Greetings. I've dabbled in OpenGL in the past and as far as I understood it the best way to do 2d games with sprite-based animation was eliminate the z plane and set up an orthographic projection so you can just use Cartesian coordinates for textures and drawing positions.
So I've been trying to implement this in android. I was just using all the build in draw functions but rendering a few hundred images separately with the vanilla drawbitmap functions was killing my framerate.
A rect shows up on the screen all right but the texture refuses to show. if you could take a look and let me know where I'm going wrong here I'd really appreciate it. Be warned I don;t have nearly as comprehensive understanding of opengl as I would like. I respect anyone that can wrap their heads around this stuff.
This is the sprite class which draws the rect with the bound texture:
public class Sprite {
private FloatBuffer vertexBuffer; // buffer holding the vertices
private FloatBuffer textureBuffer;
private int[] textures = new int[1];
private float vertices[] = {
0.0f, 0.0f,
0.0f, 32.0f,
32.0f, 0.0f,
32.0f, 32.0f
};
private float texture[] = {
0.0f, 0.0f,
0.0f, 16.0f,
16.0f, 0.0f,
16.0f, 16.0f
};
public Sprite() {
ByteBuffer byteBuffer = ByteBuffer.allocateDirect(vertices.length * 4);
byteBuffer.order(ByteOrder.nativeOrder());
vertexBuffer = byteBuffer.asFloatBuffer();
vertexBuffer.put(vertices);
vertexBuffer.position(0);
byteBuffer = ByteBuffer.allocateDirect(texture.length * 4);
byteBuffer.order(ByteOrder.nativeOrder());
textureBuffer = byteBuffer.asFloatBuffer();
textureBuffer.put(texture);
textureBuffer.position(0);
}
public void loadGLTexture(GL10 gl, Context context)
{
Bitmap bitmap = BitmapFactory.decodeResource(context.getResources(),
R.drawable.charactersprites);
gl.glGenTextures(1, textures, 0);
gl.glBindTexture(GL10.GL_TEXTURE_2D, textures[0]);
//Not sure if I need these...
//gl.glTexParameterf(GL10.GL_TEXTURE_2D, GL10.GL_TEXTURE_MIN_FILTER, GL10.GL_NEAREST);
//gl.glTexParameterf(GL10.GL_TEXTURE_2D, GL10.GL_TEXTURE_MAG_FILTER, GL10.GL_LINEAR);
GLUtils.texImage2D(GL10.GL_TEXTURE_2D, 0, bitmap, 0);
bitmap.recycle();
}
/** The draw method for the triangle with the GL context */
public void draw(GL10 gl) {
gl.glBindTexture(GL10.GL_TEXTURE_2D, textures[0]);
gl.glEnableClientState(GL10.GL_VERTEX_ARRAY);
gl.glEnableClientState(GL10.GL_TEXTURE_COORD_ARRAY);
//gl.glFrontFace(GL10.GL_CW);//is this necessary?
