Hello,

If I use a varying float variable in a fragment shader I have no more dashed lines. If I comment the line then all works well...

On an ATI X1300/X1550, with the basic shaders below, glLineStipple has no effect if I uncomment the red line !

And in the sample to reproduce below I do not use this variable !

In my "real" shader I need a variable to compute lighting : so I have light but I have no more dashed lines...

Vertex shader :

*#version 110 varying vec3 N; *

**varying float vx;**void main(void) { gl_ClipVertex = gl_ModelViewMatrix * gl_Vertex;

**vx = 1.0;**N = normalize(gl_NormalMatrix * gl_Normal); gl_Position = gl_ModelViewProjectionMatrix * gl_Vertex; }

Fragment shader :

#version 110

varying vec3 N;

** varying float vx;**

void main (void)

{

vec3 L = normalize(gl_LightSource[0].position.xyz);

**float vvx = vx;** // If I comment this useless line the card draws again dashed lines

vec3 R = normalize(-reflect(L,N));

gl_FragColor = vec4(1,0,0,1);

return;

}

Did you already see some strange things like this ? Do you have an idea of what can cause the problem ?

Thanks.