Subset of the OpenGL 3D graphics API designed for embedded devices such as mobile phones.

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2
votes
1answer
464 views

How do I draw an animated object in OpenGL ES?

I have a VBO, which I initialise like this (just an example): - (void)setupVBOs { GLuint vertexBuffer; glGenBuffers(1, &vertexBuffer); glBindBuffer(GL_ARRAY_BUFFER, vertexBuffer); ...
0
votes
1answer
652 views

libgdx game process dies on loading texture atlases

I try to load a lot of texture atlases (10) with approximately 5 (~2048x~2048)(not using PoT) .pngs each. I'm using AssetManager and there is no trouble with it on my pc but when I try it on my tablet ...
2
votes
2answers
1k views

OpenGL texture on sphere

I want to create a rolling, textured ball in OpenGL ES 1.0 for Android. With this function I can create a sphere: public Ball(GL10 gl, float radius) { ByteBuffer bb = ...
2
votes
1answer
377 views

Color bleed on voxel edges when using anti-aliasing

My Minecraft-like game uses a texture containing four block IDs in each pixel (RGBA). These IDs are used in the shader to determine what color each whole block should be. I'm having an issue with ...
1
vote
0answers
88 views

iPhone 5S - GLSL problem [closed]

I have this shader precision highp float; precision highp int; attribute vec4 POSITION; attribute vec2 TEXCOORD0; attribute vec2 TEXCOORD1; attribute vec2 TEXCOORD2; attribute vec2 TEXCOORD3; ...
5
votes
1answer
223 views

GetData() error creating framebuffer [closed]

I'm currently porting a game written in C# with XNA library to Android with Monogame. I have a Texture2D and i'm trying to get an array of uint in this way: Texture2d textureDeform = ...
2
votes
1answer
1k views

Are interleaved vertex data formats better than non-interleaved formats?

I have been reading up on data formatting for 3D objects so that I can render my meshes as fast as possible in OpenGL. I am quite new to OpenGL so bear with me. The format for interleaving your ...
1
vote
1answer
788 views

How can I handle errors when there is no valid OpenGL context?

I'm writing cross-platform (iOS, Android, OSX, Windows) library code that draws its output using OpenGL. I expect my users will often try to call my library's rendering functions without a valid ...
2
votes
4answers
2k views

Setting up OpenGL camera with off-center perspective

I'm using OpenGL ES (in iOS) and am struggling with setting up a viewport with an off-center distance point. Consider a game where you have a character in the left hand side of the screen, and some ...
3
votes
2answers
2k views

Identity matrix. Confusion. What does it really do

I understand identity matrix is like multiplying to 1. But i can't really understand why would you multiply an a matrix that will only result to the same. Also im messing up with an OpenGL code and ...
8
votes
1answer
2k views

what is world space and eye space in game development?

I'm reading a book about 3D stuff and OpenGL. The book often talks about world space and eye space. What exactly is the "world space?" Does the "eye space" mean the projection?
0
votes
1answer
787 views

What is Opengl ES ? What is gl and GLES20 mean?

I am new in opengl. I saw tutorial some have gl at the beginning and some have GLES20 at the beginner and some has GL10. What are the differences? Is GLES20 mean opengl es2 whereas GL10 mean version ...
0
votes
3answers
2k views

OpenGL ES - read content of VBO

Is it possible to read back content of VBO in OpenGL ES 2.0 ? I have tried glMapBufferOES, but there is no READ flag. I dont want any answers, like "you shouldnt do it" or "keep copy of geometry in ...
2
votes
1answer
665 views

What is the correct and most efficient approach of streaming vertex data?

Usually, I do this in my current OpenGL ES project (for iOS): Initialization: Create two VBO's and one IndexBuffer (since I will use the same indices), same size. Create two VAO's and configure ...
1
vote
1answer
235 views

Pixmaps, ByteBuffers, and Textures…Oh my

My ultimate goal is to take a specific region of the screen, and redraw it somewhere else. For example, take a square from the upper left hand corner of the screen and redraw it on the lower right ...
1
vote
1answer
2k views

How to use mipmap in OpenGL-ES

I have recently entered in the OpenGL world. I am very pleased with the performance that I got with opengl compared to those obtained with a SurfaceView and its canvas. At the same time because of the ...
2
votes
1answer
2k views

OpenGL slower than Canvas

Up to 3 days ago I used a Canvas in a SurfaceView to do all the graphics operations but now I switched to OpenGL because my game went from 60FPS to 30/45 with the increase of the sprites in some ...
0
votes
1answer
137 views

How do I load BSP files in Android?

