Can i get rid of tearing effect using RTG?

mateusz_s · Dec 15th 2021

Hi,

When running native amiga games from Aga thru Indivision_AGA_MK3 I set PAL screen settings to 100hz, I have smooth game play without tearing effect.

Is this possible while coding output thru RTG? In my fps game when iam strafing fast facing walls I got about 50-70 fps using v1200 output. And see about 3 tearing lines in when my p96 settings for 320x200 are 100hz. I made a test. I put WaitTOF() in my loop and right after that I switched bitmaps using ChangeVPBitmap like in double buffering. So the game was reacting to WaitTOF because it slowed down a bit.

The tearing lines were still there, when I change 320x200 mode to 60hz I had one tearing line.

So is it possible to sync somehow?

Jens · Dec 16th 2021

Quote from mateusz_s

When running native amiga games from Aga thru Indivision_AGA_MK3 I set PAL screen settings to 100hz, I have smooth game play without tearing effect.

Other people might be interested in that setup, so it would be nice if you'd share that config, along with the monitor type that supports it.

Quote from mateusz_s

So is it possible to sync somehow?

I can't answer that - looks like the V1200 has it's own interpretation of wait-for-frame-function. V1200 is not our product, so please understand that I can't give any hints about it (other than using a real Motorola CPU, but you probably don't want to hear that :-)).

mateusz_s · Dec 16th 2021

Quote from Jens

Other people might be interested in that setup, so it would be nice if you'd share that config, along with the monitor type that supports it.

I make new thread in Indivision forum about my settings, and give link to download:

[Indivision MK3] My game settings - for 60, 75, 144hz monitors - ready config files and manual how to make it yourself...

mateusz_s · Dec 16th 2021

I managed to get rid of tearing effect..

I had problems and bugs with allocationg proper bitmap in screenbuffer and also the bitmap adress had to be locked, this is a bit dirty code

not yet cleaned up, just tested.

I am using here triple buffering, using double buffering wasn't enough, the key system function here is ChangeScreenBuffer();

also we must lock bitmap to get its adress using for example p96LockBitMap or LockBitMapTags.

example for triple buffering in 320x200x32 mode

Code

// init
struct MsgPort* disp = CreateMsgPort();
struct MsgPort* safe = CreateMsgPort();
struct Bitmap* bm1 = AllocBitMap(320,200,32, BMF_CLEAR | BMF_DISPLAYABLE , &APP_screen->BitMap);
struct Bitmap* bm2 = AllocBitMap(320,200,32, BMF_CLEAR | BMF_DISPLAYABLE , &APP_screen->BitMap);
struct Bitmap* bm3 = AllocBitMap(320,200,32, BMF_CLEAR | BMF_DISPLAYABLE , &APP_screen->BitMap);
struct ScreenBuffer* sb1 = AllocScreenBuffer(APP_screen, 0, SB_COPY_BITMAP );
struct ScreenBuffer* sb2 = AllocScreenBuffer(APP_screen, 0,SB_COPY_BITMAP );
struct ScreenBuffer* sb3 = AllocScreenBuffer(APP_screen, 0,SB_COPY_BITMAP );
sb1->sb_BitMap = bm1;
sb2->sb_BitMap = bm2;
sb3->sb_BitMap = bm3;
sb1->sb_DBufInfo->dbi_SafeMessage.mn_ReplyPort = safe;
sb1->sb_DBufInfo->dbi_DispMessage.mn_ReplyPort = disp;
sb2->sb_DBufInfo->dbi_SafeMessage.mn_ReplyPort = safe;
sb2->sb_DBufInfo->dbi_DispMessage.mn_ReplyPort = disp;
sb3->sb_DBufInfo->dbi_SafeMessage.mn_ReplyPort = safe;
sb3->sb_DBufInfo->dbi_DispMessage.mn_ReplyPort = disp;
// loop
int frame = 0;
LOOP
{
switch (frame)
{
case 0:
{
ChangeScreenBuffer(APP_screen, sb1);
APTR handle = LockBitMapTags(sb2->sb_BitMap, LBMI_BASEADDRESS, (ULONG)&x_FBAddr2, TAG_DONE);
UnLockBitMap(handle);
// engine output buffer and render
EM_prefs.output_buffer_32 = x_FBAddr2;
EM_Update_And_Render();
}
break;
case 1:
{
ChangeScreenBuffer(APP_screen, sb2);
APTR handle = LockBitMapTags(sb3->sb_BitMap, LBMI_BASEADDRESS, (ULONG)&x_FBAddr3, TAG_DONE);
UnLockBitMap(handle);
// engine output buffer and render
EM_prefs.output_buffer_32 = x_FBAddr3;
EM_Update_And_Render(&APP_main_loop);
}
break;
case 2:
{
ChangeScreenBuffer(APP_screen, sb3);
APTR handle = LockBitMapTags(sb1->sb_BitMap, LBMI_BASEADDRESS, (ULONG)&x_FBAddr1, TAG_DONE);
UnLockBitMap(handle);
// engine output buffer and render
EM_prefs.output_buffer_32 = x_FBAddr1;
EM_Update_And_Render(&APP_main_loop);
}
break;
}
frame++;
if (frame> 2)
frame= 0;
}

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Jens · Dec 17th 2021

I fear you're not in the correct vendor's forum. This appears to be of more interest to the vendor of the V1200.