mirror of
https://github.com/lscharen/iigs-game-engine.git
synced 2024-06-15 01:29:35 +00:00
Wire up code field dispatch and return
This commit is contained in:
Lucas Scharenbroich
parent
5e757f3cc5
commit
40be26392e
121
test/App.Main.s
121
test/App.Main.s
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@ -12,6 +12,7 @@
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mx %00
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SHADOW_REG equ $E0C035
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STATE_REG equ $E0C068
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NEW_VIDEO_REG equ $E0C029
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BORDER_REG equ $E0C034 ; 0-3 = border 4-7 Text color
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VBL_VERT_REG equ $E0C02E
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@ -21,6 +22,9 @@ KBD_REG equ $E0C000
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KBD_STROBE_REG equ $E0C010
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VBL_STATE_REG equ $E0C019
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SHR_SCREEN equ $E12000
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SHR_SCB equ $E19D00
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; Typical init
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phk
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@ -59,6 +63,7 @@ VBL_STATE_REG equ $E0C019
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; Start up the graphics engine...
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jsr MemInit
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jsr GrafInit
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lda BlitBuff+2 ; Fill in this bank
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jsr BuildBank
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@ -67,9 +72,6 @@ VBL_STATE_REG equ $E0C019
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jsr AllocOneBank ; Alloc 64KB for Load/Unpack
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sta BankLoad ; Store "Bank Pointer"
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jsr GrafOn
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EvtLoop
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jsr WaitForKey
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cmp #'q'
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@ -79,8 +81,72 @@ EvtLoop
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bne :2
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brl DoLoadPic
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:2 cmp #'m'
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beq DoMessage
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bra EvtLoop
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bne :3
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brl DoMessage
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:3 cmp #'f' ; render a 'f'rame
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bne :4
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brl DoFrame
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:4 bra EvtLoop
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; Set up the code field and render it
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DoFrame
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; This sets up the environment for calling the blitter. The blitter code takes care of moving from
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; line to line and should be set up ahead of time with appropriate epilougs for lines to periodically
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; enable interrupts and other stuff. In short, we call into the code once and, when it returns, all of
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; the lines set up to render will be finished.
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tsc ; save the stack pointer
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sta stk_save+1 ; save a cycle by storing while bank is set
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ldx #80*2 ; This is the word to exit from
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ldy Tile2CodeOffset,x ; Get the offset
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lda BlitBuff+1 ; set the data bank to the code field
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sta blt_entry+2 ; Patch into the long jump
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pha
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plb
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plb
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ldal CodeFieldEvenBRA,x ; Get the value to place there
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ldx #16*2
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jsr SetConst
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jsr SetNextLine ; Link the lines together
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lda #{$2000+159+15*160} ; Set the stack address to the right edge of the screen
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ldy #0
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ldx #16*2
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jsr SetScreenAddrs
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sep #$20 ; only need to do an 8-bit store
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lda #$06 ; This is the entry address to start drawing
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ldy #CODE_ENTRY ; don't actually need to set these again
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ldx #16*2
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jsr SetConst
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rep #$30
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ldy #$F000
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jsr SetReturn
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sei ; disable interrupts
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ldal STATE_REG
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ora #$0010 ; Read Bank 0 / Write Bank 1
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stal STATE_REG
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blt_entry jml $000006 ; Jump into the blitter code $XX/YY06
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blt_return ldal STATE_REG ; Read Bank 0 / Write Bank 0
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and #$FFCF
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stal STATE_REG
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stk_save lda #0000 ; load the stack
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tcs
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cli ; re-enable interrupts
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phk ; restore data bank
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plb
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jmp EvtLoop
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HexToChar dfb '0','1','2','3','4','5','6','7','8','9','A','B','C','D','E','F'
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DoMessage
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@ -226,12 +292,10 @@ VBLTASK hex 00000000
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; Graphic screen initialization
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GrafInit ldx #$7FFE
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lda #0000
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:loop stal $E12000,x
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dex
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dex
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bne :loop
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GrafInit lda #$8888
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jsr ClearToColor
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jsr GrafOn
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jsr ShadowOn
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rts
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; Return the current border color ($0 - $F) in the accumulator
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@ -251,6 +315,22 @@ SetBorderColor sep #$20 ; ACC = $X_Y, REG = $W_Z
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rep #$20
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rts
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; Clear to SHR screen to a specific color
