added notes

_subsections/sec03/lesson-07.org

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+#+HTML_HEAD: <link rel="stylesheet" type="text/css" href="../../../../../_share/media/css/org-mode.css" />
+#+HTML_HEAD: <link rel="stylesheet" type="text/css" href="../../../_share/media/css/godot.css" />
 #+title: Section 03 - Lesson 07 | Moving the Gem
 
 * Links
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 - [[https://www.udemy.com/course/jumpstart-to-2d-game-development-godot-4-for-beginners/learn/lecture/45070467#announcements][S03:L14.07 - Moving the Gem]]
 
 * Notes
+
+we use scripting to extend node functionality
+
+** get the gem to fall
+- we need to get the Gem/Area2D node to fall
+  - if we had the sprite fall, the collision2D node would stay where it was
+
+
+*** add a script to the root node
+  - click on the attach new script button in the scene pane
+    -
+        #+ATTR_HTML: :width 200px
+       [[file:../../../_share/media/img/albert/attach_new_script.png]]
+  - one script per node is the limit
+  - you get access to all the children nodes inside the scene.
+
+*** attach node script dialogue
+- Template is generally Node: Default
+- some object types provide other templates with different boiler plate code
+
+- the node we attached a script to will have a script icon next to the eye icon
+    -
+        #+ATTR_HTML: :width 200px
+       [[file:../../../_share/media/img/albert/script_icon.png]]
+
+*** detaching script from node
+- sometimes you don't want a certain script attached to a node
+  - for testing purposes to prevent a script from doing something
+  - you want a different script, etc.
+
+- if a script is attached, then when you select the node the "script attach button" will change from a green plus to a red x
+- press the button and detach it
+
+** life cycle of a node
+*** functions
+- _ready()
+- _process(delta:float)
+
+*** tree build by stages
+1. initialization stage
+   - creation
+   - function: _init_()
+
+2. attachment stage
+   - added to tree
+   - function: _enter_tree()
+
+3. finalization stage
+   - node and children ready
+   - function: _read()
+
+*** how it is built
+- every node is given an id before it gets a name
+
+- all init functions will be called before any other stage for any other node is invoked
+
+- similarly the attachment stage, of adding nodes to other nodes takes place before any other function in any other node is activated
+  - at this point we get a name for the node
+
+- ready tells us that the node is up and ready to go, and so are its children
+  - therefore the children of the node will be set up before the parent
+  - ready will be called for the children first
+
+*** process functions
+- invoked on all nodes
+- every frame
+
+- used to update the node each frame
+
+- delta refers to the time that elapsed since previous call on previous frame
+  - use delta to normalize things
+
+**** _process(delta)
+- called in main loop
+- as fast as possible
+
+**** _physics_process(delta)
+- called in main loop
+- regular interval
+
+** adding code to move gem down
+- increase the y position
+- all node parameters can be found in inspector (including inherited)
+- position.y = position.y + speed * delta
+  - speed can be anything
+  - we multiply by delta to normalize it compared to the time of the previous frame