Develop Reference

texSubImage2D doesn't update texture

I want use OpenGL ES to draw a frame animation, so I use glTexSubImage2D to update the texture.
This function initializes the texture:
private void initTexture()
{
textures=new int[1];
GLES20.glGenTextures(1,textures,0);
//Bitmap bitmap= BitmapFactory.decodeFile(Environment.getExternalStorageDirectory()+"/xiaobizi/xiaobizi_0001.png");
Bitmap bitmap= BitmapFactory.decodeFile(Environment.getExternalStorageDirectory()+"/aa.png");
ratio=(float)bitmap.getHeight()/(float)bitmap.getWidth();
GLES20.glBindTexture(GLES20.GL_TEXTURE_2D,textures[0]);
GLES20.glTexParameteri(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_MIN_FILTER, GLES20.GL_LINEAR);
GLES20.glTexParameteri(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_MAG_FILTER, GLES20.GL_LINEAR);
GLUtils.texImage2D(GLES20.GL_TEXTURE_2D, 0, bitmap, 0);
bitmap.recycle();
}
this function to save&remove Bitmap:
mTextureMap.remove(mPathList.get(messageTag));
mTextureMap.put(mPathList.get(saveCount),BitmapFactory.decodeFile(mPathList.get(saveCount)));
private void drawMagic()
{
GLES20.glEnable(GLES20.GL_BLEND);
GLES20.glBlendFunc(GLES20.GL_ONE,GLES20.GL_ONE_MINUS_SRC_ALPHA);
GLES20.glUseProgram(programMagic);
int mPositionHandleFace = GLES20.glGetAttribLocation(programMagic, "vPosition");
GLES20.glEnableVertexAttribArray(mPositionHandleFace);
GLES20.glVertexAttribPointer(mPositionHandleFace, 2, GLES20.GL_FLOAT, false, 0, 0);
int mTexCoordLocFace = GLES20.glGetAttribLocation(programMagic, "a_texCoord" );
// Enable generic vertex attribute array
GLES20.glEnableVertexAttribArray ( mTexCoordLocFace );
// Prepare the texturecoordinates
GLES20.glVertexAttribPointer(mTexCoordLocFace, 2, GLES20.GL_FLOAT, false, 0, 0);
// Get handle to shape's transformation matrix
int mTransHandle = GLES20.glGetUniformLocation(programMagic, "transMatrix");
int mScaleHandle=GLES20.glGetUniformLocation(programMagic,"scaleMatrix");
int mRotateXHandle=GLES20.glGetUniformLocation(programMagic,"rotateXMatrix");
int mRotateZHandle=GLES20.glGetUniformLocation(programMagic,"rotateZMatrix");
int mRotateYHandle=GLES20.glGetUniformLocation(programMagic,"rotateYMatrix");
//control matrix
GLES20.glUniformMatrix4fv(mTransHandle,1,false,transMatrix,0);
GLES20.glUniformMatrix4fv(mScaleHandle,1,false,scaleMatrix,0);
GLES20.glUniformMatrix4fv(mRotateXHandle,1,false,rotateXMatrix,0);
GLES20.glUniformMatrix4fv(mRotateZHandle,1,false,rotateZMatrix,0);
GLES20.glUniformMatrix4fv(mRotateYHandle,1,false,rotateYMatrix,0);
int mtrxhandleFace = GLES20.glGetUniformLocation(programMagic, "uMVPMatrix");
// Apply the projection and view transformation
//GLES20.glUniformMatrix4fv(mtrxhandleFace, 1, false, mGLTextureTransformMatrix, 0);
GLES20.glUniformMatrix4fv(mtrxhandleFace, 1, false, mSecondTransFormMatrix, 0);
GLES20.glBindTexture(GLES20.GL_TEXTURE_2D,textures[0]);
if(i>=mTotalCount)
{
i=i-mTotalCount;
}
// update texture
GLUtils.texSubImage2D(GLES20.GL_TEXTURE_2D,0,0,0,mTextureMap.get(mPathList.get(i)));
int mSamplerLocFace = GLES20.glGetUniformLocation (programMagic, "s_texture" );
// Set the sampler texture unit to 0, where we have saved the texture.
GLES20.glUniform1i ( mSamplerLocFace, 0);
GLES20.glDrawArrays(GLES20.GL_TRIANGLE_STRIP, 0, 4);
// Disable vertex array
GLES20.glDisableVertexAttribArray(mPositionHandleFace);
GLES20.glDisableVertexAttribArray(mTexCoordLocFace);
GLES20.glBindTexture(GLES20.GL_TEXTURE_2D,0);
mDecodeHandler.sendEmptyMessage(i);
i++;
}
this is my drawFrame function.
In initTexture function if the bitmap belongs to the Frame Animation, texSubImage2D works,the texture always updating, but if i pass a bitmap that does't belongs to the Frame Animation , the function texSubImage2D does't work. In that case, the texture always was the bitmap that i passed in function initTexture didn't update.
If i called the function when opengl was dawing, the texture was black,but its shapes can be displayed properly, just the background was black.
I am searching for a long time on net. But no use. Please help or try to give some ideas how to fix this.thank u.

