I've tried to follow all the information I could find, but I am not having any luck finding the source of my texture problems and could really use a hand.
The following is piece of code in which I'm trying to draw 3 pieces of my background using glDrawTexfOES. The 3 pieces should look like green grass.
public void onDrawFrame(GL10 gl) {
gl.glClear(GL10.GL_COLOR_BUFFER_BIT | GL10.GL_DEPTH_BUFFER_BIT);
gl.glLoadIdentity();
gl.glFrontFace(GL10.GL_CW);
gl.glEnableClientState(GL10.GL_TEXTURE_COORD_ARRAY);
gl.glEnable(GL10.GL_TEXTURE_2D);
gl.glBindTexture(GL10.GL_TEXTURE_2D, grass);
gl.glColor4x(0x10000, 0x00000, 0x10000, 0x10000);
((GL11Ext) gl).glDrawTexfOES(0.0f, 0.0f, -8.0f, 32, 32);
((GL11Ext) gl).glDrawTexfOES(32.0f, 0.0f, -8.0f, 32, 32);
((GL11Ext) gl).glDrawTexfOES(64.0f, 0.0f, -8.0f, 32, 32);
}
Instead of green grass however, I'm getting 3 brown squares:
http://img109.imageshack.us/img109/9670/84615249.jpg
Any help in figuring out why my textures won't display correctly would be most appreciated!
On a related note, for building a simple 2D tiled game is glDrawTexfOES the most efficient method for generating the tiled background?
Thanks in advance,
Harry
You need to define the mapping of the image to the rectangle
You are probably just getting the top left pixel of the image.
int[]crop={0,0,text_dimx,text_dimy};
((GL11) gl).glTexParameteriv(GL10.GL_TEXTURE_2D, GL11Ext.GL_TEXTURE_CROP_RECT_OES, crop,0);
If you google most OpenGL functions you get documentation for the function, followed by examples. For that function, the results are dominated by people having trouble.
That function might be slightly faster than using textures the usual way (I haven't used it so I don't know), but simply applying a texture to a quad needs no extensions and is extremely portable.
Why don't you try that and get back to us... it could be that the function is working perfectly, but something went wrong initializing the texture. Using the uncomplicated texture-a-quad method will help you find that out as well.
Related
I would like to create an interactive 2D effect that I can put on anything. So I want to take a mostly transparent effect, render it to a texture, and put it wherever I want simply by putting it on a square.
The problem I encountered is that I can't get rid of the background color. When I put the effect over an object, the background color of the effect blocks out the object that I want to put the effect over.
Here is my code. Can anybody tell me what I'm missing?
Drawing:
GLES20.glClearColor(0.6f, 0.34f, 0.14f, 0.0f);
GLES20.glClear(GLES20.GL_COLOR_BUFFER_BIT | GLES20.GL_DEPTH_BUFFER_BIT);
GLES20.glDisable(GLES20.GL_DEPTH_TEST);
GLES20.glEnable(GLES20.GL_BLEND);
GLES20.glBlendFunc(GLES20.GL_SRC_ALPHA, GLES20.GL_ONE_MINUS_SRC_ALPHA);
ball.draw(); //This is the object a simple square draw with 2 triangles
particleSystem.renderToTexture(); //effect rendering to texture and drawing it
The render to texture code code:
public void renderToTexture(){
GLES20.glBindFramebuffer(GLES20.GL_FRAMEBUFFER, fb[0]);
GLES20.glClear( GLES20.GL_DEPTH_BUFFER_BIT | GLES20.GL_COLOR_BUFFER_BIT);
GLES20.glFramebufferTexture2D(GLES20.GL_FRAMEBUFFER, GLES20.GL_COLOR_ATTACHMENT0, GLES20.GL_TEXTURE_2D, renderTex[0], 0);
GLES20.glFramebufferRenderbuffer(GLES20.GL_FRAMEBUFFER, GLES20.GL_DEPTH_ATTACHMENT, GLES20.GL_RENDERBUFFER, depthRb[0]);
int status = GLES20.glCheckFramebufferStatus(GLES20.GL_FRAMEBUFFER);
drawRender(); //draws the effect on a fbo and saving the texture to renderTex[0]
GLES20.glBindFramebuffer(GLES20.GL_FRAMEBUFFER, 0);
GLES20.glActiveTexture(GLES20.GL_TEXTURE0);
GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, renderTex[0]);
drawEffect(); //draws a square with the effect texture on it
The problem should be here somewhere, but I have no idea what to do. I tried everything I could think of. I even triend to dispose of the background color in the shader.