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ClearToColor ldx #$7D00 ;start at top of pixel data! ($2000-9D00)
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:clearloop dex
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dex
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stal SHR_SCREEN,x ;screen location
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bne :clearloop ;loop until we've worked our way down to 0
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rts
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; Initialize the SCB
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SetSCBs ldx #$0100 ;set all $100 scbs to A
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:scbloop dex
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dex
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stal SHR_SCB,x
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bne :scbloop
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rts
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; Turn SHR screen On/Off
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GrafOn sep #$20
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lda #$81
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@ -423,22 +503,3 @@ qtRec adrl $0000
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put blitter/Template.s
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put blitter/Tables.s
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lda #BG1_ADDR
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@ -17,10 +17,180 @@
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; This table is necessary, because due to the data being draw via stack instructions, the
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; tile order is reversed.
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PER_TILE_SIZE equ 6
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PER_TILE_SIZE equ 3
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]step equ 0
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Tile2CodeOffset lup 41
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Tile2CodeOffset lup 82
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dw CODE_TOP+{]step*PER_TILE_SIZE}
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]step equ ]step+1
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--^
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; Table of BRA instructions that are used to exit the code field. Separate tables for
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; even and odd aligned cases.
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;
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; The even exit point is closest to the code field. The odd exit point is 3 bytes further
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CodeFieldEvenBRA
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bra *-3 ; 0
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bra *-6 ; 1
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bra *-9 ; 2
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bra *-12 ; 3
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bra *-15 ; 4
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bra *-18 ; 5
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bra *-21 ; 6
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bra *-24 ; 7
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bra *-27 ; 8
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bra *-30 ; 9
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bra *-33 ; 10
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bra *-36 ; 11
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bra *-39 ; 12
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bra *-42 ; 13
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bra *-45 ; 14
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bra *-48 ; 15
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bra *-51 ; 16
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bra *-54 ; 17
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bra *-57 ; 18
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bra *-60 ; 19
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bra *-63 ; 20
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bra *-66 ; 21
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bra *-69 ; 22
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bra *-72 ; 23
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bra *-75 ; 24
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bra *-78 ; 25
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bra *-81 ; 26
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bra *-84 ; 27
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bra *-87 ; 28
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bra *-90 ; 29
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bra *-93 ; 30
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bra *-96 ; 31
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bra *-99 ; 32
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bra *-102 ; 33
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bra *-105 ; 34
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bra *-108 ; 35
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bra *-111 ; 36
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bra *-114 ; 37
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bra *-117 ; 38
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bra *-120 ; 39
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bra *-123 ; 40
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bra *+126 ; 41
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bra *+123 ; 42
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bra *+120 ; 43
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bra *+117 ; 44
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bra *+114 ; 45
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bra *+111 ; 46
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bra *+108 ; 47
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bra *+105 ; 48
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bra *+102 ; 49
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bra *+99 ; 50
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bra *+96 ; 51
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bra *+93 ; 52
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bra *+90 ; 53
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bra *+87 ; 54
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bra *+84 ; 55
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bra *+81 ; 56
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bra *+78 ; 57
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bra *+75 ; 58
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bra *+72 ; 59
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bra *+69 ; 60
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bra *+66 ; 61
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bra *+63 ; 62
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bra *+60 ; 63
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bra *+57 ; 64
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bra *+54 ; 65
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bra *+51 ; 66
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bra *+48 ; 67
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bra *+45 ; 68
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bra *+42 ; 69
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bra *+39 ; 70
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bra *+36 ; 71
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bra *+33 ; 72
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bra *+30 ; 73
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bra *+27 ; 74
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bra *+24 ; 75
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bra *+21 ; 76
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bra *+18 ; 77
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bra *+15 ; 78
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bra *+12 ; 79
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bra *+9 ; 80
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bra *+6 ; 81 -- need to skip over the JMP loop that passed control back
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CodeFieldOddBRA
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bra *-6 ; 0 -- branch back 6 to skip the JMP even path
