mirror of
https://github.com/lscharen/iigs-game-engine.git
synced 2025-02-27 06:29:30 +00:00
Split up source code a bit more; work toward completing render pipeline
This commit is contained in:
Lucas Scharenbroich
parent
6b32d61fa9
commit
8ec31631eb
@ -30,6 +30,24 @@ _Div16 mac
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lsr
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<<<
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_R0W0 mac ; Read Bank 0 / Write Bank 0
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ldal STATE_REG
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and #$FFCF
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stal STATE_REG
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<<<
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_R0W1 mac ; Read Bank 0 / Write Bank 1
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ldal STATE_REG
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ora #$0010
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stal STATE_REG
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<<<
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_R1W1 mac ; Read Bank 0 / Write Bank 1
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ldal STATE_REG
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ora #$0030
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stal STATE_REG
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<<<
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****************************************
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* Basic Error Macro *
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****************************************
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@ -46,3 +64,9 @@ NoErr eom
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@ -16,38 +16,38 @@
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mx %00
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MemInit PushLong #0 ; space for result
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PushLong #$008000 ; size (32k)
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MemInit PushLong #0 ; space for result
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PushLong #$008000 ; size (32k)
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PushWord UserId
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PushWord #%11000000_00010111 ; Fixed location
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PushWord #%11000000_00010111 ; Fixed location
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PushLong #$002000
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_NewHandle ; returns LONG Handle on stack
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plx ; base address of the new handle
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pla ; high address 00XX of the new handle (bank)
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_NewHandle ; returns LONG Handle on stack
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plx ; base address of the new handle
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pla ; high address 00XX of the new handle (bank)
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_Deref
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stx Buff00
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sta Buff00+2
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PushLong #0 ; space for result
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PushLong #$008000 ; size (32k)
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PushLong #0 ; space for result
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PushLong #$008000 ; size (32k)
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PushWord UserId
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PushWord #%11000000_00010111 ; Fixed location
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PushWord #%11000000_00010111 ; Fixed location
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PushLong #$012000
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_NewHandle ; returns LONG Handle on stack
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plx ; base address of the new handle
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pla ; high address 00XX of the new handle (bank)
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_NewHandle ; returns LONG Handle on stack
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plx ; base address of the new handle
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pla ; high address 00XX of the new handle (bank)
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_Deref
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stx Buff01
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sta Buff01+2
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PushLong #0 ; space for result
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PushLong #$000A00 ; size (10 pages)
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PushLong #0 ; space for result
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PushLong #$000A00 ; size (10 pages)
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PushWord UserId
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PushWord #%11000000_00010101 ; Page-aligned, fixed bank
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PushWord #%11000000_00010101 ; Page-aligned, fixed bank
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PushLong #$000000
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_NewHandle ; returns LONG Handle on stack
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plx ; base address of the new handle
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pla ; high address 00XX of the new handle (bank)
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_NewHandle ; returns LONG Handle on stack
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plx ; base address of the new handle
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pla ; high address 00XX of the new handle (bank)
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_Deref
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stx ZeroPage
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sta ZeroPage+2
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@ -57,9 +57,28 @@ MemInit PushLong #0 ; space for result
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lup 13
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jsr AllocOneBank2
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sta BlitBuff+]step+2
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sta BlitBuffMid+]step+2
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stz BlitBuff+]step
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stz BlitBuffMid+]step
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]step equ ]step+4
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--^
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ldx #0
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ldy #0
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lda BlitBuff+2,y ; Copy the high word first
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]step equ 0
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lup 16
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sta BTableHigh+]step+2,x ; 16 lines per bank
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sta BTableHigh+]step+2+{208*2},x ; 16 lines per bank
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]step equ ]step+4
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--^
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lda BlitBuff,y
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sta BTableLow,x
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sta BTableLow+{208*2},x
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clc
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]step equ 0
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lup 15
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adc #$1000
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sta BTableLow+]step,x
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sta BTableLow+]step+{208*2},x
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]step equ ]step+4
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--^
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@ -69,14 +88,6 @@ Buff00 ds 4
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Buff01 ds 4
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ZeroPage ds 4
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; Array of addressed for the banks that hold the blitter. This is actually a double-length
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; array, which is a pattern that is used a lot in GTE. Whenever we have a situation where
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; we need to wrap around an array, we can to this be doubling the array length and using an
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; unrolled loop that starts in the middle instead of doing some kind of "mod N" or loop
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; splitting.
