basic layout

src/uxn_tutorial_day_5.gmo

@@ -0,0 +1,79 @@
+# uxn tutorial: day 5, the mouse and uxntal goodies
+
+(work in progress)
+
+this is the fifth section of the <(uxn tutorial)>! here we introduce the varvara mouse device to explore more possible interactions, and we cover the remaining elements of uxntal and uxn: the return stack, the return mode and the keep mode.
+
+we also discuss possible structures to create loops using these resources!
+
+# the mouse device
+
+the mouse device in the varvara computer has some similarities with the controller device: it has a vector that is called with any mouse event (change of buttons state, movement, wheel movement) and a couple of bytes to check its state.
+
+it also has a couple of shorts corresponding to the x,y coordinates of the mouse pointer.
+
+we see this device defined in uxntal in the following way:
+
+```
+|90 @Mouse [ &vector $2 &x $2 &y $2 &state $1 &wheel $1 ]
+```
+
+## state byte
+
+the state byte has the possible values:
+
+* 01 when the left button is pressed
+* 10 when the right button is pressed
+* 11 when both buttons are pressed
+* 00 when none of the buttons are pressed
+
+## wheel byte
+
+the wheel byte has the possible values:
+
+* 01 when the mouse wheel is moving upwards
+* ff when the mouse wheel is moving downwards
+* 00 when the mouse wheel is not moving
+
+## mouse vector
+
+the mouse vector will be fired in any of the following events:
+
+* a button was pressed
+* a button was released
+* the mouse was moved
+* the mouse wheel was moved
+
+
+here's a 1bpp sprite of a mouse pointer, taken from the uxn examples:
+
+```
+@pointer_icn [ 80c0 e0f0 f8e0 1000 ]
+```
+
+* mouse device and vector
+* return stack and mode
+* subroutines: parameters, calling, returning
+* keep mode
+* loops
+* practice: sprite as pointer
+* practice: simple drawing tool
+
+new instructions: STH, JSR 
+
+# instructions of day 5
+
+these are all the uxntal instructions that we discussed today!
+
+* STH
+* JSR
+
+# coming soon: day 6
+
+meanwhile, i invite you to keep exploring, to share your findings, and to also take a break!
+
+stay tuned!
+
+# support
+
+if you found this tutorial to be helpful, consider sharing it and giving it your <(support)> :)