How to render camera preview to texture

I develop video app on Android and use OpenGL for render and filtering video from camera via shaders. One of my shaders use two textures - one is live frame from camera and another is the previous render pass result. So I need to render picture twice - to screen for preview and to separate Texture for next render pass. To achieve it I use Frame Buffer object. Here is my code:
For init frame buffer:
private void initPredrawBuffer() {
GLES20.glActiveTexture(GLES20.GL_TEXTURE1);
prevBuffer = new int[1];
GLES20.glGenFramebuffers(1, prevBuffer, 0);
GLES20.glBindFramebuffer(GLES20.GL_FRAMEBUFFER, prevBuffer[0]);
prevTexture = new int[1];
GLES20.glGenTextures(1, prevTexture, 0);
GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, prevTexture[0]);
GLES20.glTexParameterf(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_MIN_FILTER,
GLES20.GL_NEAREST);
GLES20.glTexParameterf(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_MAG_FILTER,
GLES20.GL_LINEAR);
GLES20.glTexParameteri(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_WRAP_S,
GLES20.GL_CLAMP_TO_EDGE);
GLES20.glTexParameteri(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_WRAP_T,
GLES20.GL_CLAMP_TO_EDGE);
GLES20.glTexImage2D(GLES20.GL_TEXTURE_2D, 0, GLES20.GL_RGBA, mFrameWidth, mFrameHeight, 0, GLES20.GL_RGBA, GLES20.GL_UNSIGNED_BYTE, null);
GLES20.glFramebufferTexture2D(GLES20.GL_FRAMEBUFFER, GLES20.GL_COLOR_ATTACHMENT0, GLES20.GL_TEXTURE_2D, prevTexture[0], 0);
int[] depthRenderbuffers = new int[1];
GLES20.glGenRenderbuffers(1, depthRenderbuffers, 0);
GLES20.glBindRenderbuffer(GLES20.GL_RENDERBUFFER, depthRenderbuffers[0]);
GLES20.glRenderbufferStorage(GLES20.GL_RENDERBUFFER, GLES20.GL_DEPTH_COMPONENT16, mFrameWidth, mFrameHeight);
GLES20.glFramebufferRenderbuffer(GLES20.GL_FRAMEBUFFER, GLES20.GL_DEPTH_ATTACHMENT, GLES20.GL_RENDERBUFFER, depthRenderbuffers[0]);
int status = GLES20.glCheckFramebufferStatus(GLES20.GL_FRAMEBUFFER);
if (status != GLES20.GL_FRAMEBUFFER_COMPLETE) {
throw new RuntimeException("Incomplete buffer");
}
}
and for render:
private void draw(boolean offScreen, float[] mvpMatrix, FloatBuffer vertexBuffer, int firstVertex,
int vertexCount, int coordsPerVertex, int vertexStride,
float[] texMatrix, FloatBuffer texBuffer, int textureId, int texStride) {
GlUtil.checkGlError("draw start");
if (offScreen)
GLES20.glBindFramebuffer(GLES20.GL_FRAMEBUFFER, prevBuffer[0]);
else
GLES20.glBindFramebuffer(GLES20.GL_FRAMEBUFFER, 0);