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BlitBuff ds 4*13
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BlitBuffMid ds 4*13
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; Bank allocator (for one full, fixed bank of memory. Can be immediately deferenced)
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AllocOneBank PushLong #0
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@ -84,12 +95,12 @@ AllocOneBank PushLong #0
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PushWord UserId
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PushWord #%11000000_00011100
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PushLong #0
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_NewHandle ; returns LONG Handle on stack
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plx ; base address of the new handle
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pla ; high address 00XX of the new handle (bank)
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xba ; swap accumulator bytes to XX00
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sta :bank+2 ; store as bank for next op (overwrite $XX00)
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:bank ldal $000001,X ; recover the bank address in A=XX/00
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_NewHandle ; returns LONG Handle on stack
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plx ; base address of the new handle
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pla ; high address 00XX of the new handle (bank)
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xba ; swap accumulator bytes to XX00
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sta :bank+2 ; store as bank for next op (overwrite $XX00)
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:bank ldal $000001,X ; recover the bank address in A=XX/00
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rts
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; Variation that return pointer in the X/A registers (X = low, A = high)
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@ -99,8 +110,8 @@ AllocOneBank2 PushLong #0
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PushWord #%11000000_00011100
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PushLong #0
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_NewHandle
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plx ; base address of the new handle
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pla ; high address 00XX of the new handle (bank)
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plx ; base address of the new handle
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pla ; high address 00XX of the new handle (bank)
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_Deref
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rts
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@ -136,6 +147,18 @@ ShutDown rts
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173
src/App.Main.s
173
src/App.Main.s
@ -1,8 +1,16 @@
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; Test program for graphics stufff...
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; Test driver to exercise graphics routines.
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;
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; Allow dynamic resizing to benchmark against different games
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; The general organization of the code is
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;
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; 1. The blitter/ folder contains all of the low-level graphics primitives
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; 2. The blitter/DirectPage.s file defines all of the DP locations
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; 3. Subroutines are written to try and be stateless, but, if local
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; storage is needed, it is takes from the stack and uses stack-relative
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; addressing.
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rel
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; Allow dynamic resizing to benchmark against different games
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REL
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DSK MAINSEG
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use Util.Macs.s
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use Locator.Macs.s
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@ -17,7 +25,7 @@
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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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BORDER_REG equ $E0C034 ; 0-3 = border, 4-7 Text color
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VBL_VERT_REG equ $E0C02E
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VBL_HORZ_REG equ $E0C02F
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@ -28,6 +36,9 @@ 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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; External references
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tiledata ext
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; Typical init
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phk
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@ -46,7 +57,10 @@ SHR_SCB equ $E19D00
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_MTStartUp
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; Install interrupt handlers
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; Install interrupt handlers. We use the VBL interrupt to keep animations
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; moving at a consistent rate, regarless of the rendered frame rate. The
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; one-second timer is generally just used for counters and as a handy
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; frames-per-second trigger.
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PushLong #0
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pea $0015 ; Get the existing 1-second interrupt handler and save
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@ -72,9 +86,6 @@ SHR_SCB equ $E19D00
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ldx #6 ; Gameboy Advance size
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jsr SetScreenMode
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lda #0 ; Set the virtual Y-position
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jsr SetYPos
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; Load a picture and copy it into Bank $E1. Then turn on the screen.