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bra *-9 ; 1
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bra *-12 ; 2
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bra *-15 ; 3
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bra *-18 ; 4
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bra *-21 ; 5
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bra *-24 ; 6
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bra *-27 ; 7
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bra *-30 ; 8
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bra *-33 ; 9
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bra *-36 ; 10
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bra *-39 ; 11
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bra *-42 ; 12
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bra *-45 ; 13
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bra *-48 ; 14
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bra *-51 ; 15
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bra *-54 ; 16
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bra *-57 ; 17
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bra *-60 ; 18
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bra *-63 ; 19
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bra *-66 ; 20
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bra *-69 ; 21
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bra *-72 ; 22
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bra *-75 ; 23
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bra *-78 ; 24
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bra *-81 ; 25
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bra *-84 ; 26
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bra *-87 ; 27
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bra *-90 ; 28
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bra *-93 ; 29
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bra *-96 ; 30
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bra *-99 ; 31
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bra *-102 ; 32
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bra *-105 ; 33
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bra *-108 ; 34
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bra *-111 ; 35
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bra *-114 ; 36
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bra *-117 ; 37
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bra *-120 ; 38
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bra *-123 ; 39
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bra *-126 ; 40
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bra *+129 ; 41
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bra *+126 ; 42
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bra *+123 ; 43
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bra *+120 ; 44
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bra *+117 ; 45
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bra *+114 ; 46
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bra *+111 ; 47
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bra *+108 ; 48
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bra *+105 ; 49
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bra *+102 ; 50
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bra *+99 ; 51
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bra *+96 ; 52
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bra *+93 ; 53
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bra *+90 ; 54
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bra *+87 ; 55
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bra *+84 ; 56
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bra *+81 ; 57
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bra *+78 ; 58
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bra *+75 ; 59
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bra *+72 ; 60
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bra *+69 ; 61
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bra *+66 ; 62
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bra *+63 ; 64
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bra *+60 ; 64
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bra *+57 ; 65
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bra *+54 ; 66
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bra *+51 ; 67
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bra *+48 ; 68
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bra *+45 ; 69
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bra *+42 ; 70
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bra *+39 ; 71
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bra *+36 ; 72
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bra *+33 ; 73
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bra *+30 ; 74
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bra *+27 ; 75
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bra *+24 ; 76
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bra *+21 ; 77
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bra *+18 ; 78
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bra *+15 ; 79
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bra *+12 ; 80
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bra *+9 ; 81 -- need to skip over two JMP instructions
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@ -6,8 +6,10 @@ DP_ADDR equ entry_1-base+1
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BG1_ADDR equ entry_2-base+1
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STK_ADDR equ entry_3-base+1
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CODE_ENTRY equ entry_jmp-base+1 ; low byte of the page-aligned jump address
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CODE_TOP equ loop-base
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CODE_LEN equ top-base
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CODE_EXIT equ even_exit-base
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; Locations that need the page offset added
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PagePatches da {long_0-base+2}
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@ -22,6 +24,7 @@ PagePatches da {long_0-base+2}
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da {loop_exit_2-base+2}
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da {loop_back-base+2}
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da {loop_exit_3-base+2}
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da {even_exit-base+2}
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PagePatchNum equ *-PagePatches
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BankPatches da {long_0-base+3}
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@ -33,6 +36,158 @@ BankPatches da {long_0-base+3}
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da {long_6-base+3}
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BankPatchNum equ *-BankPatches
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; Patch out the final JMP to jump to the long JML return code
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;
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; Y = starting line * $1000
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SetReturn lda #$0280 ; BRA *+4
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sta CODE_EXIT,y
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rts
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ResetReturn lda #$004C ; JMP $XX00
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sta CODE_EXIT,y
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rts
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; Fill in the even_exit JMP instruction to jump to the next line (all but last line)
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SetNextLine lda #$F000+{entry_3-base}
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ldy #CODE_EXIT+1
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ldx #15*2
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jmp SetAbsAddrs
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; Patch an 8-bit or 16-bit value into the bank. These are a set up unrolled loops to
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; quickly patch in a constanct value, or a value from an array into a given set of
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; templates.