// Select the program.
GLES20.glUseProgram(firstFrame && firstFrameProgram > 0 ? firstFrameProgram : mProgramHandle);
GlUtil.checkGlError("glUseProgram");
// Set the texture.
GLES20.glActiveTexture(GLES20.GL_TEXTURE0);
GLES20.glBindTexture(GLES11Ext.GL_TEXTURE_EXTERNAL_OES, textureId);
// Copy the model / view / projection matrix over.
GLES20.glUniformMatrix4fv(muMVPMatrixLoc, 1, false, mvpMatrix, 0);
GlUtil.checkGlError("glUniformMatrix4fv");
// Copy the texture transformation matrix over.
GLES20.glUniformMatrix4fv(muTexMatrixLoc, 1, false, texMatrix, 0);
GlUtil.checkGlError("glUniformMatrix4fv");
// Enable the "aPosition" vertex attribute.
GLES20.glEnableVertexAttribArray(maPositionLoc);
GlUtil.checkGlError("glEnableVertexAttribArray");
// Connect vertexBuffer to "aPosition".
GLES20.glVertexAttribPointer(maPositionLoc, coordsPerVertex,
GLES20.GL_FLOAT, false, vertexStride, vertexBuffer);
GlUtil.checkGlError("glVertexAttribPointer");
// Enable the "aTextureCoord" vertex attribute.
GLES20.glEnableVertexAttribArray(maTextureCoordLoc);
GlUtil.checkGlError("glEnableVertexAttribArray");
// Connect texBuffer to "aTextureCoord".
GLES20.glVertexAttribPointer(maTextureCoordLoc, 2,
GLES20.GL_FLOAT, false, texStride, texBuffer);
GlUtil.checkGlError("glVertexAttribPointer");
// Setting Light Trails filter params
if (mProgramType == ProgramType.TEXTURE_LIGHT_TRAILS && !firstFrame) {
GLES20.glUniform1i(muTextureNew, 0);
GlUtil.checkGlError("glUniform1i muTextureNew");
GLES20.glActiveTexture(GLES20.GL_TEXTURE1);
GlUtil.checkGlError("temp glActiveTexture");
GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, prevTexture[0]);
GlUtil.checkGlError("temp glBindTexture");
GLES20.glUniform1i(muTexturePrev, 1);
GlUtil.checkGlError("glUniform1i muTexturePrev");
GLES20.glUniform1f(muLightTrailsExposure, lightTrailsKernel[0]);
GlUtil.checkGlError("glUniform1f muLightTrailsExposure");
GLES20.glUniform1f(muLightTrailsEcho, lightTrailsKernel[1]);
GlUtil.checkGlError("glUniform1f muLightTrailsEcho");
GLES20.glUniform1f(muLightTrailsLimit, lightTrailsKernel[2]);
GlUtil.checkGlError("glUniform1f muLightTrailsLimit");
GLES20.glActiveTexture(GLES20.GL_TEXTURE0);
GlUtil.checkGlError("temp glActiveTexture");
}
// Draw the rect.
GLES20.glDrawArrays(GLES20.GL_TRIANGLE_STRIP, firstVertex, vertexCount);
GlUtil.checkGlError("glDrawArrays");
GLES20.glFinish();
}
The problem is that render to frame buffer not working, and glReadPixels always return an empty array. Render to screen works fine.