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jsr AllocOneBank ; Alloc 64KB for Load/Unpack
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@ -105,7 +116,7 @@ EvtLoop
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bne :5
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jsr DoHUP
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:5 cmp #'1'
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:5 cmp #'1' ; User selects a new screen size
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bcc :6
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cmp #'9'+1
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bcs :6
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@ -116,6 +127,26 @@ EvtLoop
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:6 bra EvtLoop
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; Exit code
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Exit
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pea $0007 ; disable 1-second interrupts
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_IntSource
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PushLong #VBLTASK ; Remove our heartbeat task
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_DelHeartBeat
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pea $0015
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PushLong OldOneSecVec ; Reset the interrupt vector
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_SetVector
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PushWord UserId ; Deallocate all of our memory
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_DisposeAll
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_QuitGS qtRec
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bcs Fatal
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Fatal brk $00
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; Allow the user to dynamically select one of the pre-configured screen sizes
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;
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; 1. Full Screen : 40 x 25 320 x 200 (32,000 bytes (100.0%))
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@ -129,6 +160,7 @@ EvtLoop
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; 9. Game Boy Color : 20 x 18 160 x 144 (11,520 bytes ( 36.0%))
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;
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; X=mode number
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]ScreenModeWidth dw 320,272,256,256,280,256,240,288,160
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]ScreenModeHeight dw 200,192,200,176,160,160,160,128,144
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@ -194,45 +226,51 @@ DoHUP
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DoFrame
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; Render some tiles
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:bank equ 0
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:column equ 2
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:tile equ 4
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:bank equ 1
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:column equ 3
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:tile equ 5
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pea $0000 ; Allocate local variable space
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pea $0000
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pea $0000
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stz :bank
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stz :tile
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:bankloop
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ldx :bank
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lda :bank,s
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tax
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ldal BlitBuff+1,x ; set the data bank to the code field
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pha
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plb
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plb
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stz :column
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lda #0
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sta :column,s
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:tileloop
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ldx :column
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lda :column,s
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tax
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ldal Col2CodeOffset,x
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tay
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iny
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lda :tile
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lda :tile,s
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jsr CopyTile
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lda :tile
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lda :tile,s
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inc
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and #$000F
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sta :tile
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sta :tile,s
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lda :column
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lda :column,s
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clc
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adc #4
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sta :column
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sta :column,s
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cmp #4*40
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bcc :tileloop
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lda :bank
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lda :bank,s
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clc
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adc #4
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sta :bank
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sta :bank,s
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cmp #4*13
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bcc :bankloop
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@ -251,7 +289,18 @@ DoFrame
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pha ; push twice because we will use it later
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rep #$20
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ldx #80*2 ; This is the word to exit from
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; Set the Y-Position within the virtual buffer
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lda #0 ; Set the virtual Y-position
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jsr SetYPos
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; Just load the screen width here. This is not semantically right; we actually are taking the nummber
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; of tiles in the width of the playfield, multiplying by two to get the number of words and then
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; multiplying by two again to get an index offset. It just happens that TILES * 4 = BYTES.
