cpctelera : horizontal scrolling ?

[freemac]

I wanna to scroll big 32bit height text, but I fail. The same image is scrolled both time with a char vertical offset.

Code Select Expand



/**
* hScroll 0-80
*/
void monter(unsigned int c,u16 hScroll) {
unsigned int l;
u8* plot_column;
for (l=0;l<8;l++) {
plot_column=(u8 *)(0x4000 + l*0x800 + 80*c + hScroll%80);
*plot_column=*plot_column+0X33;
plot_column=plot_column-1;
*plot_column=*plot_column+0X33;
}
}

u8 interruptCounter=0;
interruptHander() {
interruptCounter++;
if (interruptCounter==6)  {interruptCounter=0;}
if (interruptCounter==3)  {
calque4000(); // screen 4000.

hOffset=(hOffset+1)%80;
if (hOffset/40==0) {
monter(4,hOffset);
else {
monter(3,hOffset);
}
cpct_setVideoMemoryOffset(hOffset%40);
}

}


[attach=1]

[freemac]

On http://cpctech.cpcwiki.de/source/hardmess.asm that runs with WinAPE assembler (call &2000)

I've got 3 variables inside hardmess.asm :
- screen_location : begin at &3000, increment, filter and &33FF, eat by CRTC R12/R13
- screen_plot_address : begin at &C000+80-2, increment two times, filter and &C7FF
- scroll_address : table of font pointer

I'll give a try later.

[freemac]

Still in progress...

Code Select Expand



void wait_frame_flyback() {
__asm
ld b,#0xf5   ;wait frame flyback
l1: in a,(c)
rra
jr nc,l1
__endasm;
}


void crtc(u16 R12R13) {
__asm
   push   ix
   ld   ix,#0
   add   ix,sp
   ld   h, 5 (ix)
   ld   l, 4 (ix)
ld bc,#0xbc00+12
out (c),c
inc b
out (c),h
dec b
inc c
out (c),c
inc b
out (c),l
   pop   ix
__endasm;
}

u8* screen_location=0x1000;
u8* screen_plot_address=0x4000+80-2;

void main(void) {
   int s=0;
   u8* p;
   while (1) {
      wait_frame_flyback();

      screen_location++;
      screen_location=((unsigned int)screen_location) & 0x13FF;
      crtc((u16)screen_location);

      screen_plot_address++;
      screen_plot_address++;
      screen_plot_address=((unsigned int)screen_plot_address) & 0x47FF;
      p = cpct_getScreenPtr(screen_plot_address, 0,0);
      s=(s+1)%32;
      // 32 char of 2x8
      cpct_drawSprite(g_tile_schtroumpf4x32_tileset[s], p, G_TILE_SCHTROUMPF4X32_00_W, G_TILE_SCHTROUMPF4X32_00_H);
   }
}


Does stop at (no crash) :
 

[freemac]

...

[ervin]

Interesting.
Can you please post your project folder?

[freemac]

Interesting.
Can you please post your project folder?

https://github.com/renaudhelias/CPCtelera-schtroumpfs (trunk)

ASM cpctech https://github.com/renaudhelias/CPCtelera-schtroumpfs/blob/main/hardmess.asm personalized in &4000 runing ok (call &0138)

[ervin]

I'm very sorry, I don't know what is wrong.

[freemac]

src/main.c:264: warning 154: converting integral to pointer without a cast from type 'const-int literal'

Perhaps this way (int<=>unsigned int)

[freemac]

Was just a problem of variable init :

Code Select Expand

void wait_frame_flyback() {
__asm
ld b,#0xf5   ;wait frame flyback
l1: in a,(c)
rra
jr nc,l1
__endasm;
}

void crtc(u16 R12R13) {
__asm
   push   ix
   ld   ix,#0
   add   ix,sp
   ld   h, 5 (ix)
   ld   l, 4 (ix)
ld bc,#0xbc00+12
out (c),c
inc b
out (c),h
dec b
inc c
out (c),c
inc b
out (c),l
   pop   ix
__endasm;
}

u8* screen_location; //=0x1000;
u8* screen_plot_address; //=0x4000+80-2;

void main(void) {
   int s=0;
   u8* p;
   screen_location=0x1000;
   screen_plot_address=0x4000+80-2;
   while (1) {
      wait_frame_flyback();

      screen_location++;
      screen_location=((unsigned int)screen_location) & 0x13FF;
      crtc((u16)screen_location);

      screen_plot_address++;
      screen_plot_address++;
      screen_plot_address=((unsigned int)screen_plot_address) & 0x47FF;
      p = cpct_getScreenPtr(screen_plot_address, 0,0);
      s=(s+1)%32;
      // 32 char of 2x8
      cpct_drawSprite(g_tile_schtroumpf4x32_tileset[s], p, G_TILE_SCHTROUMPF4X32_00_W, G_TILE_SCHTROUMPF4X32_00_H);
   }
}

