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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491 views

Cheap ways to do scaling ops in shader?

I've got an extensive world terrain that uses vec3 for the vertex position attribute. That's good, because the terrain has endless gradations due to the use of floating point. But I'm thinking about ...
5
votes
1answer
288 views

Can I leverage the fact that my scene is often static to improve OpenGL (JOGL) performance?

My scene is drawn based on the location of several (often several million) vertices (kept in VBO's) and a camera. I can easily tell in my code when my scene has changed and when it hasn't. There are ...
5
votes
1answer
1k views

What's the best way of drawing a glowing 3d line using LWJGL?

Sort of like a strip-light effect; not actually a light source, but just a polygon with glowing edges. Can this be done easily? Right now I'm contemplating drawing a line more than once with varying ...
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votes
2answers
1k views

Generating geometry when using VBO

Currently I am working on a project in which I generate geometry based on the players movement. A glorified very long trail, composed of quads. I am doing this by storing a STD::Vector, and removing ...
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2answers
276 views

How does a general Renderer::drawRect(0, 0, 100, 100) handle VBO's?

Lots of game engines and GUI systems have a general Renderer class with functions like: renderer.drawRect(0, 0, 100, 100); renderer.drawText(204, 452, "Hello, world!"); I understand how this could ...
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3answers
960 views

How long does it take for OpenGL to actually update the screen?

I have a simple OpenGL test app in C which draws different things in response to key input. (Mesa 8.0.4, tried with Mesa-EGL and with GLFW, Ubuntu 12.04LTS on a PC with NVIDIA GTX650). The draws are ...
4
votes
3answers
359 views

How to skip the sky in lighting shaders?

I recently implemented a sky in my deferred rendered game. It is a procedurally calculated sphere with a texture applied to it. Unfortunately all lighting shaders (light sources, ambient occlusion) ...
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3answers
2k views

What method replaces GL_SELECT for box selection?

Last 2 weeks I started working on a box selection that selects shapes using GL_SELECT and I just got it working finally. When looking up resources online, there is a significant number of posts that ...
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1answer
4k views

OpenGL ES 2.0: Moving Camera in Orthogonal (2D) Projection

I have quite large 2D game scene. The scene is much larger than the screen of the LCD. Therefore, I have to move the camera (view) in desired directions, to display particular parts of the scene. ...
3
votes
1answer
84 views

what is the very last element of a 4x4 transformation matrix for? [duplicate]

while its a similar value to its neighbour - Z translation (and I wont say if thats above or to the left for fear of sparking a religious war!) and it only seems to change when the Z translation value ...
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votes
3answers
2k views

OpenGL additive blending not working as expected

I am trying to achieve additive blending with point sprites. When the sprites overlap, all I get is solid red, when I expect to get a smooth blend from red->yellow->white. My sprite texture has all ...
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votes
2answers
2k views

FBX Importer - Texture Name

I have a problem with the FBX SDK. I read in the data for the vertex position and the uv coordinates. It works fine, but now I want to read for each polygon to which texture it belongs, so that I can ...
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2answers
231 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 ...
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votes
1answer
2k views

Can't get LWJGL lighting to work

I'm trying to enable lighting in lwjgl according to the method described by NeHe and this post. However, no matter what I try, all faces of my shapes always receive the same amount of light, or, in ...
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votes
3answers
2k views

Is “pure” OpenGL productive enough?

I know that this is a difficult question and I hope I can convey my meaning. Over time I've used many different engines from XNA over Unity to Panda3d and even tried native directX once. My final ...
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1answer
1k views

OpenGL ES Basic Fragment Shader help with transparency

I have just spent my first half hour playing with the shader language. I have modified the basic program I have which renders the texture, to allow me to colour the texture. varying vec2 texCoord; ...
2
votes
1answer
264 views

OpenGL: What are the adoption rates of the various versions (And what's a reasonable version to use)

This question is looking for updated answers for this question, which was made 1.5 years ago - as well as seeking more information. Given that OpenGL 3.0 was released just over 5 years ago, what ...
2
votes
1answer
422 views

What happens when a texture is too large for a device

The question is two fold: What happens on a device when a texture is too large for it to handle? Will it crash or simply downsize it? In Unity if I use texture atlases of size 4k and then set ...
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2answers
2k views

How to check for cube collisions?

