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

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4
votes
3answers
4k views

OpenGL ES and Screen Coordinates

Is there anyway I can make OpenGL ES 2.0 to accept coordinates (for Vextex for example) in int meaning the pixels instead of the default float system? Also how can I set the point (0,0) to be at the ...
1
vote
1answer
551 views

How to obtain contrail visual effect?

I have objects moving in OpenGL ES1 application. I want some of them to leave behind contrail – like if they would emit some radiation or something. EDIT: the kind of contrail is: light contrail – ...
4
votes
1answer
575 views

Creating a highlight halo around a selected object

I'm looking to create a halo highlight around the selected objects in my game screen. The main platform is android, but I am writing an iOS version as well, updating it whenever I successfully add the ...
1
vote
1answer
459 views

Why is my mesh generation algorithm not working properly?

I am trying to generate a grid in OpenGL ES, using known methods for triangle strips and stitching as shown in: this post and this post The code below, generates the vertices for a 4x4 grid with a ...
1
vote
1answer
2k views

2D Quads : Translation with OpenGL ES 2.0 on Android [closed]

I have a simple 2D engine that renders 2D textured quads, and right now I can scale the quad or rotate it, but when I try to translate it I have a strange distortion (the quad is squashed in the half ...
-1
votes
1answer
3k views

How to display bitmap using Texture api in android opengl

I want to display a bitmap image at screen using texture api in android opengl. Some code which I have used in our code as below. public void onSurfaceChanged(GL10 gl, int width, int height) { ...
1
vote
0answers
234 views

Getting contour without the background [closed]

I have a texture and vertex which are needed to create a set of closed polygons. For this purpose I use these functions: Code for create texture: CCSprite* spr = ...
1
vote
0answers
194 views

Remove “dots” noise (like from dot-matrix printer)

I have 2D array of floats. Using the floats, I generate image by doing proportional selection of color from between COLOR_MIN, COLOR_MAX – for maximal float value at given (x,y), I choose COLOR_MAX ...
4
votes
2answers
414 views

Geometry vs sprites

I'm developing an android game, where the enemies are geometrical shapes. Performance is a main goal for me so I was wondering if defining shapes directly in OpenGL would be more efficient than using ...
2
votes
3answers
3k views

How do I render .dae models?

I'm building a game for iOS. I'm quite new to OpenGL but what I want is to take a 3D model I have made in Google SketchUp and use it in my 3d game. The problem is I don't know how to proceed. I have ...
3
votes
2answers
5k views

Creating an OpenGL FPS camera: I have the position and orientation vectors, now what?

I have been struggling to create a first person camera in OpenGL ES 2.0 without using gluLookAt(). I grab the camera's orientation vectors (the way it's looking) from the current modelview matrix, and ...
7
votes
2answers
3k views

OpenGL ES 2.0: Mixing 2D with 3D

Is it possible to mix 2D and 3D graphics in a single OpenGL ES 2.0 game, please? I have plenty of 2D graphics in my game. The 2D graphics is represented by two triangular polygons (making up a ...
2
votes
2answers
3k views

How to use OpenGL's glUseProgram?

While in the rendering loop, is it OK to call glUseProgram? Does it have a big overhead? I'm planing to use a program for each different material in the scene. I'm a real beginner with OpenGL and I'm ...
5
votes
4answers
4k views

Geometry instancing in OpenGL ES 2.0

I am planning to do geometry instancing in OpenGL ES 2.0 Basically I plan to render the same geometry(a chair) maybe 1000 times in my scene. What is the best way to do this in OpenGL ES 2.0? I am ...
0
votes
0answers
326 views

Camera rotation flicker in OpenGL ES 2.0

I implemented an orbit camera in my own OpenGL ES 2.0 application. I was getting extensive amount of flicker while rotating the camera using the mouse. When I added the line eglSwapInterval( ..., ...
1
vote
1answer
137 views

Drawing texture does not work anymore with a small amount of triangles

When i draw lines, the vertices are well connected. But when i draw the texture inside the triangles, it only works with i<4 in the for loop, otherwise with i<5 for example, there is a ...
1
vote
1answer
303 views

Adjust sprite bounds of the visible part of texture

Is there any way to adjust the boundaries of the visible part of the sprite? To make it easier to understand: I have a texture, such as shown at figure 1. Then I break it into pieces and fill the ...
9
votes
3answers
3k views

How can I bend an object in OpenGL?

