Breakout

TUTORIAL · BREAKOUT · STAGE 5 OF 8BETA

Stage 5 · Strong bricks and levels

Two lines: bricks that take up to three hits, and a pattern for them that changes every level without any level data to type in.

Type these 2 lines into the previous stage. Line 402 replaces a line you already have: type it again in full. Or load the whole stage from the disc with CHAIN "STAGE5".

Text after :REM and indented continuation lines are Beeb-dev notes and layout: the build strips them, so they cost the BBC nothing. Typing into a real BBC, leave the notes out and join each continuation line onto the line above.

392 IF a%(rr%,ct%)>1 a%(rr%,ct%)=a%(rr%,ct%)-1   :REM a strong brick: one hit
    :ENDPROC                                     :REM off, and it stays
402 s%=1                                         :REM level 1: every brick takes one hit
    :IF l%>1 s%=1+((r%+c%+l%)MOD 3)              :REM after that, diagonal bands of 1,
    REM 2 and 3 hits that shift along one place each level

Line 402 gives level 1 nothing but single-hit bricks. From level 2 the formula 1+((r%+c%+l%)MOD 3) lays diagonal bands of 1-, 2- and 3-hit bricks that shift along by one each level. Line 392 takes one hit off a strong brick and leaves it standing (the ball still bounces, and the cell is still repainted on both pages, but the brick is drawn back in).

The bricks do not show their strength yet: every brick in a row uses the same frame. Showing damage needs a frame per strength in the sprite pack and a different frame choice in PROCbe (line 530), which is a good exercise.

Level 1 is all single-hit bricks, so you will not see this stage do anything different until you clear the first level. Line 30 starts at l%=1: change it to l%=2 to start on the strong bricks.

