OpenGL is a graphics standard and API which targets the desktop and workstation markets. It is designed to be easy to accelerate with dedicated computer hardware, and hence most implementations give greatly improved performance over traditional software rendering. Currently, OpenGL is used for ...
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0answers
4 views
Quaternion math from real world to screen
I'm writing an application (not a game per se, but close enough) where we use attitude sensors (an IMU) in the real world to affect the orientation of an object in the application's 3D space (OpenGL). ...
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0answers
9 views
In Cocos-2d-x, is there a way to get a shared OpenGL context for use with background loading
We are using parts of the Cocos-2D-X engine and we have a background loading thread which loads textures in the background. Is there a way to get a ShareGroup so we can safely bind an OpenGL context ...
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0answers
22 views
OpenGL ES 2.0 how to access LUT
I've created a look up table for my fragment shader and I'm passing it in as a uniform float array.
uniform float hueLut[360];
My program works fine on most devices but I ran across one device ...
0
votes
0answers
21 views
Easy way to compile OpenGL games for OpenGL ES? [on hold]
Is there an easy way to get the source code of an application whose graphics capabilities were written in OpenGL, and compile the same application for OpenGL ES, so it can be run on Android?
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votes
1answer
39 views
One framebuffer for each light vs unique framebuffer per light
Currently I have two ideas how to implement my lighting system:
1) Use one framebuffer per light source
no need to switch texture attachments of framebuffer
may be faster
bigger memory usage
2) ...
0
votes
3answers
65 views
Issue translating objects by one unit in the y direction
I'm currently making space invaders (in OpenGL/SDL) and I'm running into an issue with the movement of the aliens. I have a 2-d vector of aliens (5 rows of 11) and I'm translating each in the x ...
0
votes
2answers
87 views
Is game developers dealing directly with OpenGL or Direct3D [closed]
I'm in my undergraduate years and trying to become a game developer.
But I'm wondering is it worth to learn OpenGL as there're dozens of game engine nowadays, and most studio using them to ease the ...
2
votes
2answers
177 views
What happens if I don't call glNormal for some vertices?
Let's say I have an object where some vertices will have the same normal and some won't. Are these two equivalent? Note I'm working with an old OpenGL version (2.3 I think).
Option 1
...
1
vote
0answers
56 views
Memory leak with glfwSetWindowTitle? [closed]
I am using GLFW for a game, and I have a function which allows me to set the window title.
// PROBLEM WITH INCREASING MEMORY USAGE
void WindowSystem::setTitle( const string & title )
...
0
votes
1answer
69 views
Sprite quickly disappears after rendering
I'm currently making space invaders and I'm using the game loop pattern as described here. I have an entity class from which there is a spaceship derived class. The base entity class contains all of ...
0
votes
0answers
20 views
Transformation matrices and linear algebra in 2d development [closed]
I am trying to get into game development and I have started with a simple 2D platformer. I've also had some experience with XNA. At the moment I'm studying OpenGL ES and this is the second time when I ...
0
votes
0answers
34 views
Unprojecting a 2D triangle
I am looking to describe triangle in world space, given that the following are known:
Two of its vertices in screen space (or rays in the world)
One of its vertices in world space (the right angle ...
-1
votes
0answers
21 views
Using ray casting to access a function associated with an opengl mesh [duplicate]
I am doing a 3d scene in C++ using OpenGL for my project in graphics programming. I want to be able to point the camera at things and use them such as drawers light switches and chairs etc. I am ...
0
votes
1answer
43 views
Sprite Sheet Texture not being rendered
I'm making space invaders (in OpenGL/SDL) and I've run into a problem
when trying to draw the sprite for the spaceship from the spritesheet.
In my entity class, I have a pointer for the sprite that ...
1
vote
1answer
30 views
Android Opengl: Alternate values for gl_FragColor
I'm writing an Android application that utilizes opengl to perform some changes to the camera output. I've written my code in such a way that I finally figured out what is causing the performance ...
0
votes
0answers
28 views
Multithread OpenGL to Upload Meshes
My game is rendered in dynamically generated chunks, each of which has its own mesh.
Every time I generate a chunk and upload its mesh, there is a huge lag spike.
Is there a good way of eliminating ...
0
votes
1answer
27 views
GlViewport-code doesn't work in one specific screen?