Is there a way one could bend an object, like a cylinder or a plane using OpenGL? I'm an OpenGL beginner (I'm using OpenGL ES 2.0, if that matters, although I suspect, math matters most in this case, ...
0
votes
1answer
2k views

Texture displays on Android emulator but not on device

I have written a simple UI which takes an image (256x256) and maps it to a rectangle. This works perfectly on the emulator however on the phone the texture does not show, I see only a white ...
1
vote
2answers
3k views

How to determine counter-clockwise vertex winding

I've been causing myself some confusion lately with regards to vertex winding in a mesh class that i'm writing. Currently, the mesh contains the appropriate structures for: vertices (vector3) ...
1
vote
1answer
612 views

OpenGL ES 2 - glSwapBuffers?

this is what i do to blit FBO onto screen in ViewController: [m_Context presentRenderbuffer:GL_RENDERBUFFER]; but i need something like glSwapBuffers, so that i can call it somewhere from the ...
0
votes
1answer
347 views

Straightforward guidelines for converting OpenGL to OpenGL ES?

Is there a straightforward list of finite steps that I need to follow to convert an OpenGL program into an OpenGL ES that's used on the iPhone and iPad? I'd be using GLKit. I've seen some similar API ...
5
votes
3answers
12k views

glTranslate, how exactly does it work?

I have some trouble understanding how does glTranslate work. At first I thought it would just simply add values to axis to do the transformation. However then I have created two objects that would ...
1
vote
1answer
800 views

Where to start creating a 2d rain simulation with OpenGL ES 1.1?

I'm using opengl 1.1 and i'm creating a 2d side scrolling game.How can i render a 2d rain simulation?What is logic for that?
0
votes
2answers
1k views

Problem with drawing textures in OpenGL ES

I'm developing a 2D game for Android and i'm using the framework which has been told in the book which named Beginning Android Games by Mario Zechner.So my framework is well designed and using OpenGL ...
0
votes
1answer
362 views

Triangles in a C++ STL Vector as an Objective-C member sometimes draws incorrectly in OpenGL ES

The polygons draw correctly 80% of the time. When it fails, a vertex is dislocated. The polygon is consistently drawn with the wrong vertex. I checked that the vector is correct during initialization, ...
1
vote
1answer
345 views

From simple physics with a ball, to a more complicated shape

Hello fellow game devs and stack overflowers... I recently made a transition from OpenGL ES 1.1 to 2.0 (on Android via NDK) and things are going well so far. I'm working on doing a dice rolling ...
1
vote
1answer
982 views

Handling different screen densities in Android Devices?

Well, i know there are plenty of different-sized screens in devices that run Android. The SDK I code with deploys to all major desktop platforms and android. I am aware i must have special cares to ...
1
vote
3answers
5k views

Open GL ES 2.0 with Android

I was wondering if someone could recommended a book that covers both android game developement and OpenGL ES 2.0. I have found some books with OpenGL 1.0, but I have heard that the syntax for OpenGL ...
0
votes
1answer
712 views

Determining and culling non-visible vertices

Ahoy! After posting my previous question on tile maps, i've been tinkering with an implementation i'm rather pleased with so far but would like to gather some more information about submitting ...
3
votes
1answer
559 views

Can glTexImage2D() use an already existing memory block?

Can I use glTexImage2D() and / or glTexSubImage2D() (or maybe there's some other method I don't know about) with an already existing block of memory, instead of always uploading the changed pixels? I ...
0
votes
4answers
1k views

Should I use a VBO if the vertex data changes from time to time?

