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GRID.S
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GRID.S
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section text
grid_w equ 6
grid_h equ 13
grid_c equ (grid_w*grid_h)
grid_s equ 16
grid_x equ (320-(grid_s*grid_w))/2
grid_y equ 16
grid_next_pos equ (((132*scr_w)+48)*2)
; offsets for vertical checks
grid_dir_n equ (grid_w)
grid_dir_ne equ (grid_w-1)
grid_dir_nw equ (grid_w+1)
grid_dir_w equ (1)
; masks, type is bits 0-2, flags are 3-8
grid_type_mask equ $7 ; gem type mask
grid_typep_mask equ $f ; type & player flag mask
grid_xp_mask equ $f7 ; exclude fplayer mask
grid_flag_mask equ $f8 ; gem flags mask
; flags
grid_plr_f equ $8 ; player gem flag
grid_clr_f equ $10 ; clear flag
grid_fclr_f equ $20 ; force clear - still draws a gem
grid_clr_both equ $30
grid_match_f equ $40 ; mask for match flag
grid_fast_on equ $f
grid_fast_off equ 0
; flag bit numbers
grid_plr_bit equ 3
grid_clr_bit equ 4
grid_fclr_bit equ 5
grid_match_bit equ 6
grid_init: movem.l d0/a0-a2,-(sp)
; initialise grid variables
move.l #0,grid_match_c
move.l grid_i_speed,grid_speed
move.l grid_i_delay,grid_delay
move.l grid_i_delay,grid_timer
move.l #0,grid_ticks
move.l #grid_fast_off,grid_fast
move.b #0,grid_inpt_rot
move.b #1,grid_inpt_drop
; clear grid to zero
move.l #grid_c-1,d0
lea grid,a0 ; gems and flags
lea grid_st_draw,a1 ; render state of cells
lea grid_st_clear,a2
ig1: move.b #0,(a0)+
move.b #0,(a1)+
move.b #0,(a2)+
dbf d0,ig1
jsr grid_next_3
move.b #0,grid_matched
move.b #1,grid_stable
move.b #1,grid_spawn
move.l #0,grid_plr_prev
move.l #0,grid_plr_prev+4
movem.l (sp)+,d0/a0-a2
rts
grid_test: movem.l a0,-(sp)
jsr grid_init
lea grid,a0
move.b #$42,(a0)
adda.l #grid_w,a0
move.b #$42,(a0)
adda.l #grid_w,a0
move.b #$42,(a0)
move.b #$41,grid+15
move.b #$41,grid+16
move.b #$41,grid+17
lea grid,a0
adda.l #grid_c-1,a0
move.b #$41,(a0)
movem.l (sp)+,a0
rts
grid_plr_left: movem.l d0/a0-a1,-(sp)
lea grid_plr,a0
cmp.b #0,grid_plr_x(a0) ; check x-pos
beq gpl_done
move.l grid_plr_a(a0),a1 ; see if square to the
move.b (a1-1),d0 ; left is empty
and.b #grid_type_mask,d0
cmp.b #0,d0
bne gpl_done ; not empty
subq.b #1,grid_plr_x(a0) ; update player x
move.b grid_x_speed,grid_inpt_x
move.b (a1),(a1-1) ; move the gem
move.b #grid_clr_f,(a1)
subq.l #1,grid_plr_a(a0) ; update player address
cmp.b #0,grid_plr_y(a0) ; don't update other gems
; if first row of grid
beq gpl_done
subq.l #grid_w,a1 ; move 2nd gem
move.b (a1),(a1-1)
move.b #grid_clr_f,(a1)
cmp.b #1,grid_plr_y(a0)
beq gpl_done