I am currently working on a small game using LibGDX and Java.
However, I have found one oddly specific problem. I want the game to resize so that it never has to be cropped and so it never has to cut ...
0
votes
2answers
110 views
Optimising Voxel World Rendering
There are a couple of questions like this already. This one is different because it is specifically about rendering, as opposed to navigation and generation. I've implemented suggestions from here ...
0
votes
2answers
94 views
SDL or SFML: which is the best option if I only want to use OpenGL for my graphics? [closed]
I've read a lot about creating graphics with OpenGL in SDL and SFML over the past few days, and I want to know which one I should pick. As mentioned in most of the things that I've read, both allow ...
0
votes
1answer
56 views
Projection Matrix Breaks My Rectangle
This is my vertex shader, shown below.
#version 330 core
in vec3 a_position;
in vec4 a_colour;
// FOV = 70, near plane = 0.1, far plane = 1000
const mat4 u_projection = mat4(
1.428148, 0.0, ...
0
votes
0answers
35 views
SSAO attenuation problem
I followed this tutorial and I'm getting incorrect results for SSAO.
My gBuffer seems valid. Here is a picture showing Ambient Occlusion, Normalized Depth, Normals in View Space and Position.
...
0
votes
0answers
28 views
Using LibGDX (Orthographic) Camera.zoom makes tiles flicker when moving camera? [closed]
So I have some 64x64 sprites which work fine (no flicker/shuffling) when I move my camera normally
but as soon as I change the camera.zoom (was supposed to be a major mechanic in my game) level away ...
1
vote
1answer
79 views
Textures created with Photoshop show up with a white border
All of a sudden, I started having this problem. I've used libGDX + Photoshop before and never had this problem. One of my textures is showing up with a white border/glow around.
The texture is the ...
0
votes
0answers
38 views
Merging OpenGL rendering result with other graphical elements like user interface. Concepts
For my application, there are several elements drawing: An user interface elements, and several libraries for rendering part of the content of the window. Lets imagine some kind of Google Earth where ...
0
votes
0answers
29 views
Trouble with OpenGL on OS X
I'm creating an OpenGL-based game for OS X using Xcode. Everything renders correctly when I run the game in debug mode. However, running the game in release mode shows just a blank white window. This ...
0
votes
1answer
65 views
Should I always prefer a Uniform Buffer Object to a uniform variable for per-model uniforms in OpenGL?
I was looking for a way to update uniforms for all of my scene objects efficiently and I came across the following gamedev stackexchange question, where the top answer gives a bonus tip. It states:
...
0
votes
2answers
62 views
Build a vbo once every second
I have a VBO storing some data in my game. The thing is, the data can change at a rate of about a second. The data is not fixed size, meaning that some objects will sometimes be visible, sometimes ...
3
votes
1answer
60 views
Dynamically generating triangles from points
I'm working on 2D lighting.
I have a list of points that have been calculated and when I draw lines from the light origin to the point it works. The problem is connecting the points into triangles. ...
2
votes
2answers
64 views
How to display multiple textures with OpenGL without a texture atlas
I tried to dig into OpenGL a bit to use in 2D games (mainly because of shaders). There are multiple tutorials out there showcasing how to display and blend textures, and that's fine. But i haven't ...
1
vote
0answers
33 views
Drawing multiple polygons with vertex buffer object
I tried to create program in which I would draw multiplepoygons
here is fragment of what I have done:
GLuint VertexArrayID;
exampleof drawing triangle(I have more polygons, like circle, and so ...
0
votes
2answers
110 views
Switched from immediate mode to VBOs, game runs slower
trying to improve draw performance on my c++, OpenGL, SDL game. Back in school we mostly learned immediate mode, so thats how my drawing was originally implemented. When I started reading up online ...
0
votes
0answers
29 views
Open gl blending problem c++
im creating project from nearly scratch in c++..
i created skybox and terrain .
the result is catastrophic !
the terrain goes away and the ground also goes away,i dont know why ! i tried to disable ...
0
votes
0answers
23 views
glOrtho and VBO
I'm trying to send triangles to OpenGL using screen coordinates. Using the deprecated glBegin and glEnd I could just set up an orthographic projection and use screen-space coordinates as the ...
-1
votes
1answer
52 views
C++: from LWJGL to C++ with OpenGL
I've been trying my best on porting my 3D game from Java to C++, but to no avail.