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;
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; TODO: Once we start scrolling, this will be ScreenWidth + BG0_X
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ldx ScreenWidth ; This is the word to exit from
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ldy Col2CodeOffset,x ; Get the offset
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sep #$20 ; 8-bit acc
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@ -265,15 +314,17 @@ DoFrame
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lda #OPCODE_SAVE
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jsr SaveOpcode
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ldx #80*2 ; X-register is overwritten by SaveOpcode
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ldx ScreenWidth ; X-register is overwritten by SaveOpcode
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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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; 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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; Fill in the screen address of each line. This routine must be called whenever the
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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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@ -285,26 +336,11 @@ DoFrame
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ldy #$7000 ; Set the return after line 200 (Bank 13, line 8)
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jsr SetReturn
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sei ; disable interrupts
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jsr BltDispatch ; Execute the blit
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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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tsc ; save the stack pointer
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stal stk_save+1
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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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plb ; set the bank back to the code field
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ldx #80*2 ; This is the word to exit from
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ldx ScreenWidth ; This is the word to exit from
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ldal Col2CodeOffset,x ; Get the offset
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tay
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ldx #16*2
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@ -313,6 +349,10 @@ stk_save lda #0000 ; load the stack
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phk ; restore data bank
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plb
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pla ; restore the stack
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pla
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pla
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rts
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DoLoadPic
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@ -332,27 +372,6 @@ DoLoadPic
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bpl :copySHR
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rts
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Exit
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pea $0007 ; disable 1-second interrupts
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_IntSource
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PushLong #VBLTASK ; Remove our heartbeat task
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_DelHeartBeat
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pea $0015
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PushLong OldOneSecVec ; Reset the interrupt vector
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_SetVector
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PushWord UserId ; Deallocate all of our memory
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_DisposeAll
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_QuitGS qtRec
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bcs Fatal
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Fatal brk $00
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Hello str '000000' ; str adds leading length byte
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****************************************
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* Fatal Error Handler *
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****************************************
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@ -621,20 +640,12 @@ qtRec adrl $0000
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put App.Init.s
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put App.Msg.s
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put font.s
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put blitter/Template.s
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put blitter/Blitter.s
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put blitter/PEISlammer.s
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put blitter/Tables.s
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put blitter/Template.s
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put blitter/Tiles.s
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put blitter/Vert.s
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@ -42,8 +42,6 @@ Addr2ToString xba
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; A=Value
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; X=Screen offset
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WordBuff dfb 4
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ds 4
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DrawWord phx ; Save register value
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ldy #WordBuff+1
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jsr WordToString
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@ -53,27 +51,31 @@ DrawWord phx ; Save register value
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jsr DrawString
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rts
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; Rendout out the bank addresses of all the blitter fields
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:count = tmp0
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:ptr = tmp1
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:addr = tmp3
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DumpBanks stz :addr
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lda #13
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sta :count
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lda #BlitBuff
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sta :ptr
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lda #^BlitBuff
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sta :ptr+2
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; Render out the bank addresses of all the blitter fields
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DumpBanks
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:addr = 1
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:count = 3
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:ptr = 5
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pea #^BlitBuff ; pointer to address table
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pea #BlitBuff
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pea #13 ; count = 13
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pea $0000 ; addr = 0
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tsc
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phd ; save the direct page
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tcd ; set the direct page
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:loop lda [:ptr]
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tax
|
||||
ldy #2
|
||||
lda [:ptr],y
|
||||
|
||||
ldy #Hello+1
|
||||
ldy #Addr3Buff+1
|
||||
jsr Addr3ToString
|
||||
|
||||
lda #Hello
|
||||
lda #Addr3Buff
|
||||
ldx :addr
|
||||
ldy #$7777
|
||||
jsr DrawString
|
||||
@ -83,17 +85,36 @@ DumpBanks stz :addr
|
||||
adc #160*8
|
||||
sta :addr
|
||||
|
||||
inc :ptr
|
||||
inc :ptr
|
||||
inc :ptr
|
||||
inc :ptr
|
||||
lda #4
|
||||
adc :ptr
|
||||
sta :ptr
|
||||
|
||||
dec :count
|
||||
lda :count
|
||||
bne :loop
|
||||
|
||||
pld ; restore the direct page
|
||||
tcs ; restore the stack pointer
|
||||
clc
|
||||
adc #8
|
||||
tsc
|
||||
rts
|
||||
|
||||
WordBuff str '0000'
|
||||
Addr3Buff str '000000' ; str adds leading length byte
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
8
src/App.Tile.s
Normal file
8
src/App.Tile.s
Normal file
@ -0,0 +1,8 @@
|
||||
REL
|
||||
DSK TILESEG
|
||||
tiledata ENT
|
||||
ds 65536
|
||||
|
||||
|
||||
|
||||
|
||||
31
src/App.s
31
src/App.s
@ -1,13 +1,38 @@
|
||||
; IIgs Game Engine
|
||||
;
|
||||
DSK GTETestApp
|
||||
|
||||
TYP $B3 ; S16 file
|
||||
DSK GTETestApp
|
||||
XPL
|
||||
|
||||
; Segment #1 -- Main execution block
|
||||
|
||||
ASM App.Main.s
|
||||
SNA Main
|
||||
; SNA Main
|
||||
|
||||
; Segment #2 -- 64KB Tile Memory
|
||||
|
||||
ASM App.Tile.s
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
57
src/Render.s
Normal file
57
src/Render.s
Normal file
@ -0,0 +1,57 @@
|
||||
; Renders a frame of animation
|
||||
;
|
||||
; The rendering engine is built around the idea of compositing all of the moving components
|
||||
; on to the Bank 01 graphics buffer and then revealing everything in a single, vertical pass.
