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

learn more… | top users | synonyms

1
vote
1answer
66 views

How to Load Raw Bayer Images using OpenGL?

I know how to load a Raw RGB888 Buffer as a Texture using opengl. But i want to Load a Raw Bayer (Lets say BG) format Image & Interpolate it to RGB using openGL! . So far i have played around with ...
1
vote
1answer
26 views

How can I obtain information about the GPU in Cocos2d-x?

I'm trying to obtain information about the GPU that is running the game in order to use the correct texture compression for that GPU: std::string GPUInfo::getTC() { std::string TC; ...
1
vote
0answers
36 views

Libgdx implement 2d drop shadow for transparent sprites

I am a libgdx learner. For an learning application that I am developing using libgdx on android, I need to show drop shadow or glow effect when a sprite is touched. The sprites are created from a ...
-1
votes
0answers
34 views

A program in OpenGl [closed]

I wrote a program in C++ OpenGl which to insert a special character to the display window display for entering characters ... for example by enter 'A' character the open windows shows A . but i don't ...
1
vote
1answer
36 views

Give alpha to an object OpenGL ES

I am new on OpenGl and what I want to achieve is to give a texture the alpha from 1.0 to 0.0 I have been searching and only found "how to load alpha in images" but I cant find how to apply alpha to ...
1
vote
0answers
79 views

How to render multiple objects as a single object for fluid simulation?

I'm trying to do fluid simulation using particles in 2d game. I have larger particles, which interactive each other physically, those particles collide with environment (e.g wall,obstacles) to ...
0
votes
1answer
87 views

How to move 2D camera in OpenGL

I am new in OpenGL, I am making a game in 2D and I want the camera to follow the character. I started with gluLookAt() but I read that I could just move the matrix with glTranslatef() and It should ...
0
votes
0answers
39 views

OpenGL ES respecting alpha for background but not for objects

I have a problem with the alpha of my game, maybe it is solved in another post but as I am new in OpenGl and Game developemnt I dont understand most of the vocabulary and cant find a solution. The ...
0
votes
0answers
26 views

Additive blend over camera preview

I am using SurfaceTexture to draw camera preview through opengl after applying blending but new camera preview frames overwrite my previous frames although i am not clearing my color buffer. I want my ...
0
votes
0answers
29 views

Apply android.graphics.Matrix transformation to an Open GL ES shader

I am currently using a 4x4 matrix to convert from "pixel" coordinates to OpenGL ones, my scene is full screen so my screen matrix looks like this: 2f / width, 0f, 0f, 0f, 0f, -2f / height, 0f, 0f, ...
3
votes
1answer
73 views

Weird texture binding bug on Mali-400 MP

On Mali-400 MP, there's a weird bug with texture binding. Sometimes, shaders use textures from wrong samplers. On other mobile and desktop GPUs, the same code works fine, but on Mali, almost every ...
1
vote
1answer
147 views

OpenGL (ES 2.0) Function Dependencies

In OpenGL (ES 2.0), there are many functions that can be called in any order, and still others that must be called after other functions had been called and not before. For example, attaching a shader ...
1
vote
0answers
42 views

Weird blending behavior on PowerVR SGX544MP2

On PowerVR SGX544MP2, sometimes blending behaves in a very strange way for me. Instead of blending with the actual color from the previous draw calls, it tries to blend with black: (sorry about the ...
1
vote
0answers
33 views

Android OpenGLES, getting number of fragments passed depth test/Occlusion Query?

Afeter reading many blogs and searching on Internet, I did not get any sloution for getting number of fragments/pixels which are occludded or not occludded of the object on OpenGL ES3.0 Android ...
0
votes
0answers
98 views

Fixing/avoiding Z-fighting with decals OpenGL

I'm trying to draw animated flames as a decal in OpenGL (just a simple quad with an animated texture as a decal on another quad). Problem is as the camera moves away I get terrible Z-fighting in the ...
2
votes
1answer
111 views

Total Texture memory size iOS / OpenGL ES

My team is running into an issue where the amount of texture memory allocated via the glTexImage2D is high enough that it crashes the app ( at about 400 MB for iPhone 5). We're taking steps to ...
1
vote
0answers
64 views

LibGDX: Why look BitmapFont pixelated on a scene2d.ui.Dialog?

