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LaroldsJubilantJunkyardavivaceZoomTen
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Add Part 3: coding a complete shoot-em-up game (#57)
Co-authored-by: Antonio Vivace <[email protected]> Co-authored-by: Zumi <[email protected]>
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‎.gitignore

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/target/
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.DS_Store
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/po/messages.pot
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/galactic-armada/src/generated
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/galactic-armada/dist/
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/galactic-armada/obj/

‎galactic-armada/Makefile

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# You can set the name of the .gb ROM file here
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PROJECTNAME = GalacticArmada
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SRCDIR = src
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LIBDIR = libs
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OBJDIR = obj
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DSTDIR = dist
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RESDIR = $(SRCDIR)/resources
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ASMDIR = $(SRCDIR)/main
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RESSPRITES = $(RESDIR)/sprites
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RESBACKGROUNDS = $(RESDIR)/backgrounds
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GENDIR = $(SRCDIR)/generated
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GENSPRITES = $(GENDIR)/sprites
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GENBACKGROUNDS = $(GENDIR)/backgrounds
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BINS = $(DSTDIR)/$(PROJECTNAME).gb
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# Tools
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RGBDS ?=
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ASM := $(RGBDS)rgbasm
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GFX := $(RGBDS)rgbgfx
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LINK := $(RGBDS)rgblink
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FIX := $(RGBDS)rgbfix
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# Tool flags
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ASMFLAGS := -L
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FIXFLAGS := -v -p 0xFF
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# https://stackoverflow.com/a/18258352
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# Make does not offer a recursive wild card function, so here's one:
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rwildcard = $(foreach d,\
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$(wildcard $(1:=/*)), \
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$(call rwildcard,$d,$2) $(filter $(subst *,%,$2),$d) \
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)
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# https://stackoverflow.com/a/16151140
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# This makes it so every entry in a space-delimited list appears only once
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unique = $(if $1,\
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$(firstword $1) $(call unique,$(filter-out $(firstword $1),$1)) \
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)
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# Collect ASM sources from ASMDIR and LIBDIR.
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ASMSOURCES_COLLECTED = \
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$(call rwildcard,$(ASMDIR),*.asm) $(call rwildcard,$(LIBDIR),*.asm)
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OBJS = $(patsubst %.asm,$(OBJDIR)/%.o,$(notdir $(ASMSOURCES_COLLECTED)))
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all: $(BINS)
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# ANCHOR: generate-graphics
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NEEDED_GRAPHICS = \
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$(GENSPRITES)/player-ship.2bpp \
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$(GENSPRITES)/enemy-ship.2bpp \
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$(GENSPRITES)/bullet.2bpp \
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$(GENBACKGROUNDS)/text-font.2bpp \
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$(GENBACKGROUNDS)/star-field.tilemap \
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$(GENBACKGROUNDS)/title-screen.tilemap
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# Generate sprites, ensuring the containing directories have been created.
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$(GENSPRITES)/%.2bpp: $(RESSPRITES)/%.png | $(GENSPRITES)
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$(GFX) -c "#FFFFFF,#cfcfcf,#686868,#000000;" --columns -o $@ $<
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# Generate background tile set, ensuring the containing directories have been created.
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$(GENBACKGROUNDS)/%.2bpp: $(RESBACKGROUNDS)/%.png | $(GENBACKGROUNDS)
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$(GFX) -c "#FFFFFF,#cbcbcb,#414141,#000000;" -o $@ $<
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# Generate background tile map *and* tile set, ensuring the containing directories
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# have been created.
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$(GENBACKGROUNDS)/%.tilemap: $(RESBACKGROUNDS)/%.png | $(GENBACKGROUNDS)
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$(GFX) -c "#FFFFFF,#cbcbcb,#414141,#000000;" \
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--tilemap $@ \
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--unique-tiles \
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-o $(GENBACKGROUNDS)/$*.2bpp \
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$<
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# ANCHOR_END: generate-graphics
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compile.bat: Makefile
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@echo "REM Automatically generated from Makefile" > compile.bat
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@make -sn | sed y/\\/\\\\/\\\\\\\^/ | grep -v make >> compile.bat
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# ANCHOR: generate-objects
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# Extract directories from collected ASM sources and append "%.asm" to each one,
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# creating a wildcard-rule.
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ASMSOURCES_DIRS = $(patsubst %,%%.asm,\
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$(call unique,$(dir $(ASMSOURCES_COLLECTED))) \
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)
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# This is a Makefile "macro".
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# It defines a %.o target from a corresponding %.asm, ensuring the
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# "prepare" step has ran and the graphics are already generated.
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define object-from-asm
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$(OBJDIR)/%.o: $1 | $(OBJDIR) $(NEEDED_GRAPHICS)
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$$(ASM) $$(ASMFLAGS) -o $$@ $$<
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endef
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# Run the macro for each directory listed in ASMSOURCES_DIRS, thereby
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# creating the appropriate targets.
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$(foreach i, $(ASMSOURCES_DIRS), $(eval $(call object-from-asm,$i)))
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# ANCHOR_END: generate-objects
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# Link and build the final ROM.
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$(BINS): $(OBJS) | $(DSTDIR)
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$(LINK) -o $@ $^
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$(FIX) $(FIXFLAGS) $@
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# Ensure directories for generated files exist.
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define ensure-directory
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$1:
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mkdir -p $$@
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endef
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PREPARE_DIRECTORIES = \
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$(OBJDIR) $(GENSPRITES) $(GENBACKGROUNDS) $(DSTDIR)
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$(foreach i, $(PREPARE_DIRECTORIES), $(eval $(call ensure-directory,$i)))
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# Clean up generated directories.
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clean:
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rm -rfv $(PREPARE_DIRECTORIES)
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# Declare these targets as "not actually files".
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.PHONY: clean all
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‎galactic-armada/libs/input.asm

