Apple-2-SW
/
Penetrator-apple2
mirror of https://github.com/StewBC/penetrator-apple2.git
1
0
Fork 0
Code Issues Projects Releases Wiki Activity

Update README.md 

Added profile and general cleanup
This commit is contained in:
StewBC 2019-12-17 08:37:53 -08:00
parent 4f4c5c6218
commit 62420f8fe1
1 changed files with 44 additions and 12 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

56
README.md
View File

@ -19,11 +19,39 @@ also missing the demo attract mode, and the fireworks.
The game is written in 6502 assembly using the ca65 assembler.
The other interesting thing about the original is that it ran the AI and user
input twice for every world move. This version does not do it the same way. The
bullet update ran twice for each world update but now that the world moves while
the bullets move twice, the bullets could pass through the walls. To fix this
issue, I have made the bullets 50% longer.
Below is a CPU cycle profile of 1 game frame in stage 4. It's a busy frame with
bullets, bombs and enemies. Most importantly, it has a busy terrain at the top
and bottom.
| Hex | Dec | % of the | Item |
| Cycles | Cycles | Frame | |
|--------|--------|----------|---------------------|
|148F3 |84211 |100% |Total Frame |
|61F |1567 |2.0% |inputGame |
|0A |10 |0.0% |Misc |
|73 |115 |0.1% |gameWorldMove |
|05 |5 |0.0% |Misc |
|19 |25 |0.0% |gameCheckStage |
|08 |8 |0.0% |Misc |
|B80 |2944 |3.5% |gameAI |
|17 |23 |0.0% |Misc |
|7267 |29287 |34.8% |drawClearRows |
|6721 |26401 |31.4% |terrainDraw |
|38A8 |14504 |17.2% |drawEnemies |
|985 |2437 |2.9% |drawPlayer |
|581 |1409 |1.7% |drawBullets |
|6E3 |1763 |2.1% |drawBombs |
|E14 |3604 |4.3% |drawExplosions |
|06 |6 |0.0% |Misc |
|1A |26 |0.0% |drawPresent |
|11 |17 |0.0% |Misc |
|3C |60 |0.1% |Emulator error |
As can be seen, clearing the area where the world will be drawn takes almost 35%
of the frame and drawing the terrain takes another 31% of the frame. The
Emulator Error are unaccounted for cycles -discrepency between total cycles at
the start and end, vs. the cycles reported in each step. I modifies the
emulator myself to do step reporting and I assume I must have missed someting.
4. KEYS and JOYSTICK
@ -31,6 +59,9 @@ The Apple 2 gameplay works only with a joystick since you cannot detect multiple
keys down on the Apple II. The UI works with the keyboard or joystick and the
world editor uses both.
The joystick can also drive the menu's. Pressing right, for example, is
equivalent to pressing 1 (the UI menu options are selected through numbers).
The menus all show the keys to advance. There's also a help screen in the
editor.
@ -45,16 +76,16 @@ There are actually 2 programs in this. The 1st is the game, and it's in
src/apple2.
* defs.inc - Constants and definitions used throughout
* draw.inc - VERA layer drawing. drawSprite, for example
* draw.inc - HGR buffer drawing. drawSprite, for example
* edit.inc - The built-in world editor
* file.inc - Load and Save code
* fontdata.inc - A ZX Spectrum font in 16x8
* fontdata.inc - A ZX Spectrum font in reverse 8x8 - Apple II format
* game.inc - The in-game logic, AI etc. The bulk of the "game"
* input.inc - User controls for game and editor
* logo.hgr - 8Kb splash screen in HGR format
* logo.inc - file that simply does an incbin on logo.hgr
* logo.inc - File that simply does an incbin on logo.hgr
* logodata.inc - Line data for writing Penetrator and logo image data
* macros.inc - print macros mostly
* macros.inc - Print macros mostly
* penetrator.asm - Where the game starts, initial setup, etc.
* penetrator.cfg - ca65 configuration file
* rodata.inc - Read-only data such as lookup tables, sprites etc.
@ -62,8 +93,8 @@ src/apple2.
* text.inc - In game text and print functions
* trndata.inc - The world data (triplet - top, bottom and enemy pos)
* ui.inc - User facing screens, name input, etc.
* variables.inc - All non zero page variables
* zpvars.inc - The zero page variables
* variables.inc - All non zero page variables (stats, scores, draw buffers)
* zpvars.inc - The zero page variables (most variables)
The second is the ProDos loader that will auto-load the game. It's in the
src/apple2.loader folder. It has these files (all provided to me by Oliver
@ -74,7 +105,8 @@ Schmidt)
6. BUILDING THE GAME
Making the game has a few steps. Use make and the Makefile on all OSs, that would be the easiest.
Making the game has a few steps. Use make and the Makefile on all OSs, that
would be the easiest.
Start by making the loader - this needs to be done once only.
make TARGETS=apple2.loader