Apple-2gs-SW
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GSCats
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Groundwork for graphical loading screen

This commit is contained in:
blondie7575 2023-07-18 20:15:53 -07:00
parent 76cf1068be
commit df1a141d8b
7 changed files with 238 additions and 401 deletions
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8
GSCats.xcodeproj/project.pbxproj
View File

@ -15,10 +15,10 @@
700F72872112428D00225B17 /* RenumberSpriteFiles.sh */ = {isa = PBXFileReference; lastKnownFileType = text.script.sh; path = RenumberSpriteFiles.sh; sourceTree = "<group>"; };
701E708A2A649A230030C35D /* tinyNumbers.s */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.asm; path = tinyNumbers.s; sourceTree = "<group>"; };
701E708B2A660CEB0030C35D /* progressBar.s */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.asm; path = progressBar.s; sourceTree = "<group>"; };
701E708E2A67844B0030C35D /* loaderGraphics.s */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.asm; path = loaderGraphics.s; sourceTree = "<group>"; };
705456862A43E03B00A2B866 /* GeneratePixelCircle.py */ = {isa = PBXFileReference; lastKnownFileType = text.script.python; path = GeneratePixelCircle.py; sourceTree = "<group>"; };
705456882A4D336200A2B866 /* animation.s */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.asm; path = animation.s; sourceTree = "<group>"; };
7059502B1F37A0BE00BBE90F /* GenerateVRAMTable.py */ = {isa = PBXFileReference; lastKnownFileType = text.script.python; path = GenerateVRAMTable.py; sourceTree = "<group>"; };
705AAFA920040B0D001BB0ED /* terrain_e1.s */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.asm; path = terrain_e1.s; sourceTree = "<group>"; };
705C54E62124B7F300515A6B /* fan.s */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.asm; path = fan.s; sourceTree = "<group>"; };
706DF1641F2D39F700AA6680 /* loader.s */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.asm; path = loader.s; sourceTree = "<group>"; };
706DF1651F2D4A8100AA6680 /* terrain.s */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.asm; path = terrain.s; sourceTree = "<group>"; };
@ -58,14 +58,15 @@
children = (
70E9D85F1F2BD95400555C19 /* equates.s */,
700F21DE1F43E31300D7007D /* input.s */,
706DF1641F2D39F700AA6680 /* loader.s */,
701E708E2A67844B0030C35D /* loaderGraphics.s */,
70E9D8611F2BD95400555C19 /* gscats.s */,
70E9D8601F2BD95400555C19 /* graphics.s */,
70E9D8621F2BD95400555C19 /* macros.s */,
7099E3841F41022100182A82 /* gameobject.s */,
70F011D123B989B800C8873F /* random.s */,
706DF1641F2D39F700AA6680 /* loader.s */,
706DF1651F2D4A8100AA6680 /* terrain.s */,
701E708B2A660CEB0030C35D /* progressBar.s */,
705AAFA920040B0D001BB0ED /* terrain_e1.s */,
70F011D023B91B2900C8873F /* dirt.s */,
70C073091F5BAA3E009844A9 /* collision.s */,
70F086A01F4230CB002446C3 /* utility.s */,
@ -81,7 +82,6 @@
708D1B1E27B9A1A600909AFC /* crosshair.s */,
70A80FB01F43D7F200BD34C9 /* gamemanager.s */,
70E554C41F807ADB00F3C871 /* spritebank.s */,
70E9D8611F2BD95400555C19 /* gscats.s */,
70E9D8631F2BD95400555C19 /* Makefile */,
70BDCBC92006AD5F00CB51F1 /* linkerConfig */,
701E708A2A649A230030C35D /* tinyNumbers.s */,

