From f75ae45608cb9745c4c2bcc781b3cbea9ff93865 Mon Sep 17 00:00:00 2001
From: Mitja Felicijan <mitja.felicijan@gmail.com>
Date: Sat, 27 May 2023 17:49:00 +0200
Subject: Note: Drawing pixels in Plan9

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 content/notes/drawing-pixels-in-plan9.md |  66 +++++++++++++++++++++++++++++++
 content/notes/plan9-screenshot.md        |   4 ++
 static/notes/plan9-pixels.png            | Bin 0 -> 10737 bytes
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 create mode 100644 content/notes/drawing-pixels-in-plan9.md
 create mode 100644 static/notes/plan9-pixels.png

diff --git a/content/notes/drawing-pixels-in-plan9.md b/content/notes/drawing-pixels-in-plan9.md
new file mode 100644
index 0000000..e5f5af4
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+++ b/content/notes/drawing-pixels-in-plan9.md
@@ -0,0 +1,66 @@
+---
+title: "Drawing Pixels in Plan9"
+url: drawing-pixels-in-plan9.html
+date: 2023-05-27T17:41:33+02:00
+type: notes
+draft: true
+tags: [plan9, graphics]
+---
+
+I have started exploring Plan9's graphics capabilities. This is a hello world
+alternative for drawing that draws a yellow square on a blue background.
+
+![Plan9 Howdy World!](/notes/plan9-pixels.png)
+
+```c
+#include <u.h>
+#include <libc.h>
+#include <draw.h>
+#include <cursor.h>
+
+void main(int argc, char *argv[])
+{
+  ulong co;
+  Image *im, *bg;
+  co = 0xFF0000FF;
+
+  if (initdraw(nil, nil, argv0) < 0)
+  {
+    sysfatal("%s: %r", argv0);
+  }
+
+  im = allocimage(display, Rect(0, 0, 100, 100), RGB24, 0, DYellow);
+  bg = allocimage(display, Rect(0, 0, 1, 1), RGB24, 1, co);
+
+  if (im1 == nil || bg == nil)
+  {
+    sysfatal("get more memory, bub");
+  }
+
+  draw(screen, screen->r, bg, nil, ZP);
+  draw(screen, screen->r, im, nil, Pt(-40, -40));
+
+  flushimage(display, Refnone);
+
+  // Wait 10 seconds before exiting.
+  sleep(10000);
+
+  exits(nil);
+}
+```
+
+And then compile with Makefile:
+
+```makefile
+</$objtype/mkfile
+
+RC=/rc/bin
+BIN=/$objtype/bin
+MAN=/sys/man
+
+main:
+	$CC $CFLAGS main.c
+	$LD $LDFLAGS -o main main.$O
+```
+
+*This is **very cool** indeed!*
diff --git a/content/notes/plan9-screenshot.md b/content/notes/plan9-screenshot.md
index ad11358..71e5808 100644
--- a/content/notes/plan9-screenshot.md
+++ b/content/notes/plan9-screenshot.md
@@ -13,6 +13,10 @@ output it to `/dev/screen`. You can then use `topng` to convert it to a png
 image.
 
 ```sh
+# Instant screenshot.
 cat /dev/screen | topng > screen.png
+
+# Delayed screenshot (5 seconds).
+sleep 5; cat /dev/screen | topng > screen.png
 ```
 
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