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

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1answer
51 views

Is Angry Birds Made Purely Using Bitmaps/Raster graphics? [on hold]

Being a beginner game developer I would like to start creating my own engine and graphics so I am concerned about how successful games accomplish the graphics portion. My question is, are all the ...
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 ...
9
votes
3answers
3k 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 ...
1
vote
1answer
151 views

How to clip or mask entity in adnroid/andengine?

I want to implement masking with sprite in Andengine. I want same functionality as in ios class called SKCropNode which works like an masking node! Is there any workaround like this in ...
0
votes
1answer
92 views

OpenGL: How to map point inside frustrum to normal device coordinates (NDC)?

I read this article http://www.songho.ca/opengl/gl_projectionmatrix.html. It's explain how calculate projection matrix coefficients. But I completely can't understand how author perform mapping from ...
3
votes
1answer
47 views

How to hide a post-processed mesh outline when/where the mesh is hidden

I'm working on setting up an active outline in my 3d engine, a highlight effect for selected 3d characters or scenery in the screen. After working with the stencil buffer and getting some ...
0
votes
1answer
29 views

cannot implement GLSurfaceView.RENDERMODE_WHEN_DIRTY

I'm trying simply to display an openGL surface when I click the screen using GLSurfaceView.RENDERMODE_WHEN_DIRTY mode but the surface does not display when I click it , why ? my Activity : public ...
6
votes
1answer
6k views

OpenGL ES 2.0: Understanding Perspective Projection Matrix

Setting the Perspective projection matrix in Open GL (including OpenGL ES 2.0) has the following general format: glm::mat4 perspective(float fovy, float aspect, float zNear, float zFar); Notice the ...
3
votes
1answer
31 views

Libgdx - GLSL shader which uses mod doesn't seem to work properly on android

Through trial and error I've managed to come up with a scanline-ish shader I'm satisfied with. On my desktop testbed it looks like this: Basically, every 2nd(vertical) pixel is darkened. However, ...
4
votes
0answers
64 views

OpenGL: Frame partially jumps back and forth

I'm working on a project with SDL and OpenGL. The game works great on Windows, Linux, OS X and iOS. However, the Android version is showing a problem on my phone in particular. I have tested another ...
2
votes
0answers
45 views

Texture coordinates for custom geometry in SceneKit ios9

I am trying to texture the a custom plane shape I created in scenekit on iOS9. I need the texture to spread out and stretch over the entire surface. I have a vertex and fragment shader on an ...
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0answers
37 views

Stencil buffer confuse

I was trying to make two object outline. One would color the object with orange and other with green. I just wanna know if is it possible to have two object outline at the same time because every time ...
1
vote
1answer
37 views

Get Stencil buffer working iOS OpenGL ES 2.0

I have been trying to get this work but either get black screen or reporting error when using XCode to analyze the GL code like below. Any help appreciated. I am using Swift here if that making a ...
3
votes
0answers
47 views

Render triangles without index buffer in Opengl ES

I'm reversing a 3d model format from a famous game (not sure if i should mention it), which is released both for windows (app store) and for Iphone and android. The weird thing is that while the ...
14
votes
1answer
35k views

GLSL: How do I cast a float to an int?

In a GLSL fragment shader I am trying to cast a float into an int. The compiler raises an error: ERROR: 0:60: '=' : cannot convert from 'mediump float' to 'highp int' I tried raising the precision ...
4
votes
1answer
150 views

Is this the typical approach to modern OpenGL UI & Text rendering, for mobile?

I'm implementing GUI in OpenGL ES 2.0 to fit with my application framework's existing structure. I'd like to have the UI rendering eat as little mobile processing capacity as possible. So to ...
2
votes
2answers
60 views

IOS/Android Game programming [closed]

I am somewhat new to the whole game programming thing. I was wondering if I could develop a game for IOS and Android with using openGLES. if so how can I run the code on the devices and what are some ...
1
vote
0answers
26 views

How to use quaternion on another referential

I'm new on Three.js and despite a mechanical background, I can't find how quaternion works: it's like it always refers on local part referential and not the global one. I've illustrated it here : ...
1
vote
0answers
80 views

How do I draw multiple irregular polygons with OpenGL ES?

In this post I was asking how to program a map of a Risk-like game. Now that the map is pretty coded, both client and server-side, I'd like to finally draw the map. I'll try to keep least broad as ...
1
vote
2answers
116 views

How to compile with OpenGL ES on Windows?

I downloaded OpenGL ES 3.1 sdk here. But when I tried to run (or compile and run) the executable in "samples" directory, I got the following message: The program can't start because libGLESv2.dll ...
5
votes
4answers
10k views

GLM: Euler Angles to Quaternion

I hope you know GL Mathematics (GLM) because I've got a problem, I can not break: I have a set of Eular Angles and I need to perform smooth interpolation between them. The best way is converting them ...
1
vote
0answers
54 views

Using depth values for fake ambient occlusion

I'm using the normalized distance to the camera to get depth information in the fragment shader. When using this value as fragment color, it looks at lot like ambient occlusion (of course only in the ...
0
votes
1answer
3k views

Rendering Texture Quad to Screen or FBO (OpenGL ES)

I need to render the texture on the iOS device's screen or a render-to-texture frame buffer object. But it does not show any texture. It's all black. (I am loading texture with image myself for ...
3
votes
2answers
193 views

How to set borders in Rubik's cube using opengl GLSurfaceView

I'm developing a Rubik's cube game like seen in the picture. But I'm facing problems to set the cube face color with black border. public void setupSides() { int i, j, k; // Paint back blue i = 0; ...
0
votes
0answers
191 views

Transparency in GLSurfaceView

I'm new in game development. I have a view using GLSurfaceview and call in MainActivity. i want to make transparent that view. i have tried setZOrderOnTop() method in MainActivity and glClearColor() ...
2
votes
1answer
52 views

OpenGL ES God Ray Precision error

I have encountered the following (i think) precision error. (missing link need 10 rep) My source of inspiration was: (missing link need 10 rep) On the PC everything works fine, but on android it ...
0
votes
0answers
41 views

Capture what is Rendered in OpenGL

Im Making an android Game with OpenGl ES, I Want to capture what is rendered onto screen By FloatBuffer and save it for later use, For Example If this is the OutPut: I want this for Result: How ...
0
votes
1answer
1k views

Is ETC2 Texture Compression available in OpenGL ES 2.0?

