OpenTK is a C# library that wraps OpenGL, OpenCL and OpenAL.

learn more… | top users | synonyms

13
votes
3answers
6k views

How do I implement a quaternion based camera?

UPDATE The error here was a pretty simple one. I have missed a radian to degrees conversion. No need to read the whole thing if you have some other problem. I looked at several tutorials about this ...
7
votes
1answer
358 views

How do I reconfigure my GLES frame buffer after a rotation?

Note: In order to keep the question as simple as possible, I am actively changing the body of the question to reflect the current state of affairs, instead of adding stuff at the bottom. I am ...
6
votes
2answers
2k views

How do I draw anti-aliased holes in a bitmap

I have an artillery game (hobby-learning project) and when the projectile hits it leaves a hole in the ground. I want this hole to have antialiased edges. I'm using System.Drawing for this. I've tried ...
4
votes
1answer
226 views

OpenGL rendering looks squeezed

I am rendering bunch of cubes of unit size, but for some reason they look like they are squeezed a bit in the screen-space y axis. Why is this? My projection matrix: Projection = ...
4
votes
1answer
172 views

OpenGL - What steps to take to correctly set up an Uniform Block Array

I have managed to get uniform blocks to work, but I seem to make something wrong when trying to setup an array of uniform blocks. Assume this glsl: layout(std140, binding=1) uniform LightingBlock ...
4
votes
1answer
110 views

What OpenCL video cards (or FPGAs) features are needed for high speed multiplication?

I'm benchmarking some cryptographic related software and am looking for video cards that are better at parallel multiplication vs parallel addition. Is there any prior work that would graph video ...
4
votes
1answer
735 views

In an artillery game how do I mask out the part of the terrain that was hit

Let's say I want to make a really simple artillery game, something like Gorillas. I don't have any experience in games, just some basic understanding of OpenGL. I want to do this for fun and to learn ...
4
votes
1answer
249 views

Upload vertex data for particles

I am kind of beginner with opengl. I am using point sprites (currently without any texturing) for my particles. I seem to fail to get them uploaded to the GPU memory correctly. I have readed lots of ...
3
votes
4answers
2k views

Is OpenTK Dead?

Looking at OpenTK, I notice some disturbing signs: The last news item was posted on December 31st, 2010 The main forum gets about one post a day On SourceForge, the last nightly build was in March, ...
3
votes
2answers
230 views

Instead of the specified Texture, black circles on a green background are getting rendered. Why?

I'm trying to render a Texture via OpenGL. But instead of the texture black circles on a green background are rendered. (They scale, depending what the rotation of the texture is) Example: The ...
2
votes
1answer
213 views

How do I animate pieces between puzzle states?

I'm developing a simple C# puzzle game as a learning exercise, using OpenTK. It's similar to Puzzles and Dragons' puzzle part: The aim is to match 3 pieces to remove them. Removed pieces are replaced. ...
2
votes
2answers
195 views

Collisions between players at spawnpoints

I am working on a FPS/MMORPG and ran into a problem at spawnpoints, when I enabled collision detection between players. Neither player would be able to move if both spawned at the same time, because ...
2
votes
1answer
167 views

Why do I have to divide the origin of a quad by 4 instead of 2?

I'm currently transitioning from C#/XNA to C#/OpenTK but I'm getting stuck at the basics. So I have this Sprite-Class: public static bool EnableDebugDraw = true; public float X; public float Y; ...
2
votes
1answer
196 views

How do I call OpenGL methods that require pointers in C#?

I have found the following C++ code in this tutorial to draw a triangle with OpenGL 4: float points[] = { 0.0f, 0.5f, 0.0f, 0.5f, -0.5f, 0.0f, -0.5f, -0.5f, 0.0f }; GLuint vbo = 0; ...
2
votes
3answers
2k views

C# 2D Game Library?