// set the colour for the triangle
//gl.glColor4f(0.0f, 1.0f, 0.0f, 0.5f);
// Point to our vertex buffer
gl.glVertexPointer(2, GL10.GL_FLOAT, 0, vertexBuffer);
gl.glTexCoordPointer(2, GL10.GL_FLOAT, 0, textureBuffer);
// Draw the vertices as triangle strip
gl.glDrawArrays(GL10.GL_TRIANGLE_STRIP, 0, vertices.length / 2);
//Disable the client state before leaving
gl.glDisableClientState(GL10.GL_VERTEX_ARRAY);
gl.glDisableClientState(GL10.GL_TEXTURE_COORD_ARRAY);
}
}
And this is the renderer...i pass in the srfaceview to hold onto so i can get the height and width for the projection
public class GlRenderer implements Renderer {
private Sprite sprite;
private GLSurfaceView surfaceView;
private Context context;
/** Constructor to set the handed over context */
public GlRenderer(GLSurfaceView surfaceView, Context context) {
this.sprite = new Sprite();
this.surfaceView = surfaceView;
this.context = context;
}
#Override
public void onDrawFrame(GL10 gl) {
// clear Screen and Depth Buffer
gl.glClear(GL10.GL_COLOR_BUFFER_BIT | GL10.GL_DEPTH_BUFFER_BIT);
gl.glMatrixMode(GL10.GL_PROJECTION);
// Reset the Modelview Matrix
gl.glLoadIdentity();
gl.glOrthof(0.0f, surfaceView.getWidth(), surfaceView.getHeight(), 0.0f, -1.0f, 1.0f);
sprite.draw(gl);
}
#Override
public void onSurfaceCreated(GL10 gl, EGLConfig config) {
sprite.loadGLTexture(gl, this.context);
gl.glEnable(GL10.GL_TEXTURE_2D);
gl.glShadeModel(GL10.GL_SMOOTH);
gl.glClearColor(0.0f, 0.0f, 0.0f, 0.5f);
gl.glClearDepthf(1.0f);
gl.glEnable(GL10.GL_DEPTH_TEST);
gl.glDepthFunc(GL10.GL_LEQUAL);
gl.glHint(GL10.GL_PERSPECTIVE_CORRECTION_HINT, GL10.GL_NICEST);
}
}
Have you tried
glActiveTexture(GL10.GL_TEXTURE0);
before rendering sprite?
Try setting the texture environment to GL_REPLACE (using glTexEnv). If it is set to GL_MODULATE, the texture color will be multiplied by the current color (or the color from lighting, if enabled) and if this color is black, the result is just black.
Below works on my Galaxy S but I'm having trouble getting it to work on my friend's HTC using projective. Though they do work in model space... Could you try?
public void draw(GL10 gl) {
gl.glActiveTexture(GL10.GL_TEXTURE0);
gl.glBindTexture(GL10.GL_TEXTURE_2D, mTextureID);
gl.glEnable(GL10.GL_TEXTURE_2D);
gl.glEnableClientState(GL10.GL_TEXTURE_COORD_ARRAY);
gl.glTexCoordPointer(2, GL10.GL_FLOAT, 0, mCoordinateBuffer);
// Draw the mesh
gl.glFrontFace(GL10.GL_CCW);
gl.glVertexPointer(3, GL10.GL_FLOAT, 0, mVertexBuffer);
gl.glNormalPointer(GL10.GL_FLOAT, 0, mNormalBuffer);
gl.glDrawElements(GL10.GL_TRIANGLE_STRIP, mIndexBuffer.limit(), GL10.GL_UNSIGNED_BYTE, mIndexBuffer);
// Disable texture
gl.glDisable(GL10.GL_TEXTURE_2D);
gl.glDisableClientState(GL10.GL_TEXTURE_COORD_ARRAY);
}
public void loadTexture(Context context, GL10 gl) {
Bitmap bmp;
try {
bmp = BitmapFactory.decodeStream(context.getResources().openRawResource(R.drawable.texture_loading));
int[] textures = new int[1];
gl.glGenTextures(1, textures, 0);
mTextureID = textures[0];
gl.glBindTexture(GL10.GL_TEXTURE_2D, mTextureID);
// Mendatory, tells openGL how to render the texture, nearest will look sharp, smooth will look blurry
gl.glTexParameterx(GL10.GL_TEXTURE_2D, GL10.GL_TEXTURE_MIN_FILTER, GL10.GL_NEAREST);
gl.glTexParameterx(GL10.GL_TEXTURE_2D, GL10.GL_TEXTURE_MAG_FILTER, GL10.GL_NEAREST);
// Not mendatory, tells openGL what to do when sprite is bigger than object
gl.glTexParameterf(GL10.GL_TEXTURE_2D, GL10.GL_TEXTURE_WRAP_S, GL10.GL_CLAMP_TO_EDGE);
gl.glTexParameterf(GL10.GL_TEXTURE_2D, GL10.GL_TEXTURE_WRAP_T, GL10.GL_CLAMP_TO_EDGE);
// Mendatory,
// GL_REPLACE replaces all color info,
// GL_MODULATE modulates, texture will be affected by lightning
gl.glTexEnvx(GL10.GL_TEXTURE_ENV, GL10.GL_TEXTURE_ENV_MODE, GL10.GL_REPLACE);
bmp.recycle();
} catch (Error e) {
}
}
Related
Following is my Sprite code. The image drawn using this code has a black background (which covers the transparent background) and has a color overlay making the image look distorted.
