Note: Drawing pixels in Plan9

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+---
+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!*