private static void OnRenderFrame()
{
watch.Stop();
float deltaTime = (float)watch.ElapsedTicks / System.Diagnostics.Stopwatch.Frequency;
watch.Restart();
// perform rotation of the scene depending on keyboard input
if (right)
{
phi += deltaTime;
}
if (left)
{
phi -= deltaTime;
}
if (up)
{
theta += deltaTime;
}
if (down)
{
theta -= deltaTime;
}
if (theta < 0)
{
theta += (float)Math.PI * 2;
}
// set up the viewport and clear the previous depth and color buffers
Gl.Viewport(0, 0, width, height);
Gl.Clear(ClearBufferMask.ColorBufferBit | ClearBufferMask.DepthBufferBit);
// make sure the shader program and texture are being used
Gl.UseProgram(program.ProgramID);
Gl.BindTexture(flagTexture);
// calculate the camera position using some fancy polar co-ordinates
Vector3 position = 20 * new Vector3((float)(Math.Cos(phi) * Math.Sin(theta)), (float)Math.Cos(theta), (float)(Math.Sin(phi) * Math.Sin(theta)));
Vector3 upVector = ((theta % (Math.PI * 2)) > Math.PI) ? new Vector3(0, 1, 0) : new Vector3(0, -1, 0);
program["view_matrix"].SetValue(Matrix4.LookAt(position, Vector3.Zero, upVector));
program["time"].SetValue(flagTime);
flagTime += deltaTime;
Gl.BindBufferToShaderAttribute(flagVertices, program, "vertexPosition");
Gl.BindBufferToShaderAttribute(flagUVs, program, "vertexUV");
Gl.BindBuffer(flagTriangles);
Gl.DrawElements(BeginMode.Triangles, flagTriangles.Count, DrawElementsType.UnsignedInt, IntPtr.Zero);
// bind the font program as well as the font texture
Gl.UseProgram(fontProgram.ProgramID);
Gl.BindTexture(font.FontTexture);
// build this string every frame, since theta and phi can change
FontVAO vao = font.CreateString(fontProgram, string.Format("Theta: {0:0.000}, Phi: {1:0.000}, Time: {2:0.000}", theta, phi, flagTime), BMFont.Justification.Right);
vao.Position = new Vector2(width / 2 - 10, height / 2 - font.Height - 10);
vao.Draw();
vao.Dispose();
// draw the tutorial information, which is static
information.Draw();
Glut.glutSwapBuffers();
}
static void Main(string[] args)
{
Glut.glutInit();
Glut.glutInitDisplayMode(Glut.GLUT_DOUBLE | Glut.GLUT_DEPTH);
Glut.glutInitWindowSize(width, height);
Glut.glutCreateWindow("OpenGL Tutorial");
Glut.glutIdleFunc(OnRenderFrame);
Glut.glutDisplayFunc(OnDisplay);
Glut.glutKeyboardFunc(OnKeyboardDown);
Glut.glutKeyboardUpFunc(OnKeyboardUp);
Glut.glutCloseFunc(OnClose);
Glut.glutReshapeFunc(OnReshape);
// enable blending and set to accumulate the star colors
Gl.Enable(EnableCap.DepthTest);
Gl.Enable(EnableCap.Blend);
// create our shader program
program = new ShaderProgram(VertexShader, FragmentShader);
// set up the projection and view matrix
program.Use();
program["projection_matrix"].SetValue(Matrix4.CreatePerspectiveFieldOfView(0.45f, (float)width / height, 0.1f, 1000f));
program["view_matrix"].SetValue(Matrix4.LookAt(new Vector3(0, 0, 20), Vector3.Zero, new Vector3(0, 1, 0)));
program["model_matrix"].SetValue(Matrix4.Identity);
// load the flag texture
flagTexture = new Texture("flag.png");
// create the flag, which is just a plane with a certain number of segments
List <Vector3> vertices = new List <Vector3>();
List <Vector2> uvs = new List <Vector2>();
List <uint> triangles = new List <uint>();
for (int x = 0; x < 40; x++)
{
for (int y = 0; y < 40; y++)
{
