Program.cs
using System;
using System.IO;
using System.Collections.Generic;
using System.Text;
namespace DibujoOpenGL
{
class Program
{
static void Main(string[] args)
{
BinaryReader DatosSRTM = new BinaryReader(File.Open(@"c:\temp\N45E000.hgt", FileMode.Open));
VentanaDibujo demo = new VentanaDibujo(DatosSRTM);
demo.Run();
}
}
}Archivo N45E000.hgt obtenido de: http://dds.cr.usgs.gov/srtm/
A continuación una clase estática para leer el formato SRTM que tiene los datos de altura como Enteros con signo de 2 bytes en formato BigEndian (Byte más significativo primero).
Lector.cs
using System;
using System.IO;
namespace DibujoOpenGL
{
public enum ByteOrder : int
{
LittleEndian,
BigEndian
}
static class Lector
{
public static byte[] ReadBytes(BinaryReader reader, int fieldSize, ByteOrder byteOrder)
{
byte[] bytes = new byte[fieldSize];
if (byteOrder == ByteOrder.LittleEndian)
return reader.ReadBytes(fieldSize);
else
{
for (int i = fieldSize - 1; i > -1; i--)
bytes[i] = reader.ReadByte();
return bytes;
}
}
public static Int16 ReadInt16(BinaryReader reader, ByteOrder byteOrder)
{
if (byteOrder == ByteOrder.LittleEndian)
{
return (Int16)reader.ReadInt16();
}
else // Big-Endian
{
return BitConverter.ToInt16(ReadBytes(reader, 2, ByteOrder.BigEndian),0);
}
}
}
}
VentanaDibujo.cs
using System;
using System.IO;
using OpenTK;
using OpenTK.Graphics;
using OpenTK.Graphics.OpenGL;
using OpenTK.Input;
using System.Drawing;
namespace DibujoOpenGL
{
public class VentanaDibujo : GameWindow
{
private float cameraSpeed = 5f;
private Matrix4 cameraMatrix;
private float[] mouseSpeed = new float[2];
private BinaryReader datosSRTM;
private Int16[,] filas = new Int16[1201,1201];
public VentanaDibujo(BinaryReader reader)
: base(900, 600, GraphicsMode.Default, "Terreno")
{
GL.Enable(EnableCap.DepthTest);
datosSRTM = reader;
}
protected override void OnLoad(EventArgs e)
{
base.OnLoad(e);
GL.ClearColor(Color.Black);
GL.ShadeModel(ShadingModel.Smooth); // Tipo de pintado de vertices
int w = this.Width;
int h = this.Height;
cameraMatrix = Matrix4.CreateTranslation(-300f, -100f, -300f);
for (int i = 0; i <= 1200; i++)
for (int j = 0; j <= 1200; j++)
{
filas[i,j] = Lector.ReadInt16(datosSRTM, ByteOrder.BigEndian);
}
datosSRTM.Close();
}
protected override void OnRenderFrame(FrameEventArgs e)
{
GL.MatrixMode(MatrixMode.Modelview);
GL.Clear(ClearBufferMask.ColorBufferBit | ClearBufferMask.DepthBufferBit);
GL.LoadMatrix(ref cameraMatrix);
GL.Color3(Color.Gray);
GL.PolygonMode(MaterialFace.FrontAndBack, PolygonMode.Fill); // Render Modo Fill o Wire
Vector3 MyColor = new Vector3(0.0f, 0.0f, 0.0f);
GL.Color3(MyColor);
for (int i = 0; i < 600; i++)
{
GL.Begin(BeginMode.TriangleStrip);
GL.PushMatrix();
for (int j = 0; j <= 600; j++)
{
MyColor.X= 1.0f*0.01f*filas[i, j];
MyColor.Y = 0.52f * 0.01f * filas[i, j];
MyColor.Z = 0.0f * 0.01f * filas[i, j];
GL.Color3(MyColor);
GL.Vertex3(j, 0.025f * filas[i, j], -i);
MyColor.X = 1.0f * 0.01f * filas[i+1, j];
MyColor.Y = 0.52f * 0.01f * filas[i+1, j];
MyColor.Z = 0.0f * 0.01f * filas[i+1, j];
GL.Color3(MyColor);
GL.Vertex3(j, 0.025f*filas[i + 1, j], -(i + 1));
}
GL.End();
GL.PopMatrix();
}
SwapBuffers();
}
protected override void OnUpdateFrame(FrameEventArgs e)
{
float move = 50f;
float look = 0.01f;
//Rotation
if (Keyboard[Key.Left])
{
cameraMatrix = Matrix4.Mult(cameraMatrix, Matrix4.CreateRotationZ(-look));
}
if (Keyboard[Key.Right])
{
cameraMatrix = Matrix4.Mult(cameraMatrix, Matrix4.CreateRotationZ(look));
}
if (Keyboard[Key.Up])
{
cameraMatrix = Matrix4.Mult(cameraMatrix, Matrix4.Translation(0f, -move * (float)e.Time, 0.0f));
//cameraMatrix = Matrix4.Mult(cameraMatrix, Matrix4.CreateRotationX(-look));
}
if (Keyboard[Key.Down])
{
cameraMatrix = Matrix4.Mult(cameraMatrix, Matrix4.Translation(0f, move * (float)e.Time, 0.0f));
//cameraMatrix = Matrix4.Mult(cameraMatrix, Matrix4.CreateRotationX(look));
}
if (Keyboard[Key.W])
{
cameraMatrix = Matrix4.Mult(cameraMatrix, Matrix4.Translation(0f, 0.0f, move * (float)e.Time));
}
if (Keyboard[Key.S])
{
cameraMatrix = Matrix4.Mult(cameraMatrix, Matrix4.Translation(0f, 0.0f, -move * (float)e.Time));
}
if (Keyboard[Key.A])
{
cameraMatrix = Matrix4.Mult(cameraMatrix, Matrix4.Translation(move * (float)e.Time, 0f, 0f));
}
if (Keyboard[Key.D])
{
cameraMatrix = Matrix4.Mult(cameraMatrix, Matrix4.Translation(-move * (float)e.Time, 0f, 0f));
}
/* mouseSpeed[0] *= 0.9f;
mouseSpeed[1] *= 0.9f;
mouseSpeed[0] += Mouse.XDelta / 100f;
mouseSpeed[1] += Mouse.YDelta / 100f;
cameraMatrix = Matrix4.Mult(cameraMatrix, Matrix4.RotateY(mouseSpeed[0] * (float)e.Time));
cameraMatrix = Matrix4.Mult(cameraMatrix, Matrix4.RotateX(mouseSpeed[1] * (float)e.Time));*/
if (Keyboard[Key.Escape])
Exit();
}
protected override void OnResize(EventArgs e)
{
base.OnResize(e);
GL.Viewport(ClientRectangle.X, ClientRectangle.Y, ClientRectangle.Width, ClientRectangle.Height);
Matrix4 projection = Matrix4.CreatePerspectiveFieldOfView((float)Math.PI / 6, Width / (float)Height, 1.0f, 2500.0f);
GL.MatrixMode(MatrixMode.Projection);
GL.LoadMatrix(ref projection);
}
}
}
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