I have an OpenGl program that is based on the Giawa tutorials numbers 1-5.Basically I create an image, display it on the screen and make it rotate. All I want to accomplish is add keyboard events to change certain parameters of the image. For instance, in my code I want to press F6 to make the image rotate faster:
using System;
using Tao.FreeGlut;
using OpenGL;
using System;
using System.Windows;
using System.Windows.Forms;
namespace OpenGLTutorial5
{
class Program
{
private static int width = 640, height = 480;
private static ShaderProgram program;
private static VBO<Vector3> top_pyramid, cube, bottom_pyramid;
private static VBO<Vector3> top_pyramidColor, cubeColor, bottom_pyramidColor;
private static VBO<int> top_pyramidElements, cubeElements, bottom_pyramidElements;
private static System.Diagnostics.Stopwatch watch;
private static float angle;
private static int rotate = 1;
static void Main(string[] args)
{
// create an OpenGL window
Glut.glutInit();
Glut.glutInitDisplayMode(Glut.GLUT_DOUBLE | Glut.GLUT_DEPTH);
Glut.glutInitWindowSize(width, height);
Glut.glutCreateWindow("OpenGL Tutorial");
// provide the Glut callbacks that are necessary for running this tutorial
Glut.glutIdleFunc(OnRenderFrame);
Glut.glutDisplayFunc(OnDisplay);
// Glut.glutKeyboardFunc(new Glut.KeyboardCallback(OnKeyPress));
Glut.glutSpecialFunc(new Glut.SpecialCallback(OnKeyPress));
Glut.glutCloseFunc(OnClose);
// enable depth testing to ensure correct z-ordering of our fragments
Gl.Enable(EnableCap.DepthTest);
// compile the shader program
program = new ShaderProgram(VertexShader, FragmentShader);
// set the view and projection matrix, which are static throughout this tutorial
program.Use();
program["projection_matrix"].SetValue(Matrix4.CreatePerspectiveFieldOfView(0.45f, (float)width / height, 0.1f, 1000f));
program["view_matrix"].SetValue(Matrix4.LookAt(new Vector3(10, 0, 10), Vector3.Zero, Vector3.Up));
top_pyramid = new VBO<Vector3>(new Vector3[]
{
new Vector3(-1.5, 0, -0.5), new Vector3(-0.5, 1, -0.5), new Vector3(0, 0, -1.5),
new Vector3(-0.5, 1, -0.5), new Vector3(0.5, 1, -0.5), new Vector3(0, 0, -1.5),
new Vector3(0.5, 1, -0.5), new Vector3(1.5, 0, -0.5), new Vector3(0, 0, -1.5),
new Vector3(1.5, 0, -0.5), new Vector3(0.5, -1, -0.5), new Vector3(0, 0, -1.5),
new Vector3(0.5, -1, -0.5), new Vector3(-0.5, -1, -0.5), new Vector3(0, 0, -1.5),
new Vector3(-0.5, -1, -0.5), new Vector3(-1.5, 0, -0.5), new Vector3(0, 0, -1.5)
});
cube = new VBO<Vector3>(new Vector3[]
{
new Vector3(-1.5, 0, -0.5), new Vector3(-0.5, 1, -0.5), new Vector3(-0.5, 1, 0.5), new Vector3(-1.5, 0, 0.5),
new Vector3(-0.5, 1, -0.5), new Vector3(0.5, 1, -0.5), new Vector3(0.5, 1, 0.5), new Vector3(-0.5, 1, 0.5),
new Vector3(0.5, 1, -0.5), new Vector3(1.5, 0, -0.5), new Vector3(1.5, 0, 0.5), new Vector3(0.5, 1, 0.5),
new Vector3(1.5, 0, -0.5), new Vector3(1.5, 0, 0.5), new Vector3(0.5, -1, 0.5), new Vector3(0.5, -1, -0.5),
