Questions tagged [opentk]

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

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14
votes
3answers
9k 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
2answers
2k 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
1answer
6k views

Should I use retained mode or immediate mode

I'm trying to make a opengl wrapper for winforms(.net). Basically you code in gdi+ syntax but it gets rendered for opengl(using glcontrol of opentk). Which mode should I use for rendering ui? It has ...
6
votes
1answer
819 views

Dual paraboloid shadows on GLSL

I'm trying to port an XNA example to OpenTK + OpenGL, I found it here http://graphicsrunner.blogspot.com.es/2008/07/dual-paraboloid-shadow-maps.html But I'm having a really hard time, I think my maps ...
6
votes
2answers
5k 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 ...
5
votes
5answers
6k views

Is OpenTK Dead? [closed]

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, ...
5
votes
1answer
2k 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: ...
5
votes
2answers
552 views

Trying to implement forward rendering in OpenGL

I'm working on implementing forward rendering in my 2D engine, as far as I'm aware everything should be set up correctly, I've ran into some issues earlier but I'm sure I've fixed those at this point. ...
5
votes
1answer
401 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 ...
4
votes
3answers
2k 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: ...
4
votes
1answer
424 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: ...
4
votes
1answer
125 views

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

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
930 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 ...
3
votes
2answers
373 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 ...
3
votes
3answers
4k 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 ...
3
votes
3answers
2k 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 ...
3
votes
1answer
878 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 ...
3
votes
0answers
469 views

Enabling OpenGL lighting seems to disable blending

I have the following code to set up for some 2D drawing using OpenTK. I originally wrote it without any lighting considerations, but later added the lighting block. This version of the code uses ...
3
votes
1answer
400 views

Turning On/Off Vsync no longer working when rendering to an offscreen buffer

I have this reaallly strange issue that as soon as I render to an offscreen framebuffer I am no longer able to toggle VSync while my application is running. I am using OpenTK as the opengl wrapper, ...
2
votes
1answer
498 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
1answer
238 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: ...
2
votes
2answers
217 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
9k views

C# OpenTK Text rendering

I've been looking everywhere for a solution on how to render/draw text for my 2D OpenTK-based game. Been trying quite a few QuickFont ones without success (either a AccessViolation exception or text ...
2
votes
1answer
2k 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: ...
2
votes
1answer
1k views

What's the DSA version of glTexImage2D?

I want to set the initial data of a texture in an OpenGL 4.5 program (using OpenTK.Next and .NET), utilizing the new Direct State Access methods. However, I cannot find a DSA version of ...
2
votes
1answer
4k 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 ...
2
votes
1answer
3k 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 ...
2
votes
2answers
8k 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 ...
2
votes
1answer
698 views

glUniformMatrix4fv OpenTK equivalent

Very simple and quick question which surprisingly I couldn't find an answer to over the internet: what is the equivalent of glUniformMatrixfv for opentk? I've browsed all the 7 overloads of GL....
2
votes
1answer
755 views

Opentk hdr rendering with framebuffer white screen problem

I am trying to do hdr rendering with two shader programs: one simply draws a hdr texture on a fullscreen quad and the other one does tonemapping. I am trying either linear tonemapping ...
2
votes
1answer
298 views

OpenTK crashes with Mono

I've implemented OpenTK as a secondary renderer which would let me support Mac/Linux only to realize that for some reason, even without any modifications (new MonoGame project), the application would ...
2
votes
1answer
2k views

OpenGL: Draw an arrow

I'd like to know how to draw an arrow to represent a vector position, length and direction. The issue is that I can't quite find an easy way to know the location and rotation of the triangle ...
2
votes
1answer
608 views

OpenTK GL.DrawElements is never called

I found this C++ code here. It draws simple rectangle. Works great. ...
2
votes
0answers
150 views

GL.Scissor not working as expected

I have some code for rendering a button in an application and I want to clip the text if it's wider than the button itself. Here a bit of code to describe what I'm doing: ...
2
votes
0answers
1k views

Cannot convert bitmap to texture [closed]

I'm doing a little C# / OpenGL project and I can't manage to load textures properly. So here is my texture class : ...
2
votes
0answers
791 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 ...
1
vote
2answers
1k 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
127 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
212 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 fine....
1
vote
1answer
3k 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
2answers
2k 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: ...
1
vote
1answer
468 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
173 views

OpenGL Texture from Raw Data Not Rendering Correctly

Starting off the class in question is here: ...
1
vote
1answer
781 views

Applying Transformation Matrices to VBOs in OpenGL

So I've recently tried to add Vertex Buffer Object Matrix transformation to an OpenGL engine I'm working on. I could go about this by applying the matrix to a copy of each vertex individually, but ...
1
vote
1answer
485 views

Legal Implications of using Openal in Opentk Commercially

Myself and my friend are currently creating a game, which we plan on selling upon its completion. We are using opentk. I read over this: http://www.opentk.com/node/532 , and it pretty well describes ...
1
vote
1answer
809 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 (...
1
vote
1answer
8k 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 ...
1
vote
3answers
10k 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
228 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 ...
1
vote
1answer
303 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 ...