Tagged Questions

OpenGL ES 2.0 emphasizes a programmable 3D graphics pipeline (comparing to fixed-function pipeline of OpenGL ES 1.1).

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1
vote
0answers
172 views

Cylinder scrolling / wrap-around world using shaders?

I am making a 2D game using OpenGL ES 2.0 (libgdx), where the world will wrap-around itself on Y-axis. Apart from implementing the "modulo" method in my rendering code, I'm wondering whether it's ...
0
votes
1answer
151 views

Timing Calculations for Opengl ES 2.0 draw calls

I am drawing a cube in OpenGL ES 2.0 in Linux. I am calculating the time taken for each frame using below function #define NANO 1000000000 #define NANO_TO_MICRO(x) ((x)/1000) uint64_t getTick() { ...
0
votes
1answer
84 views

Particle system lifetimes in OpenGL ES 2

I don't know how to work with my particle's lifetimes. My design is simple: each particle has a position, a speed and a lifetime. At each frame, each particle should update its position like this: ...
1
vote
1answer
1k views

android: How to apply pinch zoom and pan to 2D GLSurfaceView

I want to apply pinch zoom and panning effect on GLSurfaceView. It is Image editor, so It would not be 3D object. I tried to implement using these following links: ...
0
votes
1answer
55 views

Working with floats in OpenGL ES 2

Are there any reasons or situations one would use in their shader float(1) over just 1.0 ?
1
vote
2answers
306 views

Error while reading TGA file and doing Texture Cube map

In my program, i read a TGA file with a function like this: char* LoadTGA(char* filename, int* width, int* height, int* bpp); As you can see, this function: return a char array of image data ...
2
votes
1answer
196 views

What is faster - loop in shader vs draw-call

I am doing some program, that can be written in two ways. render full screen quad and send some additional info to fragment shader. But in fragment shader I need to perform for-loop Move the loop to ...
5
votes
1answer
568 views

OpenGL ES 2.0 obscured texture is visible

Hi, I am using LibGDX and OpenGL 2.0 to create a game. So far I have created two meshes. The front mesh is the one with the brown circle texture and another mesh on the top with a green to white ...
0
votes
1answer
607 views

Drawing Text on a scene

I am not sure if I am missing something but I was thinking about how text entities are drawn on a scene, are they drawn with an offset depending on the length of the text? I notice that when I add a ...
6
votes
2answers
314 views

Implementing realistic sun reflection on a sea

I'm drawing a 3d rendered island which has a day / night cycle and a sun that rises and sets over water. The sea is rendered with a fragment shader derived from this Blinn-Phong tutorial. ...
4
votes
1answer
173 views

GetData() error creating framebuffer [closed]

I'm currently porting a game written in C# with XNA library to Android with Monogame. I have a Texture2D and i'm trying to get an array of uint in this way: Texture2d textureDeform = ...
0
votes
1answer
182 views

Version number not supported by gl2 in andengine

I am new to andengine. From various forums, i got to know that my system should support hardware virtulisation. I have installed "Intel X86" and my system didn't throw any problem regarding "HAX" now. ...
0
votes
1answer
246 views

OpenGLES 2.0 batching method and do not draw inactive object

I am researching about "batching" objects for one big VBO and reduce draw call. These are what I am doing now: Create interleaved VBO based on texture or render state (like Blending) So, for ...
1
vote
0answers
223 views

How do you tell OpenGL ES 2.0 to use a texture as the depth buffer?

I want to render a scene with an outline post processing effect in OpenGL ES 2.0. First I render all the opaque objects. Then I use a post processing shader for silhouette detection that uses the ...
0
votes
2answers
265 views

Which code is faster to convert -1 to 0 and 1 to 1?

I'm writing a shader for rendering the sides of triangles with different colors. I have a value mediump float back = dot(V, N) which is positive if the normal faces away from the camera and negative ...
3
votes
1answer
775 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 ...
1
vote
1answer
101 views

Orthogonal projection matrix affecting z-buffer on one device

I am experimenting using Matrix.orthoM for a isometric projection, rather than Matrix.frustumM. On one device, the z buffering does not appear to be working correctly and I get a cut away effect seen ...
1
vote
2answers
565 views

OpenGL ES - DrawCalls count - bottleneck?

