/// <summary>
/// Sets the attributes.
/// </summary>
/// <param name="gl">The OpenGL instance.</param>
public override void SetAttributes(OpenGL gl)
{
if (enableCullFace.HasValue)
{
gl.EnableIf(OpenGL.GL_CULL_FACE, enableCullFace.Value);
}
if (cullFaceMode.HasValue)
{
gl.CullFace((uint)cullFaceMode.Value);
}
if (enableSmooth.HasValue)
{
gl.EnableIf(OpenGL.GL_POLYGON_SMOOTH, enableSmooth.Value);
}
if (frontFaceMode.HasValue)
{
gl.FrontFace((uint)frontFaceMode.Value);
}
if (polygonMode.HasValue)
{
gl.PolygonMode(OpenGL.GL_FRONT_AND_BACK, (uint)polygonMode.Value);
}
if (offsetFactor.HasValue && offsetBias.HasValue)
{
gl.PolygonOffset(offsetFactor.Value, offsetBias.Value);
}
if (enableOffsetPoint.HasValue)
{
gl.EnableIf(OpenGL.GL_POLYGON_OFFSET_POINT, enableOffsetPoint.Value);
}
if (enableOffsetLine.HasValue)
{
gl.EnableIf(OpenGL.GL_POLYGON_OFFSET_LINE, enableOffsetLine.Value);
}
if (enableOffsetFill.HasValue)
{
gl.EnableIf(OpenGL.GL_POLYGON_OFFSET_FILL, enableOffsetFill.Value);
}
}
public override void Draw(ref OpenGL gl)
{
if (!TexturesInitialised)
{
InitializeTexture(ref gl);
}
// Clear the color and depth buffer.
gl.Clear(OpenGL.GL_COLOR_BUFFER_BIT | OpenGL.GL_DEPTH_BUFFER_BIT);
// Load the identity matrix.
gl.LoadIdentity();
gl.Enable(OpenGL.GL_TEXTURE_2D);
gl.Enable(OpenGL.GL_LIGHTING);
gl.Enable(OpenGL.GL_LIGHT0);
gl.Enable(OpenGL.GL_DEPTH_TEST);
gl.Enable(OpenGL.GL_NORMALIZE);
gl.BindTexture(OpenGL.GL_TEXTURE_2D, gtexture[0]);
gl.Color(1.0f, 1.0f, 1.0f, 0.1f);
gl.Begin(OpenGL.GL_QUADS);
gl.FrontFace(OpenGL.GL_FRONT_FACE);
gl.TexCoord(1.0f, 1.0f);
gl.Vertex(gImage1.Width, gImage1.Height, 1.0f);
gl.TexCoord(0.0f, 1.0f);
gl.Vertex(0.0f, gImage1.Height, 1.0f);
gl.TexCoord(0.0f, 0.0f);
gl.Vertex(0.0f, 0.0f, 1.0f);
gl.TexCoord(1.0f, 0.0f);
gl.Vertex(gImage1.Width, 0.0f, 1.0f);
gl.End();
gl.Disable(OpenGL.GL_TEXTURE_2D);
gl.MatrixMode(OpenGL.GL_PROJECTION);
gl.LoadIdentity();
gl.Ortho(0.0, (double)gImage1.Width, (double)gImage1.Height, 0.0, -1.0, 1.0);
gl.MatrixMode(OpenGL.GL_MODELVIEW);
gl.Disable(OpenGL.GL_DEPTH_TEST);
}
public void draw(OpenGL gl)
{
if (net)
gl.CullFace(OpenGL.GL_FRONT);
else
gl.CullFace(OpenGL.GL_BACK);
if (vertices != null)
{
gl.EnableClientState(OpenGL.GL_VERTEX_ARRAY);
gl.VertexPointer(3, OpenGL.GL_FLOAT, 0, vertices);
}
if (normals != null)
{
gl.EnableClientState(OpenGL.GL_NORMAL_ARRAY);
gl.NormalPointer(OpenGL.GL_FLOAT, 0, normals);
}
if (colors != null)
{
gl.EnableClientState(OpenGL.GL_COLOR_ARRAY);
gl.ColorPointer(3, OpenGL.GL_UNSIGNED_BYTE, 0, colors);
}
if (textCoords != null)
{
gl.EnableClientState(OpenGL.GL_TEXTURE_COORD_ARRAY);
gl.TexCoordPointer(2, OpenGL.GL_FLOAT, 0, textCoords);
}
gl.FrontFace(OpenGL.GL_CCW);
if (lengths != null && strips != null)
for (int i = 0; i < strips.Count; i++)
{
gl.DrawElements(OpenGL.GL_TRIANGLE_STRIP, lengths[i], OpenGL.GL_UNSIGNED_INT, strips[i]);
}
if (doubleSurface)
{
if (doubleNormals != null)
{
gl.NormalPointer(OpenGL.GL_FLOAT, 0, doubleNormals);
}
gl.FrontFace(OpenGL.GL_CW);
for (int i = 0; i < strips.Count; i++)
{
gl.DrawElements(OpenGL.GL_TRIANGLE_STRIP, lengths[i], OpenGL.GL_UNSIGNED_INT, strips[i]);
}
}
gl.DisableClientState(OpenGL.GL_VERTEX_ARRAY);
gl.DisableClientState(OpenGL.GL_COLOR_ARRAY);
gl.DisableClientState(OpenGL.GL_NORMAL_ARRAY);
gl.DisableClientState(OpenGL.GL_TEXTURE_COORD_ARRAY);
}
/// <summary>
/// Casts a real time 3D shadow.
