Commodore 64 Uživatelský manuál stáhnout pdf (Strana 67)

STEP 8:

CRUNCH YOUR PROGRAM INTO A SMALLER SPACE BY RUNNING TO-

GETHER ALL THE DATA'STATEMENTS, AS SHOWN IN THE SAMPLE PRO-

GRAM BELOW. Note that we asked you to write your sprite program on

a piece of paper. We did this for a good reason. The DATA STATEMENT

LINES 100- 120 in. the program. in STEP 1 are only thereto help you. see

which numbers relate to which 'groups of pixels in your sprite. Your final

program should be "crunched" like this:

~S!iImm

1121"PRHlT":J" :'POI<E53280, 5: POKE53281., 6

2(1 V=5::::24:3: POKEV+34,. 3

30 POKE53269., 4 : POKE2042, 13

4121FOF.:I'I=0T062: READQ : POKE832+t.j, Q : NEi':T

100 DATA255,255,255,128,(I,1,128,0,1,128,O.I,144,(I,

1,144,0,1..144,0,1,144,(1,1

101 DATAL44,0,1,144~0,1,144,O,1,144,e,I,144,0,1,

144, 0., 1.' 12:::., (I, L 128, 0, 1

11212DI=tTAI28, 10,1.,128.,121,1,128.,.(1,1.,128.. e.. 1..255.. 255, 25~l

20tt ;<:=200: ITI=100 : POI<E53252., :x:: POKE53253., IT'

MOVING YOUR SPRITE ON THE SCREEN

Now that you've created your sprite, let's do some interesting things.

with it. To move your sprite: smoothly across the screen, add these two

lines' to your program:

50 POKE V+5,100:FOR X=24T0255:POKE V+4,X:NEXT:POKE

V+16,4'

55 FOR X=OT065:POKE V+4,X:NEXT X:POKE V+ 16,0:GOTO 50

LINE 50 POKEs the. Y POSITION at 100 (try 50 or 229 instead for

variety). Then it sets up a FOR . . .

NEXT loop which POKEs the sprite

into X position 0 to X position 255, in order. When it reaches the 255th

position, it POKEs the RIGHT X POSITION (POKE V+ 16,4) which is re-

quired to'cross to' the riglit.side of the s<:reen.

LINE55 hasa FOR. . . NEXTloop which continues to POKEthe sprite

in.the last 65 positions on the screen. Note that the X value was reset to

zero but because you. used the RIGHTX setting (POKE V+ 16,2) X starts

over on the right side of the screen.

This line keeps going back to itself (GOTO 50).. If you just. want the

sprite to' move ONCE' across the screen and disappear, then take. out

GOT050.

PROGRAMMINGGRAPHICS 165.

1 2 ... 62 63 64 65 66 67 68 69 70 71 72 ... 82 83

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Commodore 64 Uživatelský manuál Strana 67