subq.l #grid_w,a1 ; move 3rd gem
move.b (a1),(a1-1)
move.b #grid_clr_f,(a1)
gpl_done: movem.l (sp)+,d0/a0-a1
rts
grid_plr_right: movem.l d0/a0-a1,-(sp)
lea grid_plr,a0
cmp.b #grid_w-1,grid_plr_x(a0) ; check x-pos
beq gpr_done
move.l grid_plr_a(a0),a1 ; see if square to the
move.b (a1+1),d0 ; right is empty
and.b #grid_type_mask,d0
cmp.b #0,d0
bne gpr_done ; not empty
addq.b #1,grid_plr_x(a0) ; update player x
move.b grid_x_speed,grid_inpt_x
move.b (a1),(a1+1) ; move the gem
move.b #grid_clr_f,(a1)
addq.l #1,grid_plr_a(a0) ; update player address
cmp.b #0,grid_plr_y(a0) ; don't update other gems
; if first row of grid
beq gpr_done
subq.l #grid_w,a1 ; move 2nd gem
move.b (a1),(a1+1)
move.b #grid_clr_f,(a1)
cmp.b #1,grid_plr_y(a0)
beq gpr_done
subq.l #grid_w,a1 ; move 3rd gem
move.b (a1),(a1+1)
move.b #grid_clr_f,(a1)
gpr_done: movem.l (sp)+,d0/a0-a1
rts
grid_plr_rot: movem.l d1/a0-a1,-(sp) ; rotates the player gems
; d0 determines direction
; 0 is 'up', 1 is 'down'
cmp.b #1,grid_inpt_rot
beq grid_rot_done
move.b #1,grid_inpt_rot
lea grid_plr,a0
move.l grid_plr_a(a0),a1
move.b (a1),d1
cmp.b #2,grid_plr_y(a0)
bge grid_rot_std
cmp.b #1,grid_plr_y(a0) ; first or second line?
beq grid_rot_l2
; on line one(0), one gem on screen
cmp.b #1,d0
beq grid_rot_l1d
move.b grid_plr_g3(a0),(a1)
move.b grid_plr_g2(a0),grid_plr_g3(a0)
move.b d1,grid_plr_g2(a0)
bra grid_rot_done
grid_rot_l1d: move.b grid_plr_g2(a0),(a1)
move.b grid_plr_g3(a0),grid_plr_g2(a0)
move.b d1,grid_plr_g3(a0)
bra grid_rot_done
grid_rot_l2: ; on line two, two gems on screen
cmp.b #1,d0
beq grid_rot_l2d
move.b grid_plr_g3(a0),(a1)
move.b (a1-grid_w),grid_plr_g3(a0)
move.b d1,(a1-grid_w)
bra grid_rot_done
grid_rot_l2d: move.b (a1-grid_w),(a1)
move.b grid_plr_g3(a0),(a1-grid_w)
move.b d1,grid_plr_g3(a0)
bra grid_rot_done
grid_rot_std: ; standard case, rotate in the grid
cmp.b #1,d0
beq grid_rot_stdd
move.b (a1-grid_w*2),(a1)
move.b (a1-grid_w),(a1-grid_w*2)
move.b d1,(a1-grid_w)
bra grid_rot_done
grid_rot_stdd: move.b (a1-grid_w),(a1)
move.b (a1-grid_w*2),(a1-grid_w)
move.b d1,(a1-grid_w*2)
grid_rot_done: movem.l (sp)+,d1/a0-a1
rts
grid_plr_inc_y: movem.l d0/a0-a1,-(sp)
lea grid_plr,a0
cmp.l #16,grid_plr_y_off(a0) ; if offset >= 16 then inc
blt g_piy_done ; otherwise skip
sub.l #16,grid_plr_y_off(a0)
cmp.b #1,grid_stable ; do nothing if stable
beq g_piy_done ; waiting for offset to be >= 16
g_piy_inc: addq.b #1,grid_plr_y(a0)
add.l #grid_w,grid_plr_a(a0)
cmp.b #2,grid_plr_y(a0) ; if we're on the 2nd or
bgt g_piy_done ; or 3rd row fill in other gems
beq g_piy_row3 ; on row 3?