|
||||
;
|
||||
; If there was just a scrolling screen with no sprites, the screen would just get rendered
|
||||
; in a single pass, but it gets more complicated with sprites and various effects.
|
||||
;
|
||||
; Here is the high-level pipeline:
|
||||
;
|
||||
; 1. Identify row ranges with effects. These effects can be sprites or user-defined overlays
|
||||
; 2. Turn shadowing off
|
||||
; 3. Render the background for each effect row range (in any order)
|
||||
; 4. Render the sprites (in any order)
|
||||
; 5. Turn shadowing on
|
||||
; 6. Render the background for each non-effect row, a pei slam for sprite rows, and
|
||||
; the user-defined overlays (in sorted order)
|
||||
;
|
||||
; As a concrete example, consider:
|
||||
;
|
||||
; Rows 0 - 9 have a user-defined floating overlay for a score board
|
||||
; Rows 10 - 100 are background only
|
||||
; Rows 101 - 120 have one or more sprites
|
||||
; Rows 121 - 140 are background only
|
||||
; Rows 141 - 159 have a user-defined solid overlay for an animated platform
|
||||
;
|
||||
; A floating overlay means that some background data bay show through. A solid overlay means that
|
||||
; the user-defined data covers the entire scan line.
|
||||
;
|
||||
; The renderer would proceed as:
|
||||
;
|
||||
; - shadow off
|
||||
; - render_background(0, 10)
|
||||
; - render_background(101, 121)
|
||||
; - render_sprites()
|
||||
; - shadow_on
|
||||
; - render_user_overlay_1()
|
||||
; - render_background(10, 101)
|
||||
; - pei_slam(101, 121)
|
||||
; - render_background(121, 141)
|
||||
; - render_user_overlay_2()
|
||||
;
|
||||
; Generally speaking, a PEI Slam is faster that trying to do any sort of dirty-rectangle update by
|
||||
; tracking sprinte bounding boxes. But, if an application would benefit from skipping some background
|
||||
; drawing on sprite rows, that can be handled by using the low level routines to control the left/right
|
||||
; edges of the rendered play field.
|
||||
|
||||
|
||||
Render
|
||||
|
||||
jsr ShadowOff
|
||||
|
||||
jsr ShadowOn
|
||||
rts
|
||||
|
||||
|
||||
|
||||
122
src/blitter/Blitter.s
Normal file
122
src/blitter/Blitter.s
Normal file
@ -0,0 +1,122 @@
|
||||
; This is the method that is most useful from the high-level code. We want the
|
||||
; freedom to blit a range of lines. This subroutine can assume that all of the
|
||||
; data in the code fields is set up properly.
