Function vertexLineToPolygon

core/math/Vertex.cpp:34–105

{

void vertexLineToPolygon(Vec2* points, float stroke, Vec2* vertices, unsigned int offset, unsigned int nuPoints)
{
    nuPoints += offset;
    if (nuPoints <= 1)
        return;

    stroke *= 0.5f;

    unsigned int idx;
    unsigned int nuPointsMinus = nuPoints - 1;

    for (unsigned int i = offset; i < nuPoints; i++)
    {
        idx     = i * 2;
        Vec2 p1 = points[i];
        Vec2 perpVector;

        if (i == 0)
            perpVector = (p1 - points[i + 1]).getNormalized().getPerp();
        else if (i == nuPointsMinus)
            perpVector = (points[i - 1] - p1).getNormalized().getPerp();
        else
        {
            Vec2 p2 = points[i + 1];
            Vec2 p0 = points[i - 1];

            Vec2 p2p1 = (p2 - p1).getNormalized();
            Vec2 p0p1 = (p0 - p1).getNormalized();

            // Calculate angle between vectors
            float angle = acosf(p2p1.dot(p0p1));

            if (angle < AX_DEGREES_TO_RADIANS(70))
                perpVector = p2p1.getMidpoint(p0p1).getNormalized().getPerp();
            else if (angle < AX_DEGREES_TO_RADIANS(170))
                perpVector = p2p1.getMidpoint(p0p1).getNormalized();
            else
                perpVector = (p2 - p0).getNormalized().getPerp();
        }
        perpVector = perpVector * stroke;

        vertices[idx].set(p1.x + perpVector.x, p1.y + perpVector.y);
        vertices[idx + 1].set(p1.x - perpVector.x, p1.y - perpVector.y);
    }

    // Validate vertexes
    offset = (offset == 0) ? 0 : offset - 1;
    for (unsigned int i = offset; i < nuPointsMinus; i++)
    {
        idx                     = i * 2;
        const unsigned int idx1 = idx + 2;

        Vec2 p1 = vertices[idx];
        Vec2 p2 = vertices[idx + 1];
        Vec2 p3 = vertices[idx1];
        Vec2 p4 = vertices[idx1 + 1];

        float s;