move.l grid_plr_a(a0),a1 ; on row 2, so fill in next gem
subq.l #grid_w,a1
move.b grid_plr_g2(a0),(a1)
bra g_piy_done
g_piy_row3: move.l grid_plr_a(a0),a1 ; on row 3, fill in last gem
sub.l #grid_w*2,a1
move.b grid_plr_g3(a0),(a1)
g_piy_done: movem.l (sp)+,d0/a0-a1
rts
grid_rand_gem: jsr rand
and.l #15,d0
lea grid_randoms,a2
adda.l d0,a2
cmp.b #99,(a2)
beq grid_rand_gem
move.b (a2),d0
addq.b #1,d0
rts
; fills up the next 3 gems ready for spawning
; grid_ran_gem trashes a2!!
grid_next_3: movem.l d0/a0-a2,-(sp)
lea grid_plr,a1
jsr grid_rand_gem
move.b d0,grid_plr_next(a1) ; store in the player struct
jsr grid_rand_gem
move.b d0,grid_plr_next+1(a1)
jsr grid_rand_gem
move.b d0,grid_plr_next+2(a1)
movem.l (sp)+,d0/a0-a2
rts
grid_plr_spawn: movem.l d0/a0-a2,-(sp)
lea grid,a0 ; find spawn pos
adda.l #3,a0
move.b (a0),d0
and.b #grid_type_mask,d0 ; check spawn slot
cmp.b #0,d0
beq grid_ps1
jsr game_over ; occupied, therefore DEAD
bra grid_ps_done
grid_ps1: lea grid_plr,a1
move.b #3,grid_plr_x(a1) ; player base x, y
move.b #0,grid_plr_y(a1)
move.l a0,grid_plr_a(a1) ; address of base gem
move.l #15,grid_plr_y_off(a1) ; offset to 0
moveq.l #0,d0
move.b grid_plr_next(a1),d0
gps1test: or.b #grid_plr_f,d0
move.b d0,(a0) ; update the grid
move.b grid_plr_next+1(a1),d0
or.b #grid_plr_f,d0
move.b d0,grid_plr_g2(a1) ; appear next so the player
move.b grid_plr_next+2(a1),d0 ; can still rotate through
or.b #grid_plr_f,d0
move.b d0,grid_plr_g3(a1) ; if they're not on screen
jsr grid_next_3 ; setup the next 3 gems
move.b #2,grid_st_next
move.l #grid_fast_off,grid_fast
move.b #0,grid_stable
move.b #0,grid_spawn
grid_ps_done: movem.l (sp)+,d0/a0-a2
rts
grid_update: movem.l d0-d5/a0-a5,-(sp)
; update speed if required
move.l grid_ticks,d0
addq.l #1,d0
move.l d0,grid_ticks
cmp.l #3600,d0 ; check time
blt grid_spawn_chk
move.l #0,grid_ticks ; reset
; first decrease the delay, then adjust speed
cmp.l #1,grid_delay
beq grid_dec_spd
subq.l #1,grid_delay
bra grid_spawn_chk
grid_dec_spd: cmp.l #16,grid_speed
bge grid_spawn_chk
addq.l #1,grid_speed
grid_spawn_chk: ; if stable and no matches then spawn
cmp.b #1,grid_spawn
bne gu_input
jsr grid_plr_spawn
gu_input: cmp.b #1,grid_matched
beq gu_input_done
moveq.l #0,d0
move.b joy1,d0
or.b joy2,d0
gu_input_test: cmp.b #0,grid_inpt_x
bgt gu_input_cx
btst #2,d0
beq gu_input_right
jsr grid_plr_left
gu_input_right: btst #3,d0
beq gu_input_up
jsr grid_plr_right
gu_input_cx: subq.b #1,grid_inpt_x
gu_input_up: btst #0,d0