|
||||
;
|
||||
; X = first line (inclusive), valid range of 0 to 199
|
||||
; Y = last line (inclusive), valid range >X up to 199
|
||||
;
|
||||
; The lines are based on the appearance of lines in the play field, so blitting lines 0 through
|
||||
; 19 will draw the first 20 lines on the play field, regardless of where the playfield is physically
|
||||
; on the SHR screen or the current value of StartY
|
||||
BltRange
|
||||
clc`
|
||||
|
||||
tya ; Get the address of the line that we want to return from
|
||||
adc StartY ; and create a pointer to it
|
||||
asl
|
||||
tay
|
||||
lda BTableLow,y
|
||||
sta exit_ptr
|
||||
lda BTableHigh,y
|
||||
sta exit_ptr+2
|
||||
|
||||
txa ; get the first line (0 - 199)
|
||||
adc StartY ; add in the virtual offset (0, 207) -- max value of 406
|
||||
asl
|
||||
tax ; this is the offset into the blitter table
|
||||
|
||||
sep #$20 ; 8-bit Acc
|
||||
lda BTableHigh,x ; patch in the bank
|
||||
sta blt_entry+3
|
||||
|
||||
lda BTableLow+1,x ; patch in the page
|
||||
sta blt_entry+2
|
||||
|
||||
; The way we patch the exit code is subtle, but very fast. The CODE_EXIT offset points to
|
||||
; an JMP/JML instruction that transitions to the next line after all of the code has been
|
||||
; executed. Since every code field line is bank-aligned, we know that the low-byte of the
|
||||
; operand is always $00.
|
||||
;
|
||||
; The trick we use is to patch the low byte to force the code to jump to a special return
|
||||
; function (jml blt_return) in the *next* code field line. When it's time to restore the
|
||||
; code, we can unconditionally store a $00 value to set things back to normal.
|
||||
;
|
||||
; This is the ideal situation -- patch/restore in a single 8-bit lda #imm / sta instruction
|
||||
; pair with no need to preserve the data
|
||||
|
||||
ldy #CODE_EXIT+1 ; this is a JMP or JML instruction that points to the next line.
|
||||
lda #FULL_RETURN ; this is the offset of the return code
|
||||
sta [exit_ptr],y ; patch out the low byte of the JMP/JML
|
||||
rep #$20
|
||||
|
||||
; Now we need to set up the Bank, Stack Pointer and Direct Page registers for calling into
|
||||
; the code field
|
||||
|
||||
pei BG1DataBank-1 ; Set the data bank for BG1 data
|
||||
plb
|
||||
plb
|
||||
|
||||
phd ; Save the application direct page
|
||||
lda BlitterDP ; Set the direct page to the blitter data
|
||||
tcd
|
||||
|
||||
sei ; disable interrupts
|
||||
_R0W1
|
||||
tsc ; save the stack pointer
|
||||
stal stk_save+1
|
||||
|
||||
blt_entry jml $000000 ; Jump into the blitter code $XX/YYZZ
|
||||
|
||||
blt_return _R0W0
|
||||
stk_save lda #0000 ; load the stack
|
||||
tcs
|
||||
cli ; re-enable interrupts
|
||||
pld ; restore the direct page
|
||||
|
||||
sep #$20
|
||||
ldy #CODE_EXIT+1
|
||||
lda #00
|
||||
sta [exit_ptr],y
|
||||
rep #$20
|
||||
|
||||
rts
|
||||
|
||||
; This subroutine is used to set up the BltDispatch code based on the current state of
|
||||
; the machine and/or the state of the engine. The tasks it performs are
|
||||
;
|
||||
; 1. Set the blt_entry low byte based on the graphics engine configuration
|
||||
BltSetup
|
||||
sep #$20 ; Only need 8-bits for this
|
||||
lda EngineMode
|
||||
bit #$01 ; Are both background layers enabled?
