 6c1d3c4..fd9f6a4 100644
--- a/src/fart/png.d
+++ b/src/fart/png.d
@@ -7,6 +7,7 @@ import std.digest;
 import fart.bfile;
 import fart.crc32;
 import fart.hton;
+import fart.color;
 
 private immutable ubyte[] HEADER = [0x89, 0x50, 0x4E, 0x47, 0x0D, 0x0A, 0x1A, 0x0A];
 
@@ -88,13 +89,27 @@ private void write_chunk(Chunk)(BFile file, string chunk_type, Chunk chunk)
     file.writeObject(crc_be32);
 }
 
-public void write_png(string filename, uint width, uint height, ubyte[] data)
+public void write_png(string filename, uint width, uint height, const(Color)[] data)
 {
+    if (data.length != width * height)
+        return;
+
+    ubyte[] pixel_data;
+    size_t data_index;
+    for (size_t y = 0; y < height; y++)
+    {
+        /* Filter method 0 (None) */
+        pixel_data ~= 0;
+        for (size_t x = 0; x < width; x++)
+        {
+            pixel_data ~= data[data_index++].rgba32();
+        }
+    }
     BFile file = BFile(filename);
     file.write(HEADER);
     IHDR ihdr = IHDR(width, height);
     write_chunk(file, "IHDR", ihdr);
-    IDAT idat = IDAT(data);
+    IDAT idat = IDAT(pixel_data);
     write_chunk(file, "IDAT", idat);
     IEND iend;
     write_chunk(file, "IEND", iend);
@@ -103,18 +118,16 @@ public void write_png(string filename, uint width, uint height, ubyte[] data)
 
 void png_test()
 {
-    ubyte[] pixel_data = [];
+    Color[] pixel_data = [];
     for (size_t y = 0; y < 500; y++)
     {
-        /* Filter method 0 (None) */
-        pixel_data ~= [0];
         for (size_t x = 0; x < 500; x++)
         {
             ubyte r = cast(ubyte)(x / 2);
             ubyte g = 0x80;
             ubyte b = cast(ubyte)((500 - y) / 2);
             ubyte a = cast(ubyte)((abs(cast(int)x - 250) + abs(cast(int)y - 250)) / 2);
-            pixel_data ~= [r, g, b, a];
+            pixel_data ~= Color(r / 255.0, g / 255.0, b / 255.0, a / 255.0);
         }
     }
     write_png("out.png", 500, 500, pixel_data);