new Vector3(0.5, -1, 0.5), new Vector3(0.5, -1, -0.5), new Vector3(-0.5, -1, -0.5), new Vector3(-0.5, -1, 0.5),
new Vector3(-0.5, -1, -0.5), new Vector3(-0.5, -1, 0.5), new Vector3(-1.5, 0, 0.5), new Vector3(-1.5, 0, -0.5)
});
bottom_pyramid = new VBO<Vector3>(new Vector3[]
{
new Vector3(-1.5, 0, 0.5), new Vector3(-0.5, 1, 0.5), new Vector3(0, 0, 1.5),
new Vector3(-0.5, 1, 0.5), new Vector3(0.5, 1, 0.5), new Vector3(0, 0, 1.5),
new Vector3(0.5, 1, 0.5), new Vector3(1.5, 0, 0.5), new Vector3(0, 0, 1.5),
new Vector3(1.5, 0, 0.5), new Vector3(0.5, -1, 0.5), new Vector3(0, 0, 1.5),
new Vector3(0.5, -1, 0.5), new Vector3(-0.5, -1, 0.5), new Vector3(0, 0, 1.5),
new Vector3(-0.5, -1, 0.5), new Vector3(-1.5, 0, 0.5), new Vector3(0, 0, 1.5)
});
top_pyramidColor = new VBO<Vector3>(new Vector3[]
{
new Vector3(1, 0, 0), new Vector3(1, 0, 0), new Vector3(0, 1, 0),
new Vector3(1, 0, 0), new Vector3(1, 0, 0), new Vector3(0, 1, 0),
new Vector3(1, 0, 0), new Vector3(1, 0, 0), new Vector3(0, 1, 0),
new Vector3(1, 0, 0), new Vector3(1, 0, 0), new Vector3(0, 1, 0),
new Vector3(1, 0, 0), new Vector3(1, 0, 0), new Vector3(0, 1, 0),
new Vector3(1, 0, 0), new Vector3(1, 0, 0), new Vector3(0, 1, 0)
});
cubeColor = new VBO<Vector3>(new Vector3[]
{
new Vector3(1, 0, 0), new Vector3(1, 0, 0), new Vector3(0, 0, 1), new Vector3(0,0,1),
new Vector3(1, 0, 0), new Vector3(1, 0, 0), new Vector3(0, 0, 1), new Vector3(0,0,1),
new Vector3(1, 0, 0), new Vector3(1, 0, 0), new Vector3(0, 0, 1), new Vector3(0,0,1),
new Vector3(1, 0, 0), new Vector3(1, 0, 0), new Vector3(0, 0, 1), new Vector3(0,0,1),
new Vector3(1, 0, 0), new Vector3(1, 0, 0), new Vector3(0, 0, 1), new Vector3(0,0,1),
new Vector3(1, 0, 0), new Vector3(1, 0, 0), new Vector3(0, 0, 1), new Vector3(0,0,1),
});
bottom_pyramidColor = new VBO<Vector3>(new Vector3[]
{
new Vector3(0, 0, 1), new Vector3(0, 0, 1), new Vector3(1, 1, 0),
new Vector3(0, 0, 1), new Vector3(0, 0, 1), new Vector3(1, 1, 0),
new Vector3(0, 0, 1), new Vector3(0, 0, 1), new Vector3(1, 1, 0),
new Vector3(0, 0, 1), new Vector3(0, 0, 1), new Vector3(1, 1, 0),
new Vector3(0, 0, 1), new Vector3(0, 0, 1), new Vector3(1, 1, 0),
new Vector3(0, 0, 1), new Vector3(0, 0, 1), new Vector3(1, 1, 0)
});
top_pyramidElements = new VBO<int>(new int[] {
0,1,2,
3,4,5,
6,7,8,
9,10,11,
12,13,14,
15,16,17}, BufferTarget.ElementArrayBuffer);
cubeElements = new VBO<int>(new int[]{
0,1,2,3,
4,5,6,7,
8,9,10,11,
12,13,14,15,
16,17,18,19,
20,21,22,23}, BufferTarget.ElementArrayBuffer);
bottom_pyramidElements = new VBO<int>(new int[] {
0,1,2,
3,4,5,
6,7,8,
9,10,11,
12,13,14,
15,16,17}, BufferTarget.ElementArrayBuffer);
watch = System.Diagnostics.Stopwatch.StartNew();
Glut.glutMainLoop();
}
public static void OnKeyPress(int theKey, int x, int y)
{
switch (theKey)
{
case Glut.GLUT_KEY_F6:
{
rotate += 3;
Console.WriteLine("Hallo!");
Console.ReadLine();
}
break;
}
Glut.glutPostRedisplay();
}
private static void OnClose()
{