I am newbie to OpenGL ES (so far, I used mainly DX11). Now for my scene, I have about 100 draw calls. I can use instancing, but only about half of objects can be instanced, so draw calls count would ...
-2
votes
1answer
134 views

Can't get indices with VBO working [closed]

I'm learning opengl for a few days only. Now I'm trying to use indices for my cube, but can't get it working, I don't see anything on screen. struct Vertex { GLfloat position[3]; GLfloat ...
1
vote
1answer
244 views

When to call GLBindTexture when using a spite-sheet?

Originally, I was using individual textures (ie, individual .png files) for my sprite's animation and recently altered my code so that I could put all my animation frames into 1 file (so it basically ...
6
votes
1answer
483 views

Sprite with alpha Blending in 3D world

I'm working on a game in a 3D world with elements 2D only (Like Don't starve game) for Android and IOS. Currently, I've managed "Sprite" without alpha blending, I've just put a condition in the pixel ...
1
vote
2answers
549 views

How to flip a quad (openGL es 2.0 Android / Java)

bHow would one go about 'flipping' a quad i.e., either horizontally or vertically? (Just a single quad, not everything in view). I know how to rotate a quad, this is my rotation method: public void ...
0
votes
1answer
346 views

ParallaxBackground AndEngine

I'm new to game development andengine. I want to add ParallaxBackground but I don't know how to change background on player move. I'm using arrow for moving a player. Now my question is where I write ...
7
votes
2answers
6k views

GLSL Shader - Change Hue/Saturation/Brightness

I'm trying to change the hue of an image using a GLSL fragment shader. I want to achieve something similar to Photoshop's Hue/Saturation Adjustment layer. In the following image you can see what I've ...
1
vote
1answer
524 views

GLES2-AnchorCenter branch has no org.andengine.util.color.Color

I am porting my game from GLES2 to GLES2-AnchorCenter branch. I am using import org.andengine.util.HorizontalAlign; import org.andengine.util.color.Color; import ...
6
votes
1answer
186 views

How to prevent clipping when moving through a tunnel?

I'm developing for Android using OpenGL ES 2.0. It's going to be a game where you have to fly through a tunnel without hitting the walls. However, the tunnel wall gets clipped as the player ...
2
votes
1answer
169 views

re-using objects

I'm working with openGL ES 2.0 on Android and I've created a custom 'Quad' class. This allows me to make a sprite object like so: Quad mySprite = new Quad(); mySprite.setSize(w,h); ...
1
vote
1answer
227 views

How to deal with lot of textures in one draw call?

I'am currently developing text rendering & some kind of tile based texturing for simple landscape with textures blending. e.g. something like this but in 3D. In first realization I have been used ...
2
votes
1answer
278 views

Keeping everything within one Activity

Overview My game is currently based on a single activity (rather than multiple activities) and I would like to keep it that way. At the moment, it goes straight into the game at level 1. I will ...
1
vote
0answers
440 views

How to implement OpenGL triple buffering

I'm trying to implement the triple buffering described here ...
0
votes
1answer
110 views

OpenGL ES - write code in Windows

Is it possible to write application using OpenGL ES 2.0 "emulator" from AMD (AMD OpenGL ES SDK) and then use the same code (compile again, of course) in my iOS / Android / Whatever application ? The ...
0
votes
2answers
580 views

Scale Matrix Transform without moving primitive

So I have the following.... GLbyte vShaderStr[] = "attribute vec4 vPosition; \n" "uniform mat4 move; \n" "uniform mat4 scale; \n" "void main() \n" "{ ...
1
vote
2answers
1k views

Simple Android loading screen when using OpenGL

My game uses openGL ES 2.0 on Android and it's got to the point where the pause (while loading resources) has become noticeable. All I'm after is to show a static screen (probably via an XML layout ...
1
vote
2answers
141 views

NPOT texture and video memory usage

I read in this QA that NPOT will take memory as much as next POT sized texture. It means it doesn't give any benefit than POT texture with proper management. (maybe even worse because NPOT should be ...
2
votes
1answer
356 views

Full-screen post-processing and texture size

I am newbie writing a post-processing code for mobile devices, and asking some trivial, conventional solution for a specific problem. AFAIK, post-processing in OpenGL is trivially done with FBO bound ...
0
votes
3answers
199 views

Rotating each quad in a batch separately?

