TrackNode Rotation

[Warren-Whitfield]

My apologies, I know I've asked this before, but is there any way to change the heading of the tracknode icon once created?
I've tried setLocalRotation() but it seems to have no effect.
Surely there must be some way of changing the heading? I can't believe I'm the only one that requires this functionality.

[gwaldron]

Try TrackNode::setIconRotation instead.

[Warren-Whitfield]

So the problem is I'm stuck with a previous version that doesn't support setIconRotation (3.4). Is there some kind of workaround I can try to achieve the functionality?

[gwaldron]

You could manually rotate your icon image and create a new TrackNode with the rotated image.

[Warren-Whitfield]

I'm afraid that is going to be too expensive, I need to be able to maintain ~1000 tracks on the display and with images needing to rotate almost constantly, its going to slow everything down.
So what I have done in the meantime is use your TrackNode class as an example to create my own customized one. If you want I can post the code, but basically what I've done is remove the shared stateset and use the Vertex shader to do the rotation. VS looks like this...

const char* iconVS = R"(
    //Rotation in radians
    uniform float iconRotation;

    //Center of rotation (quad center)
    uniform vec2 iconCenter;

    //Passed to fragment shader
    out vec2 oe_TargetNode_texcoord;

    void oe_TargetNode_icon_VS(inout vec4 vertex)
    {
        //Forward texcoords
        oe_TargetNode_texcoord = gl_MultiTexCoord0.st;

        //Rotate around iconCenter
        vec2 pos = vertex.xy - iconCenter;
        float c = cos(iconRotation);
        float s = sin(iconRotation);
        vertex.xy = vec2(pos.x * c - pos.y * s, pos.x * s + pos.y * c) + iconCenter;
    }
)";

Then setting the rotation is as simple as...

void cTargetNode::setHeading(double hdg)
{
    float angle = osg::DegreesToRadians(360.0 - hdg);
    _imageStateSet->getUniform("iconRotation")->set(angle);
}

[gwaldron]

Good solution!