Android OpenGLES 2.0 loading more textures

I want to load more than one textures in OpenGL and use them.
This is TextureLoader,i think it correctly loads texture on idx position.
public int[] texture = new int[10];
public int loadTexture(Context context, int resource,int idx){
GLES20.glGenTextures(idx, texture, 0);
BitmapFactory.Options bo = new BitmapFactory.Options();
Bitmap tex = BitmapFactory.decodeResource(context.getResources(), resource, bo);
GLES20.glTexParameteri(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_MIN_FILTER, GLES20.GL_NEAREST);
GLES20.glTexParameteri(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_MAG_FILTER, GLES20.GL_NEAREST);
GLES20.glTexParameteri(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_WRAP_S, GLES20.GL_CLAMP_TO_EDGE);
GLES20.glTexParameteri(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_WRAP_T, GLES20.GL_CLAMP_TO_EDGE);
GLUtils.texImage2D(GLES20.GL_TEXTURE_2D, 0, tex, 0);
tex.recycle();
if(texture[idx] == 0){
// Displays error
}
return texture[idx];
}
This is my render and I have no idea how to select loaded texture.
int mPositionHandle =
GLES20.glGetAttribLocation(riGraphicTools.sp_Image, "vPosition");
GLES20.glEnableVertexAttribArray(mPositionHandle);
GLES20.glVertexAttribPointer(mPositionHandle, 3,
GLES20.GL_FLOAT, false,
0, vertexBuffer);
int mTexCoordLoc = GLES20.glGetAttribLocation(riGraphicTools.sp_Image,
"a_texCoord" );
GLES20.glEnableVertexAttribArray ( mTexCoordLoc );
// Prepare the texturecoordinates
GLES20.glVertexAttribPointer ( mTexCoordLoc, 2, GLES20.GL_FLOAT,
false,
0, uvBuffer);
int mtrxhandle = GLES20.glGetUniformLocation(riGraphicTools.sp_Image,
"uMVPMatrix");
GLES20.glUniformMatrix4fv(mtrxhandle, 1, false, m, 0);
int mSamplerLoc = GLES20.glGetUniformLocation (riGraphicTools.sp_Image,
"s_texture" );
GLES20.glUniform1i ( mSamplerLoc, 0);
GLES20.glDrawElements(GLES20.GL_TRIANGLES, indices.length,
GLES20.GL_UNSIGNED_SHORT, drawListBuffer);
GLES20.glDisableVertexAttribArray(mPositionHandle);
GLES20.glDisableVertexAttribArray(mTexCoordLoc);

It looks like you have most of what you need, assuming that you filled the buffers with the necessary data. There's one call in your code where the arguments are not what you must have intended:
GLES20.glGenTextures(idx, texture, 0);
With the Java bindings in Android, the first argument is the number of ids you want to generate, the second an array of ids, the 3rd the start index in the array where the generated ids are stored. So to generate one id, and store it as texture[idx], the correct arguments are:
GLES20.glGenTextures(1, texture, idx);
Then, for the core part of your question, the call you are looking for is glBindTexture(). This call defines which specific texture most texture-related OpenGL operations use. You will need this call in multiple places.
In your loadTexture() method, both GLES20.glTexParameteri() and GLUtils.texImage2D() operate on the currently bound texture. So before those calls, you need to add this call to bind your new texture:
GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, texture[idx]);
You need the same call before the draw operation. So somewhere in your render method, before you call GLES20.glDrawElements(), use a glBindTexture() call that looks just like the one above, with the idx value of the texture you want to use. This is where you really choose which of the textures you loaded is applied during rendering.
There are mechanisms that allow you to bind multiple textures at the same time. This is mainly useful if your shader needs to sample from multiple textures. You most likely won't need this yet. But once you get to that point, you will want to read up on "texture units", and look up the glActiveTexture() call.