21
Makefile
View File

@ -14,13 +14,13 @@ VOLNAME=GSAPP
IMG=DiskImageParts
EMU=/Applications/GSplus.app/Contents/MacOS/gsplus
ADDR=0800
CODEBANK=CODEBANK\#060000
CODEBANKE1=CODEBANKE1\#060800
EXEC=$(PGM)\#06$(ADDR)
SOUNDBANK=SOUNDBANK\#060000
FONTBANK=FONTBANK\#060000
PGM=gscats
MRSPRITE=../MrSprite/mrsprite
GENART=Art/Generated
GENSOUND=Sound/Generated
@ -29,9 +29,9 @@ PALETTE=a4dffb a4dffb 008800 886611 cc9933 eebb44 dd6666 ff99aa 777777 ff0000 b7
SPRITES=SpriteBank
SPRITEBANK=$(SPRITES)\#060000
FLIPLIST=$(wildcard Art/*Fan.gif) $(wildcard Art/*Spit*.gif)
REMOTESYMBOLS=-Wl $(shell ./ParseMapFile.py *.map)
REMOTESYMBOLS= # -Wl $(shell ./ParseMapFile.py *.map) <- Use this to share symbols across code banks
all: clean diskimage terrain_e1 fonts $(PGM) loader emulate
all: clean diskimage fonts $(PGM) loader emulate
emulate:
# Leading hypen needed because GSPlus maddeningly returns code 1 (error) always and for no reason
@ -51,24 +51,16 @@ $(PGM):
$(CAD) ADDFILE $(PGM).2mg /$(VOLNAME) $(SPRITEBANK)
$(CAD) ADDFILE $(PGM).2mg /$(VOLNAME) $(SOUNDBANK)
$(CAD) ADDFILE $(PGM).2mg /$(VOLNAME) $(FONTBANK)
rm -f $(CODEBANK)
rm -f $(FONTBANK)
rm -f $(PGM).o
rm -f terrain_e1.map
loader:
@PATH=$(PATH):/usr/local/bin; $(CL65) -t apple2enh --cpu 65816 --start-addr $(ADDR) -lloader.lst loader.s -o $(EXEC)
$(CAD) ADDFILE $(PGM).2mg /$(VOLNAME) $(EXEC)
rm -f $(EXEC)
rm -f loader.o
terrain_e1:
@PATH=$(PATH):/usr/local/bin; $(CL65) -t apple2enh -C linkerConfig --cpu 65816 --start-addr $(ADDR) -l -vm -m terrain_e1.map terrain_e1.s -o $(CODEBANKE1)
$(CAD) ADDFILE $(PGM).2mg /$(VOLNAME) $(CODEBANKE1)
rm -f $(CODEBANKE1)
rm -f terrain_e1.o
fonts:
rm -rf $(FONTBANK)
./CompileFont.py 4 5 48 0 "tinyNum" "Art/Assets/TinyNumbers.gif" > fonts.s
@ -82,9 +74,6 @@ clean:
rm -f $(PGM).o
rm -f loader
rm -f loader.o
rm -f terrain_e1.o
rm -f terrain_e1.map
rm -f terrain_e1
rm -f Art/*m.gif
rm -f $(GENART)/*
rm -f $(PGM).2mg

2
equates.s
View File

@ -13,6 +13,8 @@ VRAMBANK = $e10000
SHADOWVRAMBANK = $010000
PRODOS = $bf00 ; MLI entry point
PRODOSRETURN = $300 ; Indirect jump to get back to ProDOS from any bank
BORDERCOLORCACHE= $304 ; Save system border color so we can put it back
TEXTCOLORCACHE = $306 ; Save system text colors so we can put it back
ENSONIQ_CONTROL = $e1c03c ; Ensoniq-related registers/locations
ENSONIQ_DATA = $e1c03d

7
gscats.s
View File

@ -20,12 +20,7 @@ mainBank2:
BITS8
lda #$f0
sta TEXTCOLOR
BITS16
; Set up video
jsr initSCBs
SHRVIDEO
SHADOWMEMORY
BITS16
jmp beginGameplay

