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View Full Version : [AMD11.12] {pack,unpack}Half2x16 Incorrect



_blitz
01-19-2012, 02:41 PM
I'm expecting the following shader to draw a triangle accross the screen, but it does not behave that way.


#version 420 core

void main()
{
vec2[] vertices = vec2[](vec2(-1.0),vec2(1.0,-1.0),vec2(0.0,1.0));
gl_Position = vec4(vertices[gl_VertexID],0.0,1.0);
uint compressed = packHalf2x16(gl_Position.xy);
gl_Position.xy = unpackHalf2x16(compressed);
}

I have attached an image showing the difference between not using the pack/unpack functions (left) and using them (right). AFAIK, the images should be similar.

Code can be downloaded here (https://github.com/jdupuy/unpack/zipball/master) (gmake and vs2010 projects are provided).

Hongwei Li
01-20-2012, 09:56 PM
I believe it is a driver bug. We are looking into it.

_blitz
01-26-2012, 01:14 PM
Issue remains with Catalyst 12.1