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

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2
votes
3answers
4k views

How can I convert an image from raw data in Android without any munging?

I have raw image data (may be .png, .jpg, ...) and I want it converted in Android without changing its pixel depth (bpp). In particular, when I load a grayscale (8 bpp) image that I want to use as ...
2
votes
0answers
788 views

Weird y offset when using custom frag shader (Cocos2d-x)

I'm trying to mask a sprite so I wrote a simple fragment shader that renders only the pixels that are not hidden under another texture (the mask). The problem is that it seems my texture has its y-...
1
vote
0answers
493 views

How can I reduce draw calls when using glBufferSubData and DYNAMIC_DRAW?

At first I had the problem where I had about 150 rectangles rendered every tick. I only used STATIC_DRAW and glBufferData. I added support for DYNAMIC_DRAW and glBufferSubData and now I have a very ...
0
votes
1answer
143 views

OpenGL ES 1 Pixel Error?

I am developing a game on android using OpenGL ES 1.0 for Android OS. It is a 2d game using a simple Orthographic projection and textures for the sprites. One of these textures has a small line (it ...
3
votes
2answers
2k views

Cocos2D: Upgrading from OpenGL ES 1.1 to 2.0

I have recently starting upgrading my ios game to the latest Cocos2D (2.0 rc), and I am having some difficulties upgrading my texture generation code to OpenGL 2.0. In the old version I generated ...
0
votes
1answer
325 views

Is there a way to use the RGB channels of a texture as the alpha channel when applying multitexturing using OpenGL ES 1.1?

I have been trying to get texture compression using ETC1 (specifically PKM files) working for some time now. I am trying to do this without having to upgrade to OpenGL ES 2 so I have been using multi-...
0
votes
1answer
404 views

Which texture do I bind to when implementing multi-texturing?

I have been having some issues getting multi-texturing to work using OpenGL ES 1.1. I have two PKMs - one with RGB's and one for alphas and I am trying to combine the two as below: int ...
3
votes
1answer
2k views

How do I generate mipmap .png and model .obj files for LibGDX?

I'm playing a bit with LibGDX (OpenGL ES 2.0 wrapper for Android). I found some sample code which used prepared files to load models and mipmap textures for them, e.g., at https://github.com/libgdx/...
6
votes
1answer
470 views

OpenGL 2.0 - Texture animation with 'pixelated' effect

I'm looking for a way to reproduce the effect I've tried to sketch in the image below with OpenGL ES 2.0. The idea is to let a drop of color fall over a cube which get filled with a kind of '...
3
votes
1answer
451 views

Texture mapping a complex object on openGL ES

I dont have much experience with openGL ES (or openGL), but i do get the general idea of texture mapping, which is each vertex should be mapped for the relevant UV coordinates of the texture we choose ...
8
votes
3answers
3k 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 ...
0
votes
1answer
295 views

Point rotation around point, accuracy question

I study OpenGL ES 2.0. But I think it's more a C++ question rather then an OpenGL one. I am stuck with the following rotation question: It is known, that rotation transformation can be applied using ...
3
votes
1answer
5k views

Android OpenGL ES RENDERMODE_WHEN_DIRTY implementation

I am trying to understand RENDERMODE_WHEN_DIRTY so that I could save battery life wherever possible.. I made this sample application so that GlSurfaceView is updated with random color only when the ...
6
votes
1answer
1k views

OpenGL ES object rotation around z axis

I have an object on my screen which is presented rotated and panned, But i have 2 problems regarding the z axis rotations. It's a bit tricky to explain so i uploaded 2 videos to describe each problem. ...
4
votes
1answer
2k views

How to outline a 3D object with a cartoon style stroke? [duplicate]

How could I draw (stroke) the outline of a 3D object in a cartoon style with GLKit? I'm referring to something like this: However we can start with a simple line around the object and then try to ...
1
vote
0answers
302 views

How can I use a Seekbar as a brightness slider?

I am using the GLSurfaceView Renderer. I want changes to a seek bar's progress to increase the brightness of a GLSurfaceView proportionally. How do I apply a color matrix to a GLSurface view? Is ...
2
votes
1answer
406 views

How do I apply a texture over a material in OpenGL ES?

How can I apply a texture over a material? I've set up an object with the following material: GLKBaseEffect *effect; effect.colorMaterialEnabled = false; effect.material.ambientColor = ...
1
vote
0answers
404 views

iOS OpenGLES - Multithread Game loop - Render and Update

I am trying to implementing multi-threaded game loop in iOS. (Actaully, two thread - Render and Update) This is my structure. Update Loop Has logic and at the end of loop, save update state. (...
1
vote
1answer
272 views

Android Object get Jagged at the border

I am new to OpenGL ES 1 in android. My 3D Model border getting Jagged. Please help me to look like a smooth border instead of jagged. Screenshot : http://i.stack.imgur.com/1Gq83.png private class ...
0
votes
2answers
401 views

Texture size and scaling, 2D, for OpenGl ES 1.0/1.1

I read everywhere that you have to use a power of two size for your texture width and height, like 16, 32 or 64, but right now my sprite drawing is based on Grid.java from SpriteMethodTest, and I set ...
0
votes
1answer
534 views

“Quad” background showing on OpenGl ES 1.0/1.1 Sprites

I modeled my sprite drawing on Grid.java and GLSprite.java from SpriteMethodTest, using 2D OpenGl ES 1.0/1.1 on Android, but the "quad" sprite background shows when two sprites overlap each other. I'...
2
votes
1answer
509 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
697 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 = ByteBuffer.allocateDirect(...
2
votes
1answer
422 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 ...
5
votes
1answer
232 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 = game.Content....
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
931 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
3k 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 ...
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
892 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
717 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
258 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
3k 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
149 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
133 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
349 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
396 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
4k 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: gl.glTranslatef(...
13
votes
4answers
19k 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 vertices[]...
1
vote
1answer
509 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. ...