140
loader.s
View File

@ -6,6 +6,9 @@
; Created by Quinn Dunki on 7/29/17
;
.a16
.i16
.include "equates.s"
.include "macros.s"
@ -15,8 +18,48 @@ MAINENTRY = $020000
.org $800
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; BORDER_COLOR
;
; Trashes A
;
.macro BORDER_COLOR color
SAVE_AXY
BITS8
lda BORDERCOLOR
and #$f0
ora color
sta BORDERCOLOR
BITS16
RESTORE_AXY
.endmacro
main:
OP8 ; We launch in emulation. Stay there for now
BITS16
NATIVE
SHRVIDEO
SHADOWMEMORY
; Cache system colors
BITS8
lda BORDERCOLOR
sta BORDERCOLORCACHE
lda TEXTCOLOR
sta TEXTCOLORCACHE
BITS16
; Throw up a loading screen
lda #loaderPalette
sta PARAML0
lda #0
jsr setPalette
; jsr initSCBs
BORDER_COLOR #$7
lda #$1111
jsr slowColorFill
EMULATION
; Open the main code file
jsr PRODOS
@ -50,6 +93,11 @@ main:
.byte $cc
.addr fileClose
bra mainContinue
ioError:
brk
mainContinue:
NATIVE
; Copy rest of code into bank 2 (needed if code size exceeds BUFFERSIZE)
@ -60,59 +108,6 @@ main:
EMULATION
;;;;;;;;;;;;;;;;;;;;;
; Open the E1 code file
jsr PRODOS
.byte $c8
.addr fileOpenCodeE1
bne ioError
; Load the code into bank 0
jsr PRODOS
.byte $ca
.addr fileRead
bne ioError
; Close the file
jsr PRODOS
.byte $cc
.addr fileClose
jmp loadData
; Note that we skip E1 code bank loading now. This was used for the
; fill mode terrain renderer, which is disabled until further notice
; There isn't enough safe room in E1 to do everything we wanted and the fill
; mode rendering isn't useful enough to keep
NATIVE
; Copy code into bank E1
ldx fileReadLen
lda #$E1
ldy #$800 ; Must match terrain_e1 .org
jsr copyBytes
; Copy vram table into bank E1
; Note that there's a GS memory manager jump table at 1680 - 16BB
; in E1 that we have to work around. If we step on it, warm reboots and other
; critical things start to fail.
phb
lda #vramRowInvertedSpanLookupEnd-vramRowInvertedSpanLookup-1
ldx #vramRowInvertedSpanLookupEnd-1
ldy #$16C0 + vramRowInvertedSpanLookupEnd-vramRowInvertedSpanLookup-1 ; Must match terrain_e1 vramRowInvertedSpanLookup
mvp $e1,$00 ; Note that ca65 reverses src,dest. Grrr.
plb
EMULATION
ioError:
brk
;;;;;;;;;;;;;;;;;;;;;
loadData:
; Open the sprite bank file
jsr PRODOS
.byte $c8
@ -238,30 +233,26 @@ loadData:
sta PRODOSRETURN
jml MAINENTRY
returnToProDOS:
SYNCDBR
EMULATION
