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

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2
votes
3answers
2k views

glGetFloatv – should it be avoided? Can it be replaced?

Platform is OpenGL ES 1.x. I am using glGetFloatv() to get MODELVIEW matrix. This allows me to compute points, where I need to draw a shadow effect. This is very handy, as I can forget about ...
1
vote
1answer
432 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, ...
1
vote
2answers
1k views

Android OpenGL textures sometimes corrupted

Just trying to get some sprites (textured squares) to draw from a texture atlas and 50% of the time after the application is first launched/ reorientated/ brought from sleep these various graphical ...
0
votes
1answer
138 views

android opengl-es spritesheet display number

Whats the best way to display numbers on android with opengl using a spritesheet? I like to display the number "294" using the spritesheet: http://i.stack.imgur.com/wv5Zh.png
4
votes
1answer
4k views

Sea water shader using only fragment processor

I have a game that runs on mobile devices (OpenGL ES 2.0) and for which I would like to create some sea water using the shaders. Now, the plane on which the sea water texture will be has only 4 ...
2
votes
1answer
115 views

Touch point on the near plane

I have a matrix created with either orthoM or frustumM GL function, where the near plane is logically the surface of the tablet. I would like to translate touch locations to their location on the near ...
1
vote
2answers
427 views

Lights system with shaders in OpenGL?

In more than just 1 occasion, i read about 2 ways of doing a light's system in OpenGL: normal way? i don't know how to call this one with the shaders ( GLSL ) The problem is i don't get the ...
6
votes
1answer
2k views

OpenGL ES 2.0 Best Practices / Architecture Guide

I've recently started working with OpenGL (ES 2.0) on the Android. While there is lots of documentation about the basics, I can't seem to find much about the overall architecture of OpenGL. In ...
1
vote
1answer
1k views

Shader authoring/editing tools for GLSL ES

Since Render Monkey has been discontinued (perhaps due to the complexity of today's shading languages), there are few successors that can match its functionality. Is there any useful tool for material ...
4
votes
3answers
6k 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 ...
3
votes
2answers
1k views

Cocos2d v2.0 and OpenGL 2.0/1.0: where to start

I started developing my very first game 3 months ago using Cocos2d 2.0 for iPhone. I am now in the stage where I'd like to add some cool effects to the bullets and some special weapons (see my ...
1
vote
2answers
3k views

Trying to Draw a 2D Triangle in OpenGL ES 2.0

I'm trying to convert a code from OpenGL to OpenGL ES 2.0 (for the BlackBerry PlayBook). So far what I got is this (just the part of the code that should draw the triangle): void setupScene() { ...
0
votes
1answer
157 views

Writing a basic shader for large input files

I started writing a shader for my iOS app and instead of starting from scratch i used this tutorial here: http://www.raywenderlich.com/3664/opengl-es-2-0-for-iphone-tutorial I wrote an import ...
1
vote
1answer
650 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
757 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 – ...
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
vote
0answers
270 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 = ...
5
votes
3answers
1k 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
0answers
223 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
492 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
5k 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 ...
0
votes
2answers
640 views

Help with Meshes, and Shading

In a game I'm making in LibGdx, I wish to incorporate a ripple effect. I'm confused as to how I get access to the individual pixels on the screen, or any way to influence them (apart from what I can ...
3
votes
2answers
7k 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 ...
0
votes
3answers
7k views

2D Rendering with OpenGL ES 2.0 on Android (matrices not working)

So I'm trying to render two moving quads, each at different locations. My shaders are as simple as possible (vertices are only transformed by the modelview-projection matrix, there's only one color). ...
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 ...
1
vote
1answer
184 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 ...
7
votes
4answers
6k 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 ...
2
votes
4answers
950 views

How to create OpenGL (ES 1.0) texture programmatically?

I need to draw inside a buffer and then upload it as texture to OpenGL. So basicaly unsigned char* buffer and then call to glTexImage2D(). I will be using Marmalade mobile SDK and OpenGL ES 1.0.
1
vote
1answer
359 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 ...
0
votes
1answer
365 views

Extra fire simulation on iPad device

I have with me an iOS app for iPad which creates a few fire simulations over a png.Well,its working well exactly how we wanted it but when we are testing it on a device,we get an extra fire ...
2
votes
2answers
5k 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) ...
2
votes
1answer
958 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
440 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 ...
6
votes
3answers
20k 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 ...
0
votes
2answers
2k 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 ...
1
vote
1answer
524 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 ...
0
votes
1answer
458 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
1k 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 ...
0
votes
1answer
1k 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
2answers
2k views

Can I use PBOs for textures in iOS?

As far as I can see, there is no GL_PIXEL_UNPACK_BUFFER. Also, the OpenGL ES 2.0 specification (and as far as I know, no iOS device currently supports OpenGL ES > 2.0) states that glMapBufferOES() can ...
3
votes
1answer
761 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 ...
1
vote
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
3answers
6k 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 ...
1
vote
1answer
1k 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?
1
vote
1answer
1k 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 ...
0
votes
4answers
2k 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 ...
10
votes
2answers
7k 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
2answers
195 views

How to export deform modifier animation into a game engine?

Hi we animated a simple plane with deform modifier to give a folding cloth like effect. How do we export it from maya so that we are able to import into our game engine. Can we export them as a ...
-1
votes
1answer
847 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
votes
1answer
4k 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) { ...