beq gu_input_down
move.l d0,-(sp)
move.l #0,d0
jsr grid_plr_rot
move.l (sp)+,d0
bra gu_input_fire
gu_input_down: btst #1,d0
beq gu_input_crot
move.l d0,-(sp)
move.l #1,d0
jsr grid_plr_rot
move.l (sp)+,d0
bra gu_input_fire
gu_input_crot: move.b #0,grid_inpt_rot
gu_input_fire: btst #7,d0 ; drop gems
beq gu_input_cdrop ; clear drop flag
cmp.b #1,grid_inpt_drop
beq gu_input_done
move.b #1,grid_inpt_drop
move.l #grid_fast_on,grid_fast ; enable fast drop
lea grid_plr,a0
bra gu_input_done
gu_input_cdrop: cmp.b #1,grid_inpt_drop ; if drop flag is set
bne gu_input_cfast ; then clear & set delay
move.b #0,grid_inpt_drop
move.l grid_delay,grid_timer
gu_input_cfast: move.l #grid_fast_off,grid_fast ; clear fast flag
gu_input_done: ; don't do any updates while the timer
; is counting down
move.l grid_timer,d0
cmp.l #0,d0
beq gu_init
subq.l #1,d0
move.l d0,grid_timer
; if the counter has just hit 0
; we're ready to go again
cmp.l #0,d0
bne gu_done
; if we're not doing a fast drop then
; reset the timer according to the delay
cmp.l #grid_fast_on,grid_fast
beq gu_init
move.l grid_delay,grid_timer
gu_init: ; pre-processing before the main update
; for now this just clears existing flags
; later on it should allow for double
; buffering so logic can be run every frame
lea grid,a0
lea grid_st_clear,a5
move.l #grid_c-1,d0
gu_init_loop: btst #grid_match_bit,(a0) ; check for match
beq gu_init_clear
move.b #grid_clr_f,(a0)+ ; found, set clear
dbf d0,gu_init_loop
bra gu_init_done
gu_init_clear: and.b #grid_typep_mask,(a0)+ ; clear flags except for
dbf d0,gu_init_loop ; player flag
bra gu_init_done
gu_init_skip: dbf d0,gu_init_loop
; start at end of grid (bottom of screen)
; and move values down, flagging squares
; that need to be cleared when drawing
gu_init_done:
move.b #1,grid_stable ; reset stable flag
lea grid,a0 ; grid data
lea grid_st_draw,a4 ; grid render state
lea grid_st_clear,a5 ; grid clear state
adda.l #grid_c-1,a0
adda.l #grid_c-1,a4
adda.l #grid_c-1,a5
move.l #grid_w*(grid_h-1)-1,d0
lea grid_plr,a2 ; update player offset
move.l grid_plr_y_off(a2),d5
add.l grid_speed,d5
or.l grid_fast,d5
move.l d5,grid_plr_y_off(a2)
gu_loop: moveq.l #0,d3
move.b (a0),d3
and.b #grid_type_mask,d3 ; type of gem in d3
cmp.b #0,d3
beq gu_empty ; skip filled squares
bra gu_skip
gu_empty: move.l a0,a1 ; get square above
suba.l #grid_w,a1 ; address into a1
moveq.l #0,d4
move.b (a1),d4
btst #grid_plr_bit,d4 ; is gem above a player
beq gu_l1 ; gem?