; Restore system colors
lda BORDERCOLOR
and #$f0
ora BORDERCOLORCACHE
sta BORDERCOLOR
lda TEXTCOLORCACHE
sta TEXTCOLOR
rts
ioErrorJmp:
jmp ioError
; This table lives here in the loader because we need to copy
; it to a specific free hole in bank E1
vramRowInvertedSpanLookup:
.word $9d00,$9c60,$9bc0,$9b20,$9a80,$99e0,$9940,$98a0,$9800,$9760,$96c0,$9620,$9580,$94e0,$9440,$93a0,$9300,$9260,$91c0,$9120
.word $9080,$8fe0,$8f40,$8ea0,$8e00,$8d60,$8cc0,$8c20,$8b80,$8ae0,$8a40,$89a0,$8900,$8860,$87c0,$8720,$8680,$85e0,$8540,$84a0
.word $8400,$8360,$82c0,$8220,$8180,$80e0,$8040,$7fa0,$7f00,$7e60,$7dc0,$7d20,$7c80,$7be0,$7b40,$7aa0,$7a00,$7960,$78c0,$7820
.word $7780,$76e0,$7640,$75a0,$7500,$7460,$73c0,$7320,$7280,$71e0,$7140,$70a0,$7000,$6f60,$6ec0,$6e20,$6d80,$6ce0,$6c40,$6ba0
.word $6b00,$6a60,$69c0,$6920,$6880,$67e0,$6740,$66a0,$6600,$6560,$64c0,$6420,$6380,$62e0,$6240,$61a0,$6100,$6060,$5fc0,$5f20
.word $5e80,$5de0,$5d40,$5ca0,$5c00,$5b60,$5ac0,$5a20,$5980,$58e0,$5840,$57a0,$5700,$5660,$55c0,$5520,$5480,$53e0,$5340,$52a0
.word $5200,$5160,$50c0,$5020,$4f80,$4ee0,$4e40,$4da0,$4d00,$4c60,$4bc0,$4b20,$4a80,$49e0,$4940,$48a0,$4800,$4760,$46c0,$4620
.word $4580,$44e0,$4440,$43a0,$4300,$4260,$41c0,$4120,$4080,$3fe0,$3f40,$3ea0,$3e00,$3d60,$3cc0,$3c20,$3b80,$3ae0,$3a40,$39a0
.word $3900,$3860,$37c0,$3720,$3680,$35e0,$3540,$34a0,$3400,$3360,$32c0,$3220,$3180,$30e0,$3040,$2fa0,$2f00,$2e60,$2dc0,$2d20
.word $2c80,$2be0,$2b40,$2aa0,$2a00,$2960,$28c0,$2820,$2780,$26e0,$2640,$25a0,$2500,$2460,$23c0,$2320,$2280,$21e0,$2140,$20a0
vramRowInvertedSpanLookupEnd:
loaderPalette:
.word $0aef,$06af,$0080,$0861,$0c93,$0eb4,$0d66,$0f9a,$0777,$0f00,$0bbb,$ddd,$007b,$0a5b,$0000,$0fff
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
@ -329,13 +320,6 @@ fileOpenCode:
.byte 0 ; Result (file handle)
.byte 0 ; Padding
fileOpenCodeE1:
.byte 3
.addr codePathE1
.addr $9200 ; 1k below BASIC.SYSTEM
.byte 0 ; Result (file handle)
.byte 0 ; Padding
fileRead:
.byte 4
.byte 1 ; File handle (we know it's gonna be 1)
@ -371,11 +355,11 @@ fileOpenFonts:
codePath:
pstring "/GSAPP/CODEBANK"
codePathE1:
pstring "/GSAPP/CODEBANKE1"
spritePath:
pstring "/GSAPP/SPRITEBANK"
soundPath:
pstring "/GSAPP/SOUNDBANK"
fontPath:
pstring "/GSAPP/FONTBANK"
.include "loaderGraphics.s"