I understand that Opengl directly cannot load BSP files. How would I go about loading them into my Android game?
1
vote
1answer
4k views

How to do frame by frame animation in android using open gl es

I have application in some part i am using AndroidDrawable for animation but it giving jerking effect that why i planed to change the code to Open Gl ES for better performance .so far i have googled ...
8
votes
1answer
3k views

Optimizing performance of a heavy fragment shader

I need help optimizing the following set of shaders: Vertex: precision mediump float; uniform vec2 rubyTextureSize; attribute vec4 vPosition; attribute vec2 a_TexCoordinate; varying vec2 tc; ...
1
vote
1answer
1k views

rendering transparent meshes in LibGDX

Building open this tutorial - https://code.google.com/p/libgdx/wiki/ProjectionViewportCamera I have constructed a class for generating polygon meshes. But i cannot figure out how to render semi ...
1
vote
1answer
2k views

how to make cross platform 3d games using modern opengl? [closed]

How to create games that run on windows, Linux, mac os x, android, ios, wp8 etc.... using c/c++, opengl 3 or 4 and opengl es 2.0. any tutorials or videos on how to create cross-platform 3d games.
-2
votes
2answers
132 views

In OpenGL, how to confirm a primitive is rendered properly

I have to confirm that a primitive (say triangle) is rendered properly in opengl. I can use the glGetError() after a opengl draw calls(glDrawElement/glDrawArrays) Is it enough to confirm ? Is there ...
1
vote
0answers
60 views

OpenGL ES - jagged edge [duplicate]

I need to render roads and some direction marks on top of them. I render roads as triangled geometry, same goes for marks (see picture - road is purple, mark is red, ignore z-fighting). Problem goes ...
1
vote
1answer
315 views

How to set tranparency for one image only in openGL ES in Android?

I code game on Android where I have several sprites. My goal is to set gl.glColor4f(1f, 1f, 1f, 0.2f) a.e. transparency only for specific image. (I don't like Photoshop). In my case its image that ...
2
votes
0answers
373 views

Displacement Mapping opengl-es [closed]

I need to do an application similar to this Morfo. And I posted a question here where the answer states the solution is "Displacement Mapping" . And I googled this to do it in opengles. I couldnt get ...
3
votes
4answers
3k views

IOS OpenGl transparency performance issue

I have built a game in Unity that uses OpenGL ES 1.1 for IOS. I have a nice constant frame rate of 30 until i place a semi transparent texture over the top on my entire scene. I expect the drop in ...
2
votes
1answer
2k views

How to scale openGL textures by a ratio based on height/width (or alternative)

I have been able to successfully allow my UI to extend over edges of my game on higher resolutions by using the Android Guide and by implementing this code on the GL10 object: ...
12
votes
4answers
17k views

What is the purpose of glScissor?

I know that it is more efficient than stencil test, but am I right assuming that the same functionality could be achieved using projection transformations with viewport?
0
votes
1answer
2k views

How to get drawn Image width/height on the screen with openGL ES on Android?

I need to know how to get drawn image length and width. I have this code so far where I draw Radar in left top corner with hard-coded coordinates: int _SRC = R.drawable._item; ... float ...
32
votes
4answers
22k views

Workaround to losing the OpenGL context when Android pauses?

The Android documentation says: There are situations where the EGL rendering context will be lost. This typically happens when device wakes up after going to sleep. When the EGL context is ...
1
vote
1answer
461 views

How to change/modify or animate an existing OpenGL object on Android?

I maybe know understand it all a little bit better so i thoug i make a new shorter question to eventually get an answer. Get back or delete an existing OpenGL object, then change it and draw at new. ...
2
votes
1answer
549 views

How to know in OPenGL ES android that one object crosses another?