If I have a very large number of vertices, but they're static for about 70% - 80% of their life time, should I use a VBO for them? If so, what usage should I specify? This doesn't sound like a case ...
8
votes
2answers
4k views

Tile map/terrain implementation with differing heights of neighbouring tiles

Ahoy! I'm looking for some information about tile maps, or rather, what a specific type of tile map is called. I'm interested in the kind of implementation used in rollercoaster tycoon, or the ...
1
vote
1answer
811 views

How can I add a parallax effect into my side-scrolling game? [duplicate]

How can I add a parallax effect into my side-scrolling game? I read a lot about parallax scrolling so I know what the logic is and what parallax is but I can't create a dynamic parallax effect. I ...
-1
votes
1answer
699 views

Scrolling and Parallax scrolling in 2D game

I'm developing a 2D side-scrolling game.I have a scrollable bitmap for background with size 2400x480.How can i scroll this bitmap?I have searched for algorithms but i can't find any solution. I know ...
1
vote
1answer
741 views

Keeping track of onscreen objects in opengl es on Android

In a small game Im working on I was able to implement ray picking with an opensource 3d engine called min3d but I cant figure how to keep track of what object is onscreen. I will some times have ...
3
votes
1answer
1k views

Android how to get opengl 3D coordinates in ontouch event

I created a cube in opengl and it rotates in ontouch event. To to this I created a CustomSurfaceView as follows public class CustomSurfaceView extends GLSurfaceView { @Override public boolean ...
2
votes
1answer
1k views

Open GL Android frame-by-frame animation tutorial/example code

My first question was asked wrong, so I need to ask again :) I found out, that I will have to do an OpenGL animation for my Android game. The closest (known) example is Talking Tom (but I don't know ...
0
votes
3answers
888 views

does opengl automatically handle offscreen rendering?

I'm wondering if opengl can automatically manage offscreen rendering. I mean if it can detect and ignore sprites and textures if they are rendered out of screen. if it makes any difference i'm ...
5
votes
1answer
281 views

Where to store shaders

I have an OpenGL renderer which has a Scene member variable. The Scene object can contain N SceneObjects. I use these SceneObjects for storing the vertex position and any transforms. My question is, ...
3
votes
1answer
6k views

Is it possible to overlay EditText box on a GLSurfaceView on Android?

I am trying to add a "PlayerName" box on top of a opengl menu background, is this possible? I've tried various layouts, but they don't seem to allow an EditText box to appear on top What is the ...
1
vote
0answers
137 views

Strange and erratic transformations when using OpenGL VBOs to render scene

I have an existing iOS game with fairly simple scenes (all textured quads) and I'm using Apple's "Texture2D" class. I'm trying to convert this class to use VBOs since the vertices of my objects ...
1
vote
0answers
179 views

Creation of .des files from .png files?

A DES file is text file. In this file you can find information about the atlas(sprrite sheet) file including: where to find atlas (sprite sheet) image AND describe the position of original image on ...
0
votes
1answer
2k views

OpenGL es glDrawTexfOES() 2D texture is totaly black no color

First of all I know this is a duplicated question and I check out another questions but didn't helped! I'm trying to convert my android game from canvas system to the GL10. After lots of googling I ...
2
votes
1answer
763 views

OpenGL ES drop shadows for 2D sprites

I've got a an OpenGL scene rendered with a bunch of sprites, and I'd like to automagically add drop shadows to all of them. Here's a picture showing what I mean: The scene uses orthographic ...
2
votes
1answer
2k views

How to get the texture coordinate of a neighbouring pixel for a blur shader?

I'm still having some trouble to get my head around fragment shaders and doing some image processing on textures. The context is a 2D sprite: a simple texture painted on a quad. All done with OpenGL ...
3
votes
0answers
1k views

OpenGL ES 2.0 Camera advices and general thoughts for a 2D engine [closed]

I'm working on my first 2D OpenGL engine for iOs 5+ using GLKit (that's to say: OpenGL ES 2.0). While I am on a good path and a lot of things are implemented and nicely working, I'd like to share with ...
2
votes
1answer
2k views

Are OpenGL Textures more memory efficient than Android Bitmaps?

I have a custom application that deals with many Bitmaps tiles that are 256x256 images (png,jpg). I'm currently using the View 2d canvas and bring in all images as RGB_565. Although I'm generally ...
8
votes
4answers
2k views

Order independent transparency in particle system

I'm writing a particle system and would like to find a trick to achieve proper alpha blending without sorting particles because: Each particle is a point sprite in a single mesh and I can't use ...
0
votes
2answers
211 views

Transition between two Views

i want to animation the transition between game screens , in my game loop i have a function called getCurrentScreen() which returns a Screen object this Screen Class has a function called present() ...