164
loaderGraphics.s Normal file
View File

@ -0,0 +1,164 @@
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; slowColorFill
; Fills the screen with a color (or two). Slow because it has to run from
; bank 0 on the slow graphics path
;
; A = 4:4:4:4 = Palette entries to fill
;
; Trashes X,Y
slowColorFill:
ldy #200
ldx #$2000
slowColorFillLoop:
; 80 STAs, for 1 line
; sta VRAMBANK,x inx inx
.byte $9F,$00,$00,$E1,$e8,$e8,$9F,$00,$00,$E1,$e8,$e8,$9F,$00,$00,$E1,$e8,$e8,$9F,$00,$00,$E1,$e8,$e8,$9F,$00,$00,$E1,$e8,$e8,$9F,$00,$00,$E1,$e8,$e8,$9F,$00,$00,$E1,$e8,$e8,$9F,$00,$00,$E1,$e8,$e8
.byte $9F,$00,$00,$E1,$e8,$e8,$9F,$00,$00,$E1,$e8,$e8,$9F,$00,$00,$E1,$e8,$e8,$9F,$00,$00,$E1,$e8,$e8,$9F,$00,$00,$E1,$e8,$e8,$9F,$00,$00,$E1,$e8,$e8,$9F,$00,$00,$E1,$e8,$e8,$9F,$00,$00,$E1,$e8,$e8
.byte $9F,$00,$00,$E1,$e8,$e8,$9F,$00,$00,$E1,$e8,$e8,$9F,$00,$00,$E1,$e8,$e8,$9F,$00,$00,$E1,$e8,$e8,$9F,$00,$00,$E1,$e8,$e8,$9F,$00,$00,$E1,$e8,$e8,$9F,$00,$00,$E1,$e8,$e8,$9F,$00,$00,$E1,$e8,$e8
.byte $9F,$00,$00,$E1,$e8,$e8,$9F,$00,$00,$E1,$e8,$e8,$9F,$00,$00,$E1,$e8,$e8,$9F,$00,$00,$E1,$e8,$e8,$9F,$00,$00,$E1,$e8,$e8,$9F,$00,$00,$E1,$e8,$e8,$9F,$00,$00,$E1,$e8,$e8,$9F,$00,$00,$E1,$e8,$e8
.byte $9F,$00,$00,$E1,$e8,$e8,$9F,$00,$00,$E1,$e8,$e8,$9F,$00,$00,$E1,$e8,$e8,$9F,$00,$00,$E1,$e8,$e8,$9F,$00,$00,$E1,$e8,$e8,$9F,$00,$00,$E1,$e8,$e8,$9F,$00,$00,$E1,$e8,$e8,$9F,$00,$00,$E1,$e8,$e8
.byte $9F,$00,$00,$E1,$e8,$e8,$9F,$00,$00,$E1,$e8,$e8,$9F,$00,$00,$E1,$e8,$e8,$9F,$00,$00,$E1,$e8,$e8,$9F,$00,$00,$E1,$e8,$e8,$9F,$00,$00,$E1,$e8,$e8,$9F,$00,$00,$E1,$e8,$e8,$9F,$00,$00,$E1,$e8,$e8
.byte $9F,$00,$00,$E1,$e8,$e8,$9F,$00,$00,$E1,$e8,$e8,$9F,$00,$00,$E1,$e8,$e8,$9F,$00,$00,$E1,$e8,$e8,$9F,$00,$00,$E1,$e8,$e8,$9F,$00,$00,$E1,$e8,$e8,$9F,$00,$00,$E1,$e8,$e8,$9F,$00,$00,$E1,$e8,$e8
.byte $9F,$00,$00,$E1,$e8,$e8,$9F,$00,$00,$E1,$e8,$e8,$9F,$00,$00,$E1,$e8,$e8,$9F,$00,$00,$E1,$e8,$e8,$9F,$00,$00,$E1,$e8,$e8,$9F,$00,$00,$E1,$e8,$e8,$9F,$00,$00,$E1,$e8,$e8,$9F,$00,$00,$E1,$e8,$e8
