230 lines
3.6 KiB
ArmAsm
230 lines
3.6 KiB
ArmAsm
;
|
|
; projectile
|
|
; Code and data structures related to the projectiles
|
|
;
|
|
; Created by Quinn Dunki on 8/13/17
|
|
;
|
|
|
|
|
|
projectileData:
|
|
; gameobject data
|
|
.word -1 ; Pos X in pixels (from left terrain edge)
|
|
.word 0 ; Pos Y in pixels (from bottom terrain edge)
|
|
|
|
.word 0 ; Pos X (12.4 fixed point)
|
|
.word 0 ; Pos Y (12.4 fixed point)
|
|
.word 0 ; Velocity X (8.8 fixed point)
|
|
.word 0 ; Velocity Y (8.8 fixed point)
|
|
|
|
.word 0,0 ; Padding
|
|
|
|
JD_POSX = 0 ; Byte offsets into projectile data structure
|
|
JD_POSY = 2
|
|
JD_PRECISEX = 4
|
|
JD_PRECISEY = 6
|
|
JD_VX = 8
|
|
JD_VY = 10
|
|
|
|
GRAVITY = $ffff ; 8.8 fixed point
|
|
|
|
|
|
.macro PROJECTILEPTR_Y
|
|
tya ; Pointer to projectil structure from index
|
|
asl
|
|
asl
|
|
asl
|
|
asl
|
|
tay
|
|
.endmacro
|
|
|
|
|
|
|
|
projectileParams:
|
|
.word 0 ; Starting pos X
|
|
.word 0 ; Starting pos Y
|
|
.word 0 ; Initial angle
|
|
.word 0 ; Initial power
|
|
|
|
|
|
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
|
|
; fireProjectile
|
|
;
|
|
; Trashes SCRATCHL
|
|
;
|
|
fireProjectile:
|
|
SAVE_AXY
|
|
|
|
; Set up projectile structure
|
|
ldy #0
|
|
lda #projectileData ; Only one active at a time for now
|
|
sta SCRATCHL
|
|
|
|
lda projectileParams ; X pos
|
|
sta (SCRATCHL),y
|
|
iny
|
|
iny
|
|
lda projectileParams+2 ; Y pos
|
|
sta (SCRATCHL),y
|
|
iny
|
|
iny
|
|
|
|
lda projectileParams ; Fixed point version of X pos
|
|
asl
|
|
asl
|
|
asl
|
|
asl
|
|
sta (SCRATCHL),y
|
|
iny
|
|
iny
|
|
|
|
lda projectileParams+2 ; Fixed point version of Y pos
|
|
asl
|
|
asl
|
|
asl
|
|
asl
|
|
sta (SCRATCHL),y
|
|
iny
|
|
iny
|
|
|
|
lda projectileParams+4 ; Convert angle to vector
|
|
asl
|
|
tax
|
|
lda angleToVectorX,x ; Velocity X
|
|
sta (SCRATCHL),y
|
|
iny
|
|
iny
|
|
|
|
lda projectileParams+4 ; Convert angle to vector
|
|
asl
|
|
tax
|
|
lda angleToVectorY,x ; Velocity Y
|
|
sta (SCRATCHL),y
|
|
|
|
RESTORE_AXY
|
|
rts
|
|
|
|
|
|
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
|
|
; updateProjectiles
|
|
;
|
|
; Trashes SCRATCHL
|
|
;
|
|
updateProjectiles:
|
|
SAVE_AY
|
|
lda projectileData+JD_POSX
|
|
bmi updateProjectilesDone
|
|
|
|
; Integrate gravity over velocity
|
|
lda projectileData+JD_VY
|
|
clc
|
|
adc #GRAVITY
|
|
sta projectileData+JD_VY
|
|
|
|
; Integrate X velocity over position
|
|
lda projectileData+JD_VX
|
|
; Convert 8.8 to 12.4
|
|
cmp #$8000
|
|
ror
|
|
cmp #$8000
|
|
ror
|
|
cmp #$8000
|
|
ror
|
|
cmp #$8000
|
|
ror
|
|
clc
|
|
adc projectileData+JD_PRECISEX
|
|
sta projectileData+JD_PRECISEX
|
|
|
|
; Convert to integral for rendering
|
|
lsr
|
|
lsr
|
|
lsr
|
|
lsr
|
|
sta projectileData+JD_POSX
|
|
bmi updateProjectilesDelete
|
|
cmp #TERRAINWIDTH-GAMEOBJECTWIDTH-1
|
|
bpl updateProjectilesDelete
|
|
|
|
; Integrate Y velocity over position
|
|
lda projectileData+JD_VY
|
|
; Convert 8.8 to 12.4
|
|
cmp #$8000
|
|
ror
|
|
cmp #$8000
|
|
ror
|
|
cmp #$8000
|
|
ror
|
|
cmp #$8000
|
|
ror
|
|
clc
|
|
adc projectileData+JD_PRECISEY
|
|
sta projectileData+JD_PRECISEY
|
|
|
|
; Convert to integral for rendering
|
|
lsr
|
|
lsr
|
|
lsr
|
|
lsr
|
|
sta projectileData+JD_POSY
|
|
bmi updateProjectilesDelete
|
|
cmp #201
|
|
bpl updateProjectilesDelete
|
|
|
|
updateProjectilesDone:
|
|
RESTORE_AY
|
|
rts
|
|
|
|
updateProjectilesDelete:
|
|
ldy #0
|
|
jsr deleteProjectile
|
|
bra updateProjectilesDone
|
|
|
|
|
|
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
|
|
; deleteProjectile
|
|
;
|
|
; Y = Projectile index
|
|
; Trashes A
|
|
;
|
|
deleteProjectile:
|
|
PROJECTILEPTR_Y
|
|
lda #-1
|
|
sta projectileData+JD_POSX,y
|
|
rts
|
|
|
|
|
|
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
|
|
; renderProjectiles
|
|
;
|
|
;
|
|
renderProjectiles:
|
|
pha
|
|
lda projectileData
|
|
bmi renderProjectilesDone
|
|
|
|
lda #projectileData
|
|
sta PARAML0
|
|
jsr renderGameobject
|
|
|
|
renderProjectilesDone:
|
|
pla
|
|
rts
|
|
|
|
|
|
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
|
|
; unrenderProjectiles
|
|
;
|
|
;
|
|
unrenderProjectiles:
|
|
pha
|
|
lda projectileData
|
|
bmi unrenderProjectilesDone
|
|
|
|
lda #projectileData
|
|
sta PARAML0
|
|
jsr unrenderGameobject
|
|
|
|
unrenderProjectilesDone:
|
|
pla
|
|
rts
|