I use only LWJGL with OpenGL but I cannot find any other library in C++ that supports as much as LWJGL does for Java. ...
0
votes
2answers
69 views
How do game engines manage to 'detect' the opengl supported in a computer
I am learning OpenGL 3.3 and OpenGL 2.1. I want to make a game engine with both. So far I can do advanced stuff with both of them. I noticed that graphics engines like Irrlicht support OpenGL 1.x to ...
0
votes
1answer
40 views
Issue with detecting collisions in Pong
I've been working on making Pong in OpenGL and SDL and currently have both paddles and the game ball set up properly. I have an Object (or Entity) class which is used to instantiate each of the ...
0
votes
1answer
33 views
OpenGL dynamic font glyph cache library
I have begun work on an OpenGL application (all on my own and with little knowledge) and started with FTGL, rendering true type fonts, which, with alot of text has a great impact on frames per second.
...
3
votes
1answer
80 views
Mesh's triangles don't move properly during skeletal animation
I've been trying to implement skeletal animation in my engine using this tutorial, and I've been having problems. Using the model they provided, I get results like this:
But on some other models, ...
1
vote
0answers
49 views
Front Face Culling with Shadowmapping
To avoid shadow acne I usualy use front face culling which works great. But for my current implementation the mesh is a quite complex terrain (depending on the lod level) and than the shading (dot ...
1
vote
1answer
65 views
Performance of glDrawElements vs glDrawRangeElements vs glDrawArrays
I've looked around on the web trying to find a good answer to this, but am unable to find one. Different forums mention driver bugs and the likes, but these discussions are usually almost 10 years ...
1
vote
1answer
76 views
SDL2, OpenGL, Nvidia laptop screen tearing
EDIT 2016-03-06.
Note 1: Apparently this is a known issue with Nvidia.
If you've found here due to same problem, please stoke the collective "please fix it" by filing a "question" at ...
4
votes
0answers
85 views
Windows vs OSX Performance with SDL, OpenGL [closed]
I have been writing an SDL OpenGL game in c++ for a couple of years now, writing my own engine for the most part (using Box2d for physics). I'm primarily a mac user, so I've been using xCode to write ...
1
vote
1answer
52 views
OpenGL Applications Bring computer to halt
Whenever I run any application that utilizes the OpenGL interface, my entire computer comes to a halt, but it doesn't do this when it utilizes the DirectX interface. I run both Linux (Ubuntu 15.10) ...
-1
votes
1answer
30 views
[opengl]get world position after rotate object by pivot
I need to rotate an object around a pivot,so I use this theory:
Translate the object to Pivot position
Rotate the object
Translate back the object from Pivot position
everything works fine,I can ...
0
votes
1answer
33 views
OpenGL - Quad is being separated like a two triangles after blending
I wanted to add transparency for my UI elements, so I enabled blending by adding:
glEnable(GL_BLEND);
glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
before renderer and
glDisable(GL_BLEND);
...
0
votes
1answer
53 views
OpenGL texture 2d array won't render with depth > 1
Below code uploads my texture memory that's described in the passed parameters. When 'vPixelData' only holds 1 item/texture it is rendered properly, but once there's 2 or more nothing shows up.
...
0
votes
0answers
31 views
How do I implement a LWJGL orthogonal matrix?
As seen on the official LWJGL page, I tried. But failed.
All the things I've found on SO and other sites didn't answer anything that had to do with this specifically. I've been on this for weeks. It's ...
0
votes
1answer
49 views
OpenGL GLSL vector of sampler2D
If im trying to create an obj. file loader in c++ and draw it with opengl i need to use multiple textures in the fragment shader.I know i can just use:
`uniform sampler2D Texture1`
`uniform ...
0
votes
0answers
20 views
How to copy texture of type GL_TEXTURE_EXTERNAL_OES to a texture of type GL_TEXTURE_2D
How to copy texture of type GL_TEXTURE_EXTERNAL_OES to a texture of type GL_TEXTURE_2D ?
How to find the internal format of texture ?
0
votes
1answer
51 views
How do I calculate a vertex's position on the CPU?
I'm creating light processor and I need light position and vertex position after translating, rotating and scaling (to calculate distance between them to check if light is affecting my vertex ...
