Drawing textured polygons with libgdx

Question

I'm having a problem with my rendering cycle using libgdx, basically I need to fill an area with a square texture, and the last part of this area may be smaller or with a different shape than the texture, so it means that i need to render a quad of arbitrary form and slap the texture on it, cutting the parts I don't need.

Basically this is the form of the polygons i need to draw

I'm a bit lost on how to do this, so far I've seen that the PolygonRegion and PolygonSpriteBatch might do it for me, but I'm a bit wary of instancing a new heavy object I'll use only on one object.

Is there any alternative? Perhaps the Mesh class but i'd like to be certain.

Its not clear what "the last part of this area may be smaller or with a different shape" means. Can you make a picture of what you want? Or point to an existing game/app that does something similar? — P.T.
Thanks for answering, I added the image, hopefully it's all clear now — Lama

P.T. P.T. · Accepted Answer · 2012-12-07T22:26:18

I suggest using a Mesh to define exactly what region you want. Defining the vertex points and mapping those to the texture coordinates is a bit fiddly, but its good to know what's going on underneath some of the higher level APIs (like the *Batch bits). Additionally, the *Batch APIs are designed to share the weight of uploading a single texture across multiple objects, which sounds like it might not apply in this case. (On the other hand, even if the Batch objects are a bit "heavyweight", they may not actually be a problem in practice.)

Another approach to consider is to render the object as a square mesh, but to define your texture with transparent pixels for all the pixels outside the region. (I'm assuming the non-square shape is something you can know offline, and isn't dynamic.)

Drawing textured polygons with libgdx

2 Answers