How can I improve transparent image drawing on open gl es.
class Ship {
public int life = 5;
public FloatBuffer ShipVertexBuffer;
public FloatBuffer ShipTextureBuffer;
public PieceCluster cluster;
//! TEXTURES
private int[] textures = new int[1];
//! TEXTURES
public float ShipVerticles[] = {
0, 0, // лево низ
0, 30, // лево вверх
30, 0, // право низ
30, 30 // право вверх
};
//! TEXTURES
public float ShipTextures[] = {
0.0f, 1.0f,
1.0f, 1.0f,
0.0f, 0.0f,
1.0f, 0.0f
};
//! TEXTURES
public Ship(PieceCluster c) {
//! Буффер вертексов
cluster = c;
ByteBuffer bb = ByteBuffer.allocateDirect(36);
bb.order(ByteOrder.nativeOrder());
ShipVertexBuffer = bb.asFloatBuffer();
ShipVertexBuffer.put(ShipVerticles);
ShipVertexBuffer.position(0);
//! TEXTURES
bb = ByteBuffer.allocateDirect(ShipTextures.length * 4);
bb.order(ByteOrder.nativeOrder());
ShipTextureBuffer = bb.asFloatBuffer();
ShipTextureBuffer.put(ShipTextures);
ShipTextureBuffer.position(0);
//! TEXTURES
}
public void loadGLTexture(GL10 gl) {
// loading texture
// generate one texture pointer
Bitmap bitmap = cluster.Picture;
gl.glGenTextures(1, textures, 0);
// ...and bind it to our array
gl.glBindTexture(GL10.GL_TEXTURE_2D, textures[0]);
// create nearest filtered texture
// gl.glTexParameterf(GL10.GL_TEXTURE_2D, GL10.GL_TEXTURE_MIN_FILTER, GL10.GL_NEAREST);
// gl.glTexParameterf(GL10.GL_TEXTURE_2D, GL10.GL_TEXTURE_MAG_FILTER, GL10.GL_LINEAR);
// Use Android GLUtils to specify a two-dimensional texture image from our bitmap
gl.glTexParameterf(GL10.GL_TEXTURE_2D, GL10.GL_TEXTURE_MIN_FILTER, GL10.GL_NEAREST);
gl.glTexParameterf(GL10.GL_TEXTURE_2D, GL10.GL_TEXTURE_MAG_FILTER, GL10.GL_NEAREST);
gl.glTexParameterf(GL10.GL_TEXTURE_2D, GL10.GL_TEXTURE_WRAP_S, GL10.GL_CLAMP_TO_EDGE);
gl.glTexParameterf(GL10.GL_TEXTURE_2D, GL10.GL_TEXTURE_WRAP_T, GL10.GL_CLAMP_TO_EDGE);
GLUtils.texImage2D(GL10.GL_TEXTURE_2D, 0, bitmap, 0);
// Clean up
bitmap.recycle();
}
public void draw(GL10 gl, float x, float y) {
//! TEXTURE
gl.glBindTexture(GL10.GL_TEXTURE_2D, textures[0]);
gl.glEnableClientState(GL10.GL_VERTEX_ARRAY);
gl.glEnableClientState(GL10.GL_TEXTURE_COORD_ARRAY);
//! TEXTURE
gl.glColor4f(0.0f, 1.0f, 0.0f, 1.0f);
gl.glTranslatef(x, y, 0.0f);
gl.glVertexPointer(2, GL10.GL_FLOAT, 0, ShipVertexBuffer);
//! TEXTURE
gl.glTexCoordPointer(2, GL10.GL_FLOAT, 0, ShipTextureBuffer);
//! TEXTURE
gl.glDrawArrays(GL10.GL_TRIANGLE_STRIP, 0, 4);
//! TEXTURE
gl.glDisableClientState(GL10.GL_VERTEX_ARRAY);
gl.glDisableClientState(GL10.GL_TEXTURE_COORD_ARRAY);
//! TEXTURE
}
It doesn't look like you've enabled blending.