Opengl Es 2.0 - Displaying multiple textures

So I'm able to display 1 texture at a time but I have a problem with displaying more textures. The render function is called for every texture separately (tex_nr), not sure if that's a good approach. Here's the rendering code:
private void Render(float[] m, int tex_nr) {
// Set our shaderprogram to image shader
GLES20.glUseProgram(riGraphicTools.sp_Image);
// clear Screen and Depth Buffer, we have set the clear color as black.
GLES20.glClear(GLES20.GL_COLOR_BUFFER_BIT | GLES20.GL_DEPTH_BUFFER_BIT);
// get handle to vertex shader's vPosition member
int mPositionHandle = GLES20.glGetAttribLocation(riGraphicTools.sp_SolidColor, "vPosition");
// Enable generic vertex attribute array
GLES20.glEnableVertexAttribArray(mPositionHandle);
// Prepare the triangle coordinate data
GLES20.glVertexAttribPointer(mPositionHandle, 3,
GLES20.GL_FLOAT, false,
0, vertexBuffer);
// Get handle to texture coordinates location
int mTexCoordLoc = GLES20.glGetAttribLocation(riGraphicTools.sp_Image,
"a_texCoord" );
// Enable generic vertex attribute array
GLES20.glEnableVertexAttribArray ( mTexCoordLoc );
// Prepare the texturecoordinates
GLES20.glVertexAttribPointer ( mTexCoordLoc, 2, GLES20.GL_FLOAT,
false,
0, uvBuffer);
// Get handle to shape's transformation matrix
int mtrxhandle = GLES20.glGetUniformLocation(riGraphicTools.sp_Image,
"uMVPMatrix");
// Apply the projection and view transformation
GLES20.glUniformMatrix4fv(mtrxhandle, 1, false, m, 0);
// Get handle to textures locations
int mSamplerLoc = GLES20.glGetUniformLocation (riGraphicTools.sp_Image,
"s_texture" );
// Set the sampler texture unit to where we have saved the texture.
GLES20.glUniform1i ( mSamplerLoc, tex_nr);
// Draw the triangle
GLES20.glDrawElements(GLES20.GL_TRIANGLES, indices.length,
GLES20.GL_UNSIGNED_SHORT, drawListBuffer);
// Disable vertex array
GLES20.glDisableVertexAttribArray(mPositionHandle);
GLES20.glDisableVertexAttribArray(mTexCoordLoc);
}
And here the loading textures code:
texturenames = new int[GameObject.spritePaths.size()];
GLES20.glGenTextures(GameObject.spritePaths.size(), texturenames, 0);
for(int i = 0; i < GameObject.spritePaths.size(); i++)
{
// Retrieve our image from resources.
int id = mContext.getResources().getIdentifier(GameObject.spritePaths.get(i), null, mContext.getPackageName());
// Temporary create a bitmap
Bitmap bmp = BitmapFactory.decodeResource(mContext.getResources(), id);
// Bind texture to texturename
GLES20.glActiveTexture(GLES20.GL_TEXTURE0+i);
GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, texturenames[i]);
// Set filtering
GLES20.glTexParameteri(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_MIN_FILTER, GLES20.GL_LINEAR);
GLES20.glTexParameteri(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_MAG_FILTER, GLES20.GL_LINEAR);
// Load the bitmap into the bound texture.
GLUtils.texImage2D(GLES20.GL_TEXTURE_2D, 0, bmp, 0);
// We are done using the bitmap so we should recycle it.
bmp.recycle();
}
As a result of this code, only the last loaded texture is displayed and I have no idea why the former ones do not show up. I would be very grateful for any clues!
edit:
Actually, I have just found out that I can display all of the textures that I loaded but only 1 at a time. So I guess that the problem isn't connected with loading? It looks as if each consecutive Render call(my function) prevented the drawing in the previous call...