vertices.Add(new Vector3((x - 20) / 5.0f, (y - 20) / 10.0f, 0));
uvs.Add(new Vector2(x / 39.0f, 1 - y / 39.0f));
if (y == 39 || x == 39)
{
continue;
}
triangles.Add((uint)(x * 40 + y));
triangles.Add((uint)((x + 1) * 40 + y));
triangles.Add((uint)((x + 1) * 40 + y + 1));
triangles.Add((uint)(x * 40 + y));
triangles.Add((uint)((x + 1) * 40 + y + 1));
triangles.Add((uint)(x * 40 + y + 1));
}
}
flagVertices = new VBO <Vector3>(vertices.ToArray());
flagUVs = new VBO <Vector2>(uvs.ToArray());
flagTriangles = new VBO <uint>(triangles.ToArray(), BufferTarget.ElementArrayBuffer);
// load the bitmap font for this tutorial
font = new BMFont("font24.fnt", "font24.png");
fontProgram = new ShaderProgram(BMFont.FontVertexSource, BMFont.FontFragmentSource);
fontProgram.Use();
fontProgram["ortho_matrix"].SetValue(Matrix4.CreateOrthographic(width, height, 0, 1000));
fontProgram["color"].SetValue(new Vector3(1, 1, 1));
information = font.CreateString(fontProgram, "OpenGL C# Tutorial 11");
watch = System.Diagnostics.Stopwatch.StartNew();
Glut.glutMainLoop();
}
static void Main(string[] args)
{
Glut.glutInit();
Glut.glutInitDisplayMode(Glut.GLUT_DOUBLE | Glut.GLUT_DEPTH);
Glut.glutInitWindowSize(width, height);
Glut.glutCreateWindow("OpenGL Tutorial");
Glut.glutIdleFunc(OnRenderFrame);
Glut.glutDisplayFunc(OnDisplay);
Glut.glutKeyboardFunc(OnKeyboardDown);
Glut.glutKeyboardUpFunc(OnKeyboardUp);
Glut.glutCloseFunc(OnClose);
Glut.glutReshapeFunc(OnReshape);
// enable blending and set to accumulate the star colors
Gl.Enable(EnableCap.DepthTest);
Gl.Enable(EnableCap.Blend);
// create our shader program
program = new ShaderProgram(VertexShader, FragmentShader);
// set up the projection and view matrix
program.Use();
program["projection_matrix"].SetValue(Matrix4.CreatePerspectiveFieldOfView(0.45f, (float)width / height, 0.1f, 1000f));
program["view_matrix"].SetValue(Matrix4.LookAt(new Vector3(0, 0, 20), Vector3.Zero, Vector3.Up));
program["model_matrix"].SetValue(Matrix4.Identity);
// load the flag texture
flagTexture = new Texture("flag.png");
// create the flag, which is just a plane with a certain number of segments
List<Vector3> vertices = new List<Vector3>();
List<Vector2> uvs = new List<Vector2>();
List<int> triangles = new List<int>();
for (int x = 0; x < 40; x++)
{
for (int y = 0; y < 40; y++)
{
vertices.Add(new Vector3((x - 20) / 5.0, (y - 20) / 10.0, 0));
uvs.Add(new Vector2(x / 39.0, 1 - y / 39.0));
if (y == 39 || x == 39) continue;
triangles.Add(x * 40 + y);
triangles.Add((x + 1) * 40 + y);
triangles.Add((x + 1) * 40 + y + 1);
triangles.Add(x * 40 + y);
triangles.Add((x + 1) * 40 + y + 1);
triangles.Add(x * 40 + y + 1);
}
}
flagVertices = new VBO<Vector3>(vertices.ToArray());
flagUVs = new VBO<Vector2>(uvs.ToArray());
flagTriangles = new VBO<int>(triangles.ToArray(), BufferTarget.ElementArrayBuffer);
// load the bitmap font for this tutorial
font = new BMFont("font24.fnt", "font24.png");
fontProgram = new ShaderProgram(BMFont.FontVertexSource, BMFont.FontFragmentSource);
fontProgram.Use();
fontProgram["ortho_matrix"].SetValue(Matrix4.CreateOrthographic(width, height, 0, 1000));
fontProgram["color"].SetValue(new Vector3(1, 1, 1));
information = font.CreateString(fontProgram, "OpenGL C# Tutorial 11");
watch = System.Diagnostics.Stopwatch.StartNew();
Glut.glutMainLoop();
}
