• Advertisement
  • Popular Tags

  • Popular Now

  • Advertisement
  • Similar Content

    • By codelyoko373
      I wasn't sure if this would be the right place for a topic like this so sorry if it isn't.
      I'm currently working on a project for Uni using FreeGLUT to make a simple solar system simulation. I've got to the point where I've implemented all the planets and have used a Scene Graph to link them all together. The issue I'm having with now though is basically the planets and moons orbit correctly at their own orbit speeds.
      I'm not really experienced with using matrices for stuff like this so It's likely why I can't figure out how exactly to get it working. This is where I'm applying the transformation matrices, as well as pushing and popping them. This is within the Render function that every planet including the sun and moons will have and run.
      if (tag != "Sun") { glRotatef(orbitAngle, orbitRotation.X, orbitRotation.Y, orbitRotation.Z); } glPushMatrix(); glTranslatef(position.X, position.Y, position.Z); glRotatef(rotationAngle, rotation.X, rotation.Y, rotation.Z); glScalef(scale.X, scale.Y, scale.Z); glDrawElements(GL_TRIANGLES, mesh->indiceCount, GL_UNSIGNED_SHORT, mesh->indices); if (tag != "Sun") { glPopMatrix(); } The "If(tag != "Sun")" parts are my attempts are getting the planets to orbit correctly though it likely isn't the way I'm meant to be doing it. So I was wondering if someone would be able to help me? As I really don't have an idea on what I would do to get it working. Using the if statement is truthfully the closest I've got to it working but there are still weird effects like the planets orbiting faster then they should depending on the number of planets actually be updated/rendered.
    • By Jens Eckervogt
      Hello everyone, 
      I have problem with texture
      using System; using OpenTK; using OpenTK.Input; using OpenTK.Graphics; using OpenTK.Graphics.OpenGL4; using System.Drawing; using System.Reflection; namespace Tutorial_05 { class Game : GameWindow { private static int WIDTH = 1200; private static int HEIGHT = 720; private static KeyboardState keyState; private int vaoID; private int vboID; private int iboID; private Vector3[] vertices = { new Vector3(-0.5f, 0.5f, 0.0f), // V0 new Vector3(-0.5f, -0.5f, 0.0f), // V1 new Vector3(0.5f, -0.5f, 0.0f), // V2 new Vector3(0.5f, 0.5f, 0.0f) // V3 }; private Vector2[] texcoords = { new Vector2(0, 0), new Vector2(0, 1), new Vector2(1, 1), new Vector2(1, 0) }; private int[] indices = { 0, 1, 3, 3, 1, 2 }; private string vertsrc = @"#version 450 core in vec3 position; in vec2 textureCoords; out vec2 pass_textureCoords; void main(void) { gl_Position = vec4(position, 1.0); pass_textureCoords = textureCoords; }"; private string fragsrc = @"#version 450 core in vec2 pass_textureCoords; out vec4 out_color; uniform sampler2D textureSampler; void main(void) { out_color = texture(textureSampler, pass_textureCoords); }"; private int programID; private int vertexShaderID; private int fragmentShaderID; private int textureID; private Bitmap texsrc; public Game() : base(WIDTH, HEIGHT, GraphicsMode.Default, "Tutorial 05 - Texturing", GameWindowFlags.Default, DisplayDevice.Default, 4, 5, GraphicsContextFlags.Default) { } protected override void OnLoad(EventArgs e) { base.OnLoad(e); CursorVisible = true; GL.GenVertexArrays(1, out vaoID); GL.BindVertexArray(vaoID); GL.GenBuffers(1, out vboID); GL.BindBuffer(BufferTarget.ArrayBuffer, vboID); GL.BufferData(BufferTarget.ArrayBuffer, (IntPtr)(vertices.Length * Vector3.SizeInBytes), vertices, BufferUsageHint.StaticDraw); GL.GenBuffers(1, out iboID); GL.BindBuffer(BufferTarget.ElementArrayBuffer, iboID); GL.BufferData(BufferTarget.ElementArrayBuffer, (IntPtr)(indices.Length * sizeof(int)), indices, BufferUsageHint.StaticDraw); vertexShaderID = GL.CreateShader(ShaderType.VertexShader); GL.ShaderSource(vertexShaderID, vertsrc); GL.CompileShader(vertexShaderID); fragmentShaderID = GL.CreateShader(ShaderType.FragmentShader); GL.ShaderSource(fragmentShaderID, fragsrc); GL.CompileShader(fragmentShaderID); programID = GL.CreateProgram(); GL.AttachShader(programID, vertexShaderID); GL.AttachShader(programID, fragmentShaderID); GL.LinkProgram(programID); // Loading texture from embedded resource texsrc = new Bitmap(Assembly.GetEntryAssembly().GetManifestResourceStream("Tutorial_05.example.png")); textureID = GL.GenTexture(); GL.BindTexture(TextureTarget.Texture2D, textureID); GL.TexParameter(TextureTarget.Texture2D, TextureParameterName.TextureMagFilter, (int)All.Linear); GL.TexParameter(TextureTarget.Texture2D, TextureParameterName.TextureMinFilter, (int)All.Linear); GL.TexImage2D(TextureTarget.Texture2D, 0, PixelInternalFormat.Rgba, texsrc.Width, texsrc.Height, 0, PixelFormat.Bgra, PixelType.UnsignedByte, IntPtr.Zero); System.Drawing.Imaging.BitmapData bitmap_data = texsrc.LockBits(new Rectangle(0, 0, texsrc.Width, texsrc.Height), System.Drawing.Imaging.ImageLockMode.ReadOnly, System.Drawing.Imaging.PixelFormat.Format32bppRgb); GL.TexSubImage2D(TextureTarget.Texture2D, 0, 0, 0, texsrc.Width, texsrc.Height, PixelFormat.Bgra, PixelType.UnsignedByte, bitmap_data.Scan0); texsrc.UnlockBits(bitmap_data); GL.Enable(EnableCap.Texture2D); GL.BufferData(BufferTarget.TextureBuffer, (IntPtr)(texcoords.Length * Vector2.SizeInBytes), texcoords, BufferUsageHint.StaticDraw); GL.BindAttribLocation(programID, 0, "position"); GL.BindAttribLocation(programID, 1, "textureCoords"); } protected override void OnResize(EventArgs e) { base.OnResize(e); GL.Viewport(0, 0, ClientRectangle.Width, ClientRectangle.Height); } protected override void OnUpdateFrame(FrameEventArgs e) { base.OnUpdateFrame(e); keyState = Keyboard.GetState(); if (keyState.IsKeyDown(Key.Escape)) { Exit(); } } protected override void OnRenderFrame(FrameEventArgs e) { base.OnRenderFrame(e); // Prepare for background GL.Clear(ClearBufferMask.ColorBufferBit); GL.ClearColor(Color4.Red); // Draw traingles GL.EnableVertexAttribArray(0); GL.EnableVertexAttribArray(1); GL.BindVertexArray(vaoID); GL.UseProgram(programID); GL.BindBuffer(BufferTarget.ArrayBuffer, vboID); GL.VertexAttribPointer(0, 3, VertexAttribPointerType.Float, false, 0, IntPtr.Zero); GL.ActiveTexture(TextureUnit.Texture0); GL.BindTexture(TextureTarget.Texture3D, textureID); GL.BindBuffer(BufferTarget.ElementArrayBuffer, iboID); GL.DrawElements(BeginMode.Triangles, indices.Length, DrawElementsType.UnsignedInt, 0); GL.DisableVertexAttribArray(0); GL.DisableVertexAttribArray(1); SwapBuffers(); } protected override void OnClosed(EventArgs e) { base.OnClosed(e); GL.DeleteVertexArray(vaoID); GL.DeleteBuffer(vboID); } } } I can not remember where do I add GL.Uniform2();
    • By Jens Eckervogt
      Hello everyone
      For @80bserver8 nice job - I have found Google search. How did you port from Javascript WebGL to C# OpenTK.?
      I have been searched Google but it shows f***ing Unity 3D. I really want know how do I understand I want start with OpenTK But I want know where is porting of Javascript and C#?
       