[freemac]

That run fine now (with CPCtelera sprite 2x32 !)
https://github.com/renaudhelias/CPCtelera-schtroumpfs/releases/tag/CPCtelera-schtroumpfs_v0.2

[attach=1]

[freemac]

rupture+scrolling 32bit height CPCtelera.

https://github.com/renaudhelias/CPCtelera-schtroumpfs/releases/tag/CPCtelera-schtroumpfs_v0.3

[attach=1]

[freemac]

Merry Christmas - schtroumpf 

https://www.pouet.net/prod.php?which=87628

run"launch
Based on http://cpctech.cpcwiki.de/source/hardmess.asm using CPCtelera sprites
3 ruptures (C000,8000,C000)
scroll in &8000 because the program is too big with char set. I regret that I'm not using 3 ruptures C000,8000,4000.
music in &C000 bank7.

[attach=1,msg195938]

I've got glitch on some char after a long message display.

[freemac]

I miss something from http://cpctech.cpcwiki.de/source/hardmess.asm 

[attach=1,msg195942]

[attach=2,msg195942]

My source just displaying &8000 area (like on the screenshots), same problem with &4000.
https://github.com/renaudhelias/CPCtelera-schtroumpfs/tree/main/hellorenaud/src

[freemac]

I hacked the bug but using "space chars", my text is sized 128 (step%128), the bug in this case is on last chars (at fix offset)

https://github.com/renaudhelias/CPCtelera-schtroumpfs
https://github.com/renaudhelias/CPCtelera-schtroumpfs/blob/main/hellorenaud/hellorenaud.dsk

I filled the 8000-BFFF with xFF (pink), the first scrolling has a pink line during AZERTYUIOPQSDFG message, the second scrolling time has a white line during AZERTYUIOPQSDFG message
[attach=1,msg196002]

[freemac]

I try my own draw function :

Code Select Expand

void draw(u8* image, u8* plot, u8 width, u8 height) {
   u8 x;
   u8 y;
   u8* cur_plot;
   u8* cur_image;
   for (y=0;y<height;y++) {
      for (x=0;x<width;x++) {
         cur_plot=plot+0x4000+ ((y / 8u) * 80u) + ((y % 8u) * 2048u) + x;
         //cur_image=image+y*width+x;
         //cur_plot=((u16)cur_plot) & 0x7FFF;
         *cur_plot=0x0F;//*cur_image;
      }
   }
}

I've got my bug :
[attach=1,msg196077]

That's running :

Code Select Expand

void draw(u8* image, u8* plot, u8 width, u8 height) {
   u8 x;
   u8 y;
   u8* cur_plot;
   u8* cur_image;
   for (y=0;y<height;y++) {
      for (x=0;x<width;x++) {
         cur_plot=plot+0x4000+ ((y / 8u) * 80u) + ((y % 8u) * 2048u) + x;
         if (cur_plot<0x4000) {
            cur_plot=cur_plot-0x4000;
         }
         //cur_image=image+y*width+x;
         *cur_plot=0x0F;//*cur_image;
      }
   }
}
[attach=2,msg196077]

But with chars it still bug (no more pink line, but still white lines) :
   [attach=3,msg196077]
I try to modulo while strange things happen :

Code Select Expand

void draw(u8* image, u8* plot, u8 width, u8 height) {
u8 x;
u8 y;
u8* cur_plot;
u8* cur_image;
for (y=0;y<height;y++) {
for (x=0;x<width;x++) {
cur_plot=plot+ 0x4000 +((y / 8u) * 80u) + ((y % 8u) * 2048u) + x;
cur_image=image+y*width+x;
if (cur_plot<0x4000) {
cur_plot=cur_plot-0x4000;
cur_image=image+((y+1)%height)*width+x;
}
*cur_plot=*cur_image;
}
}
}
Still not correct but here I saw some time two lines per character, and when it happens (two line only), this lines seems interchangeables :
[attach=4,msg196077]