You have a call to glClear() in your Render() method:
// clear Screen and Depth Buffer, we have set the clear color as black.
GLES20.glClear(GLES20.GL_COLOR_BUFFER_BIT | GLES20.GL_DEPTH_BUFFER_BIT);
This does pretty much what the name suggests, and what's also captured in your comment: It clears all rendering that has been done so far. So if you call the Render() method multiple times, only the rendering from the last call will be visible.
If you want to invoke Render() multiple times for the same frame, you will need to take it out of Render(), and call it only once at the start of rendering the frame.
There's another thing in your code that looks slightly suspicious:
int mPositionHandle = GLES20.glGetAttribLocation(riGraphicTools.sp_SolidColor, "vPosition");
....
int mTexCoordLoc = GLES20.glGetAttribLocation(riGraphicTools.sp_Image, "a_texCoord");
Unless sp_SolidColor and sp_Image have the same value, you're querying attribute locations from two different shader programs. Since sp_Image is the program you are using, you should pass it in as the first parameter for both these calls.

OpenGL ES Android Bitmap Texture not showing

I'm trying to draw a square and add a texture to it. I'm just starting with OpenGL and I'm following this tutorial http://blog.uncle.se/2012/02/opengl-es-tutorial-for-android-part-vi-textures/.
Here is the code for my squares draw procedure:
public void draw(float[] mvpMatrix) {
// Add program to OpenGL environment
GLES20.glUseProgram(mProgram);
// get handle to vertex shader's vPosition member
mPositionHandle = GLES20.glGetAttribLocation(mProgram, "vPosition");
// Enable a handle to the triangle vertices
GLES20.glEnableVertexAttribArray(mPositionHandle);
// Prepare the triangle coordinate data
GLES20.glVertexAttribPointer(mPositionHandle, COORDS_PER_VERTEX,
GLES20.GL_FLOAT, false,
vertexStride, vertexBuffer);
// get handle to fragment shader's vColor member
mColorHandle = GLES20.glGetUniformLocation(mProgram, "vColor");
// Set color for drawing the square
GLES20.glUniform4fv(mColorHandle, 1, color, 0);
/** now trying to add the texture */
Bitmap bitmap = BitmapFactory.decodeResource(chamRenderer.context.getResources(),
R.drawable.ic_launcher);
// Create an int array with the number of textures we want,
// in this case 1.
int[] textures = new int[1];
// Tell OpenGL to generate textures.
GLES20.glGenTextures(1, textures, 0);
GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, textures[0]);
// Scale up if the texture if smaller.
GLES20.glTexParameterf(GLES20.GL_TEXTURE_2D,
GLES20.GL_TEXTURE_MAG_FILTER,
GLES20.GL_LINEAR);
// scale linearly when image smalled than texture
GLES20.glTexParameterf(GLES20.GL_TEXTURE_2D,
GLES20.GL_TEXTURE_MIN_FILTER,
GLES20.GL_LINEAR);
// get handle to shape's transformation matrix
mMVPMatrixHandle = GLES20.glGetUniformLocation(mProgram, "uMVPMatrix");
Renderer.checkGlError("glGetUniformLocation");
// Apply the projection and view transformation
GLES20.glUniformMatrix4fv(mMVPMatrixHandle, 1, false, mvpMatrix, 0);
Renderer.checkGlError("glUniformMatrix4fv");
// Draw the square
GLES20.glDrawElements(GLES20.GL_TRIANGLES, drawOrder.length,
GLES20.GL_UNSIGNED_SHORT, drawListBuffer);
// Disable vertex array
GLES20.glDisableVertexAttribArray(mPositionHandle);
}
The blue colour display fine but theirs no hope with the texture, no errors, just nothing their. Like I said I'm very now to OpenGL. Thanks :)

If I am reading this right it is displaying the blue and white squares (that looks like tiles) but not the texture? The texture is the image stored in bitmap variable. You do not do anything after creating the bitmap. It looks like you have not finished the tutorial yet; the code is that they use to render it is not in your code. Look under the part that says UV mapping and look at that code and make sure you include that code.