When I use BitmapFonts directly on the stage table, the fonts looks normal (not pixelated). But when I use the same BitmapFont with the same size on a scene2d.ui.Dialog, the font looks pixelated. ...
0
votes
0answers
36 views

OpenGL ES 1.0 Create a Trapezoidal perspective scaling on a texture while using Ortho

I am using an Ortho projection to do most of my stuff and i am happy with it since i basically do everything on the same plane, now however i need to create a simple "flip card" effect on an object ...
0
votes
1answer
95 views

how to retain the animated position in opengl es 2.0

I am doing frame based animation for 300 frames in opengl es 2.0 I want a rectangle to translate by +200 pixels in X axis and also scaled up by double (2 units) in the first 100 frames Then, the ...
0
votes
1answer
49 views

equivalent texture function to texture2D in OpenGL-ES?

I'm trying to figure it out how can implement the same result using texture2D. The result expected is a luminescence operation but I couldn't replicate the same functionality using texture2D for iOS. ...
0
votes
0answers
285 views

Android OpenGL ES 1.0 - Glow/Bloom effect

I'm currently building an Android space fighter game which uses OpenGL ES 1.0. For several technical reasons, I cannot at this point upgrade to 2.0. I really want to add a "glow" effect to glowing ...
0
votes
1answer
70 views

Generating multiple instances of one opengl object with random coordinates

Sorry if the question is dumb but my brain just cannot solve it for some reason.. So I've made one opengl object public static Square ball = new Square(75,75); And I am trying to make it so that ...
0
votes
1answer
388 views

How to change pixel color of Texture with Fragment Shader

I want to change the pixel color of a texture. I don't know where to start and what to add. Really need help, I only find useless snippets in the internet. My current Code: public void ...
2
votes
0answers
255 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 ...
0
votes
1answer
81 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 ...
0
votes
1answer
109 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 ...
0
votes
1answer
157 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 ...
1
vote
0answers
211 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
139 views

How do I implement multi-texturing using OpenGL ES 1.1 to combine separate RGB and alpha PKMs?

I have been trying to reduce the memory footprint of my textures in a Android game that I wrote without too much success. Based on research that I have done it seems that a good approach is to ...
1
vote
1answer
246 views

Texture compression strategy for Android OpenGL ES that caters for alphas

I have a 2d Android game that is currently causing certain devices to run out of memory. I have a number of PNGs (about 10 MBs in total) that I use in the game at various times. At some points in the ...
0
votes
1answer
93 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 ...
6
votes
1answer
293 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 ...
0
votes
1answer
553 views

Is ETC2 Texture Compression available in OpenGL ES 2.0?

However, I have an ES 2.0 app and would like to use ETC2 texture compression if it is available (i.e. I am running on a device that supports ES 3.0 standard). Is it possible to use ETC2 in ES ...
0
votes
0answers
120 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
181 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 = ...
6
votes
1answer
798 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. ...
2
votes
1answer
724 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
1answer
403 views

Decoupling rendering pipeline (for UI responsiveness): Multithreading and multiple contexts?

Warning! Wall of text (see <TL;DR> paragraphs below for short version) I have been noticing something in quite many games (most recently in cutting-edge RTS games such as Uber Entertainment's ...
1
vote
0answers
193 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. ...
0
votes
2answers
142 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
0answers
71 views

Trying to use Sprite Batching with GL_COLOR_ARRAY in OpenGl ES 1.0/1.1

I'm trying to create a sprite batcher that uses GL10.GL_COLOR_ARRAY using OpenGl ES 1.0/1.1 on Android. I found two different sources that seem like they would work, they both have statements that ...
0
votes
1answer
310 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. ...
3
votes
1answer
189 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 ...
0
votes
1answer
291 views

How do I “reset” the color in OpenGl ES 1.0/1.1?

In my 2D game I use glColor4f() to set the color and draw my screen border rectangles but when I try to start drawing my game objects, made up of a texture on a rectangular "quad", using ...
2
votes
1answer
314 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); ...
4
votes
3answers
834 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
380 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
1answer
205 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
82 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; ...
1
vote
1answer
312 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 ...