C++ (Cpp) vgPointAlongPath示例

示例#1

文件： PathOpenVG.cpp 项目： azrul2202/WebKit-Smartphone

FloatPoint Path::pointAtLength(float length, bool& ok)
{
    VGfloat x = 0, y = 0;
    m_path->makeCompatibleContextCurrent();

    vgPointAlongPath(m_path->vgPath(), 0, vgGetParameteri(m_path->vgPath(), VG_PATH_NUM_SEGMENTS),
                     length, &x, &y, 0, 0);
    ok = (vgGetError() == VG_NO_ERROR);
    return FloatPoint(x, y);
}

示例#2

文件： PathOpenVG.cpp 项目： azrul2202/WebKit-Smartphone

float Path::normalAngleAtLength(float length, bool& ok)
{
    VGfloat tangentX, tangentY;
    m_path->makeCompatibleContextCurrent();

    vgPointAlongPath(m_path->vgPath(), 0, vgGetParameteri(m_path->vgPath(), VG_PATH_NUM_SEGMENTS),
                     length, 0, 0, &tangentX, &tangentY);
    ok = (vgGetError() == VG_NO_ERROR);
    return atan2f(tangentY, tangentX) * 180.0 / piFloat; // convert to degrees
}

示例#3

文件： star-oddeven.c 项目： Distrotech/mesa-demos

static void draw_marks(VGPath path)
{
    VGfloat point[2], tangent[2];
    int i = 0;

    for (i = 0; i < 1300; i += 50) {
        vgPointAlongPath(path, 0, 6, i,
                         point + 0, point + 1,
                         tangent + 0, tangent + 1);
        draw_point(point[0], point[1]);
    }
}