/// <summary>
/// The forms paint routine where all drawing happens.
/// </summary>
private void frmHelloCube_Paint(object sender, PaintEventArgs e)
{
// start with identity every frame
m_viewMatrix.Identity();
// view transform: move the coordinate system away from the camera
m_viewMatrix.Translate(0, 0, m_camZ);
// model transform: rotate the coordinate system increasingly
m_modelMatrix.Identity();
//m_modelMatrix.Translate(1, 0, 0);
m_modelMatrix.Rotate(m_rotAngle += 0.05f, 0, 1, 0);
m_modelMatrix.Scale(2, 2, 2);
// build combined matrix out of viewport, projection & modelview matrix
SLMat4f m = new SLMat4f();
m.Multiply(m_viewportMatrix);
m.Multiply(m_projectionMatrix);
m.Multiply(m_viewMatrix);
m.Multiply(m_modelMatrix);
// transform all vertices into screen space (x & y in pixels and z as the depth)
SLVec3f[] v2 = new SLVec3f[8];
for (int i = 0; i < m_v.Length; ++i)
{
v2[i] = m.Multiply(m_v[i]);
}
Graphics g = e.Graphics;
g.SmoothingMode = SmoothingMode.AntiAlias;
// draw front square
g.DrawLine(Pens.Red, v2[0].x, v2[0].y, v2[1].x, v2[1].y);
g.DrawLine(Pens.Red, v2[1].x, v2[1].y, v2[2].x, v2[2].y);
g.DrawLine(Pens.Red, v2[2].x, v2[2].y, v2[3].x, v2[3].y);
g.DrawLine(Pens.Red, v2[3].x, v2[3].y, v2[0].x, v2[0].y);
// draw back square
g.DrawLine(Pens.Green, v2[4].x, v2[4].y, v2[5].x, v2[5].y);
g.DrawLine(Pens.Green, v2[5].x, v2[5].y, v2[6].x, v2[6].y);
g.DrawLine(Pens.Green, v2[6].x, v2[6].y, v2[7].x, v2[7].y);
g.DrawLine(Pens.Green, v2[7].x, v2[7].y, v2[4].x, v2[4].y);
// draw from front corners to the back corners
g.DrawLine(Pens.Blue, v2[0].x, v2[0].y, v2[4].x, v2[4].y);
g.DrawLine(Pens.Blue, v2[1].x, v2[1].y, v2[5].x, v2[5].y);
g.DrawLine(Pens.Blue, v2[2].x, v2[2].y, v2[6].x, v2[6].y);
g.DrawLine(Pens.Blue, v2[3].x, v2[3].y, v2[7].x, v2[7].y);
// Tell the system that the window should be repaint again
this.Invalidate();
}