cmp.l #16,d5 ; yes, so check yoff
blt gu_l2 ; < 16 so skip
; (but still unstable)
gu_l1: and.b #grid_type_mask,d4 ; type of above in d4
cmp.b #0,d4
beq gu_skip ; empty above, no-op
move.b (a1),d4
and.b #grid_typep_mask,d4 ; else move the gem down
move.b d4,(a0) ; with the player flag bit
or.b #grid_fclr_f,(a0) ; force clear before draw
move.b #grid_clr_f,(a1) ; and set above to 0 with clear
move.b #2,(a5-grid_w)
move.b #2,(a4) ; draw over two frames
gu_l2: move.b #0,grid_stable ; clear stable flag
gu_skip:
suba.l #1,a0
suba.l #1,a4
suba.l #1,a5
dbf d0,gu_loop
; after main update loop
lea grid_plr,a0 ; see if player gems have dropped
cmp.l #16,grid_plr_y_off(a0)
blt gu_done ; nope, do nothing else
cmp.b #1,grid_stable ; is the grid stable
bne gu_unstable ; nope, still falling
jsr grid_matches ; check for matches
move.l #0,grid_plr_y_off(a0) ; clear the player offset
lea grid,a0 ; now stable clear player
lea grid_st_draw,a4 ; flags for player gems but
move.l #grid_c-1,d0 ; force draw so they're not cleared
gu_s_loop: btst #grid_plr_bit,(a0)
beq gu_s_loop_s
and.b #grid_xp_mask,(a0) ; clear player flag
move.b #2,(a4) ; force draw
gu_s_loop_s: addq.l #1,a0
addq.l #1,a4
dbf d0,gu_s_loop
cmp.b #0,grid_matched ; stable, if no matches spawn
beq gu_spawn
jsr sfx_match
bra gu_done
gu_spawn: jsr sfx_drop
move.b #1,grid_spawn
gu_unstable: jsr grid_plr_inc_y ; otherwise increment player y
gu_done:
movem.l (sp)+,d0-d5/a0-a5
rts
; Match testing
;
; Looping throught he array backwards so x & y are based
; on an origin in the bottom right, confusing the east
; and west checks
;
; Test Direction | Condition
;================|=============
; E | x > 1
; W | x < (w - 2)
; N | y < (h - 2)
;
; NE | N && E
; NW | N && W
;
; Only need to check four directions as these cover the rest
; automatically. W, NW, N, and NE are all substractions when
; working backwards through the grid so use those ease.
grid_matches: movem.l d0-d6/a0-a3,-(sp)
; start at end (bottom right)
; don't need to check the last two rows as
; they'll be covered by the other tests
gm_start: lea grid,a0
move.b #0,grid_matched ; reset the overall match flag
adda.l #grid_c-1,a0
move.l #grid_c-1,d0
sub.l #grid_w*2,d0
moveq.l #0,d1 ; x
moveq.l #0,d2 ; y
moveq.l #0,d3 ; current value
moveq.l #0,d4 ; track blanks in d4 so we
moveq.l #0,d5 ; can stop on a row of blank
gm_loop: move.b (a0),d3
btst #grid_clr_bit,d3 ; flagged as clear?
bne gm_skip
and.b #grid_type_mask,d3
cmp.b #0,d3 ; empty?
beq gm_skip
moveq.l #0,d6
move.l #grid_dir_n,d5
jsr grid_check_3
cmp #1,d1 ; north east?
ble gm_north_west ; no, check nw
move.l #grid_dir_ne,d5
jsr grid_check_3
gm_north_west: cmp #grid_w-2,d1 ; no nw, so no west
bge gm_skip
move.l #grid_dir_nw,d5 ; both nw & w
jsr grid_check_3
move.l #grid_dir_w,d5
jsr grid_check_3
bra gm_skip
gm_west: cmp #grid_w-2,d1 ; check west?
bge gm_skip
move #grid_dir_w,d5
jsr grid_check_3
gm_skip: addq.l #1,d1
cmp.l #grid_w,d1
bne gm_noinc ; end of row?
moveq.l #0,d1 ; reset x
addq.l #1,d2 ; inc y
gm_noinc:
addq.l #1,d4
suba.l #1,a0 ; next gem
dbf d0,gm_loop
; set the timer to run whether there was a match
; or not so there's a gap before the player's
; next gems drop.