[freemac]

Code Select Expand

void draw(u8* image, u8* plot, u8 width, u8 height) {
u8 x;
u8 y;
u8* cur_plot;
u8* cur_image;
for (y=0;y<height;y++) {
for (x=0;x<width;x++) {
cur_plot=plot+ 0x4000 +((y / 8u) * 80u) + ((y % 8u) * 2048u) + x;
if (cur_plot<0x4000) {
cur_plot=cur_plot-0x4000;
cur_image=image+((y+1)%height)*width+x;
*cur_plot=0xF0;
} else {
cur_image=image+y*width+x;
*cur_plot=*cur_image;
}
}
}
}
Using this code, lines appears in red ! (0xF0)
[attach=1]

[andycadley]

A cursory glance at your calculations suggest you're assuming that all the bytes on a line will be contiguous. But if you hardware scroll the screen this won't necessarily be true, simply adding X to get further along the line doesn't work for the character row that includes the wrap-around

[freemac]

A cursory glance at your calculations suggest you're assuming that all the bytes on a line will be contiguous. But if you hardware scroll the screen this won't necessarily be true, simply adding X to get further along the line doesn't work for the character row that includes the wrap-around

So I need to isolate the complete 1st, 2nd and 3nd char-row that includes the wrap-around and try a mod 8 on then ?

http://cpctech.cpcwiki.de/source/hardmess.asm is simple, I think you can compensate the *plot offset.

[freemac]

I succeed in compensation but it is very slow (for loop instead of using standard sprite function)
I think that I have to reverse about one screen back, in order to put the sprite correctly using cpct_drawTileAligned2x8_f() function.

Is there a method for reversing one screen offset back ? 

Code Select Expand


void draw_char(u8 c, u8* image, u8* plot) {
...
   // that last_plot test work fine
   last_plot=plot+ 0x4000 +80u*c+ 0x3801;
   if (last_plot<0x4000) {
   // that test for detecting a char outside of screen don't work. But as last_plot do work, I use last_plot.
   //if (plot-0x8000>640*200/8 ) {
   // 0xFFCF : last value of a screen snapshot, don't work also
   //if (plot+0x4000>0xFFCF || plot+0x4000<0x4000) {
      // minus one screen (rewind) - DON'T WORK, that is what I want to correct here...
      //(0xC000 + ((nY / 8u) * 80u) + ((nY % 8u) * 2048u) + nX)
      //(0xC000 + ((640 / 8u) * 80u) + ((640 % 8u) * 2048u) + 200)
      // (640 / 8u) * 80u == 0x1900
      // 640*200/8 == 0x3E80
      //cur_plot = plot - 640*200/8;
      cur_plot = plot - 0x4000 + 80u*c;
      // so then don't work
      p = cpct_getScreenPtr(cur_plot+0x4000, 0,8*c);
      cpct_drawTileAligned2x8_f((u8*)image+(2* 8 ) *c, p);
// all that work fine (hacking (without screen rewind), but slowly
//      for (y=0;y<8;y++) {
//         for (x=0;x<2;x++) {
//            cur_plot=plot+ 0x4000 +80u*c+ ((y % 8u) * 2048u) + x;
//            cur_image=image+(c*8+((y+1)%8 ))*2+x;
//            if (cur_plot<0x4000) {
//               cur_plot=cur_plot-0x4000;
//            }
//            *cur_plot=*cur_image;
//         }
//      }
   } else {
      // no problem by here
      p = cpct_getScreenPtr(plot+0x4000, 0,8*c);
      cpct_drawTileAligned2x8_f((u8*)image+(2* 8 )*c, p);
   }

[freemac]

Two plot counters, of same size, with a fix offset ? One per screen...

[freemac]

https://github.com/renaudhelias/CPCtelera-schtroumpfs/blob/CPCtelera-schtroumpfs_v0.6/hellorenaud/hellorenaud.dsk

It runs 

[attach=1,msg196215]

https://github.com/renaudhelias/CPCtelera-schtroumpfs/blob/main/hellorenaud/src/txt_scroll_hard.c

I used finally 1 addons screen counter, and several char counters.

[freemac]

https://www.youtube.com/watch?v=GtMpdsgGsFo

[funkheld]

the horizontal scrolling with the cpc is always an impure display that does not give a clean picture in the game.


you can't reach the atari800 and the c64 with this scroll.


greeting