1 Reply Latest reply on May 20, 2014 8:48 AM by homerj

    scaling with byte texcoord vertices



           I am working to get the OpenGl ES1.1 conformance test passing and I am failing the texture test due to what I see as a scaling issue.  A two pixel texture is created and then I scale the texture matrix to be 1/4 and then select the texcoord vertices to be {1,1},{3,1},{1,3},{3,3} as GL_BYTES.  This should draw both pixel but only the latter pixel is drawn.  If I changed the texcorrd vertices to be 0 and 1 instead of 1 and 3, the picture is drawn correctly using both pixels.  Its like there is an issue with scaling of the texcoord vertices.  I also verified that the texture matrix had the correct values (0.25), I tried changing the texture matrix to be 1/256 and the results were the same, 1 and 3 drew the latter pixel, 0 and 1 drew both pixels.  I verified that the texcoord vertices were beign loaded into memory correctly (01010301 01030303).


           Has anyone seen an issue like this or know where in the driver/registers the chip would load the texture matrix information or combine it with the texcoord vertices to select the texture pixels?  I have gone over the evergreen 3D register document for the last two days but have not found a solution.


           This is my first post so let me know if I have to be more specific or if there is more information that is needed.  A snippet is attached.




        • Re: scaling with byte texcoord vertices

          Still trying to work through this issue and could use some help.  It is out last issue before conformace is achieved.


          Texcoords vertices are not being scaled.  I don't think its a rounding issue since I can scale 1/512 and vertices 0,0 0,1 1,0 1,1 still give us a valid answer.  I have run out of things to try to address this issue and could use some ideas.