443 - simple graphics primitives

http://docs.racket-lang.org/graphics/Mouse_Operations.html

Like with the text mode primitives, we still don't have a story for
writing white-box tests for code using these.

1 files changed, 20 insertions, 0 deletions

diff --git a/graphics.mu b/graphics.mu
new file mode 100644
index 00000000..c4520c8f
--- /dev/null
+++ b/graphics.mu
@@ -0,0 +1,20 @@
+; open a viewport, print coordinates of mouse clicks
+; currently need to ctrl-c to exit after closing the viewport
+(function main [
+  (graphics-on)
+  { begin
+    (pos:integer-integer-pair click?:boolean <- mouse-position)
+    { begin
+      (break-if click?:boolean)
+      (loop 2:blocks)
+    }
+    (x:integer <- get pos:integer-integer-pair 0:offset)
+    (y:integer <- get pos:integer-integer-pair 1:offset)
+    (print-primitive x:integer)
+    (print-primitive ((", " literal)))
+    (print-primitive y:integer)
+    (print-primitive (("\n" literal)))
+    (loop)
+  }
+  (graphics-off)
+])