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;
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; Because we have structured everything as parallel code blocks, most updates to the blitter
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; reduce to storing a constant value and have an amortized cost of just a single store.
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;
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; The utility of these routines is that they also handle setting just a range of lines.
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;
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; X = number of lines * 2, 0 to 32
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; Y = starting line * $1000
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; A = value
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;
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; Set M to 0 or 1
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SetConst jmp (:tbl,x)
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:tbl da :bottom-00,:bottom-03,:bottom-06,:bottom-09
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da :bottom-12,:bottom-15,:bottom-18,:bottom-21
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da :bottom-24,:bottom-27,:bottom-30,:bottom-33
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da :bottom-36,:bottom-39,:bottom-42,:bottom-45
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da :bottom-48
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:top sta $F000,y
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sta $E000,y
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sta $D000,y
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sta $C000,y
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sta $B000,y
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sta $A000,y
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sta $9000,y
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sta $8000,y
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sta $7000,y
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sta $6000,y
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sta $5000,y
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sta $4000,y
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sta $3000,y
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sta $2000,y
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sta $1000,y
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sta $0000,y
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:bottom rts
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; SetScreenAddrs
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;
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; A = initial screen location (largest)
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; Y = starting line * $1000
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; X = number of lines
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;
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; Automatically decrements address by 160 bytes each line
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SetScreenAddrs sec
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jmp (:tbl,x)
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:tbl da :bottom-00,:bottom-03,:bottom-09,:bottom-15
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da :bottom-21,:bottom-27,:bottom-33,:bottom-39
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da :bottom-45,:bottom-51,:bottom-57,:bottom-63
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da :bottom-69,:bottom-75,:bottom-81,:bottom-87
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da :bottom-93
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:top sta STK_ADDR+$F000,y
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sbc #160
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sta STK_ADDR+$E000,y
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sbc #160
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sta STK_ADDR+$D000,y
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sbc #160
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sta STK_ADDR+$C000,y
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sbc #160
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sta STK_ADDR+$B000,y
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sbc #160
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sta STK_ADDR+$A000,y
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sbc #160
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sta STK_ADDR+$9000,y
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sbc #160
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sta STK_ADDR+$8000,y
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sbc #160
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sta STK_ADDR+$7000,y
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sbc #160
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sta STK_ADDR+$6000,y
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sbc #160
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sta STK_ADDR+$5000,y