/// </summary>
/// <param name="gl">The OpenGL object.</param>
/// <param name="lights">The lights.</param>
private void CastShadow(OpenGL gl)
{
// Set the connectivity, (calculate the neighbours of each face).
SetConnectivity();
// Get the lights in the scene.
var lights = TraverseToRootElement().Traverse <Light>(l => l.IsEnabled && l.On && l.CastShadow);
// Get some useful references.
var faces = ParentPolygon.Faces;
// Go through every light in the scene.
foreach (var light in lights)
{
// Every face will have a visibility setting.
bool[] facesVisible = new bool[faces.Count];
// Get the light position relative to the polygon.
Vertex lightPos = light.Position;
lightPos = lightPos - ParentPolygon.Transformation.TranslationVertex;
// Go through every face, finding out whether it's visible to the light.
for (int nFace = 0; nFace < faces.Count; nFace++)
{
// Get a reference to the face.
Face face = faces[nFace];
// Is this face facing the light?
float[] planeEquation = face.GetPlaneEquation(ParentPolygon);
float side = planeEquation[0] * lightPos.X +
planeEquation[1] * lightPos.Y +
planeEquation[2] * lightPos.Z + planeEquation[3];
facesVisible[nFace] = (side > 0) ? true : false;
}
// Save all the attributes.
gl.PushAttrib(OpenGL.GL_ALL_ATTRIB_BITS);
// Turn off lighting.
gl.Disable(OpenGL.GL_LIGHTING);
// Turn off writing to the depth mask.
gl.DepthMask(0);
gl.DepthFunc(OpenGL.GL_LEQUAL);
// Turn on stencil buffer testing.
gl.Enable(OpenGL.GL_STENCIL_TEST);
// Translate our shadow volumes.
ParentPolygon.PushObjectSpace(gl);
// Don't draw to the color buffer.
gl.ColorMask(0, 0, 0, 0);
gl.StencilFunc(OpenGL.GL_ALWAYS, 1, 0xFFFFFFFF);
gl.Enable(OpenGL.GL_CULL_FACE);
// First Pass. Increase Stencil Value In The Shadow
gl.FrontFace(OpenGL.GL_CCW);
gl.StencilOp(OpenGL.GL_KEEP, OpenGL.GL_KEEP, OpenGL.GL_INCR);
DoShadowPass(gl, lightPos, facesVisible);
// Second Pass. Decrease Stencil Value In The Shadow
gl.FrontFace(OpenGL.GL_CW);
gl.StencilOp(OpenGL.GL_KEEP, OpenGL.GL_KEEP, OpenGL.GL_DECR);
DoShadowPass(gl, lightPos, facesVisible);
gl.FrontFace(OpenGL.GL_CCW);
ParentPolygon.PopObjectSpace(gl);
// Enable writing to the color buffer.
gl.ColorMask(1, 1, 1, 1);
// Draw A Shadowing Rectangle Covering The Entire Screen
gl.Color(light.ShadowColor);
gl.Enable(OpenGL.GL_BLEND);
gl.BlendFunc(OpenGL.GL_SRC_ALPHA, OpenGL.GL_ONE_MINUS_SRC_ALPHA);
gl.StencilFunc(OpenGL.GL_NOTEQUAL, 0, 0xFFFFFFF);
gl.StencilOp(OpenGL.GL_KEEP, OpenGL.GL_KEEP, OpenGL.GL_KEEP);
Sphere shadow = new Sphere();
shadow.Transformation.ScaleX = shadowSize;
shadow.Transformation.ScaleY = shadowSize;
shadow.Transformation.ScaleZ = shadowSize;
shadow.Render(gl, RenderMode.Design);
gl.PopAttrib();
}
}