Opentk/Source/Examples/OpenGL/T11_Julia_Set.cs
2008-04-13 18:43:15 +00:00

292 lines
11 KiB
C#

#region --- License ---
/* Licensed under the MIT/X11 license.
* Copyright (c) 2006-2008 the OpenTK Team.
* This notice may not be removed from any source distribution.
* See license.txt for licensing detailed licensing details.
*
* Written by Christoph Brandtner
*/
#endregion
using System;
using System.Windows.Forms;
using System.Diagnostics;
using System.Drawing;
using System.Drawing.Imaging;
using System.IO;
using OpenTK;
using OpenTK.Graphics;
namespace Examples.Tutorial
{
/// <summary>
/// Demonstrates how to render an animated Julia Set in real-time. Quality is sacrificed for speed.
/// Info about the fractal: http://en.wikipedia.org/wiki/Julia_set
/// One more major optimization could be applied (exploit the symmetry of the image with RTT), but
/// that would make the program alot more complicated to follow. You can do this as an exercise.
/// </summary>
[Example("GLSL Animated Julia Set", ExampleCategory.GLSL)]
public class T11_Julia_Set : GameWindow
{
public T11_Julia_Set()
: base(512, 512)
{
}
#region Private Fields
// GLSL Objects
int VertexShaderObject, FragmentShaderObject, ProgramObject;
int TextureObject;
// Julia Variables for animation
float AnimOffsetX = 0.213f; // using non-zero as starting point to make it more interesting
float AnimOffsetY = 0.63f;
const double AnimSpeedX = 0.65; // anim speed scaling is solely used to make the anim more interesting
const double AnimSpeedY = 1.05;
const double AnimCosinusPercent = 0.85f; // scales the cosinus down to 85% to avoid the (boring) borders
float UniformScaleFactorX; // fractal horizontal scaling is only affected by window resize
float UniformScaleFactorY; // fractal vertical scaling is only affected by window resize
float UniformOffsetX = 1.8f; // fractal horizontal offset
float UniformOffsetY = 1.8f; // fractal vertical offset
// Text drawing (for fps)
TextPrinter printer = new TextPrinter();
TextureFont font = new TextureFont(new Font(FontFamily.GenericSansSerif, 14.0f));
#endregion private Fields
#region OnLoad
/// <summary>
/// Setup OpenGL and load resources here.
/// </summary>
/// <param name="e">Not used.</param>
public override void OnLoad(EventArgs e)
{
// Check for necessary capabilities:
if (!GL.SupportsExtension("VERSION_2_0"))
{
MessageBox.Show("You need at least OpenGL 2.0 to run this example. Aborting.",
"GLSL not supported", MessageBoxButtons.OK, MessageBoxIcon.Exclamation);
this.Exit();
}
this.VSync = VSyncMode.On;
GL.Disable(EnableCap.Dither);
GL.ClearColor(0.2f, 0f, 0.4f, 0f);
// declare some variables for tracking which shader did compile, and which texture to use
string[] ShaderFilenames = new string[2];
ShaderFilenames[0] = "Data/Shaders/JuliaSet_SM3_FS.glsl";
ShaderFilenames[1] = "Data/Shaders/JuliaSet_SM2_FS.glsl";
byte CurrentOption = 0;
string LogInfo;
#region Shaders
// Load&Compile Vertex Shader
using (StreamReader sr = new StreamReader("Data/Shaders/JuliaSet_VS.glsl"))
{
VertexShaderObject = GL.CreateShader(ShaderType.VertexShader);
GL.ShaderSource(VertexShaderObject, sr.ReadToEnd());
GL.CompileShader(VertexShaderObject);
}
GL.GetShaderInfoLog(VertexShaderObject, out LogInfo);
if (LogInfo.Length > 0 && !LogInfo.Contains("hardware"))
Trace.WriteLine("Vertex Shader Log:\n" + LogInfo);
else
Trace.WriteLine("Vertex Shader compiled without complaint.");
// Load&Compile Fragment Shader
FragmentShaderObject = GL.CreateShader(ShaderType.FragmentShader);
do
{
using (StreamReader sr = new StreamReader(ShaderFilenames[CurrentOption]))
{
GL.ShaderSource(FragmentShaderObject, sr.ReadToEnd());
GL.CompileShader(FragmentShaderObject);
}
GL.GetShaderInfoLog(FragmentShaderObject, out LogInfo);
if (LogInfo.Length > 0 && !LogInfo.Contains("hardware"))
Trace.WriteLine("Compiling " + ShaderFilenames[CurrentOption] + " failed!\nLog:\n" + LogInfo);
else
{
Trace.WriteLine("Fragment Shader compiled without complaint.");
break;
}
if (++CurrentOption > 1)
{
MessageBox.Show("Neither SM2 nor SM3 Fragment Shader compiled successfully. Aborting.",
"Fatal Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
this.Exit();
}
} while (true);
// Link the Shaders to a usable Program
ProgramObject = GL.CreateProgram();
GL.AttachShader(ProgramObject, VertexShaderObject);
GL.AttachShader(ProgramObject, FragmentShaderObject);
GL.LinkProgram(ProgramObject);
// make current
GL.UseProgram(ProgramObject);
// Flag ShaderObjects for delete when app exits
GL.DeleteShader(VertexShaderObject);
GL.DeleteShader(FragmentShaderObject);
#endregion Shaders
#region Textures
// Load&Bind the 1D texture for color lookups
GL.ActiveTexture(TextureUnit.Texture0); // select TMU0
GL.GenTextures(1, out TextureObject);
GL.TexParameter(TextureTarget.Texture1D, TextureParameterName.TextureMagFilter, (int)TextureMagFilter.Linear);
GL.TexParameter(TextureTarget.Texture1D, TextureParameterName.TextureMinFilter, (int)TextureMinFilter.Linear);
GL.TexParameter(TextureTarget.Texture1D, TextureParameterName.TextureWrapS, (int)(TextureWrapMode)All.ClampToEdge);
Bitmap bitmap = new Bitmap("Data/JuliaColorTable.bmp");
BitmapData data = bitmap.LockBits(new Rectangle(0, 0, bitmap.Width, bitmap.Height), ImageLockMode.ReadOnly, System.Drawing.Imaging.PixelFormat.Format24bppRgb);
GL.TexImage1D(TextureTarget.Texture1D, 0, PixelInternalFormat.Rgb8, data.Width, 0, OpenTK.Graphics.PixelFormat.Bgr, PixelType.UnsignedByte, data.Scan0);
bitmap.UnlockBits(data);
#endregion Textures
}
#endregion
#region OnUnLoad
public override void OnUnload(EventArgs e)
{
GL.DeleteTextures(1, ref TextureObject);
GL.DeleteProgram(ProgramObject); // implies deleting the previously flagged ShaderObjects
}
#endregion
#region OnResize
/// <summary>
/// Respond to resize events here.