I have 2 objects on the screen: static: non-static: non-static object moves randomly over the screen. How do I know that non-static Object cross the "+" (static). Both objects I draw by using ...
6
votes
2answers
3k views

Using two shaders instead of one with IF statements

I've been working on porting a relatively large opengl ES 1.1 source to ES 2.0. In OpenGL ES 2.0 (which means, everything uses shaders), I want to draw a teapot three times. The first one, with a ...
2
votes
0answers
556 views

multi-threading for openGL in Android? [closed]

In my old game based on canvas and bitmaps I used surfaceHolder and Thread to call onDraw: public class GameThread extends Thread { private SurfaceHolder _surfaceHolder; private ScreenObjectsView ...
3
votes
2answers
219 views

How to change dynamically vertices during call “draw” method?

I'm new in openGL world and I try to figure out followed problem: How can I change size/zoom dynamically for my spritesheet. This class represents some creature fetched from spritesheet and animate ...
4
votes
1answer
271 views

Is it possible to apply a texture inside a GL_LINE_LOOP?

I am creating a game using Box2D and OpenGL ES 1.1. I am taking the b2PolygonShape vertices and converting them into an OpenGL ES 1.1 GL_LINE_LOOP. The debugging view looks great, but now I want to ...
3
votes
2answers
2k views

Improving performance of a particle system (OpenGL ES)

I'm in the process of implementing a simple particle system for a 2D mobile game (using OpenGL ES 2.0). It's working, but it's pretty slow. I start getting frame rate battering after about 400 ...
3
votes
1answer
370 views

Rotate an image and get back to its original position - opengles glkit

I need to rotate an image in opengles GLkit and get it back to its original position in GLkit. rotation += 5; _modelViewMatrix = GLKMatrix4Rotate( _modelViewMatrix, GLKMathDegreesToRadians(5), 1, 0, ...
0
votes
1answer
278 views

bump mapping with 2 normal maps

I was wondering if its actually possible to do bump mapping with 2 normal maps... I have tried doing it this way however I get a function overload on max and dot. uniform sampler2D n_mapTex; uniform ...
1
vote
2answers
7k views

How to create a projection matrix in OpenGL ES 2.0 [closed]

So I have the following... float s = 0.5f; void renderFrameLine() { glClearColor(0.0f, 0.0f, 0.0f, 1.0f); glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); GLfloat vVertices[] = { s, s, ...
0
votes
1answer
1k views

Android/OpenGL ES2: How do I set fragment shader value using C;

This should be easy So I am using the following to create a fragment shader. GLbyte fShaderStr[] = "precision mediump float;" "void main() \n" "{ ...
3
votes
2answers
2k views

OpenGL ES 2.0: 2D game rendering, no performance gain with glDraw call batching

I just did a small benchmark. To my surprise batching sprites into a single draw call doesn't give any significant performance boost. Following are my results: Hardware: iPod touch 4 Extra info: ...
5
votes
2answers
2k views

Implementing fog of war in opengl es 2.0 game

Hi game development community, this is my first question here! ;) I'm developing a tactics/strategy real time android game and I've been wondering for some time what's the best way to implement an ...
3
votes
2answers
1k views

OpenGL ES 2.0: Enabling hi-res on iOS

I created an empty iOS project and then added a custom GLView class which is then added to AppDelegate. I have following questions: 1) How do I enable hi-res retina mode on iPhone 4? Currently I am ...
7
votes
4answers
4k views

Sprite Animation in Android with OpenGL ES

How to do a sprite animation in android using OpenGL ES? What i have done : Now I am able to draw a rectangle and apply my texture(Spritesheet) to it What I need to know : Now the rectangle shows ...
1
vote
2answers
981 views

Calling glGetError() in release builds?

Currently, I'm calling glGetError() after each OpenGL function call in order to be able to detect and report bugs. I've been reading that glGetError() calls should be reduced to once per frame in ...
6
votes
2answers
2k views

OpenGL 3.0+ framebuffer to texture/images

I need a way to capture what is rendered on screen, i have read about glReadPixels but it looks really slow. Can you suggest a more efficient or just an alternative way for just copying what is ...
0
votes
1answer
822 views

iOS OpenGL ES 2.0 How to Billboard on Sphere and Rotate with Sphere

I have a sphere (earth) in OpenGL ES 2.0 for iOS. I also have markers that I want to place at lat/lons on the earth - but I want the markers to always face the user ( billboards ) but also move with ...
2
votes
1answer
2k views

Game Development at iOS, Android and PC with OpenGL ES

I'm beginning iOS apps development, and my aim is to make games to launch on App Store. But I want to know if it's possible to program a game on Xcode with OpenGL ES (C++ game logic), integrate it on ...