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

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8
votes
4answers
12k 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 ...
31
votes
4answers
18k 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
337 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
408 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 ...
5
votes
2answers
2k 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
436 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
156 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
202 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
278 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
239 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 ...
0
votes
2answers
5k 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
1k 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
835 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
690 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
1k 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
685 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 ...
0
votes
1answer
372 views

texture won't move OpenGL ES 2.0

I want be able to move my texture in GLSL I have set my texture to wrap S and wrap T but not sure why it wont move my fragment shader looks like this at the moment uniform sampler2D n_mapTex; ...
0
votes
1answer
179 views

texture movement stutters

Hey I at the moment I have got my texture to move however it stutters as I increment by 0.001 every second. My animation is done via FPS if that make sense and here is some code FrameCount++; ...
2
votes
1answer
4k views

How do I implement a score database in Android?

I making a 2D game for Android using OpenGL-ES technology. It is a space shooting game where the player shoots enemy ships. I want to keep a track of score for the amount of enemy ships destroyed ...
0
votes
3answers
452 views

Simple iOS glDrawElements - BAD_ACCESS

You can copy paste this into the default OpenGl template created in Xcode. Why am I not seeing anything :-) It is strange as the glDrawArrays(GL_TRIANGLES, 0, 3); is working fine, but with ...
7
votes
4answers
5k views

Updating OpenGL ES 1.1 based iPhone game to use Open GL ES 2.0

I'm fairly new to anything OpenGL in general. I've made an OpenGL ES 1.1 based 2D iPhone game by working from sample code. I'm under the impression that OpenGL ES 2.0 is substantially different from ...
1
vote
1answer
236 views

Switching from OpenGL ES 1.0 to 2.0

I have been developing an Android app using OpenGL 1.0 for quite some time using a naive approach to rendering, basically making a call to glColor4f(...) and glDrawArrays(...) with FloatBuffers each ...
4
votes
2answers
7k views

Drawing a circle in OpenGL ES Android, squiggly boundaries

I am new to OpenGL ES and facing a hard time drawing a circle on my GLSurfaceView. Here's what I have so far. The circle class public class MyGLBall { private int points=40; private float ...
-1
votes
1answer
668 views

Why doesn't onSurfaceCreated ever run in this code?

I create my game element this way in my activity: public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); mGame = new Game(this); mGame.bootstrap(); ...
2
votes
0answers
283 views

iPhone GLSL shader dynamic branching issue

I am trying to pass an array of vec3 as uniform and then iterate through them on each pixel. The size of array varies on situations so I can't make the loop with constant number of iterations. ...
1
vote
0answers
72 views

Android opengles how to use glunproject

How to use glunproject in my android app? I have the following parts in my engine: A projection matrix A view matrix for the camera A model matrix for each of the objects in my world. This matrix ...
0
votes
1answer
623 views

Get back or delete an existing OpenGL object, then change it and draw at new. How?

With OpenGL i'm drawing for example a circle. Can i take this drawn circle back out of the window and change something and then draw it back on the window? Or can i /have to delete it and then draw ...
3
votes
0answers
943 views

How to make the background of an OpenGL object transparent? [closed]

It sounds so simple but i didn't get it to work. The Background of my FrameLayout where i add the GLSurfaceView in is colored blue but there is only black. So here is my method to initiate the ...
2
votes
1answer
351 views

How to draw an OpenGL object in another on Android? -> Eyes and Eyeballs

As i allready wrote in another question: I'm working on OpenGL since a Week, so i'm new to the most stuff. (also my englisch isn't the best. Hop you can understand the most anyway) So i'm ...
4
votes
2answers
2k views

How to send multiple MVP matrices to a vertex shader in OpenGL ES 2.0

I'm working my way through optimizing the rendering of sprites in a 2D game using OpenGL ES and I've hit the limit of my knowledge when it comes to GLSL and vertex shaders. I have two large float ...
1
vote
1answer
565 views

Selecting and moving object in OpenGL Gameplay3D Engine

I'm using Gameplay3d as a game engine to develop a simple board game. PEG Solitaire I've come to the part where I've created a 2D grid for all the movable object, empty locations and also where it's ...
2
votes
2answers
2k views

GLSL Motion blur on mobile.. possible at acceptable framerates?