The posted code looks perfectly fine. You will need to make sure that the texture you use for the color render target (renderTex[0]) has an alpha component.
Note that the number of texture formats in ES 2.0 that are guaranteed to be color-renderable is very limited. The only two with an alpha component (see table 4.5. in the spec) are GL_RGBA4 and GL_RGB5_A1. Most notably, this does not include GL_RGBA with 8 bits per component.
So for defining a color-renderable texture with alpha component that is guaranteed to work across all ES 2.0 implementations, you will have to use GL_RGBA for the internal format, and GL_UNSIGNED_SHORT_4_4_4_4 or GL_UNSIGNED_SHORT_5_5_5_1 for the type argument of glTexImage2D().
Most common devices (at least all the ones I have seen) do support the OES_rgb8_rgba8 extension, which adds support for rendering to 8 bit component textures. But if you want to be completely portable, you should check for the presence of this extension before using render targets with those formats.
I know this question is old, but i also encountered it right now and the solution for me was to do something with the GLSurfaceView. Just add these lines after setting the context
glSurfaceView.setEGLConfigChooser(8, 8, 8, 8, 0, 0);
glSurfaceView.getHolder().setFormat(PixelFormat.TRANSLUCENT);
I was already using GL_RGBA format and was really annoyed that nothing else was working, but this worked like magic.
I'm working on an OpenGL application, specifically for Android with OpenGL ES (2.0 I think). I can currently draw objects independently and rotate the scene all at once. I need to be able to translate/rotate individual objects independently and then rotate/translate the whole scene together. How can I accomplish this? I've read several threads explaining how to push/pop matrices but I'm pretty sure this functionality was deprecated along with the fixed function pipeline of OpenGL 1.1.
To give some perspective, below is the onDrawFrame method for my renderer. Field, Background and Track are all classes I've made that encapsulate vertex data and the draw method draws the appropriate matrices to the supplied context, in this case GL10 'gl'.
//clear the screen
gl.glClear(GL10.GL_COLOR_BUFFER_BIT |GL10.GL_DEPTH_BUFFER_BIT);
// TODO Auto-generated method stub
gl.glMatrixMode(GL10.GL_MODELVIEW);
gl.glLoadIdentity();
GLU.gluLookAt(gl, 0, 0, 60, 0, 0, 0, 0, 2, 0);//setup camera
//apply rotations
long time = SystemClock.uptimeMillis();
float angle = ((int)time)/150.0f;
gl.glRotatef(55.0f, -1, 0, 0);//rotates whole scene
gl.glRotatef(angle, 0, 0, -1);//rotates whole scene
MainActivity.Background.draw(gl);
MainActivity.Track.draw(gl);
MainActivity.Field.draw(gl);
*Update: As it turns out, I can push and pop matrices. Is there anything wrong with the pushing/popping method? It seems to be a very simple way of independently rotating and translating objects which is exactly what I need. *
There should be nothing wrong with using glPushMatrix and glPopMatrix. The Android implementation of ES 2.0, to my understanding, has default shaders which behave exactly like the default fixed-function pipeline, and you can use the fixed-function pipeline functions. They will behave identically.
I am trying to develop an android drawing app.In this app I am using texture to draw.
I want to draw translucent texture one over another to get continuous translucent line but I am only able to get this:
As you can see in part B circular translucent textures appear one over other. I want line to appear as in part A.
I am adding information of texture drawing like width,height,x&y coordinate in ArrayList spriteArray.
The blending function used is- gl.glBlendFunc(GL10.GL_ONE, GL10.GL_ONE_MINUS_SRC_ALPHA);
To set opacity of texture-gl.glColor4f(1, 1, 1, opacityValue);
I have also used gl.glBlendFunc(GL10.GL_SRC_ALPHA, GL10.GL_ONE_MINUS_SRC_ALPHA);it does not work either.
Any help to solve this problem will be appreciated.
If you need more information please tell me.
drawFrame code:enter code here
gl.glMatrixMode(GL10.GL_TEXTURE);
gl.glEnable(GL10.GL_TEXTURE_2D);
gl.glBlendFunc(GL10.GL_ONE, GL10.GL_ONE_MINUS_SRC_ALPHA);
gl.glColor4f(1, 1, 1, opacityValue);
for (int x = 0; x < GLSurfaceView.mSpriteArray.size(); x++) {
int
mTextureName=GLSurfaceView.mSpriteArray.get(x).textureName;
gl.glBindTexture(GL10.GL_TEXTURE_2D, mTextureName);
// Draw using the DrawTexture extension.
