Sparse_Invaders_Source_ _Macros.txt - simondotm/stardot-wiki GitHub Wiki
;-------------------------------------------------------------------------------
; Macros ...
; Written by Neil Beresford.
;
; Copyright 2008,2009 Neil Beresford
;
; This file is part of Sparse Invaders.
; Sparse Invaders is free software: you can redistribute it and/or modify
; it under the terms of the GNU General Public License as published by
; the Free Software Foundation, either version 3 of the License, or
; (at your option) any later version.
;
; Sparse Invaders is distributed in the hope that it will be useful,
; but WITHOUT ANY WARRANTY; without even the implied warranty of
; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
; GNU General Public License for more details.
;
; You should have received a copy of the GNU General Public License
; along with Sparse Invaders. If not, see <http://www.gnu.org/licenses/>.
;
;
;-------------------------------------------------------------------------------
;-------------------------------------------------------------------------------
; Mode change ...
; A trashed
;-------------------------------------------------------------------------------
.macro MODE
LDA #$16
JSR oswrch
LDA _1
JSR oswrch
.macend
;-------------------------------------------------------------------------------
.macro CURSOROFF
LDA #10
STA $FE00
LDA #32
STA $FE01
.macend
;-------------------------------------------------------------------------------
.macro WAIT_VBLANK
LDA #19
jsr osbyte
.macend
;-------------------------------------------------------------------------------
; PushRegs
;
;-------------------------------------------------------------------------------
.macro PUSHREGS
PHA ; preserve the registers
TXA
PHA
TYA
PHA
.macend
;-------------------------------------------------------------------------------
; PopRegs
;
;-------------------------------------------------------------------------------
.macro POPREGS
PLA ; restore the regs
TAY
PLA
TAX
PLA
.macend
;-------------------------------------------------------------------------------
;-------------------------------------------------------------------------------
.macro CHECK_KEY ; checks the key, trashes the regs ...
LDA #$81
LDX #0
LDY #0
JSR osbyte
CPY #0
.macend
;-------------------------------------------------------------------------------
; Change background colour
; _1 Colour to change to
; all regs trashed...
;
;-------------------------------------------------------------------------------
.macro BORDERCOLOUR
lda #155
ldx #_1
jsr $fff4
.macend
;-------------------------------------------------------------------------------
; Store16bit - _1 Value to be stored
; _2 Place to store
; A trashed
;
;-------------------------------------------------------------------------------
.macro STORE16BIT
LDA _1
STA _2
LDA _1+1
STA _2+1
.macend
;-------------------------------------------------------------------------------
; Add16bit - _1 Value 1
; _2 Value 2
; _3 Result
; A trashed and also carry
;-------------------------------------------------------------------------------
.macro ADD16BIT
CLC ;Ensure carry is clear
LDA _1+0 ;Add the two least significant bytes
ADC _2+0
STA _3+0 ;... and store the result
LDA _1+1 ;Add the two most significant bytes
ADC _2+1 ;... and any propagated carry bit
STA _3+1 ;... and store the result
.macend
;-------------------------------------------------------------------------------
; Sub16bit - _1 Value 1
; _2 Value 2
; _3 Result
; A trashed and also carry
;-------------------------------------------------------------------------------
.macro SUB16BIT
SEC ;Ensure carry is clear
LDA _1+0 ;Sub the two most significant bytes
SBC _2+0
STA _3+0 ;... and store the result
LDA _1+1 ;sub the two least significant bytes
SBC _2+1 ;... and any propagated carry bit
STA _3+1 ;... and store the result
.macend
;-------------------------------------------------------------------------------
; Multiply by 8 the 16bit contents in
;
;
;-------------------------------------------------------------------------------
.macro MUL8
CLC
LDA _1
ASL
ROL _1+1
ASL
ROL _1+1
ASL
ROL _1+1
STA _1
.macend
;-------------------------------------------------------------------------------
; Multiply by 6 A and store in _1
;
;
;-------------------------------------------------------------------------------
.macro MUL6
ASL
STA _1
ASL
CLC
ADC _1
STA _1
.macend
;-------------------------------------------------------------------------------
; Multiply by 3 A and store in _1
;
;
;-------------------------------------------------------------------------------
.macro MUL3
STA _1
ASL
CLC
ADC _1
STA _1
.macend
;-------------------------------------------------------------------------------
; Multiply by 5 A and store in _1
;
;
;-------------------------------------------------------------------------------
.macro MUL5
STA _1
ASL
ASL
CLC
ADC _1
STA _1
.macend
;-------------------------------------------------------------------------------
; Multiply by 32 the 16bit contents in
;
;
;-------------------------------------------------------------------------------
.macro MUL32
CLC
LDA _1
ASL
ROL _1+1
ASL
ROL _1+1
ASL
ROL _1+1
ASL
ROL _1+1
ASL
ROL _1+1
STA _1
.macend
;-------------------------------------------------------------------------------
; Divide by 6 A and store in _1
;
;
;-------------------------------------------------------------------------------
.macro DIV6
LSR
STA _1
LSR
SEC
SBC _1
STA _1
.macend
;-------------------------------------------------------------------------------
; Multipy 8bit by 8, then add to 16bit address
; uses scratch reg temp($76) for uppper 8bits in
; multiply by 8
;
;-------------------------------------------------------------------------------
.macro MUL8ADDTOADDRESS
LDA #0 ; multiply by 8
STA TEMP
CLC
ASL _1
ROL TEMP
ASL _1
ROL TEMP
ASL _1
ROL TEMP
LDA _1 ; now the addition to the 16bit
CLC
ADC _2
STA _2
LDA TEMP
ADC _2+1
STA _2+1
.macend
;-------------------------------------------------------------------------------
; Add A to 16bit value ...
;-------------------------------------------------------------------------------
.macro ADDTO16BIT
CLC
ADC _1
STA _1
LDA _1+1
ADC #0
STA _1+1
.macend
;-------------------------------------------------------------------------------
; End of Macros
;-------------------------------------------------------------------------------