top_pyramid.Dispose();
top_pyramidColor.Dispose();
top_pyramidElements.Dispose();
program.DisposeChildren = true;
program.Dispose();
}
private static void OnDisplay()
{
}
private static void OnRenderFrame()
{
// calculate how much time has elapsed since the last frame
watch.Stop();
float deltaTime = (float)watch.ElapsedTicks / System.Diagnostics.Stopwatch.Frequency;
watch.Restart();
// use the deltaTime to adjust the angle of the cube and pyramid
angle += deltaTime;
// set up the OpenGL viewport and clear both the color and depth bits
Gl.Viewport(0, 0, width, height);
Gl.Clear(ClearBufferMask.ColorBufferBit | ClearBufferMask.DepthBufferBit);
// use our shader program
Gl.UseProgram(program);
//top pyramid
program["model_matrix"].SetValue(Matrix4.CreateRotationY(angle * rotate) * Matrix4.CreateTranslation(new Vector3(0.0f, 0, 1)));
Gl.BindBufferToShaderAttribute(top_pyramid, program, "vertexPosition");
Gl.BindBufferToShaderAttribute(top_pyramidColor, program, "vertexColor");
Gl.BindBuffer(top_pyramidElements);
//top pyramid
Gl.DrawElements(BeginMode.Triangles, top_pyramidElements.Count, DrawElementsType.UnsignedInt, IntPtr.Zero);
//cubes
program["model_matrix"].SetValue(Matrix4.CreateRotationY(angle * rotate) * Matrix4.CreateTranslation(new Vector3(0.0f, 0, 1)));
Gl.BindBufferToShaderAttribute(cube, program, "vertexPosition");
Gl.BindBufferToShaderAttribute(cubeColor, program, "vertexColor");
Gl.BindBuffer(cubeElements);
//cubes
Gl.DrawElements(BeginMode.Quads, cubeElements.Count, DrawElementsType.UnsignedInt, IntPtr.Zero);
//bottom pyramid
program["model_matrix"].SetValue(Matrix4.CreateRotationY(angle * rotate) * Matrix4.CreateTranslation(new Vector3(0.0f, 0, 1)));
Gl.BindBufferToShaderAttribute(bottom_pyramid, program, "vertexPosition");
Gl.BindBufferToShaderAttribute(bottom_pyramidColor, program, "vertexColor");
Gl.BindBuffer(bottom_pyramidElements);
//top pyramid
Gl.DrawElements(BeginMode.Triangles, bottom_pyramidElements.Count, DrawElementsType.UnsignedInt, IntPtr.Zero);
Glut.glutSwapBuffers();
}
public static string VertexShader = @"
#version 130
in vec3 vertexPosition;
in vec3 vertexColor;
out vec3 color;
uniform mat4 projection_matrix;
uniform mat4 view_matrix;
uniform mat4 model_matrix;
void main(void)
{
color = vertexColor;
gl_Position = projection_matrix * view_matrix * model_matrix * vec4(vertexPosition, 1);
}
";
public static string FragmentShader = @"
#version 130
in vec3 color;
out vec4 fragment;
void main(void)
{
fragment = vec4(color, 1);
}
";
}
}
The image displays correctly, however when I do press F6 the image stops rotating at all. Any ideas on how to fix this?
I suspect that your problem has nothing to do with OpenGL. Looking at your handler for the F6 key, it has the following code:
The last of these lines waits for you to enter text on the standard input. I believe it will block until you enter something. Take out the
ReadLine()call, and see if that fixes the problem.