((GL11Ext) gl).glDrawTexfOES(x, y, 0, width, height);
}
This question is about OpenGL ES 1.x programming for Android.
I followed this tutorials and tested code on Samsung Galaxy Ace and it lagged a bit.
Some code of that tutorial:
public void onDrawFrame(GL10 gl) {
// Clears the screen and depth buffer.
gl.glClear(GL10.GL_COLOR_BUFFER_BIT | GL10.GL_DEPTH_BUFFER_BIT);
// Replace the current matrix with the identity matrix
gl.glLoadIdentity();
// Translates 10 units into the screen.
gl.glTranslatef(0, 0, -10);
// SQUARE A
// Save the current matrix.
gl.glPushMatrix();
// Rotate square A counter-clockwise.
gl.glRotatef(angle, 0, 0, 1);
// Draw square A.
square.draw(gl);
// Restore the last matrix.
gl.glPopMatrix();
// SQUARE B
// Save the current matrix
gl.glPushMatrix();
// Rotate square B before moving it, making it rotate around A.
gl.glRotatef(-angle, 0, 0, 1);
// Move square B.
gl.glTranslatef(2, 0, 0);
// Scale it to 50% of square A
gl.glScalef(.5f, .5f, .5f);
// Draw square B.
square.draw(gl);
// SQUARE C
// Save the current matrix
gl.glPushMatrix();
// Make the rotation around B
gl.glRotatef(-angle, 0, 0, 1);
gl.glTranslatef(2, 0, 0);
// Scale it to 50% of square B
gl.glScalef(.5f, .5f, .5f);
// Rotate around it's own center.
gl.glRotatef(angle*10, 0, 0, 1);
// Draw square C.
square.draw(gl);
// Restore to the matrix as it was before C.
gl.glPopMatrix();
// Restore to the matrix as it was before B.
gl.glPopMatrix();
// Increse the angle.
angle++;
}
What are the week parts here?
What should one do to optimize OpenGL ES program for Android?
Should I rather use NDK in big graphics projects?
Is it worth goind direct to OpenGL ES 2.0?
As far as I didn't find any good and complex book on OpenGL ES 1.x programming for Android, I adress this question to honorable users of Stackoverflow.
Would appreciate any help.
Define lag? It might be helpful to look at framerate to get a better sense of performance.
But TBH, so long as square.draw(gl) is doing what it implies, then this is a very simple program. There is nothing performance heavy about this code.
I get the sense though that this is more of a speculative question for a bigger project. Some things to consider is what kind of graphical effects you will be trying to achieve. Will OpenGL ES 1.x be powerful enough for you? If you need to write custom shader code, you must use ES 2.0. Remember though, 2.0 requires you to write everything as a shader. It rips out many of the 1.0 features and gives those features to the developer to implement and customize. So development will be more complex and more time consuming.
As a warining, do not dive straight into the NDK as a starting point. All of these OpenGL calls are already native. It will be much (much much) easier to write an Android app in Java land than in C/C++ using JNI.
As a final word, early optimization is the root of all evil. Once you have selected your technologies, implemented a solution, and measured its performance, you can then worry about optimizing the code!
I´m trying to rotate a sprite using drawtexture but nothing happens. I´m using the following code:
gl.glRotatef(90, 0, 0, 1.0f);
gl.glBindTexture(GL10.GL_TEXTURE_2D, TextureID);
(GL11Ext) gl).glDrawTexfOES(x, y, z, width, height);
The texture is drawn to the screen but it is not rotated... Anyone? :)
From the OES_draw_texture extension:
Xs and Ys are given directly in window (viewport) coordinates.
So the passed in coordinates are not transformed by the modelview and projection matrices, which is what glRotatef changes. In short, this extension does not support rotated sprites.
If you want those, the simplest is to draw standard rotated quads instead.
After testing quite a bit og different ways to do this, I found the answer was right in front of me the whole time... I was using the SpriteMethodTest example as my codebase, but I ignored the VBO extension part there, wich basically has all the needed functionality.
SpriteMethodTest: http://code.google.com/p/apps-for-android/source/browse/trunk/#trunk/SpriteMethodTest