Background In my app I use the following code to rotate my quad: Code //Rotate the quad Matrix.setIdentityM(mRotationMatrix, 0); Matrix.translateM(mRotationMatrix, 0, centreX, centreY, 0f); ...
1
vote
2answers
839 views

“Non-additive” alpha blending in OpenGL ES 2.0, Android (AndEngine)

I have several monochromatic sprites and I render them with alpha = 0.25 (all of them the same value). I want to "paint" with them, so when they overlap, the alpha won't be added. I am not sure if I ...
1
vote
2answers
915 views

Libgdx: Am I abusing Vector2? Is there a better way to do my position updates and rendering?

I'm simulating hair in a game. Currently I have a HairField object, which has a position defined by a Vector2. Each HairField has multiple Hair objects in a list, each with a position defined by a ...
0
votes
1answer
79 views

OpenGL ES 2.0: Texture does not appear to be correct [closed]

Here are my shaders... GLbyte vShaderStr[] = "attribute vec4 vPosition; \n" "attribute vec2 texPosition; \n" "attribute vec4 inColor; \n" "varying vec4 fragColor; \n" "varying vec2 ...
2
votes
1answer
387 views

Combining 2D and 3D in game engine

I've implemented basic 3D functionality and made little "2.5D" demo in orthographic projection using OpenGL ES 2 and Box2D. Now I want to make completely two-dimensional game (using sprites) and ...
0
votes
1answer
100 views

OpenGL ES2: Changing Z doesn't appear to change the location of triangle

So I am very new to OpenGL out I am playing around and trying to create a rectangle. GLfloat vVertices[] = { -0.5f, -0.5f, 0.0f, -0.5f, 0.5f, 0.0f, 0.5f, -0.5f, 0.0f,0.5f,0.5f,0.0f}; ...
8
votes
1answer
634 views

GL ES: Fragment shader optimization

Summary: I get FPS slowdown as soon as I try to tint the sprites (i.e: multiply texture with color in the fragment shader) Details: Hardware: iPod touch 4 I am drawing 700 sprites on the screen ...
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: ...
7
votes
1answer
1k views

Optimizing performance of a heavy fragment shader

I need help optimizing the following set of shaders: Vertex: precision mediump float; uniform vec2 rubyTextureSize; attribute vec4 vPosition; attribute vec2 a_TexCoordinate; varying vec2 tc; ...
3
votes
2answers
665 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 ...
6
votes
1answer
755 views

Android game loop's effect on cpu/battery usage - unexpected results

I will try to keep this question as concise and as readable as I can. I recently came across an odd problem with my Android game that I'm developing. It's an openGL ES 2.0 game and initially I was ...
0
votes
0answers
236 views

How to render alpha channeled animated 2D sprites in OpenGL ES 2.0

I searched, but I can't find specifically how to render animated 2D sprites with an alpha channel onto a 3D polygon, z=0, in OpenGL ES 2.0. This is just a basic 2D concept, but since I'm using, ...
1
vote
1answer
74 views

I have a frag shader, one with an empty s_lightMap, how and why is it effecting the output?

I have an image of concrete rocks of different shades of colors, and I'm applying this shader, but without referencing s_lightMap's uniform in my program: precision mediump float; ...
1
vote
1answer
369 views

Centering GLViewport position within physical screen

I'm developing my app on one device and want it to display at the same ratio on all other devices. Currently what I have is 'image 1' in my image below - the game fits perfectly onto my development ...
-1
votes
1answer
96 views

Specifying 3D objects in a game [closed]

I have hands on experience in OpenGLES 2.0 , OpenGL and wish to apply the same in a 3D game development in Android. My idea is to develop a Combat game having fighter planes. I am trying to create a ...