|
||||
beq :oneLyr
|
||||
lda #entry_2-base
|
||||
bra :twoLyr
|
||||
:oneLyr lda #entry_3-base
|
||||
:twoLyr sta blt_entry+1 ; set the low byte of the JML
|
||||
rep #$20
|
||||
rts
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
@ -9,6 +9,12 @@ ScreenTileHeight equ 12 ; Height of the playfield in 8x8 blocks
|
||||
ScreenTileWidth equ 14 ; Width of the playfield in 8x8 blocks
|
||||
|
||||
StartY equ 16 ; Which code buffer line displays first on screen. Range = 0 to 207
|
||||
EngineMode equ 18 ; Defined the mode/capabilities that are enabled
|
||||
; bit 0: 0 = Single Background, 1 = Parallax
|
||||
DirtyBits equ 20 ; Identify values that have changed between frames
|
||||
|
||||
BG1DataBank equ 22 ; Data bank that holds BG1 layer data
|
||||
BlitterDP equ 23 ; Direct page address the holder blitter data
|
||||
|
||||
bstk equ 224 ; 16-byte stack to push bank addresses
|
||||
|
||||
@ -21,6 +27,9 @@ tmp5 equ 250
|
||||
tmp6 equ 252
|
||||
tmp7 equ 254
|
||||
|
||||
DIRTY_BIT_BG0_X equ $0001
|
||||
DIRTY_BIT_BG0_Y equ $0002
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
@ -1,17 +1,17 @@
|
||||
; Collection of data tables
|
||||
;
|
||||
|
||||
; Tile2CodeOffset
|
||||
; Col2CodeOffset
|
||||
;
|
||||
; Takes a tile number (0 - 40) and returns the offset into the blitter code
|
||||
; Takes a column number (0 - 81) and returns the offset into the blitter code
|
||||
; template.
|
||||
;
|
||||
; This is used for rendering tile data into the code field. For example, is we assume that
|
||||
; we are filling in the operans for a bunch of PEA values, we could do this
|
||||
; we are filling in the operands for a bunch of PEA values, we could do this
|
||||
;
|
||||
; ldy tileNumber*2
|
||||
; ldy tileColumn*2
|
||||
; lda #DATA
|
||||
; ldx Tile2CodeOffset,y
|
||||
; ldx Col2CodeOffset,y
|
||||
; sta $0001,x
|
||||
;
|
||||
; This table is necessary, because due to the data being draw via stack instructions, the
|
||||
@ -207,3 +207,17 @@ ScreenAddr lup 200
|
||||
; playfield is less than 200 lines tall, then any values after 2 * PLAYFIELD_HEIGHT are undefine.
|
||||
RTable ds 400
|
||||
|
||||
; Array of addresses for the banks that hold the blitter.
|
||||
BlitBuff ds 4*13
|
||||
|
||||
; The blitter table (BTable) is a double-length table that holds the full 4-byte address of each
|
||||
; line of the blit fields. We decompose arrays of pointers into separate high and low words so
|
||||
; that everything can use the same indexing offsets
|
||||
BTableHigh ds 208*2*2
|
||||
BTableLow ds 208*2*2
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
File diff suppressed because it is too large
Load Diff
94
src/blitter/Tiles.s
Normal file
94
src/blitter/Tiles.s
Normal file
@ -0,0 +1,94 @@
|
||||
; Collection of functions that deal with tiles. Primarily rendering tile data into
|
||||
; the code fields.
|
||||
;
|
||||
; Tile data can be done faily often, so these routines are performance-sensitive.
|
||||
;
|
||||
; CopyTileConst -- the first 16 tile numbers are reserved and can be used
|
||||
; to draw a solid tile block
|
||||
; CopyTileLinear -- copies the tile data from the tile bank in linear order, e.g.
