Looped Live Code Editing — Handmade Hero — Episode Guide

2:45Review of the live code editing feature

4:13Building a demo to show gameplay tuning workflow

9:00Testing the demo

11:20Adding jumping

14:10Necessary improvements to square drawing

15:44Jump tuning

16:52Problems with gameplay tuning and a solution

18:19Making a loop editor for code

19:33The ease of storing the input stream in memory

20:25Writing it out to disk instead

21:49Creating a win32_state structure that we can pass around

22:30Press L to record

24:41Usage code for recording and playback

25:36Implementing the record and playback functions

28:14Functions to handle the recording output file

31:04Functions to handle reading in the recording file

32:22Some code to loop the input playback

34:56Testing the recording and playback

37:48Bug-fixing

40:06Input record success, moving on to record game state

42:27Implementing recording of game state

47:54Testing, and a failure to loop

49:43Successful looped editing demonstration

54:50Playing around with window types

59:47Transparent Window! And Access Violation!

1:01:56Improvements to transparent window.

1:03:47Final Thoughts

1:06:24Q&A

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1:06:24Q&A

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1:06:24Q&A

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1:06:50Does Win32PlayBackInput need to return status in case the file read fails and/or reaches the end, since in those cases the function output data structures will be stale or invalid?

1:08:36Will this break when you make changes to the game_state structure?

1:11:30Why didn't you use a switch for all the VKCode stuff?

1:11:54Since it's mostly zeroes, do you think it'd be worth writing out the game state in a sparse way using a simple RLE or something, or is performance sufficient? Or perhaps that would make performance worse?

1:13:22What's on the schedule for next week?

1:13:57Are you going to show how to create more debug tools like this?

1:15:01Regarding saving game state for recording, won't we run into problems if we port a system that doesn't allow us to specify a base address?

1:16:08Any chance for a high-level overview while cleaning up?

1:16:45Isn't a two gig snapshot of your game memory crazy huge though?

1:19:17I think your sine wave is a tad bit off on land of the jump.

1:19:38I'm thinking maybe less about the error and more about what happens at the end of the stream when it loops, doesn't that generate an extra repeated input event played back, or am I missing something?

1:21:25Can you clarify if function pointers are part of that game_state block, maybe elaborate on what could ever cause it to fail or misalign?

1:24:26How can we make the playback work if we have no base address?

1:25:40Wouldn't the address spaces of two game_state's clash?

1:27:00Would a memory-mapped file that doesn't commit to disk be faster to read/write from?

1:27:58I thought you were going to use the memory snapshot as a game save, but you're using it like a save state in an emulator.

1:28:30How easy do you think it is to re-arrange an existing codebase so that it supports the instant live code editing feature, and what steps would need to be taken to get there?

1:30:02Will there be a Christmas special?

1:30:18How will replay work once you have start-up logic for the game? How will it be skipped? Will it just work?

1:31:04Clarification of earlier question (How often do you look up code?) How often do you study code on your own?

1:33:22Perhaps ReBaseImage() regarding loading dll at location?

1:33:51Suggestion to add -mix to the linker for fixed dll location.

1:35:14How long did it take for you to get to a point where you can concieve of a feature and with little effort know exactly what you need to accomplish to realize that feature?

1:38:43Couldn't you create an offset pointer struct which overloads the unary * operator?

1:40:43Have you got some good explanation on how you architect code, is that in the text you wrote about your work on the Witness?

1:42:06I have to spend a lot of time unlearning what I was taught just to get to features which should be easy, but were made hard by the kind of programming I learned in school. Have you had a similar painful unlearning process?

1:44:51Wrap-up

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1:44:51Wrap-up

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1:44:51Wrap-up

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