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sbc #160
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sta STK_ADDR+$4000,y
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sbc #160
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sta STK_ADDR+$3000,y
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sbc #160
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sta STK_ADDR+$2000,y
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sbc #160
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sta STK_ADDR+$1000,y
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sbc #160
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sta STK_ADDR+$0000,y
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:bottom rts
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; SetAbsAddres
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;
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; A = absolute address (largest)
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; Y = offset
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; X = number of lines
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;
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; Stores a value and decrements by $1000 for each line
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SetAbsAddrs sec
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jmp (:tbl,x)
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:tbl da :bottom-00,:bottom-03,:bottom-09,:bottom-15
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da :bottom-21,:bottom-27,:bottom-33,:bottom-39
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da :bottom-45,:bottom-51,:bottom-57,:bottom-63
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da :bottom-69,:bottom-75,:bottom-81,:bottom-87
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da :bottom-93
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:top sta $F000,y
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sbc #$1000
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sta $E000,y
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sbc #$1000
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sta $D000,y
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sbc #$1000
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sta $C000,y
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sbc #$1000
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sta $B000,y
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sbc #$1000
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||||
sta $A000,y
|
||||
sbc #$1000
|
||||
sta $9000,y
|
||||
sbc #$1000
|
||||
sta $8000,y
|
||||
sbc #$1000
|
||||
sta $7000,y
|
||||
sbc #$1000
|
||||
sta $6000,y
|
||||
sbc #$1000
|
||||
sta $5000,y
|
||||
sbc #$1000
|
||||
sta $4000,y
|
||||
sbc #$1000
|
||||
sta $3000,y
|
||||
sbc #$1000
|
||||
sta $2000,y
|
||||
sbc #$1000
|
||||
sta $1000,y
|
||||
sbc #$1000
|
||||
sta $0000,y
|
||||
:bottom rts
|
||||
|
||||
; Full up a full bank with blitter templates. Currently we can fit 16 lines per bank, so need
|
||||
; a total of 13 banks to hold the 208 lines to full-screen support
|
||||
|
||||
target equ 0
|
||||
BuildBank
|
||||
stz target
|
||||
|
|
@ -182,12 +337,37 @@ long_5 ldal entry_jmp+1-base
|
|||
long_6 stal *+5-base
|
||||
dfb $4C,$00,$00 ; Jump back to address in entry_jmp (this takes 13 cycles, is there a better way?)
|
||||
|
||||
even_exit jmp $1000 ; Jump to the next line. We set up the blitter to do 8 or 16 lines at a time
|
||||
; ; before restoring the machine state and re-enabling interrupts. This makes
|
||||
; ; the blitter interrupt friendly to allow things like music player to continue
|
||||
; ; to function.
|
||||
;
|
||||
; ; When it's time to exit, the next_entry address points to an alternate exit point
|
||||
; JMP opcode = $4C, JML opcode = $5C
|
||||
even_exit jmp $1000 ; Jump to the next line.
|
||||
ds 1 ; space so that the last line in a bank can be patched into a JML
|
||||
full_return jml blt_return ; Full exit
|
||||
|
||||
; Special epilogue: skip a number of bytes and jump back into the code field. This is useful for
|
||||
; large, floating panels in the attract mode of a game, or to overlay solid
|
||||
; dialog.
|
||||
|
||||
epilogue_1 tsc
|
||||
sec
|
||||
sbc #0
|
||||
tcs
|
||||
jmp $0000 ; This jumps back into the code field
|
||||
:out jmp $0000 ; This jumps to the next epilogue chain element
|
||||
ds 1
|
||||
|
||||
; Special epilogue: re-enable interrupts. Used every 8 or 16 lines to allow music to continue playing
|
||||
epilogue_2 ldal STATE_REG ; Read Bank 0 / Write Bank 0
|
||||
and #$FFCF
|
||||
stal STATE_REG
|
||||
ldal stk_save ; restore the stack
|
||||
tcs
|
||||
cli
|
||||
nop ; Give a couple of cycles
|
||||
sei
|
||||
ldal STATE_REG
|
||||
ora #$0010 ; Read Bank 0 / Write Bank 1
|
||||
stal STATE_REG
|
||||
jmp $0000
|
||||
ds 1
|
||||
|
||||
; These are the special code snippets -- there is a 1:1 relationship between each snippet space
|
||||
; and a 3-byte entry in the code field. Thus, each snippet has a hard-coded JMP to return to
|
||||
|
|
@ -273,6 +453,9 @@ top
|
|||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
|
|
|||
Loading…
Reference in New Issue
Block a user