move.l #8,grid_timer
cmp.b #1,grid_matched
bne match_skip
add.l #24,grid_timer
move.l #grid_fast_on,grid_fast
match_skip: movem.l (sp)+,d0-d6/a0-a3
rts
grid_check_3: ; d3 holds current value
; d5 holds offset to use
; a0 points to current square
; d6,a1-a2 are for working
movem.l d0/d6/a0-a2,-(sp)
move.l a0,a1
suba.l d5,a1
move.l #0,d6
move.b (a1),d6
and.l #grid_type_mask,d6
cmp d6,d3
bne gc3_noop ; no match
move.l a1,a2
suba.l d5,a2
move.b (a2),d6
and.b #grid_type_mask,d6
cmp d6,d3
bne gc3_noop ; no match
beq gc3_setflags
gc3_setflags: or.b #grid_match_f,(a0) ; match!
or.b #grid_match_f,(a1) ; flag ready for
or.b #grid_match_f,(a2) ; clearing next time
jsr game_inc_scr ; increment score, 10 per
; group of 3, so 4=20, 5=30
addq.l #1,grid_match_c ; inc. grid match count
move.b #1,grid_matched ; set global flag
gc3_noop: movem.l (sp)+,d0/d6/a0-a2
rts
grid_draw: ; draw gems to screen
movem.l d0-d7/a0-a5,-(sp)
cmp.b #0,grid_st_next ; draw the next 3 gems
beq dg_skip_next
subq.b #1,grid_st_next
jsr grid_draw_next
dg_skip_next: lea grid_plr,a2
moveq.l #0,d0
move.l grid_plr_y_off(a2),d0
move.l d0,d5 ; keep the offset
lea grid,a2
lea grid_st_draw,a4
lea grid_st_clear,a5
movea.l screen_adr,a1 ; start of grid in buffer
adda.l #grid_x*2,a1
adda.l #grid_y*scr_w*2,a1
move.l screen_adr,a0 ; clear player gems from
move.l grid_plr_prev+4,d0 ; previous location
cmp.l #0,d0
beq dg_loop_init
adda.l d0,a0 ; previous location
jsr dg_drawbg
suba.l #scr_w*grid_s*2,a0
cmp.l screen_adr,a0
blt dg_loop_init
jsr dg_drawbg
suba.l #scr_w*grid_s*2,a0
cmp.l screen_adr,a0
blt dg_loop_init
jsr dg_drawbg
dg_loop_init: ; update offset buffer (if double buffering)
move.l grid_plr_prev,grid_plr_prev+4
; clear in case there are no more player gems
move.l #0,grid_plr_prev
move.l #grid_c-1,d2 ; loop counter
moveq.l #0,d3 ; tracks x-wrapping
moveq.l #0,d4
dg1:
move.b (a2),d4 ; get gem in d4
movea.l a1,a0
;btst #grid_clr_bit,d4 ; need to clear?
;bne dg_bg
cmp.b #0,(a5)
beq dg_chk_match
subq.b #1,(a5)
jsr dg_drawbg
dg_chk_match: btst #grid_match_bit,d4 ; matched?
bne dg_match
btst #grid_plr_bit,d4 ; player gem? add offset
beq dg_clear_chk ; gem is offset from above
; unless the grid is stable
; and then draw where they are
cmp.l #1,grid_stable
beq dg_clear_chk
suba.l #scr_w*2*16,a0 ; > 0 so do offset
move.l d5,d6
mulu.l #scr_w*2,d6
adda.l d6,a0
move.l a0,d7 ; store gem screen offset
sub.l screen_adr,d7 ; from start of screen
move.l d7,grid_plr_prev
bra dg_type
dg_clear_chk: btst #grid_fclr_bit,d4 ; clear bg if force flag
beq dg_draw_chk ; is set
jsr dg_drawbg
movea.l a1,a0
bra dg_type
dg_draw_chk: cmp.b #0,(a4) ; two frames of draw for static
beq dg_clear
subq.b #1,(a4)
dg_type: and.b #grid_type_mask,d4
cmp.b #0,d4
beq dg_clear
movea.l #grid_spr_firsts,a3
movea.l 0(a3,d4.l*4),a3
jsr (a3)
bra dg_clear
dg_match: ; gems have been matched to do animations
move.l a1,a0 ; get anim frame
move.l #32,d0
sub.l grid_timer,d0
cmp.l #17,d0 ; only have 8 frames
bgt dg_clear
lsr #1,d0
jsr dg_drawbg
move.l a1,a0
cmp.l #8,d0 ; clears last frame
beq dg_clear
and.b #grid_type_mask,d4
movea.l #grid_spr_maps,a3 ; find the map to use
movea.l 0(a3,d4.l*4),a3
jsr grid_draw_gem
bra dg_clear
dg_bg: move.l a1,a0
jsr dg_drawbg
dg_clear:
adda.l #1,a2 ; next square
adda.l #1,a4 ; next in state buffers
adda.l #1,a5
adda.l #grid_s*2,a1 ; next screen pos
addq.l #1,d3 ; end of row?
