1 line
8.0 KiB
Plaintext
1 line
8.0 KiB
Plaintext
\\ documentation for dargon demo tcas20130106start the dragon with : <pos int> DRAG or with : <1 or -1> <pos int> DRAGON DRAG clears the screen, defines the starting point and executes DRAGON. The variable STEPSIZE defines the size of steps between 1 and 3 (larger values will produce grabage) odd numbers as input values do not work DDEMO is a loop executing the DRAGON demo which can be stopped with a keypress once the 2nd dragon is fully painted (it is recommended to press a key a little in advance) \ dragon-loadscreen cas20130106 Onlyforth \needs Graphics include line_a.fb Onlyforth GEM also Graphics also decimal 1 5 +thru \ dragon s.2 03oct86we Variable angle Variable stepsize 1 stepsize ! Variable color 1 color ! Variable xcood Variable ycood \ set_pixel 03oct86we Label ?step stepsize pcrel) D2 move D1 tst 0<> IF D2 neg THEN rts Code set_pixel xcood pcrel) D3 move ycood pcrel) D4 move angle pcrel) D0 move 1 # D0 asr D0 D1 move 1 D0 andi 1 # D1 asr 1 D1 andi D0 tst 0= IF ?step bsr D2 D3 add D3 xcood R#) move THEN D0 tst 0<> IF ?step bsr D2 D4 add D4 ycood R#) move THEN D3 SP -) move D4 SP -) move color pcrel) SP -) move ;c: put_pixel ; \ dragon s.3 03oct86we Code turn ( n -- ) angle pcrel) D0 move SP )+ D0 add D0 angle R#) move Next end-code : dragon recursive ( stepw rec_tiefe -- ) dup 0= IF 2drop set_pixel ELSE over turn 1 over 1- dragon over 2* negate turn -1 over 1- dragon drop turn THEN ; \ dragon s.4 03oct86we : drachen 2 stepsize ! 100 xcood ! 200 ycood ! 1 14 dragon 101 xcood ! 200 ycood ! 1 14 dragon 100 xcood ! 201 ycood ! 1 14 dragon 101 xcood ! 201 ycood ! 1 14 dragon 1 stepsize ! ; : schubs 100 0 DO I 112 over - 400 272 2over >r 1+ r> 1- scr>scr LOOP ; \ dragon s.5 03oct86we : drag ( n -- ) page angle off 100 xcood ! 200 ycood ! 1 swap dragon ; : ddemo 16 drag schubs 0 color ! 199 xcood ! 100 ycood ! 1 16 dragon 1 color ! drachen ; \ 03oct86we |