Copper wait

[geldo79]

Hi,

short and maybe stupid question: Is it possible to tell the copper to change the bg color to a specific colour, but only inside my playfield? In my case the whole screen changes to the new colour.

Greetings Christian

[deimos]

Originally Posted by geldo79

Hi,

short and maybe stupid question: Is it possible to tell the copper to change the bg color to a specific colour, but only inside my playfield? In my case the whole screen changes to the new colour.

Greetings Christian

You could change it at the beginning and end of each line, maybe?

[geldo79]

How can i do that? I thought i could only wait for a line (y position)....

[deimos]

Originally Posted by geldo79

How can i do that? I thought i could only wait for a line (y position)....

No, you can wait for a horizontal position too. It's just a little bit more tricky because you have to take into account the time that each move takes as well.

http://eab.abime.net/attachment.php?...0&d=1572886472

In that picture I've reused the colours on the map in the round horizon thing to give 10 colours on an 8 colour display.

Edit: Here's the code I used for that. It's C with my own macros, but you'll get the idea.

        // this loop takes us past the rollover
        for (UWORD i = 0xe4; i < 0x124; i++) {
            COP_INSTR(i << 8 | 0x01, 0xfffe)
            COP_INSTR(COLOR04, BLUE_RGB)
            COP_INSTR(COLOR05, GREEN_RGB)
            
            COP_INSTR(i << 8 | 0xc7, 0xfffe)
            COP_INSTR(COLOR04, 0x005c)
            COP_INSTR(COLOR05, 0x0731)

            if (i == 0xff)
                COP_INSTR(0xffdf, 0xfffe) // handle rollover
        }

You have to calculate the horizontal position to wait till, it doesn't correspond to pixels, but given that I had to change multiple colours I ended up doing it by trial and error. A smarter person might tell you how to calculate it.

Your copper code might end up with a loop rather than many lines.

Edit: Actually, thank you, I hadn't considered reusing colour 0. I'm going to try and see if I can get an extra colour on my main screen like that.

[mcgeezer]

You can make the copper wait on horizontal positions as well.

Geezer

[ross]

Originally Posted by deimos

Edit: Actually, thank you, I hadn't considered reusing colour 0. I'm going to try and see if I can get an extra colour on my main screen like that.

Yes, it is possible, as many games did to get one more color back in the days (Beast, Agony, Lionheart, etc.).
You have to do it for every line, so used if you have lot of splits (as these games).

[mcgeezer]

I did it in Rygar on the hi-score screen... it changes the colour for 18 lines lines at a specific start and end horizontal position.

Here's the code snippet...

  moveq   #$12,d7

        move.l  #$7201fffe,d2   ; Wait VPOS $72  HPOS 01
        move.l  #$7285fffe,d3   ; Wait VPOS $72  HPOS $85
        move.l  #$72a5fffe,d4   ; Wait VPOS $72  HPOS $a5

        move.l  a1,COPPTR_HISCORE_CYCLE(a4)
.cycle:
        move.l  d2,(a1)+                        ; 4
        move.l  #$01900800,(a1)+                ; 8
        move.l  #$01a00bbb,(a1)+                ; 12

        move.l  d3,(a1)+
        move.l  #$019000f0,(a1)+
        move.l  #$01a00f0f,(a1)+                ; 24

        move.l  d4,(a1)+
        move.l  #$01900800,(a1)+
        move.l  #$01a00bbb,(a1)+                ; 36

        add.l   #$01000000,d2
        add.l   #$01000000,d3
        add.l   #$01000000,d4
        dbf     d7,.cycle

[geldo79]

Originally Posted by ross

You have to do it for every line, so used if you have lot of splits (as these games).

Thus, for waiting for a specific horizontal position, i have to insert some more moves into my copperlist....ok. But if i want to have my bg color black at both sides of the screen, and some other color in the playfield, i would have to insert a lot of moves, because i would have to change the color back to black at the right end of each line. And if i have to do that for each line as you mentioned........


Or did i miss something?

[ross]

Originally Posted by geldo79

Thus, for waiting for a specific horizontal position, i have to insert some more moves into my copperlist....ok. But if i want to have my bg color black at both sides of the screen, and some other color in the playfield, i would have to insert a lot of moves, because i would have to change the color back to black at the right end of each line. And if i have to do that for each line as you mentioned........


Or did i miss something?

Of course only on lines where you want a different COLOR00 in playfield.
But yes, a COLOR00 change at the left edge and a COLOR00 back to black at the right edge.

[geldo79]

Well, i would like to have it on every line