gl_ClipDistance nightmare
category: code [glöplog]
Hello.
I've implemented some custom clipping planes, and it looks that they work (at least with points), but I can't make it work with a geometry shader (transforms lines to triangle strips for wide lines) running.
If I don't touch the gl_ClipDistance values into the geometry shader I don't have clipping, ok. But I haven't found a way of copying the values.
This way I get a ERROR: 0:38: Indirect index into implicitly-sized array
This way the compiler hangs.
Now I get, ERROR: Input of geometry shader '<in gl_PerVertex.gl_ClipDistance>' differs in type/qualifiers to that written by vertex shader.
It doesn't matter if gl_ClipDistance is defined with a size or not.
This is my vertex shader.
Thanks.
I've implemented some custom clipping planes, and it looks that they work (at least with points), but I can't make it work with a geometry shader (transforms lines to triangle strips for wide lines) running.
If I don't touch the gl_ClipDistance values into the geometry shader I don't have clipping, ok. But I haven't found a way of copying the values.
This way I get a ERROR: 0:38: Indirect index into implicitly-sized array
Code:
out float gl_ClipDistance[];
void main()
{
...
gl_Position = vec4(p0.xy + offset * w0, gl_in[0].gl_Position.zw);
for ( int i = 0; i < MAX_CLIP_PLANES; ++i )
gl_ClipDistance[i] = gl_in[0].gl_ClipDistance[i];
_vertex_color = _color[0];
EmitVertex();
This way the compiler hangs.
Code:
out float gl_ClipDistance[];
void main()
{
...
gl_Position = vec4(p0.xy + offset * w0, gl_in[0].gl_Position.zw);
gl_ClipDistance = gl_in[0].gl_ClipDistance;
_vertex_color = _color[0];
EmitVertex();
Now I get, ERROR: Input of geometry shader '<in gl_PerVertex.gl_ClipDistance>' differs in type/qualifiers to that written by vertex shader.
It doesn't matter if gl_ClipDistance is defined with a size or not.
Code:
out float gl_ClipDistance[];
void main()
{
...
gl_Position = vec4(p0.xy + offset * w0, gl_in[0].gl_Position.zw);
gl_ClipDistance[0] = gl_in[0].gl_ClipDistance[0];
_vertex_color = _color[0];
EmitVertex();
This is my vertex shader.
Code:
#ifdef GL_ES
precision highp float;
#endif
#define MAX_CLIP_PLANES 6
layout(std140) uniform ClipPlanes
{
uniform vec4 clipPlanes[MAX_CLIP_PLANES];
};
out float gl_ClipDistance[MAX_CLIP_PLANES];
void applyClipping(mat4 modelMatrix, vec3 position)
{
for ( int i = 0; i < MAX_CLIP_PLANES; ++i )
gl_ClipDistance[i] = dot(modelMatrix * vec4(position, 1.0), clipPlanes[i]);
}
layout(location = 0) in vec3 position;
flat out vec4 _color;
void main (void)
{
gl_Position = modelViewProjectionMatrix * vec4(position, 1.0);
applyClipping(modelMatrix, position);
}
Thanks.
Sorry, I fotgot to change the category.
Ok, partial fixed.
I've to call applyClipping() into geometry shader, not into vertex shader. But it looks that the lines are clipped "too early".
I've to call applyClipping() into geometry shader, not into vertex shader. But it looks that the lines are clipped "too early".
Fixed.
I don't understand why I couldn't find the error between yesterday and this morning, but some minutes after I post here I realized what I was doing wrong.
I don't understand why I couldn't find the error between yesterday and this morning, but some minutes after I post here I realized what I was doing wrong.
Sometimes all it takes is a cardboard programmer or something to facilitate the similar rubber duck debugging to see the problem you spent so long on already. While I don't practice the latter, I've also found temporarily giving up and going off to other things or sleeping causes me to see it almost right away when I come back because I've lost most of the context I had and have to step through it again.