Try adding glEnable(GL_BLEND) before your draw call. Use glBlendFunc() and glBlendEquation() to change the blending style to suit what effect you want.
I have next problem.
I'm write some android app which uses opengl es 1.0
I'm using GLSurfaceView and custom Renderer. Here are methods of my custom renderer onDrawFrame, onSurfaceChanged, onSurfaceChanged:
#Override
public void onDrawFrame(GL10 gl) {
gl.glEnableClientState(GL10.GL_VERTEX_ARRAY);
gl.glEnableClientState(GL10.GL_TEXTURE_COORD_ARRAY);
// clear Screen and Depth Buffer
gl.glClear(GL10.GL_COLOR_BUFFER_BIT | GL10.GL_DEPTH_BUFFER_BIT);
// Reset the Modelview Matrix
gl.glLoadIdentity();
// Drawing
gl.glTranslatef(0f, 0f, -3.0f); // move 5 units INTO the screen
// is the same as moving the camera 5 units away
// gl.glScalef(0.5f, 0.5f, 0.5f); // scale the square to 50%
// otherwise it will be too large
square.draw(gl, mScrollable.getIndexA(), mScrollable.getIndexB(), mScrollable.getAlphaValue()); // Draw the triangle
}
#Override
public void onSurfaceChanged(GL10 gl, int width, int height) {
if(height == 0) { //Prevent A Divide By Zero By
height = 1; //Making Height Equal One
}
gl.glViewport(0, 0, mWidth, mHeight); //Reset The Current Viewport
gl.glMatrixMode(GL10.GL_PROJECTION); //Select The Projection Matrix
gl.glLoadIdentity(); //Reset The Projection Matrix
//Calculate The Aspect Ratio Of The Window
GLU.gluPerspective(gl, 45.0f, (float) width / (float) height, 0.1f, 100.0f);
gl.glMatrixMode(GL10.GL_MODELVIEW); //Select The Modelview Matrix
gl.glLoadIdentity(); //Reset The Modelview Matrix
}
#Override
public void onSurfaceCreated(GL10 gl, EGLConfig config) {
// Load the texture for the square
square.loadGLTexture(gl, this.context);
gl.glEnable(GL10.GL_BLEND);
gl.glBlendFunc(GL10.GL_SRC_ALPHA, GL10.GL_ONE_MINUS_SRC_ALPHA);
gl.glEnable(GL10.GL_TEXTURE_2D); //Enable Texture Mapping ( NEW )
gl.glShadeModel(GL10.GL_SMOOTH); //Enable Smooth Shading
gl.glClearColor(0.0f, 0.0f, 0.0f, 0.5f); //Black Background
gl.glClearDepthf(1.0f); //Depth Buffer Setup
gl.glEnable(GL10.GL_DEPTH_TEST); //Enables Depth Testing
gl.glDepthFunc(GL10.GL_LEQUAL); //The Type Of Depth Testing To Do
//Really Nice Perspective Calculations
gl.glHint(GL10.GL_PERSPECTIVE_CORRECTION_HINT, GL10.GL_NICEST);
}
And my Square class to render textures:
private int[] textures;
private GL10 mGl;
private FloatBuffer vertexBuffer; // buffer holding the vertices
private float vertices[] = {
-1.0f, -1.8f, 0.0f, // V1 - bottom left
-1.0f, 1.3f, 0.0f, // V2 - top left
1.0f, -1.8f, 0.0f, // V3 - bottom right
1.0f, 1.3f, 0.0f // V4 - top right
};
private FloatBuffer textureBuffer; // buffer holding the texture coordinates
private float texture[] = {
// Mapping coordinates for the vertices
0.0f, 1.0f, // top left (V2)
0.0f, 0.0f, // bottom left (V1)
1.0f, 1.0f, // top right (V4)
1.0f, 0.0f // bottom right (V3)
};
private GlAnimationCache cacheHelper;