.byte $9F,$00,$00,$E1,$e8,$e8,$9F,$00,$00,$E1,$e8,$e8,$9F,$00,$00,$E1,$e8,$e8,$9F,$00,$00,$E1,$e8,$e8,$9F,$00,$00,$E1,$e8,$e8,$9F,$00,$00,$E1,$e8,$e8,$9F,$00,$00,$E1,$e8,$e8,$9F,$00,$00,$E1,$e8,$e8
.byte $9F,$00,$00,$E1,$e8,$e8,$9F,$00,$00,$E1,$e8,$e8,$9F,$00,$00,$E1,$e8,$e8,$9F,$00,$00,$E1,$e8,$e8,$9F,$00,$00,$E1,$e8,$e8,$9F,$00,$00,$E1,$e8,$e8,$9F,$00,$00,$E1,$e8,$e8,$9F,$00,$00,$E1,$e8,$e8
dey
beq slowColorFillLoopDone
jmp slowColorFillLoop
slowColorFillLoopDone:
rts
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; initSCBs
; Initialize all scanline control bytes
;
; Trashes A,X
initSCBs:
lda #0
ldx #$0100 ;set all $100 scbs to A
initSCBsLoop:
dex
dex
sta $e19d00,x
bne initSCBsLoop
rts
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; setScanlinePalette
; Set the palette for a given scan line
;
; PARAML0 = Palette index
; X = Start scan line
; Y = Count
setScanlinePalette:
pha
setScanlinePaletteLoop:
lda $e19d00,x
ora PARAML0
sta $e19d00,x
inx
dey
bne setScanlinePaletteLoop
pla
rts
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; setPalette
; Set all colors in a palette from memory
; PARAML0 = Pointer to 32 color bytes
; A = Palette index
;
setPalette:
SAVE_XY
asl
asl
asl
asl
asl
BITS8A
sta setPaletteLoop_SMC+1
BITS16
ldx #0
ldy #0
setPaletteLoop:
lda (PARAML0),y
setPaletteLoop_SMC:
sta $e19e00,x ; Self-modifying code!
iny
iny
inx
inx
cpx #32
bne setPaletteLoop
RESTORE_XY
rts
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; Vertical blank checkers
;
; The Brutal Deluxe version, taken from LemminGS
;
nextVBL:
lda #75
pha
nextVBL0:
lda $e0c02e
and #$7f
cmp 1,s
blt nextVBL0
cmp #100
bge nextVBL0
pla
waitVBL:
lda $e0c018
bpl waitVBL
rts
; The Apple version, taken from GS Tech Note 039
;
syncVBL:
;sei
BITS8
syncVBL0:
ldaA $C02f
asl ; VA is now in the Carry flag
ldaA $C02e
rol ; Roll Carry into bit 0
cmp #200 ; A now contains line number
blt syncVBL0
BITS16
;cli
rts
; The old style //e version
;
vblSync:
BITS8
waitVBLToFinish:
lda $E0C019
bmi waitVBLToFinish
waitVBLToStart:
lda $E0C019
bpl waitVBLToStart
BITS16
rts

