multiple texture slots for bitmap

keszegh

meshes can have multiple textures (to use them in custom shaders): Mesh:setTexture(texture,slot)
on the other hand in the wiki this is not the case for Bitmaps: Bitmap:setTexture(texture)
maybe the wiki is wrong? if not, can this feature be added to bitmaps too?

hgy29

They are available on Pixel, would that do ?

keszegh

well, i guess changing a bitmap to a pixel is not too hard. thanks for the tip.

MoKaLux

I am trying this code but it crashes when running it the second time or trying to stop the player!

local pix = Pixel.new(0xffffff, 1, 128*2, 128*2) local tex = Texture.new("gfx/test.png") local tex2 = Texture.new("gfx/checkbox.png") pix:setTexture(tex, 0) pix:setTexture(tex2, 1) stage:addChild(pix)

Am I missing something?

hgy29

@MoKaLux, it is a bug, I fixed it: https://github.com/gideros/gideros/commit/79a18a0caef3f7d276ef7b8808af4a962ccac364

MoKaLux

allow me some feedback please.
I tried this code with latest changes:

application:setBackgroundColor(0x9c9c9c)   local tex = Texture.new("gfx/star.png") -- 263*98 px local tex2 = Texture.new("gfx/balls/mine.png") -- 96*96 px local texw, texh = tex:getWidth(), tex:getHeight()   local bgpix = Pixel.new(0x00ff00, 1, texw/2+2, texh/2+2) -- green Pixel background local pix = Pixel.new(0xffffff, 1, texw/2, texh/2)   pix:setTexture(tex, 0) -- group test3 pix:setTexture(tex2, 1) -- group test3   -- position bgpix:setPosition(-1, -1) -- order stage:addChild(bgpix) -- green Pixel background stage:addChild(pix)

The app doesn't crash anymore but I only see 1 texture (I think I am missing something, maybe I need a shader?).

Anyhow, can anybody (keszegh ) give a use case for such a need of having multiple textures for Pixels (we can parent multiple pixels if we need)? Maybe it's for saving memory or increasing speed or for normal maps, or shaders, or ... ?

Thank you


EDIT: silly me it was written in the wiki that slot is used with shader in the parameters . I made it more clear by adding a note in the description

EDIT2: added an example from the https://forum.giderosmobile.com/discussion/8671/lua-shader-question-how-to-read-and-write-pixel-info-from-texture OP question https://wiki.gideros.rocks/index.php/Pixel:setTexture, I could get a mask but not much else!

hgy29

@MoKaLux, it is only useful with custom shaders. Shaders can grab texels from more than just one texture when computing a pixel value, for example for bump mapping or shadow mapping, or to apply a gradient map to a greyscale height field. Possibilities and use cases are endless.

keszegh

i don't have an example in hand, but it is for shader purposes indeed. you can use e.g. second texture as a normal map etc. you just need to declare the textures one by one in Shader.new. see your last post here and the answer of @hgy29 :
https://forum.giderosmobile.com/discussion/comment/68068#Comment_68068