cmp #grid_w,d3
bne dg_next
; yep, move to next row of grid
adda.l #scr_w*grid_s*2-grid_w*grid_s*2,a1
moveq.l #0,d3
dg_next:
dbf d2,dg1
lea.l grid_plr,a2 ; if the player is on the first
cmp.b #2,grid_plr_y(a2) ; 3 rows the bg needs to be cleared
bgt dg_done ; above to clip the player gems
dg_brk: move.l screen_adr,a0
move.l a0,a1
moveq.l #0,d0
move.b grid_plr_x(a2),d0 ; x-pos
lsl.l #5,d0 ; * 16
adda.l d0,a0
adda.l #grid_x*2,a0
jsr dg_drawbg
dg_done: movem.l (sp)+,d0-d7/a0-a5
rts
dg_drawbg: movem.l d0-d1/a0-a1,-(sp) ; draw 16x16 of bg at a0, using
; offset based on a0-screen_adr
move.l a0,d0
sub.l screen_adr,d0
lea background,a1
adda.l d0,a1
move.l #3,d1
dg_bg_loop:
REPT grid_s/4
move.l (a1)+,(a0)+
move.l (a1)+,(a0)+
move.l (a1)+,(a0)+
move.l (a1)+,(a0)+
move.l (a1)+,(a0)+
move.l (a1)+,(a0)+
move.l (a1)+,(a0)+
move.l (a1)+,(a0)+
adda.l #scr_w*2-grid_s*2,a0
adda.l #scr_w*2-grid_s*2,a1
ENDR
dbf d1,dg_bg_loop
movem.l (sp)+,d0-d1/a0-a1
rts
grid_draw_next: movem.l d0-d2/a0-a4,-(sp) ; draws the next 3 gems
move.l #scr_w*16*2,d2 ; offset for each square
movea.l screen_adr,a0
move.l a0,a1 ; copy screen buffer to a1
adda.l #grid_next_pos,a0
move.l a0,a3
lea grid_plr,a4
moveq.l #0,d0
lea grid_spr_firsts,a2 ; map of sprites
move.b grid_plr_next+2(a4),d0 ; find the right entry in the main
cmp.b #0,d0
beq gdn_done
lsl #2,d0 ; index into sprite map
adda.l d0,a2
move.l (a2),a2 ; draw bg then sprite!
jsr dg_drawbg
jsr (a2)
adda.l d2,a3 ; screen offset
move.l a3,a0
move.b grid_plr_next+1(a4),d0 ; get the next gem
lsl #2,d0
lea grid_spr_firsts,a2
adda.l d0,a2
move.l (a2),a2
jsr dg_drawbg
jsr (a2)
adda.l d2,a3
move.l a3,a0
move.b grid_plr_next(a4),d0 ; and the last
lsl #2,d0
lea grid_spr_firsts,a2
adda.l d0,a2
move.l (a2),a2
jsr dg_drawbg
jsr (a2)
gdn_done: movem.l (sp)+,d0-d2/a0-a4
rts