I have been struggling to implement a simple linear motion blur effect on mobile (Android, OpenGLES 2.0) but it just seems to destroy my framerate. I'm rendering to texture (FBO) then applying a ...
3
votes
2answers
3k views

Point Sprites vs Textured Quads in Open GLES 2.0

I'm wondering what would perform better, point sprites (GL_POINTS) or regular sprites (GL_TRIANGLES). Here's the scenario: I am developing a simple particle system to allow me to produce various ...
1
vote
0answers
169 views

Android multi screen rendering

Is it possible on Android to render specifically / only, to the connected Monitor/TV on the hdmi port? If so, is it possible to use OpenGL ES to render a different scene on the monitor and on the ...
7
votes
1answer
666 views

How wise is this multithreading architecture?

I'm rewriting a game engine I wrote in an attempt to parallelize as much as possible. I'm considering making properties which may be accessed from multiple threads all use accessors which use boost ...
13
votes
5answers
10k views

Complete Math Library for use in OpenGL ES 2.0 Game? [closed]

Are you aware of a complete (or almost complete) cross platform math library for use in OpenGL ES 2.0 games? The library should contain: Matrix2x2, Matrix 3x3, Matrix4x4 classes Quaternions ...
0
votes
1answer
1k views

Create cylinder using OpenGL-ES [closed]

I want to draw cone using OpenGL ES I have gone through many links to draw cylinder but I don't have any idea or approach to draw the cylinder. I've seen the gluCylinder function for OpenGL, but no ...
1
vote
1answer
424 views

Why do my pyramids fade black and then back to colour again [closed]

I have the following vertecies and norms GLfloat verts[36] = { -0.5, 0, 0.5, 0, 0, -0.5, 0.5, 0, 0.5, 0, 0, -0.5, 0.5, 0, 0.5, 0, 1, 0, -0.5, 0, 0.5, 0, 0, -0.5, 0, 1, 0, 0.5, 0, 0.5, -0.5, 0, ...
0
votes
0answers
94 views

Make a layer over an image and adjust its co-ordinates by touch

I need to make a layer over an image and adjust the layer to fit to image and get its co-ordinates of the layer. I need to adjust the layer by touch and pinch. The sample image is as below. I need ...
3
votes
3answers
8k views

OpenGL ES 2.0: Vertex and Fragment Shader for 2D with Transparency

Could I knindly ask for correct examples of OpenGL ES 2.0 Vertex and Fragment shader for displaying 2D textured sprites with transparency? I have fairly simple shaders that display textured polygon ...
1
vote
1answer
291 views

opengles display human face in iphone and animate it?

I need to make a human 2D face to 3D face. I used this link to load an ".obj" file and map the textures. This example is only for cube and pyramid. I loaded a human face ".obj" file. This loads the ...
1
vote
1answer
141 views

Does iOS support BC4 compressed texture?

I've been designing a new OpenGL image algorithm using BC4 textures at its core. It works well accross Windows and Mac, my main targets up to now. But today, the customer added a new requirement : it ...
1
vote
1answer
494 views

OpenGL ES screen to world coordinate

I am currently attempting to convert my screen coordinates to world coordinates, to be able to interact with objects. I am using glm and unProject to try and achieve this, so far this is my code: ...
-1
votes
1answer
672 views

2d triangle with OpenGL-Es on Android

hey I am trying to draw a triangle on opengl es . I just followed a tutorial to do it. eventhough everything seems to be fine it does not work. everytime I run my code it sends me back to main menu. ...