Opentk/Source/Examples/OpenGL/GluTessellation.cs

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9 KiB
C#

#region --- License ---
/* Copyright (c) 2006-2008 the OpenTK team
* See license.txt for licensing details
*/
#endregion
using System;
using System.Diagnostics;
using OpenTK;
using OpenTK.OpenGL;
using OpenTK.OpenGL.Enums;
using OpenTK.OpenAL;
using OpenTK.OpenAL.Enums;
using OpenTK.Audio;
using OpenTK.Input;
using System.Runtime.InteropServices;
namespace Examples
{
[Example("GLU Tesselation Functions Test", ExampleCategory.OpenGL, 10)]
public class Test : GameWindow
{
int startList;
IntPtr tess;
// Define the signatures for the callback functions, and declare the callbacks.
delegate void BeginCallbackDelegate(BeginMode mode);
delegate void EndCallbackDelegate();
delegate void VertexCallbackDelegate(IntPtr v);
delegate void ErrorCallbackDelegate(GluErrorCode code);
unsafe delegate void CombineCallbackDelegate(
[MarshalAs(UnmanagedType.LPArray, SizeConst = 3)]double[] coordinates,
[MarshalAs(UnmanagedType.LPArray, SizeConst = 4)]double*[] vertexData,
[MarshalAs(UnmanagedType.LPArray, SizeConst = 4)]float[] weight,
double** dataOut);
BeginCallbackDelegate tessBegin;
EndCallbackDelegate tessEnd;
ErrorCallbackDelegate tessError;
VertexCallbackDelegate tessVertex;
CombineCallbackDelegate tessCombine;
public Test() : base()
{
Keyboard.KeyDown += KeyDownHandler;
}
#region --- GLU Tessellation callbacks ---
#region BeginHandler
void BeginHandler(BeginMode mode)
{
GL.Begin(mode);
}
#endregion
#region EndHandler
void EndHandler()
{
GL.End();
}
#endregion
#region VertexHandler
void VertexHandler(IntPtr v)
{
unsafe { GL.Vertex3((double*)v); }
}
#endregion
#region ErrorHandler
void ErrorHandler(GluErrorCode code)
{
System.Windows.Forms.MessageBox.Show(
String.Format("GLU Error {0}: {1}", code.ToString(), Glu.ErrorString(code)),
"An error occured while tesselating.");
this.Exit();
}
#endregion
#region CombineHandler
unsafe double*[] combineData;
int data_index = 0;
unsafe void CombineHandler(double[] coordinates, double*[] data, float[] weight, double** dataOut)
{
// Workaround Mono 1.2.6 bug with unsafe inline initializers
if (combineData == null)
combineData = new double*[16];
double* out_data = combineData[data_index] = (double*)Marshal.AllocHGlobal(6 * sizeof(double));
int i;
out_data[0] = coordinates[0];
out_data[1] = coordinates[1];
out_data[2] = coordinates[2];
for (i = 3; i < 6; i++)
{
double* real_data = (double*)data[i-3];
out_data[i] = weight[0] * real_data[0] +
weight[1] * real_data[1] +
weight[2] * real_data[2] +
weight[3] * real_data[3];
}
data_index++;
*dataOut = out_data;
}
#endregion
#endregion
#region KeyDownHandler
public void KeyDownHandler(KeyboardDevice sender, Key key)
{
switch (key)
{
case Key.Escape:
this.Exit();
return;
}
}
#endregion
#region OnResize
protected override void OnResize(OpenTK.Platform.ResizeEventArgs e)
{
GL.Viewport(0, 0, Width, Height);
GL.MatrixMode(MatrixMode.Projection);
GL.LoadIdentity();
Glu.Ortho2D(0.0, (double)Width, 0.0, (double)Height);
}
#endregion
#region OnLoad
public override void OnLoad(EventArgs e)
{
double[][] rect = new double[4][] {
new double[] {50.0, 50.0, 0.0},
new double[] {200.0, 50.0, 0.0},
new double[] {200.0, 200.0, 0.0},
new double[] {50.0, 200.0, 0.0}
};
double[][] tri = new double[3][] {