I'm looking for a C# 2D game library based on something like OpenTK which wraps OpenGL for C# Basically something like Slick2D (2D game library for Java) which is based on LWJGL which is an OpenGL ...
2
votes
2answers
862 views

Using multiple indexes with buffer objects in OpenTK

I've got multiple buffers in OpenGL holding data on position, normals and texcoords. I also have an equal number of buffers holding distinct index data for each of those buffers. I quite like this ...
2
votes
1answer
136 views

OpenTK GL.DrawElements is never called

I found this C++ code here. It draws simple rectangle. Works great. #define GLEW_STATIC #include <iostream> #include <glew.h> #include <freeglut.h> const GLchar* vertexSource = ...
2
votes
0answers
329 views

OpenGL drawing 500k triangles [closed]

I want to render big, izometric 2d map (using ortho projection). I am using OpenTK and aiming for OpenGL 3.3. Perfect option would be to draw 512x512 map of tiles, which is 262144 blocks -> 524288 ...
2
votes
1answer
318 views

Incorrect lighting results with deferred rendering

I am trying to render a light-pass to a texture which I will later apply on the scene. But I seem to calculate the light position wrong. I am working on view-space. In the image above, I am ...
1
vote
2answers
423 views

I enabled and setup glBlendFunc, but my texture has a white outline. What am I doing wrong?

You can see most of my source code in this question: Instead of the specified Texture, black circles on a green background are getting rendered. Why? Now I have the problem, that my texture has a ...
1
vote
1answer
92 views

Why are my objects rotating with my camera?

I am working with this C# library that wraps OpenGL. I am trying to understand why my objects in the scene are rotating as I yaw my camera (view matrix). Here is an image where I have 4 separate ...
1
vote
1answer
2k views

Why doesn't my texture display with this GLSL shader?

I am trying to display a DXT1 compressed texture on a quad using a VBO and shaders, but I have been unable to get it working. All I get is a black square. I know my texture is uploaded properly ...
1
vote
1answer
82 views

OpenGL - Buffer Usage

I am currently working on a little OpenGL project. At the moment I am trying to find a good solution for rendering multiple objects. I have set up a terrain with its own buffers, which works just ...
1
vote
2answers
237 views

Why swapping buffers takes different amounts of time?

When my program starts, almost nothing is on screen, just couple of lights and spheres. My FPS is at ~50. The Speed measurements looks like this: UpdateFrame took 0 ms Clearing lights queue: 0 ms ...
1
vote
1answer
393 views

Does OpenTK work in Windows 8?

While looking up OpenTK, I found a couple of references to threads that talk about Windows 8 support: This one from 2011 claims that OpenTK works on a Win8 preview A newer one from 2012 leaves the ...
1
vote
1answer
195 views

Opentk LookAt() and 'eye' argument rotating

I'm trying to create rotating camera, which looks down by 45 deegre like this: However my code for rotating eye vector is not working properly and I achieve vertical rotation, when it should be ...
1
vote
1answer
144 views

How to create a regular grid of triangles correctly?

I am trying to create an terrain using opentk/opengl. I have a problem with the VBO/IBO. I think a picture of the problem is the best way to show it: I dont understand why the last triangle of a ...
1
vote
2answers
2k views

Drawing multiple objects from one Vertex Buffer Object in OpenGL/OpenTK

I am trying to experimenting drawing method using VBO in OpenGL. Many people normally use 1 vbo to store one object data array. I was trying to do something quite opposite which is storing multiple ...
1
vote
3answers
2k views

How can I convert screen coordinatess to world coordinates in OpenTK?

I'm making a windows forms application with opengl view. I need to get the mouse coords converted to the opengl world coords. Well, my Y coord gets converted wrong. It's hard to explain, so here is ...
1
vote
2answers
176 views

Point[] and Tri not “could not be found”

Hi I'm trying to learn how to load a .obj file using OpenTK in windows Forms. I have seen a lot of examples out there, but I do see almost everyone uses List, and Point[]. Code example show these ...
1
vote
1answer
228 views

OpenAL seems to ignore sound attentuation/orientation for long sounds

I don't know how else to describe it in the title, sorry. My sound engine currently works perfectly with listener positioning and sound positioning to create the attentuation and panning effects. At ...
1
vote
1answer
340 views

Input in OpenTK

How to use Input in OpenTK 1.0? There is not much info around, some classes are unfinished. What I want to achieve, is to be able to use input not only in OnUpdate function, but also in other classes ...
1
vote
1answer
1k views

OpenGL - Calculating camera view matrix

Problem I am calculating the model, view and projection matrices independently to be used in my shader as follows: gl_Position = projection * view * model * vec4(in_Position, 1.0); When I try to ...
1
vote
1answer
470 views