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 1.1/2.0, and if ...
0
votes
0answers
68 views

How can I get float values using glReadPixels? [Android NDK es3.0]

c++ code: float* data = (float*)malloc(texWidth*texHeight*sizeof(float)); // or GLfloat float* result = (float*)malloc(texWidth*texHeight*sizeof(float)); // or GLfloat for (int i = 0; i < texWidth ...
2
votes
1answer
75 views

Working around the current sad state of mobile GPU drivers

I'm working on a OpenGL ES3 app for Android: for various reasons, I decided to roll my own mini-OpenGL rendering engine. So far so good. Problem is, the GPU drivers in the mobile industry are such ...
0
votes
2answers
199 views

Is it possible to convert vec4 to int in GLSL (using OpenGL ES)

I need GPU to do some computations, and I pass shader an int array using glTexImage2D (internal format is GL_RGBA). I use texture() to get the data, but it returns a vec4 value. Is it possible to ...
0
votes
1answer
111 views

Basic vertex shader, moving

I am new in shader concepts and I am trying to implement a sprite of 8x8 in OpenGL ES. I want to move the texture in the vertex shader but I cant figure out how to this, my code may be wrong, feel ...
0
votes
0answers
68 views

Camera rotation destroy scene objects orientation

I fight with that for some time and searching internet but I don't have any answer for my problem. In few words i want to have orbiting camera on screen and objects which I want also rotate ...
0
votes
1answer
210 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 ...
2
votes
1answer
163 views

Is it possible to completely avoid copying image data when uploading textures to the GPU on iOS?

I am not a game developer, but I have been doing iOS software engineering for many years. I have a particular interest in graphics and animation, but the finer details are still a little foreign to ...
1
vote
1answer
407 views

Bad performance using VBO with OpenGL ES in Android

I'm making an Android app and I need to draw some polygons using OpenGL ES. I'm able to render them but I'm disappointed with performance. I updated the code to use VBO but I didn't notice any ...
0
votes
1answer
170 views

OpenGL ES 2.0 2D-Image displaying

I have followed the official OpenGL ES tutorial to create a working OpenGL-environment. I have been able to do anything I wanted to except for displaying 2D-images. To do so I worked through this ...
3
votes
1answer
833 views

How do I draw a circular portion of a texture within LibGDX using an OpenGL ES shader?

What is the simplest way to implement a shader to draw a circular portion of a full screen texture where the circle is dynamically resized as part of an animation using LibGDX? Is a shader even the ...
1
vote
1answer
97 views

Does glScissor affect stencil and depth buffer operations?

I know glScissor() affects glColorMask() and glDepthMask(), but does it affect the stencil and depth buffers? For example: glEnable(GL_DEPTH_TEST); glEnable(GL_SCISSOR_TEST); ...
1
vote
2answers
779 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 ...
0
votes
1answer
258 views

OpenGL ES 1.0 to OpenGL ES 2.0, I cant draw a square

I am learning open GL ES 2.0 and I just made 1 easy game for 1.0 I am following tutorials but I cant understand this thing In OpenGL ES 1.0 if I define a square that way: private float[] vertices = ...
3
votes
0answers
95 views

Does anyone know what technique was used in Minecraft to create shadows? [closed]

Specifically I want to know the technique used to render shadows under animals and players. I would like to create shadows like that for my own block game but I don't even know what to google. Any ...
6
votes
1answer
2k views

Sprite sheet textures picking up edges of adjacent texture

I have a custom sprite routine (openGL 2.0) which uses a simple sprite sheet (my textures are arranged horizontally next to each other). So, for example, here is a test sprite sheet with 2 simple ...
0
votes
3answers
687 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 ...
0
votes
1answer
247 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
159 views

How to make a stereoscopic 3D Game with SDL for iOS

I was looking up google for an answer the whole night but didn't find anything. Yesterday I found some VR demos and games on the AppStore, with stereoscopig (dual rendered) screens. So you put your ...
0
votes
1answer
97 views

OpenGL light calculation

I want to add somebasic point lights to my OpenGL application. I read here that I have to caluclate the light in a pre-projection space: Lighting can be done in any pre-projection space (e.g., ...
6
votes
1answer
3k views

How do I get smooth edges with OpenGL on Android?

Here is a screenshot that maybe makes clear what my problem is. I'm only drawing 2D circles with OpenGL. I already read the following: ...
1
vote
2answers
367 views

Problems with rendering a SkyBox

At the moment I'm writing an Android OpenGL ES 2.0 game but now I get stuck on rendering a SkyBox. Here is my (a bit simplified) code for the SkyBox: float vertices [] = ...
8
votes
2answers
5k views

In OpenGL, how can I discover the depth range of a depth buffer?

I am doing a GL multi-pass rendering app for iOS. The first pass renders to a depth buffer texture. The second pass uses the values in the depth buffer to control the application of a fragment shader. ...