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;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
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; It's straight from: https://gbdev.io/gb-asm-tutorial/part2/input.html
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; In their words (paraphrased): reading player input for gameboy is NOT a trivial task
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; So it's best to use some tested code
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;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
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include "src/main/utils/hardware.inc"
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SECTION "Input", ROM0
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Input::
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; Poll half the controller
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ld a, P1F_GET_BTN
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call .onenibble
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ld b, a ; B7-4 = 1; B3-0 = unpressed buttons
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; Poll the other half
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ld a, P1F_GET_DPAD
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call .onenibble
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swap a ; A3-0 = unpressed directions; A7-4 = 1
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xor a, b ; A = pressed buttons + directions
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ld b, a ; B = pressed buttons + directions
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; And release the controller
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ld a, P1F_GET_NONE
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ldh [rP1], a
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; Combine with previous wCurKeys to make wNewKeys
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ld a, [wCurKeys]
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xor a, b ; A = keys that changed state
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and a, b ; A = keys that changed to pressed
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ld [wNewKeys], a
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ld a, b
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ld [wCurKeys], a
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ret
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.onenibble
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ldh [rP1], a ; switch the key matrix
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call .knownret ; burn 10 cycles calling a known ret
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ldh a, [rP1] ; ignore value while waiting for the key matrix to settle
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ldh a, [rP1]
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ldh a, [rP1] ; this read counts
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or a, $F0 ; A7-4 = 1; A3-0 = unpressed keys
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.knownret
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ret