297
terrain_e1.s
View File

@ -1,297 +0,0 @@
;
; terrain (in E1 bank)
;
; Fill-mode terrain rendering code snippets
; that live in bank E1 for maximum speed.
;
; Created by Quinn Dunki on 7/29/17
;
.include "equates.s"
.include "macros.s"
UNRENDERCACHESTACK = $7ff ; Stack downwards from bottom of VRAM. Mirrored from $01 into $E1!
OP16
.org $800
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; renderTerrainSpans:
;
;
renderTerrainSpans:
SAVE_AXY
SAVE_DBR
FASTGRAPHICS
lda #UNRENDERCACHESTACK ; Prepare unrender cache
tcs
lda #MAXTERRAINHEIGHT-1
sec
sbc lastCompiledTerrainY
beq renderTerrainRowSpansSkip ; All terrain needs compiled rendering
renderTerrainSpansLoop:
sta PARAML1
; Find row data
lda PARAML1
asl ; Shifts must match SPANROWBYTES
asl
asl
asl
asl
tay
lda terrainSpanData,y
sta SCRATCHL ; Track span color
; Find VRAM row
lda PARAML1
asl
tax
lda vramRowInvertedSpanLookup,x
tax
adc #160
sta PARAML0 ; Watch for end of VRAM row
; Find span that intersects left logical edge
lda #0
clc
renderTerrainRowSpansFindLeftLoop:
adc terrainSpanData+2,y
cmp leftScreenEdge
bpl renderTerrainRowSpansFoundLeft
iny
iny
sta CACHEDATA
lda SCRATCHL
eor #%110000 ; Toggle span color cache
sta SCRATCHL
lda CACHEDATA
bra renderTerrainRowSpansFindLeftLoop
renderTerrainRowSpansFoundLeft:
sec
sbc leftScreenEdge ; A now holds remainder of leftmost span
; and Y points to leftmost span
renderTerrainRowSpansLoop:
sta SCRATCHL2
; Set fill mode byte for this span
lda SCRATCHL
sta VRAMBANK,x
; Cache the index we wrote to so we can erase later
phx
; Advance to end of span
clc
txa
adc SCRATCHL2
cmp PARAML0
bpl renderTerrainRowSpansDone
tax
; Prepare for next span
iny
iny
lda SCRATCHL
eor #%110000 ; Toggle span color cache
sta SCRATCHL
lda terrainSpanData+2,y
bra renderTerrainRowSpansLoop
renderTerrainRowSpansDone:
lda PARAML1
dec
bne renderTerrainSpansLoop
pea 0 ; Null-terminate the unrender cache
renderTerrainRowSpansSkip:
SLOWGRAPHICS
RESTORE_DBR
RESTORE_AXY
rtl
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; unrenderTerrainSpans:
;
;
unrenderTerrainSpans:
SAVE_AXY
SAVE_DBR
phb
pea $e1e1 ; Work entirely in bank E1 for all local read/writes
plb
plb
ldy #UNRENDERCACHESTACK-1
unrenderTerrainSpansLoop:
lda 0,y
beq unrenderTerrainSpansDone
tax
lda #0
sta a:0,x
dey
dey
bra unrenderTerrainSpansLoop
unrenderTerrainSpansDone:
plb
RESTORE_DBR
RESTORE_AXY
rtl
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; compileTerrainSpans:
;
;
compileTerrainSpans:
pha
SAVE_DBR
lda #0
compileTerrainSpansLoop:
sta PARAML1
jsr compileTerrainSpansRow
lda PARAML1
inc
cmp #MAXTERRAINHEIGHT
bne compileTerrainSpansLoop
RESTORE_DBR
pla
rtl
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; compileTerrainSpansRow:
;
; PARAML1 = Row index (bottom relative)
;
; Trashes SCRATCHL
;
compileTerrainSpansRow:
SAVE_AXY
lda PARAML1
asl ; Shifts must match SPANROWBYTES
asl
asl
asl
asl
clc
adc #terrainSpanData
sta SCRATCHL
ldy #0
ldx #TERRAINWIDTH-2
lda terrainDataFar,x ; Figure out start value for row
cmp PARAML1
bcs compileTerrainSpansRowInitGreen
compileTerrainSpansRowInitBlack:
lda #$0010 ; First span is black
sta (SCRATCHL) ; Initialize the row
inc SCRATCHL
inc SCRATCHL
ldy #-1
compileTerrainSpansRowBlackStart:
iny
compileTerrainSpansRowBlackLoop:
lda terrainDataFar,x
cmp PARAML1
bcs compileTerrainSpansBlackEnd
dex
dex
iny
cpx #-2
bne compileTerrainSpansRowBlackLoop
compileTerrainSpansBlackEnd:
tya ; Store this span's length
sta (SCRATCHL)
inc SCRATCHL
inc SCRATCHL
dex ; Begin searching for next span
dex
cpx #0
bmi compileTerrainSpansRowDone
ldy #0
bra compileTerrainSpansRowGreenStart
compileTerrainSpansRowDone:
RESTORE_AXY
rts
compileTerrainSpansRowInitGreen:
lda #$0020 ; First span is green
sta (SCRATCHL) ; Initialize the row
inc SCRATCHL
inc SCRATCHL
ldy #-1
compileTerrainSpansRowGreenStart:
iny
compileTerrainSpansRowGreenLoop:
lda terrainDataFar,x
cmp PARAML1
bcc compileTerrainSpansGreenEnd
dex
dex
iny
cpx #-2
bne compileTerrainSpansRowGreenLoop
compileTerrainSpansGreenEnd:
tya ; Store this span's length
sta (SCRATCHL)
inc SCRATCHL
inc SCRATCHL
dex ; Begin searching for next span
dex
cpx #0
bmi compileTerrainSpansRowDone
ldy #0
bra compileTerrainSpansRowBlackStart
terrainSpanData:
.repeat MAXTERRAINHEIGHT
.word 0 ; Start value (0=BG)
.repeat MAXSPANSPERROW
.word 0 ; Length (in bytes)
.endrepeat
.endrepeat
vramRowInvertedSpanLookup = $16C0 ; This table is copied to here by the loader
.export renderTerrainSpans
.export unrenderTerrainSpans
.export compileTerrainSpans
; Suppress some linker warnings - Must be the last thing in the file
.SEGMENT "ZPSAVE"
.SEGMENT "EXEHDR"
.SEGMENT "STARTUP"
.SEGMENT "INIT"
.SEGMENT "LOWCODE"