Rotating a polygon

[lavaswordman]

Is there a way to redraw a polygon you already created but just rotated


GD.Clear();

GD.Begin(POINTS);

        GD.PointSize(16 * 20);

        GD.ColorRGB(0xFFFFFF);

        GD.Vertex2ii(277, 30);

        GD.ColorRGB(0x3498db);

        GD.PointSize(16 * 10);

        GD.Vertex2ii(277, 30);

GD.ColorRGB(0xFFFFFF);

Poly po;

po.begin();

po.v(16 * 274, 16 * -5);

po.v(16 * 282, 16 * -5);

po.v(16 * 286, 16 * 15);

po.v(16 * 270, 16 * 15);

po.draw();I would like to rotate and redraw this polygon by an angle pi/6 as I am trying to design a gear like so

[dl14]

From the gd2 cook book

// Apply a rotation around pixel (64, 64)
static void rotate_64_64(uint16_t a)
{
GD.cmd_translate(F16(64),F16(64));
GD.cmd_rotate(a);
GD.cmd_translate(F16(-64), F16(-64));
}

//main code:
GD.ClearColorRGB(0x602010);
GD.Clear();
GD.BlendFunc(SRC_ALPHA, ZERO);
GD.Begin(BITMAPS);
GD.Vertex2ii(10, 72);
rotate_64_64(DEGREES(22.5));
GD.cmd_setmatrix();
GD.Vertex2ii(176, 72);
rotate_64_64(DEGREES(22.5));
GD.cmd_setmatrix();
GD.Vertex2ii(342, 72);
GD.swap();

this will display three images (all of them rotated)

[dl14]

Remember that the angle specified is in Furmans where 1 F = 360 / 65536 degrees