      Thanks!
    • By mike44
      Hi
      I draw in a OpenGL framebuffer. All is fine but it eats FPS (frames per second), hence I wonder if I could execute the framebuffer drawing only every 5-10th loop or so?
      Many thanks
       
    • By cebugdev
      hi all,
      how to implement this type of effect ? 
      Also what is this effect called? this is considered volumetric lighting?
      what are the options of doing this? 
      a. billboard? but i want this to have the 3D effect that when we rotate the camera we can still have that 3d feel.
      b. a transparent 3d mesh? and we can animate it as well?
      need your expert advise.
       
      additional:
      2. how to implement things like fireball projectile (shot from a monster) (billboard texture or a 3d mesh)?
       
      Note: im using OpenGL ES 2.0 on mobile. 
       
      thanks!
  • Advertisement
  • Advertisement
Sign in to follow this  

OpenGL [Resolved] called glewInit() but glCreateProgram() still crashes my application

This topic is 1851 days old which is more than the 365 day threshold we allow for new replies. Please post a new topic.

If you intended to correct an error in the post then please contact us.

Recommended Posts

Dealing with a curious issue.

 

I have three projects in Visual Studio (each in separate solutions)

 

1. glfx0.70 (an OpenGL shader creation library available here. It compiles to a static library 'glfx.lib')

2. my project (a fairly sophisticated game engine).

3. a tutorial project (a barebone opengl application that draws a triangle, that I got here )

 

My objective is to get the glfx functions working in my project. What I've observed is that if I call glCreateProgram() from within my project, it works fine. But if I call a glfx function which in turn calls glCreateProgram, it crashes instantly.

 

However, if I call glfx from within the tutorial project, no crashing occurs. I understand forgetting glewInit() is usually is the culprit here, but it has been called in my application prior to invoking any functions from glfx. Its as if the static library, glfx.lib is connected to a separate instance of glew that hasn't been initialized. However, adding 'glewInit()' inside the glfx code doesn't fix the problem either.

 

Any advice or ideas would be appreciated.

 

Thanks!

 

Share this post


Link to post
Share on other sites
Advertisement

Yes I'm sure!

 

After checking for consistency in the library references, I noticed that some of the header/library files referenced were different versions of glew. So I made sure they all point to the same thing.

 

At this point, here's what happens!

 

I put a message box right before glewInit() in my application to make sure it is called first. It is indeed being called before the error occurs.

 

If I put glewInit() inside the first function call of glfx, the program doesn't crash. So somehow calling glewInit in my application is not influencing the glew instance of glfx.

 

Still don't exactly know how to resolve this though.. :(

Share this post


Link to post
Share on other sites

Yes!

 

As I said, I can directly call glCreateProgram from within my application, and it works fine. But if (at the exact same location) I call a function from the glfx library, which in turn calls GlCreateProgram,it crashes. However! If I call glewInit() a second time, within glfx, it doesn't crash.

 

I think its clear that this has something to do with how glew is being linked between my application and the glfx library.

Share this post


Link to post
Share on other sites

The only explanation for this is that glfx is using it's own, separate, GL context.  From a quick parse over the glfx source this isn't something it normally does (it does create one in it's main function, but it seems that's only if it's compiled as a standalone application rather than as a lib, see http://code.google.com/p/glfx/source/browse/trunk/src/glfxc.cpp).

 

Based on that I'm pointing my finger at you either compiling glfx incorrectly or linking glfx incorrectly to your main program.  I'd advise that you use your debugger here; set a breakpoint at your first glfx call and step through line-by-line to see what it's doing.  You should very quickly find your culprit.

Share this post


Link to post
Share on other sites

are you sure your graphics card actually supports shaders, and have you installed the correct drivers (not falling back on the default driver?).

Share this post


Link to post
Share on other sites

are you sure your graphics card actually supports shaders, and have you installed the correct drivers (not falling back on the default driver?).

 

I'd say "yes" to this on account of:

 

What I've observed is that if I call glCreateProgram() from within my project, it works fine.

 

That leads me to suspect that a second GL context is being created, which - from looking at the glfx code - leads me to suspect that the OP has messed-up the inclusion of glfx in his main project somehow.

Share this post


Link to post
Share on other sites

Issue resolved!

 

There were two reasons. First, there was a hidden, older version of "glew.h" that was removed from my visual studio project, but still sitting inside the project folders. So when i called #include "glew.h" it was opening this hidden file.

 

Second, I needed to add 'GLEW_STATIC' to my pre-processor definitions. (GLEW_STATIC is already added to the glfx project) I guess this makes sure the gl context is linked together at compile time and not kept separate.

 

This fixed my problem. I appreciate everyone's suggestions and advice!

Share this post


Link to post
Share on other sites
Sign in to follow this  

  • Advertisement