‎galactic-armada/libs/sporbs_lib.asm

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; Sprite Objects Library - by Eievui
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;
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; This is a small, lightweight library meant to facilitate the rendering of
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; sprite objects, including Shadow OAM and OAM DMA, single-entry "simple" sprite
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; objects, and Q12.4 fixed-point position metasprite rendering.
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;
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; The library is only 127 bytes of ROM0, 160 bytes of WRAM0 for Shadow OAM, and a
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; single HRAM byte for tracking the current position in OAM.
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;
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; The library is relatively simple to use, with 4 steps to rendering:
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; 1. Call InitSprObjLib during initilizations - This copies the OAMDMA function to
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; HRAM.
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; 2. Call ResetShadowOAM at the beginning of each frame - This hides all sprites
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; and resets hOAMIndex, allowing you to render a new frame of sprites.
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; 3. Call rendering functions - Push simple sprites or metasprites to Shadow OAM.
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; 4. Wait for VBlank and call hOAMDMA - Copies wShadowOAM to the Game Boy's OAM in
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; just 160 M-cycles. Make sure to pass HIGH(wShadowOAM) in the a register.
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;
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; Copyright 2021, Eievui
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;
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; This software is provided 'as-is', without any express or implied
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; warranty. In no event will the authors be held liable for any damages
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; arising from the use of this software.
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;
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; Permission is granted to anyone to use this software for any purpose,
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; including commercial applications, and to alter it and redistribute it
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; freely, subject to the following restrictions:
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;
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; 1. The origin of this software must not be misrepresented; you must not
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; claim that you wrote the original software. If you use this software
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; in a product, an acknowledgment in the product documentation would be
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; appreciated but is not required.
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; 2. Altered source versions must be plainly marked as such, and must not be
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; misrepresented as being the original software.
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; 3. This notice may not be removed or altered from any source distribution.
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;
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INCLUDE "src/main/utils/hardware.inc"
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SECTION "OAM DMA Code", ROM0
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OAMDMACode::
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LOAD "OAM DMA", HRAM
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; Begin an OAM DMA, waiting 160 cycles for the DMA to finish.
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; This quickly copies Shadow OAM to the Game Boy's OAM, allowing the PPU to draw
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; the objects. hOAMDMA should be called once per frame near the end of your
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; VBlank interrupt. While an OAM DMA is running no sprites objects can be drawn
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; by the PPU, which makes it preferrable to run within the VBlank interrupt, but
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; it can be run at any point if more than 40 sprite objects are needed.
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; @param a: High byte of active Shadow OAM. Shadow OAM must be aligned to start
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; at the beginning of a page (low byte == $00).
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hOAMDMA::
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ldh [rDMA], a
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ld a, 40
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.wait
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dec a
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jr nz, .wait
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ret
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ENDL
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OAMDMACodeEnd::
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SECTION "Initialize Sprite Object Library", ROM0
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; A wrapper or the InitSprObjLib code
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; from: https://github.com/eievui5/gb-sprobj-lib
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; The library is relatively simple to get set up. First, put the following in your initialization code:
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; Initilize Sprite Object Library.
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InitSprObjLibWrapper::
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call InitSprObjLib
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; Reset hardware OAM
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xor a, a
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ld b, 160
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ld hl, _OAMRAM
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.resetOAM
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ld [hli], a
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dec b
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jr nz, .resetOAM
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ret
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; Initializes the sprite object library, copying things such as the hOAMDMA
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; function and reseting hOAMIndex
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; @clobbers: a, bc, hl
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InitSprObjLib::
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; Copy OAM DMA.
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ld b, OAMDMACodeEnd - OAMDMACode
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ld c, LOW(hOAMDMA)
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ld hl, OAMDMACode
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.memcpy
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ld a, [hli]
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ldh [c], a
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inc c
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dec b
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jr nz, .memcpy
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xor a, a
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ldh [hOAMIndex], a ; hOAMIndex must be reset before running ResetShadowOAM.
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ret
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SECTION "Reset Shadow OAM", ROM0
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; Reset the Y positions of every sprite object that was used in the last frame,
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; effectily hiding them, and reset hOAMIndex. Run this function each frame
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; before rendering sprite objects.
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; @clobbers: a, c, hl
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ResetShadowOAM::
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xor a, a ; clear carry
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ldh a, [hOAMIndex]
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rra
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rra ; a / 4
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and a, a
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jr z, .skip
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ld c, a
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ld hl, wShadowOAM
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xor a, a
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.clearOAM
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ld [hli], a
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inc l
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inc l
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inc l
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dec c
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jr nz, .clearOAM
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ldh [hOAMIndex], a
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.skip
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ret
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SECTION "Render Simple Sprite", ROM0
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; Render a single object, or sprite, to OAM.
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; @param b: Y position
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; @param c: X position
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; @param d: Tile ID
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; @param e: Tile Attribute
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; @clobbers: hl
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RenderSimpleSprite::
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ld h, HIGH(wShadowOAM)
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ldh a, [hOAMIndex]
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ld l, a
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ld a, b
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add a, 16
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ld [hli], a
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ld a, c
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add a, 8
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ld [hli], a
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ld a, d
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ld [hli], a
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ld a, e
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ld [hli], a
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ld a, l
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ldh [hOAMIndex], a
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ret
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SECTION "Render Metasprite", ROM0
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; Render a metasprite to OAM.
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; @param bc: Q12.4 fixed-point Y position.
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; @param de: Q12.4 fixed-point X position.
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; @param hl: Pointer to current metasprite.
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RenderMetasprite::
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; Adjust Y and store in b.
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ld a, c
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rrc b
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rra
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rrc b
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rra
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rrc b
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rra
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rrc b
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rra
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ld b, a
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; Adjust X and store in c.
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ld a, e
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rrc d
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rra
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rrc d
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rra
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rrc d
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rra
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rrc d
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rra
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ld c, a
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; Load Shadow OAM pointer.
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ld d, HIGH(wShadowOAM)
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ldh a, [hOAMIndex]
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ld e, a
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; Now:
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; bc - Y, X
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; de - Shadow OAM
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; hl - Metasprite
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; Time to render!
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.loop
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; Load Y.
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ld a, [hli]
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add a, b
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ld [de], a
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inc e
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; Load X.
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ld a, [hli]
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add a, c
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ld [de], a
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inc e
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; Load Tile.
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ld a, [hli]
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ld [de], a
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inc e
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; Load Attribute.
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ld a, [hli]
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ld [de], a
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inc e
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; Check for null end byte.
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ld a, [hl]
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cp a, 128
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jr nz, .loop
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ld a, e
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ldh [hOAMIndex], a
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ret
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SECTION "Shadow OAM", WRAM0, ALIGN[8]
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wShadowOAM::
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ds 160
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SECTION "Shadow OAM Index", HRAM
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; The current low byte of shadow OAM.
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hOAMIndex::
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db

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