GLSL - std140 uniform block - fields(vec, float, mat4) always 0.0

Ok, First of all, if just use uniforms everthing works like it should. Switching to uniform blocks nothing goes, as all values look like 0.0. I tested this with various if-then-else stuff within the ...
1
vote
1answer
634 views

C# OpenTK - Getting world coordinates of points that are altered by matrices

I have written a skeletal animation system for a game i am working on. To draw lines that represent a skeleton, i use the GL matrix, and multiply it by each bone a long the body. For example before ...
1
vote
0answers
33 views

Incorrect Texcoords for Bitmap Font? [on hold]

I am writing some code to display text using a bitmap font. However, when I run my game to see my results, I am greeted with a blank screen. I changed the texture to pure white to see if it was even ...
1
vote
1answer
225 views

Understanding implementation of glu.PickMatrix() [closed]

I am working on an OpenGL project which requires object selection feature. I use OpenTK framework to do this; however OpenTK doesn't support glu.PickMatrix() method to define the picking region. I ...
0
votes
2answers
1k views

OpenTK 2D Engine [closed]

I'm looking for a 2D gaming engine for C#/Windows. OpenTK seems reasonable, albeit made for 3D. I didn't find anything (other than an old thread from 2008) that talks about a 2D game engine. Are ...
0
votes
2answers
898 views

Can't render to FBO using a shader

I've added functionality so that I can render to a framebuffer (for post-processing and stuff). I can successfully render to my framebuffer and then render that framebuffer, but anything with a ...
0
votes
1answer
164 views

OpenGL: I only see one square instead of a cube / giving information to vertex shader

I am new to OpenGL and tried to follow this tutorial. I use C# and OpenTK. So I translate the C++ Code from the Tutorial: My C#-Code: /* Hintergrundfarbe */ ...
0
votes
1answer
1k views

Draw quad with OpenGL VBO using OpenTK

I'm trying to learn how to use VBO (Vertex Buffer Objects) by putting together a simple program that draws a quad to the screen using OpenTK (C# OpenGL bindings). Unfortunately I'm not seeing ...
0
votes
4answers
528 views

Missing triangles in model

I am having an issue where triangles in a model aren't being shown. The left is wireframe, the right is the finished image. For some reason a bunch of the triangles aren't being shown. The project ...
0
votes
1answer
100 views

GLSL: Vertex attribute to int

I'm trying to write a shader which renders a multitextured geometry wihout rerendering the geometry with each texture. In my test I'm not using textures, I just convert the texture index to a color ...
0
votes
2answers
291 views

OpenGL UseProgram() fails

I have a rather strange exception on my application using OpenTK on Linux (ArchLinux with Mono 3.2.8) with GL.UseProgram(). I wrote a class to combine multiple files to one program: public sealed ...
0
votes
1answer
170 views

How do I prevent clicking at the end of each sound play in OpenAL?

I have put together a basic sound handler class for use in my game. It uses OpenAL. It's a simple method at the moment to play sounds - here's an extract from a switch block: case "EATEN_PILL": ...
0
votes
2answers
583 views

Translate extrinsic rotations to intrinsic rotations ( Euler angles )

The problem I have is very frustrating: I am using the Jitter Physics library which gives Quaternion rotations, you can extract the extrinsic rotations but I need intrinsic rotations to rotate in ...
0
votes
1answer
83 views

Normals not rotated correctly

While rendering a cube to the gbuffer (diffuse, normal, depth) I noticed something odd when applying rotations. I build a world matrix for the cube as follows: Yaw = Yaw % MathUtil.PI2; Pitch = Pitch ...
0
votes
1answer
99 views

OpenGL not rendering full scene, it is a mystery [closed]

I am trying to draw a scene in the sort of style of mock vector graphics. I've helped on a 2D game before with GLSL, but I tried to keep a simple approach to this project since I'm working by myself, ...
0
votes
0answers
226 views

Play streaming sound in OpenTK?

What's the simplest way to make a sound stream from disk and play in OpenTK?
-1
votes
1answer
624 views

Problem rendering VBO [closed]

I'm developing a game engine using OpenTK. I'm trying to get to grips with the use of VBO's. I've run into some trouble because somehow it doesn't render correctly. Thus far I've used immediate mode ...