|
||||
; 32 consecutive bytes are copied
|
||||
|
||||
|
||||
; CopyTile
|
||||
;
|
||||
; Copy a solid tile into one of the code banks
|
||||
;
|
||||
; B = bank of the code field
|
||||
; A = Tile ID (0 - 1023)
|
||||
; Y = Base Adddress in the code field
|
||||
|
||||
CopyTile cmp #$0010
|
||||
bcc :FillWord
|
||||
cmp #$0400
|
||||
bcc :CopyTileMem
|
||||
rts ; Tile number is too large
|
||||
|
||||
:TilePatterns dw $0000,$1111,$2222,$3333
|
||||
dw $4444,$5555,$6666,$7777
|
||||
dw $8888,$9999,$AAAA,$BBBB
|
||||
dw $CCCC,$DDDD,$EEEE,$FFFF
|
||||
|
||||
:FillWord asl
|
||||
tax
|
||||
ldal :TilePatterns,x
|
||||
|
||||
CopyTileConst sta: $0000,y
|
||||
sta: $0003,y
|
||||
sta $1000,y
|
||||
sta $1003,y
|
||||
sta $2000,y
|
||||
sta $2003,y
|
||||
sta $3000,y
|
||||
sta $3003,y
|
||||
sta $4000,y
|
||||
sta $4003,y
|
||||
sta $5000,y
|
||||
sta $5003,y
|
||||
sta $6000,y
|
||||
sta $6003,y
|
||||
sta $7000,y
|
||||
sta $7003,y
|
||||
rts
|
||||
|
||||
:CopyTileMem asl
|
||||
asl
|
||||
asl
|
||||
asl
|
||||
asl
|
||||
tax
|
||||
|
||||
CopyTileLinear ldal tiledata+0,x
|
||||
sta: $0000,y
|
||||
ldal tiledata+2,x
|
||||
sta: $0003,y
|
||||
ldal tiledata+4,x
|
||||
sta $1000,y
|
||||
ldal tiledata+6,x
|
||||
sta $1003,y
|
||||
ldal tiledata+8,x
|
||||
sta $2000,y
|
||||
ldal tiledata+10,x
|
||||
sta $2003,y
|
||||
ldal tiledata+12,x
|
||||
sta $3000,y
|
||||
ldal tiledata+14,x
|
||||
sta $3003,y
|
||||
ldal tiledata+16,x
|
||||
sta $4000,y
|
||||
ldal tiledata+18,x
|
||||
sta $4003,y
|
||||
ldal tiledata+20,x
|
||||
sta $5000,y
|
||||
ldal tiledata+22,x
|
||||
sta $5003,y
|
||||
ldal tiledata+24,x
|
||||
sta $6000,y
|
||||
ldal tiledata+26,x
|
||||
sta $6003,y
|
||||
ldal tiledata+28,x
|
||||
sta $7000,y
|
||||
ldal tiledata+30,x
|
||||
sta $7003,y
|
||||
rts
|
||||
|
||||
|
||||
25
src/blitter/Vert.s
Normal file
25
src/blitter/Vert.s
Normal file
@ -0,0 +1,25 @@
|
||||
; Subroutines that deal with the vertical scrolling and rendering. The primary function
|
||||
; of these routines are to adjust tables and patch in new values into the code field
|
||||
; when the virtual Y-position of the play field changes.
|
||||
|
||||
|
||||
; SetBG0YPos
|
||||
;
|
||||
; Set the virtual position of the primary background layer. In addition to
|
||||
; updating the direct page state locations, this routine needs to
|
||||
SetBG0YPos
|
||||
cmp StartY
|
||||
beq :nochange
|
||||
sta StartY ; Save the position
|
||||
lda #DIRTY_BIT_BG0_Y ; Mark that it has changed
|
||||
tsb DirtyBits
|
||||
:nochange
|
||||
rts
|
||||
|
||||
; Based on the current value of StartY in the direct page. Set up the dispatch
|
||||
; information so that the BltDispatch driver will render the correct code field
|
||||
; lines in the the correct order
|
||||
_ApplyBG0YPos
|
||||
|
||||
|
||||
|
||||
Loading…
x
Reference in New Issue
Block a user