VI and image part

Houge · 04-24-2017 06:06 PM

Hello!
How can i combine VI buffering (with VI.image()) for 3d drawing and Image.drawPart?
VI allows drawing only full images, not parts.

Zervox · 04-24-2017 06:49 PM

some time ago I made this

VI Decal
is this similar to what you need?
it uses Vtx3DTex position and texture coordinates to allow you to decide the UV(part) of the image to draw

Houge · 04-24-2017 08:41 PM

Very nice, but it draws full image, and I want to take image atlas and draw animation using VI, but Atlas uses drawPart, because it keeps all frames on one image.

So it's not the thing I need smile

P.S. if i crop a part of an atlas into new image it's too heavy to do it every frame.

UPD:
OK i figured it out smile

Zervox · 04-24-2017 10:31 PM

Glad it worked out. smile

Houge · 04-25-2017 07:43 AM

Just for information, fast implementation

Code:

Int frame = N;

    C ImageAtlas::Part &part = T._atlas->parts[frame];

    if(C Image *image = atlas->images.addr(part.image_index))

    {

        if(part.rotated)

        {

            v[3].tex.set(part.tex_rect.lu().x, part.tex_rect.lu().y);

            v[0].tex.set(part.tex_rect.ld().x, part.tex_rect.ld().y);

            v[1].tex.set(part.tex_rect.rd().x, part.tex_rect.rd().y);

            v[2].tex.set(part.tex_rect.ru().x, part.tex_rect.ru().y);

        }

        else

        {

            v[0].tex.set(part.tex_rect.lu().x, part.tex_rect.lu().y);

            v[1].tex.set(part.tex_rect.ld().x, part.tex_rect.ld().y);

            v[2].tex.set(part.tex_rect.rd().x, part.tex_rect.rd().y);

            v[3].tex.set(part.tex_rect.ru().x, part.tex_rect.ru().y);

        }

        VI.image(image);

        VI.face(v[0], v[1], v[2], v[3]);

        VI.end(); 

    }

This example does not use image offset in Atlas (but it should), so it shall be added.
This example draws animation using part.tex_rect placed in VI.tex.

Zervox · 04-25-2017 09:09 AM

Very nice, mine was written just as test code, glad to see it inspired a better solution for in with atlas, at the time I had written my own Atlas and packer solution. smile

VI and image part
Author	Message