Method lineLinearGradient

dep/agg/src/agg2d.cpp:504–533

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void Agg2D::lineLinearGradient(double x1, double y1, double x2, double y2, Color c1, Color c2, double profile)
{
    int i;
    int startGradient = 128 - int(profile * 128.0);
    int endGradient   = 128 + int(profile * 128.0);
    if (endGradient <= startGradient) endGradient = startGradient + 1;
    double k = 1.0 / double(endGradient - startGradient);
    for (i = 0; i < startGradient; i++)
    {
        m_lineGradient[i] = c1;
    }
    for (; i < endGradient; i++)
    {
        m_lineGradient[i] = c1.gradient(c2, double(i - startGradient) * k);
    }
    for (; i < 256; i++)
    {
        m_lineGradient[i] = c2;
    }
    double angle = atan2(y2-y1, x2-x1);
    m_lineGradientMatrix.reset();
    m_lineGradientMatrix *= agg::trans_affine_rotation(angle);
    m_lineGradientMatrix *= agg::trans_affine_translation(x1, y1);
    m_fillGradientMatrix *= m_transform;
    m_lineGradientMatrix.invert();
    m_lineGradientD1 = 0;
    m_lineGradientD2 = sqrt((x2-x1) * (x2-x1) + (y2-y1) * (y2-y1));
    m_lineGradientFlag = Linear;
    m_lineColor = Color(0,0,0);  // Set some real color
}


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