Theorical question about the planes

[alko]

how to fast draw compressed images ("-1" in gfx.res) on the planes for real-time animation consisting of 2 or 3 frames ?

[Stef]

There is no way of doing real time fast compressed video.
Even without compression the bandwidth alone is not fast enough to allow fullscreen animation at 20 FPS.
You need to enlarge blank period if you want fast and large animation and so reduce the vertical resolution or you need to reduce the animation resolution (something as 160x128) to get 20 FPS without touching blanking.

[alko]

I do not need a very fast frame rates.
at least to update image does not slow down the gameplay, and that is not visible process of updating pictures.

Code: Select all

main()
{
....
while(1)
{
update_game();
fon_anim();
}
}


static void fon_anim()
{
fon_anim_count++;
if(fon_anim_count==5)
{ 
VDP_drawImageEx(BPLAN, &image1, TILE_ATTR_FULL(PAL1, FALSE, FALSE, FALSE, ind), 0, 0, FALSE, TRUE);
//ind += fon1.tileset->numTile;
}
if(fon_anim_count==10){ 
VDP_drawImageEx(BPLAN, &image2, TILE_ATTR_FULL(PAL1, FALSE, FALSE, FALSE, ind), 0, 0, FALSE, TRUE);
//ind += fon1.tileset->numTile;
}
if(fon_anim_count>=15)fon_anim_count=0;
}

[cero]

To do it slow, and not have partial updates show, you need to double buffer. Which means: both planes will be used for your animation, nothing left for your game but sprites.

[alko]

if do not use compression then picture is updated faster, but the lag is still there.

[alko]

however, mirroring planes useful in the development of top-down games for generate terrain.

for example:

[Stef]

Of course it is It's why tilemap are always optimized to handle flipped tiles whatever is the compression parameter.

[alko]

how to fast fill a PLANE of the array identical pictures (for example 32*32 or 64*64 each picture) directly from VDP-RAM

[Stef]

Not sure to understand what you mean, fast fill tilemap ? Or fast fill tile data ?

[alko]

let us suppose have a picture img1 (size 32*32)
if to do

Code: Select all

int i;
int j;
for(i=0;i<10;i++)
{
for(j=0;j<8;j++)
{
VDP_drawImageEx(BPLAN, &img1, TILE_ATTR_FULL(PAL1, FALSE, FALSE, FALSE, ind), i*4, j*4, FALSE, TRUE);
}
}

then it turns out that every time the image is decompressed from the ROM in the VDP-RAM.

[Stef]

let us suppose have a picture img1 (size 32*32)
if to do

Code: Select all

int i;
int j;
for(i=0;i<10;i++)
{
for(j=0;j<8;j++)
{
VDP_drawImageEx(BPLAN, &img1, TILE_ATTR_FULL(PAL1, FALSE, FALSE, FALSE, ind), i*4, j*4, FALSE, TRUE);
}
}

then it turns out that every time the image is decompressed from the ROM in the VDP-RAM.

Indeed. An image is composed from a TileSet (set of tiles) and a Map (tilemap), here what you want to do it just updating the tilemap in the loop so you can just start by uploading the tileset once then updating the tilemap :

Code: Select all

int i, j;
Map map*;

// upload TileSet of image in VRAM (unpack tileset first if needed)
VDP_loadTileSet(img1.tileset, ind, TRUE);
// load the palette
VDP_setPalette(PAL1, img1.palette->data);
// unpack the map once so we don't do it as each setMap(..) call
map = unpackMap(img.map, NULL);

for(i=0;i<10;i++)
{
  for(j=0;j<8;j++)
  {
    // wait for VSync
    VDP_waitVSync();
    VDP_setMap(VDP_PLAN_B, map, TILE_ATTR_FULL(PAL1, FALSE, FALSE, FALSE, ind), i*4, j*4);
  }
}

And that is !

[alko]

is possible to set visible or invisible plane ?

[Stef]

Err no... You have to modify the tilemap and set it to transparent tiles only :-/