new double[] {75.0, 75.0, 0.0},
new double[] {125.0, 175.0, 0.0},
new double[] {175.0, 75.0, 0.0}
};
double[][] star = new double[5][] {
new double[] {250.0, 50.0, 0.0, 1.0, 0.0, 1.0},
new double[] {325.0, 200.0, 0.0, 1.0, 1.0, 0.0},
new double[] {400.0, 50.0, 0.0, 0.0, 1.0, 1.0},
new double[] {250.0, 150.0, 0.0, 1.0, 0.0, 0.0},
new double[] {400.0, 150.0, 0.0, 0.0, 1.0, 0.0}
};
GL.ClearColor(System.Drawing.Color.SteelBlue);
tess = Glu.NewTess();
startList = GL.GenLists(3);
tessVertex = this.VertexHandler;
tessBegin = this.BeginHandler;
tessEnd = this.EndHandler;
tessError = this.ErrorHandler;
unsafe { tessCombine = this.CombineHandler; }
Trace.Assert(tessVertex != null, "Failed to load tesselator callback function.");
Trace.Assert(tessBegin != null, "Failed to load tesselator begin callback function.");
Trace.Assert(tessEnd != null, "Failed to load tesselator end callback function.");
Trace.Assert(tessError != null, "Failed to load tesselator error callback function.");
Trace.Assert(tessCombine != null, "Failed to load tesselator combine callback function.");
Glu.TessCallback(tess, TessCallback.TessVertex, tessVertex);
Glu.TessCallback(tess, TessCallback.TessBegin, tessBegin);
Glu.TessCallback(tess, TessCallback.TessEnd, tessEnd);
Glu.TessCallback(tess, TessCallback.TessError, tessError);
// rectangle with triangular hole inside
GL.NewList(startList, ListMode.Compile);
GL.ShadeModel(ShadingModel.Flat);
Glu.TessBeginPolygon(tess, IntPtr.Zero);
Glu.TessBeginContour(tess);
Glu.TessVertex(tess, rect[0], rect[0]);
Glu.TessVertex(tess, rect[1], rect[1]);
Glu.TessVertex(tess, rect[2], rect[2]);
Glu.TessVertex(tess, rect[3], rect[3]);
Glu.TessEndContour(tess);
Glu.TessBeginContour(tess);
Glu.TessVertex(tess, tri[0], tri[0]);
Glu.TessVertex(tess, tri[1], tri[1]);
Glu.TessVertex(tess, tri[2], tri[2]);
Glu.TessEndContour(tess);
Glu.TessEndPolygon(tess);
GL.EndList();
Glu.TessCallback(tess, TessCallback.TessVertex, tessVertex);
Glu.TessCallback(tess, TessCallback.TessBegin, tessBegin);
Glu.TessCallback(tess, TessCallback.TessEnd, tessEnd);
Glu.TessCallback(tess, TessCallback.TessError, tessError);
Glu.TessCallback(tess, TessCallback.TessCombine, tessCombine);
// smooth shaded, self-intersecting star
GL.NewList(startList + 1, ListMode.Compile);
GL.ShadeModel(ShadingModel.Smooth);
Glu.TessWindingRuleProperty(tess, TessWinding.TessWindingPositive);
Glu.TessBeginPolygon(tess, IntPtr.Zero);
Glu.TessBeginContour(tess);
Glu.TessVertex(tess, star[0], star[0]);
Glu.TessVertex(tess, star[1], star[1]);
Glu.TessVertex(tess, star[2], star[2]);
Glu.TessVertex(tess, star[3], star[3]);
Glu.TessVertex(tess, star[4], star[4]);
Glu.TessEndContour(tess);
Glu.TessEndPolygon(tess);
GL.EndList();
}
#endregion
#region OnUnload
public override void OnUnload(EventArgs e)
{
if (tess != IntPtr.Zero)
Glu.DeleteTess(tess);
GL.DeleteLists(startList, 3);
while (data_index != 0)
unsafe { Marshal.FreeHGlobal((IntPtr)combineData[data_index--]); }
}
#endregion
#region OnRenderFrame
public override void OnRenderFrame(RenderFrameEventArgs e)
{
GL.Clear(ClearBufferMask.ColorBufferBit);
GL.Color3(1.0f, 1.0f, 1.0f);
GL.CallList(startList);
GL.CallList(startList + 1);
GL.Flush();
this.SwapBuffers();
}
#endregion
public static void Main()
{
using (Test test = new Test())
{
Utilities.SetWindowTitle(test);
test.Run(30.0, 0.0);
}
}
}
}