/// </summary>
/// <param name="e">Contains information on the new GameWindow size.</param>
/// <remarks>There is no need to call the base implementation.</remarks>
protected override void OnResize(OpenTK.Platform.ResizeEventArgs e)
{
// Magic numbers so the fractal almost fits inside the window.
// If changing this, also change the -1.6f offset in the fragment shader accordingly.
UniformScaleFactorX = Width / (UniformOffsetX * 2f);
UniformScaleFactorY = Height / (UniformOffsetY * 2f);
GL.Viewport(0, 0, Width, Height);
GL.MatrixMode(MatrixMode.Projection);
GL.LoadIdentity();
GL.Ortho(-1.0, 1.0, -1.0, 1.0, 0.0, 1.0); // 2D setup
GL.MatrixMode(MatrixMode.Modelview);
GL.LoadIdentity();
}
#endregion
#region OnUpdateFrame
/// <summary>
/// Add your game logic here.
/// </summary>
/// <param name="e">Contains timing information.</param>
/// <remarks>There is no need to call the base implementation.</remarks>
public override void OnUpdateFrame(UpdateFrameEventArgs e)
{
base.OnUpdateFrame(e);
if (Keyboard[OpenTK.Input.Key.Escape])
{
this.Exit();
}
}
#endregion
#region OnRenderFrame
/// <summary>
/// Add your game rendering code here.
/// </summary>
/// <param name="e">Contains timing information.</param>
/// <remarks>There is no need to call the base implementation.</remarks>
public override void OnRenderFrame(RenderFrameEventArgs e)
{
//this.Title = "FPS: " + 1 / e.Time;
GL.Clear(ClearBufferMask.ColorBufferBit);
// First, render the next frame of the Julia fractal.
GL.UseProgram(ProgramObject);
// advance the animation by elapsed time, scaling is solely used to make the anim more interesting
AnimOffsetX += (float)(e.Time * AnimSpeedX);
AnimOffsetY += (float)(e.Time * AnimSpeedY);
// pass uniforms into the fragment shader
// first the texture
GL.Uniform1(GL.GetUniformLocation(ProgramObject, "COLORTABLE"), TextureObject);
// the rest are floats
GL.Uniform1(GL.GetUniformLocation(ProgramObject, "CETX"), (float)(Math.Cos(AnimOffsetX) * AnimCosinusPercent));
GL.Uniform1(GL.GetUniformLocation(ProgramObject, "CETY"), (float)(Math.Cos(AnimOffsetY) * AnimCosinusPercent));
GL.Uniform1(GL.GetUniformLocation(ProgramObject, "SCALINGX"), UniformScaleFactorX);
GL.Uniform1(GL.GetUniformLocation(ProgramObject, "SCALINGY"), UniformScaleFactorY);
GL.Uniform1(GL.GetUniformLocation(ProgramObject, "OFFSETX"), UniformOffsetX);
GL.Uniform1(GL.GetUniformLocation(ProgramObject, "OFFSETY"), UniformOffsetY);
// Fullscreen quad. Using immediate mode, since this app is fragment shader limited anyways.
GL.Begin(BeginMode.Quads);
{
GL.Vertex2(-1.0f, -1.0f);
GL.Vertex2(1.0f, -1.0f);
GL.Vertex2(1.0f, 1.0f);
GL.Vertex2(-1.0f, 1.0f);
}
GL.End();
// Then, render the fps:
GL.UseProgram(0);
printer.Begin();
GL.Color3(Color.PaleGoldenrod);
printer.Draw((1 / e.Time).ToString("F2"), font);
printer.End();
SwapBuffers();
}
#endregion
#region public static void Main()
/// <summary>
/// Entry point of this example.
/// </summary>
[STAThread]
public static void Main()
{
using (T11_Julia_Set example = new T11_Julia_Set())
{
Utilities.SetWindowTitle(example);
example.Run(30.0);
}
}
#endregion
}
}