https://github.com/DW0RKiN/Flood-fill

Flood fill algorithm for ZX Spectrum
https://github.com/DW0RKiN/Flood-fill

compo flood-fill-algorithm z80 zx-spectrum

Last synced: about 2 months ago
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Flood fill algorithm for ZX Spectrum

• Host: GitHub
• URL: https://github.com/DW0RKiN/Flood-fill
• Owner: DW0RKiN
• License: bsd-3-clause
• Created: 2015-09-12T19:53:14.000Z (over 9 years ago)
• Default Branch: master
• Last Pushed: 2015-09-15T16:28:12.000Z (over 9 years ago)
• Last Synced: 2024-07-30T21:10:03.779Z (5 months ago)
• Topics: compo, flood-fill-algorithm, z80, zx-spectrum
• Language: Assembly
• Size: 762 KB
• Stars: 2
• Watchers: 2
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

        
# Flood-fill

Flood fill algorithms optimizing for minimum memory ( Z80 / ZX Spectrum )

Contribution to competition Size Z80 Programming Challenge #5

http://www.retroprogramming.com/2015/07/z80-size-programming-challenge-5.html

min-size-fill.asm 

------------------

171 bytes + 10 bytes stack

Right hand flood fill algorithm 

    LOOPING_MODE = false;

    set DIRECTION;

    set MASK;

    while ( 1 ) {

    TEST_1:         // Drzime se prave steny

    if MASK == ? ? ?

               ?   0

               ? ? ? TURN_RIGHT();

    TEST_2:         // Jsme zazdeni?

    if MASK == ? 1 ?

               1   1

               ? 1 ? { DRAW_PIXEL(); EXIT; }

    

    TEST_3:         // Slepa ulicka?  

    if MASK == ? 0 ?

               1   1

               ? 1 ? { FILL_AND_STEP(); continue; }

    TEST_4:         // Prekazka?

    if MASK == ? 1 ?

               ?   ?

               ? ? ? { TURN_LEFT(); continue; }

    TEST_5:         // Brana?   . 0 .     ? 0 ?      ? 0 1

                    //          1   ? =>  1   1  or  1   0

                    //          . . .     ? ? ?      ? ? ?

    if MASK == ? ? ?

               1   ?

               ? ? ? { STEP(); continue; }

    TEST_6:         // Slouporadi

    if MASK == ? 0 1      1 0 ?      ? ? ?      ? ? ?

               ?   0  or  0   ?  or  0   ?  or  ?   0

               ? ? ?      ? ? ?      1 0 ?      ? 0 1 { STEP(); continue; }

    FILL_AND_STEP(); 

    }

    ; --------------

    FILL_AND_STEP() {

       DRAW_PIXEL;

       LOOPING_MODE = false;

       NOW_XY += DIRECTION;

       set MASK;

    }

    ; -------------

    STEP() {

    

    if ( LOOPING_MODE ) {

    

       if ( BEGIN_LOOP_XY == NOW_XY )) {

            if ( LOOP_DIRECTION == NOW_DIRECTION ) { 

                FILL_AND_STEP(); 

                return; 

            } else { 

                LOOPING_MODE = false; 

                NOW_DIRECTION = LOOP_DIRECTION;  // smer musime dodrzet, hrozi zacykleni

                // lepsi je ale zakazat LOOPING_MODE dokud neprojdu krizovatkou

            }

        }

    } else {

        ; Je to krizovatka? Tzn. ma krome mezery vepredu jeste 2 mezery

        if  ! ( MASK == ? ? ?       ? ? ?      ? ? ?      ? ? ?

                        1   0  or   0   1  or  0   0  or  0   0

                        ? 0 ?       ? 0 ?      ? 0 ?      ? 1 ? ) { 

            LOOPING_MODE = true;  

            LOOP_BEGIN_XY = NOW_XY; 

            LOOP_DIRECTION = NOW_DIRECTION;

        }

    }

    

    NOW_XY += DIRECTION;

    set MASK;

    

    }

    

queue-fill.asm

--------------

84 bytes

Vyplneni pomoci emulace fronty na zasobniku. Musi byt vypnute preruseni, protoze v urcitem okamziku pomalu presouvame SP az k zarazce a pak ho vratime zpet na puvodni hodnotu. Mezitim se ale nesmi prepsat data co lezi mezi temito adresami na zasobniku prerusenim.