I want a method, which takes two "ObjectBox" objects (A "ObjectBox" has .getX() .getY() .getZ() .getSizeX() .getSizeY() .getSizeZ() methods) as a parameter and return true if the two Boxes are ...
2
votes
2answers
1k views

LWJGL multiple keyboard/mouse input checks

As in many game libraries such as LWJGL, you can check mouse/keyboard events with Mouse.isButtonDown or Keyboard.IsKeyDown. I want to check for button/key presses, not if it's currently pressed down ...
2
votes
1answer
1k views

smooth shading vs flat shading, what's the difference in the models?

I'm loading the exact same model with Assimp, except one is exported from Blender, shaded smoothly, and the other was exported from Blender, shaded flatly. Here is my results from loading both into my ...
2
votes
2answers
142 views

setting the position in different resolution

I have a normal game window which is 640*480, and everything is fine, but when I try to maximize the window, the objects translate to different positions on the screen, for example If I have a circle ...
2
votes
2answers
658 views

Is this a reliable method of parsing glGetShaderInfoLog()?

I want to get a list of errors and their line numbers so I can display the error information differently from how it's formatted in the error string and also to show the line in the output. It looks ...
2
votes
1answer
2k views

Zooming to point of interest

I have the following variables: Point of interest which is the position(x,y) in pixels of the place to focus. Screen width,height which are the dimensions of the window. Zoom level which sets the ...
2
votes
1answer
216 views

How to debug pyglet/opengl bus errors

I'm using pyglet for game development, and sometimes encounter "bus errors". They are not consistently repeatable, and whenever I try to do simple debugging (eg move/remove variables, etc), the errors ...
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votes
2answers
1k views

How should I do 3D games through Java on a mac?

I have been self-teaching myself Java on the mac mostly because the language is cross-platform. Recently, I have been only able to develop 2D games using the Graphics2D class. Now, I want to learn ...
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votes
2answers
3k views

camera movement along with model

I am making a game in which a cube travels along a maze with the motive of crossing the maze safely. I have two problems in this. The cube needs to have a smooth movement like it is traveling on a ...
2
votes
4answers
1k views

Multiplatform GLSL shader validator?

Im working on a multiplatform (Pc,Mac,Linux) game that uses shaders quite extensively. Since we do not have any funding, it is pretty hard to test our game on all possible hardware configurations. ...
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vote
1answer
183 views

Architecture to draw many different objects in OpenGL

I have some objects that I want to draw. I am not sure how I can create my architecture in a way where I can draw everything as fast as possible. As example: class MyObject { float[] vertices; ...
1
vote
1answer
271 views

How can I improve the performance of texture switching without resorting to atlasing?

I'd like to use texture images that are not a sprite sheet or other form of texture atlas, mainly because I'll be consistently adding and swapping textures while I figure out the direction my game ...
1
vote
1answer
1k views

Basic Car Movement, Converting 2D Vectors to 3D problems

I'm trying to follow this guys method for steering a basic car. Link. It's the first example I can sort of get my head around and I'm trying to convert it to a working 3D version. To get some scope, ...
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vote
2answers
138 views

Modern opengl for direct3d programmers [duplicate]

I don't think this is quite the same questions as this one but if you disagree feel free to close this :) With SteamOS being announced yesterday I can see that it's entirely possible that opengl will ...
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vote
1answer
374 views

SDL_Image and typical SDL BMP loading fails completely

been messing with OpenGL and SDL for a pair of weeks. The thing is quite weird. I have been loading a texture from a BMP and using a really easy shader to make it work, and so far it has worked very ...
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vote
0answers
220 views

