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<root>­/­parties­/­2022­/­vccc22­/­christmas_star_challenge/wolfchild_c64_basic_vc3-2022.zip

File size:
24 438 bytes (23.87K)
File date:
2022-12-30 11:32:14
Download count:
all-time: 4

Preview

  • file_id.diz 1.02K
  • result.png 9.25K
  • source.png 16.62K
  • source.txt 150B
  • star.prg 126B

file_id.diz

Wolfch!ld's Star V1.0

Author: Wolfch!ld (Andras Baranovszky)
Category: Christmas Challenge or Wild
System:   C64
Language: BASIC
Len source code: 150 bytes
Len exe file:    N/A
Len code only:   N/A
Instructions:
Code wirtten with CBM PRG Sutio 4.0 + Vice Emulator 3.6.1 SDL2
Run Vice, drag and drop the prg file into it, wait :)
Description:
I used direct screen memory addresses to POKE stars to screen.
I drawing four 13x13 triangle which overlap each other.

Each poke is somthing like that:

poke a - 5 + x - c + (y*40),42
poke a + 5 - x - c + (y*40),42
poke a - 5 + x + c - (y*40),42
poke a + 5 - x + c - (y*40),42

Where:

"a" 		center screen memory address of the star (1523)
+/- 5		start drawing stars inside rows (horizontal diffelence from "a")
+/- "x"     actual star position inside rows
+/- "c"     9*40 char +/- (vertical diffelence from "a")
+/- "y*40"	actual row
42			chr$(42)

Comments:
If you want understand how its work, just delete 1,2 or 3 poke commands or change 42 to 1,2,3,4 in four pokes.