The whole of stage 5, ready to type in: the EGFX helpers merged and the notes stripped (88 BASIC lines)
5 MODE 1:HIMEM=&2400
20 PROCeginit:PROCegcompanion(7,&81,255)
30 DIM a%(5,7):l%=1:e%=4:f%=-4:PROCresetlevel
40 PROCstartscreen
50 p%=152:b%=160:y%=192:sv%=1:d%=4:u%=b%:v%=y%:w%=p%:aa%=b%:bb%=y%:cc%=p%
60 REPEAT:IF d%>=3 PROCegbegin:PROCdrawbricks:PROCbatdraw(p%):PROCegpresent:PROCegbegin:PROCdrawbricks:PROCbatdraw(p%):PROCegpresent:d%=0:aa%=p%:u%=p%:bb%=192:v%=192
65 PROCegdirtybegin
75 z%=INKEY(-98):x%=INKEY(-67):sp%=INKEY(-99)
80 IF z% p%=p%-12
90 IF x% p%=p%+12
100 IF p%<8 p%=8
110 IF p%>288 p%=288
120 IF sv%=1 b%=p%+8:y%=192:IF sp% sv%=0
130 IF sv%=0 PROCmoveball
150 IF aa%<>b% OR bb%<>y% PROCegcompact(aa%,bb%,1,0,7,&87)
155 IF cc%<>p% PROCbatclear(cc%)
160 IF d%>0 AND d%<3 PROCbe
161 IF d%>0 AND d%<3 d%=d%-1
180 IF cc%<>p% OR (bb%<=205 AND bb%+7>=202 AND aa%<=p%+15 AND aa%+7>=p%) PROCbatdraw(p%)
181 IF sv%<>2 PROCegcompact(b%,y%,0,0,7,&87)
185 aa%=u%:bb%=v%:cc%=w%:u%=b%:v%=y%:w%=p%
190 PROCegpresent
200 UNTIL INKEY(-17)
210 MODE 7:END
220 DEF PROCstartscreen
230 PROCegbegin:FOR y%=24 TO 88 STEP 8:PROCegline(40,y%,280,y%,(y% DIV 8) MOD 4):NEXT:PROCegtext("BRICKFALL",120,48):PROCegline(64,80,256,80,3)
240 PROCegtext("PRESS SPACE",112,176):PROCegpresent
250 REPEAT:UNTIL INKEY(0)=32:*FX 15
260 ENDPROC
300 DEF PROCmoveball
310 nx%=b%+e%:ny%=y%+f%
320 IF nx%<=8 nx%=8:e%=-e%
325 IF nx%>=288 nx%=288:e%=-e%
330 IF ny%<24 ny%=24:f%=-f%
340 IF ny%>240 sv%=1:f%=-4:nx%=p%+8:ny%=192
350 IF ny%<=205 AND ny%+7>=202 AND f%>0 AND nx%+3>=p% AND nx%+3<p%+16 ny%=194:f%=-f%:e%=e%+SGN(nx%+3-p%-8)
355 IF ny%>107 OR ny%+7<40 OR nx%+7<64 OR nx%>247 GOTO 380
360 r0%=(ny%-40)DIV12:IF r0%<0 r0%=0
362 r1%=(ny%+7-40)DIV12:IF r1%>5 r1%=5
364 c0%=(nx%-64)DIV24:IF c0%<0 c0%=0
366 c1%=(nx%+7-64)DIV24:IF c1%>7 c1%=7
368 h%=0:FOR rr%=r0% TO r1%:FOR ct%=c0% TO c1%
370 IF h%=0 AND a%(rr%,ct%)>0 PROCbrickhit
372 NEXT:NEXT
380 b%=nx%:y%=ny%:ENDPROC
382 DEF PROCbrickhit
384 IF nx%>79+ct%*24 OR nx%+7<64+ct%*24 OR ny%>47+rr%*12 OR ny%+7<40+rr%*12 ENDPROC
385 IF d%=1 PROCbe
386 h%=1:hr%=rr%:hc%=ct%:d%=2
388 IF y%+7<40+rr%*12 OR y%>47+rr%*12 f%=-f% ELSE e%=-e%
390 nx%=b%+e%:ny%=y%+f%
392 IF a%(rr%,ct%)>1 a%(rr%,ct%)=a%(rr%,ct%)-1:ENDPROC
394 a%(rr%,ct%)=0:n%=n%-1:IF n%=0 PROCnextlevel
396 ENDPROC
400 DEF PROCresetlevel:n%=0:FOR r%=0 TO 5:FOR c%=0 TO 7
402 s%=1:IF l%>1 s%=1+((r%+c%+l%)MOD 3)
404 a%(r%,c%)=s%:n%=n%+1:NEXT:NEXT:ENDPROC
410 DEF PROCnextlevel:l%=l%+1:e%=4+l%:f%=-e%:PROCresetlevel:sv%=1:d%=4:ENDPROC
420 DEF PROCdrawbricks:FOR r%=0 TO 5:egb%?8=8:FOR c%=0 TO 7:egb%?(16+c%*5)=2+r%:egb%?(17+c%*5)=(64+c%*24) AND 255:egb%?(18+c%*5)=0:egb%?(19+c%*5)=40+r%*12:egb%?(20+c%*5)=0:NEXT:PROCegcall(34):NEXT:ENDPROC
500 DEF PROCbatclear(x%):bt%=&6E82+2*x%:FOR q%=0 TO 3:!bt%=0:bt%=bt%+8:NEXT:ENDPROC
510 DEF PROCbatdraw(x%):bt%=&6E82+2*x%:FOR q%=0 TO 3:!bt%=&FF0F0FFF:bt%=bt%+8:NEXT:ENDPROC
530 DEF PROCbe:PROCegcompact(64+hc%*24,40+hr%*12,9+SGN(a%(hr%,hc%))*(hr%-7),0,7,&81):ENDPROC
1000 DEF PROCeginit
1010 IF HIMEM>&2400 OR TOP>&2200 PRINT "EGFX MEM":END
1020 DIM egb% 63:LOCAL egi%
1025 FOR egi%=0 TO 63:egb%?egi%=0:NEXT
1040 egb%?0=64:egb%?1=8:egb%?2=69:egb%?3=71:egb%?4=1
1045 PROCegcall(0):ENDPROC
1050 DEF PROCegcall(egf%)
1070 egb%?5=egf%:egb%?7=0
1080 A%=&C0:X%=egb% MOD 256:Y%=egb% DIV 256:CALL &FFF1
1090 IF egb%?7<>&A5 PRINT "NO EGFX ROM":END
1095 IF egf%>=11 AND egf%<>22 AND egf%<>23 AND egb%?6<>0 PRINT "EG ERROR":END
1100 ENDPROC
1110 DEF PROCegxy(egx%,egy%)
1120 egb%?8=egx%:egb%?9=egx% DIV 256
1130 egb%?10=egy%:egb%?11=egy% DIV 256:ENDPROC
1140 DEF PROCegbegin:PROCegcall(1):ENDPROC
1144 DEF PROCegdirtybegin:egb%?8=255:PROCegcall(38):ENDPROC
1150 DEF PROCegpresent:PROCegcall(6):ENDPROC
1180 DEF PROCegtext(egs$,egx%,egy%)
1190 PROCegxy(egx%,egy%):$(egb%+22)=egs$+CHR$0:PROCegcall(7):ENDPROC
1260 DEF PROCegline(egx%,egy%,egex%,egey%,egc%)
1270 PROCegxy(egx%,egy%):egb%?13=egc%:egb%?16=egex% AND 255:egb%?17=(egex% AND &FFFF) DIV 256
1280 egb%?20=egey% AND 255:egb%?21=(egey% AND &FFFF) DIV 256:PROCegcall(10):ENDPROC
1820 DEF PROCegcompanion(b%,p%,h%):egb%?8=b%:egb%?9=p%:egb%?10=h%:PROCegcall(33):ENDPROC
2110 DEF PROCegcompact(x%,y%,i%,f%,b%,p%)
2120 PROCegxy(x%,y%):egb%?12=i%:egb%?14=f%:egb%?16=b%:egb%?17=p%:PROCegcall(37):ENDPROC

Try it: redesign the band pattern (one expression changes the whole wall), or make the top row always take three hits.

← Stage 4: Bricks Stage 6: Score and HUD →