protected override void OnLoad(EventArgs e)
{
base.OnLoad(e);
glControl1_Resize(this, EventArgs.Empty); // Ensure the Viewport is set up correctly
GLHelper.ClearColor(PixelFarm.Drawing.Color.LightGray);
}
public override void Load()
{
//draw 1
FormTestWinGLControl form = new FormTestWinGLControl();
var canvas = PixelFarm.Drawing.DrawingGL.CanvasGLPortal.P.CreateCanvas(0, 0, 800, 600);
form.SetGLPaintHandler((o, s) =>
{
//-----------------------------
//see: lazyfoo.net/tutorials/OpenGL/26_the_stencil_buffer/index.php
//-----------------------------
//test gradient brush
//set value for clear color
GLHelper.ClearColor(PixelFarm.Drawing.Color.White);
GL.ClearStencil(0); //set value for clearing stencil buffer
//actual clear here
GL.Clear(ClearBufferMask.ColorBufferBit | ClearBufferMask.StencilBufferBit);
//-------------------
//disable rendering to color buffer
GL.ColorMask(false, false, false, false);
//start using stencil
GL.Enable(EnableCap.StencilTest);
//place a 1 where rendered
GL.StencilFunc(StencilFunction.Always, 1, 1);
//replace where rendered
GL.StencilOp(StencilOp.Replace, StencilOp.Replace, StencilOp.Replace);
//render to stencill buffer
GL.Begin(BeginMode.Triangles);
{
GL.Vertex2(20, 20);
GL.Vertex2(100, 20);
GL.Vertex2(60, 80);
}
GL.End();
//-----------------
//render color
GL.ColorMask(true, true, true, true);
//where a 1 was not rendered
GL.StencilFunc(StencilFunction.Equal, 1, 1);
//keep the pixel
GL.StencilOp(StencilOp.Keep, StencilOp.Keep, StencilOp.Keep);
//draw
GL.Begin(BeginMode.Quads);
{
GL.Color3(1f, 0, 0);
GL.Vertex2(5, 5);
GL.Color3(1f, 1, 0);
GL.Vertex2(100, 5);
GL.Color3(1f, 0, 1);
GL.Vertex2(100, 100);
GL.Color3(1f, 1, 1);
GL.Vertex2(5, 100);
}
GL.End();
GL.Disable(EnableCap.StencilTest);
});
form.Show();
}
/// <summary>
/// Setup OpenGL and load resources here.
/// </summary>
/// <param name="e">Not used.</param>
protected override void OnLoad(EventArgs e)
{
GLHelper.ClearColor(PixelFarm.Drawing.Color.White);
//GL.Enable(EnableCap.PolygonSmooth);
//GL.Enable(EnableCap.Blend);
//GL.BlendFunc(BlendingFactorSrc.SrcAlphaSaturate, BlendingFactorDest.One);
//GL.Hint(HintTarget.PolygonSmoothHint, HintMode.DontCare);
//glCullFace(GL_BACK);
//GL.BlendFunc(BlendingFactorSrc.SrcAlphaSaturate, BlendingFactorDest.One);
//glEnable(GL_CULL_FACE);
//glBlendFunc(GL_SRC_ALPHA_SATURATE, GL_ONE);
//glClearColor(0.0, 0.0, 0.0, 0.0);
//glEnable(GL_LINE_SMOOTH);
//glEnable(GL_BLEND);
//glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
//glHint(GL_LINE_SMOOTH_HINT, GL_DONT_CARE);
}
private void greenButton_Click(object sender, EventArgs e)
{
GLHelper.ClearColor(PixelFarm.Drawing.Color.Green);
glControl1.Invalidate();
}
protected void GLClearColor(System.Drawing.Color c)
{
GLHelper.ClearColor(PixelFarm.Drawing.Conv.ToColor(c));
}