Detect Sprites, they are in Shape or Not which random draw in Cocos2d

I have searched a lot on web and found some of help ful links as exact my question. Link 1 Link 2 But still i am not success to achieve this, i have done some of code lines, as like draw line by ...
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vote
1answer
3k views

LWJGL - Mixing 2D and 3D

I'm trying to mix 2D and 3D using LWJGL. I have wrote 2D little method that allow me to easily switch between 2D and 3D. protected static void make2D() { glEnable(GL_BLEND); ...
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vote
4answers
2k views

searching for “university kind” free online course about OPENGL [closed]

I know there are a lot of free university courses, but I'm trying to find one about OpenGL. Do you know where can I find one, online?
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1answer
896 views

Multiple buffering in OpenGL on Windows

What is the most common way modern games perform triple buffering ? What does the SwapBuffers exactly do in terms of OpenGL states ? Is it possible to perform double and triple buffering ...
1
vote
1answer
940 views

Translating local to global coordinates in ARToolkit / OpenGL

Ok, so I've tried reading over the other questions and something's just not clicking for me. I am working on an augmented reality application using ARToolkit, however it should just be straight ...
1
vote
1answer
343 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 ...
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vote
2answers
554 views

OpenGL Camera causes spatial distortion

I'm trying to implement a 3D camera of the "Orbit around the origin" variety in a game engine I'm developing in order to learn about 3D graphics and game programming. I have a basic handle on the ...
1
vote
1answer
1k views

Restoring projection matrix

I am learning to use FBOs and one of the things that I need to do when rendering something onto user defined FBO, I have to setup the projection, modelview and viewport for it. Once I am done ...
0
votes
1answer
142 views

GLSL to Cg fragment shader

I have found very useful resource on the Swiftless website on OpenGL. Unfortunately, I cannot manage to adapt a GLSL fragment shader to my project, which uses Cg. Here it is: uniform sampler2D ...
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votes
0answers
133 views

Slick2D/LWJGL Drawing coloured lights problem

I am using the Slick2D engine. I've followed this snippet for creating light sources. I have followed step step, added what is actually important for me, and tested it and the lighting effects ...
0
votes
1answer
108 views

How does OpenGL determine different outputs with shaders?

Lets say I have this GLSL code: #version 330 out vec4 outputColor; void main() { float lerpValue = gl_FragCoord.y / 500.0f; outputColor = mix(vec4(1.0f, 1.0f, 1.0f, 1.0f), ...
0
votes
1answer
271 views

Textures not displaying. Problem with fragment and vertex shaders

Hi i have newbe question. I am sending to gpu textures unit and they dont display. This is simple version of my fragment and vertexshader. (More complicated version also dont work with other textures ...
0
votes
1answer
90 views

How can texture packing improve performance?

Let's say I let a user give my library (a GUI system) multiple textures for rendering elements. What would be the performance impact of rendering with each of those textures separately versus, say, ...
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1answer
662 views

Simple curiosity about glDrawElements function

I've written a very simple OpenGL program displaying a white cube. To do the job done I recovered vertex position and indice data from an OBJ file that describes my cube. Here's the OBJ file content : ...
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0answers
81 views

Rendering a model with transparent or translucent uv map applied doesn't work

Before I try to make anything transparent, the model renders nicely. When I change the uv layout so that one piece of the model will be transparent, it renders horribly. This is the result with a ...
0
votes
1answer
108 views

Is it possible to display no white images/sprites when using the latest Android OS?

Was it okay to use Texture.setEnforcePotImages(false) in order to disable conditional width and height pixel size that requires power of 2? I'm planning to sell the game app at Google Play. I want to ...
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1answer
179 views

Where to store OpenGL object id:s

When working with OpenGL, you often recieve integer id:s to keep track of OpenGL objects. For example, representing a simple mesh, you may have a number of references to objects like so: GLuint ...