public void loadGLTexture(GL10 gl, Context context) {
// loading texture
mGl = gl;
gl.glGenTextures(mImageEntityList.size(), textures, 0);
cacheHelper = new GlAnimationCache(mContext, mImageEntityList, mGlRenderer, mGlSurfaceView);
cacheHelper.initCache(); //it init cache in background thread
}
public void removeTextureAt(int position){
mGl.glDeleteTextures(1, textures, position);
}
public void bindTextureAt(final Bitmap bitmap, int position){
// generate one texture poi, 0);
// ...and bind it to our array
mGl.glBindTexture(GL10.GL_TEXTURE_2D, textures[position]);
mGl.glVertexPointer(2, GL10.GL_FLOAT, 0, vertexBuffer);
mGl.glTexCoordPointer(2, GL10.GL_FLOAT, 0, textureBuffer);
// create nearest filtered texture
mGl.glTexParameterf(GL10.GL_TEXTURE_2D, GL10.GL_TEXTURE_MIN_FILTER, GL10.GL_NEAREST);
mGl.glTexParameterf(GL10.GL_TEXTURE_2D, GL10.GL_TEXTURE_MAG_FILTER, GL10.GL_LINEAR);
//Different possible texture parameters, e.g. GL10.GL_CLAMP_TO_EDGE
// gl.glTexParameterf(GL10.GL_TEXTURE_2D, GL10.GL_TEXTURE_WRAP_S, GL10.GL_REPEAT);
// gl.glTexParameterf(GL10.GL_TEXTURE_2D, GL10.GL_TEXTURE_WRAP_T, GL10.GL_REPEAT);
// Use Android GLUtils to specify a two-dimensional texture image from our bitmap
GLUtils.texImage2D(GL10.GL_TEXTURE_2D, 0, GLUtils.getInternalFormat(bitmap), bitmap, GLUtils.getType(bitmap), 0);
bitmap.recycle();
}
private int prevIndex = 0;
/** The draw method for the square with the GL context */
public void draw(GL10 gl, int indexA, int indexB, float alpha) {
// bind the previously generated texture
if(prevIndex != indexA){
cacheHelper.synchronizeCache(indexA);
prevIndex = indexA;
}
// Point to our buffers
gl.glEnableClientState(GL10.GL_VERTEX_ARRAY);
gl.glEnableClientState(GL10.GL_TEXTURE_COORD_ARRAY);
gl.glBindTexture(GL10.GL_TEXTURE_2D, textures[indexA]);
// Set the face rotation
gl.glFrontFace(GL10.GL_CW);
// Point to our vertex buffer
gl.glVertexPointer(3, GL10.GL_FLOAT, 0, vertexBuffer);
gl.glTexCoordPointer(2, GL10.GL_FLOAT, 0, textureBuffer);
gl.glColor4f(1, 1, 1, 1f);
// Draw the vertices as triangle strip
gl.glDrawArrays(GL10.GL_TRIANGLE_STRIP, 0, vertices.length / 3);
//Disable the client state before leaving
gl.glDisableClientState(GL10.GL_VERTEX_ARRAY);
gl.glDisableClientState(GL10.GL_TEXTURE_COORD_ARRAY);
gl.glBindTexture(GL10.GL_TEXTURE_2D, textures[indexB]);
// Set the face rotation
gl.glFrontFace(GL10.GL_CW);
// Point to our vertex buffer
gl.glVertexPointer(3, GL10.GL_FLOAT, 0, vertexBuffer);
gl.glTexCoordPointer(2, GL10.GL_FLOAT, 0, textureBuffer);
gl.glColor4f(1, 1, 1, Math.abs(alpha));
// Draw the vertices as triangle strip
gl.glDrawArrays(GL10.GL_TRIANGLE_STRIP, 0, vertices.length / 3);
//Disable the client state before leaving
gl.glDisableClientState(GL10.GL_VERTEX_ARRAY);
gl.glDisableClientState(GL10.GL_TEXTURE_COORD_ARRAY);
}
So, the problem is next: On Samsung S5, Alcatel One Touch 4033D and Motorolla Droid Razr textures are rendered fine. But on Samsung Galaxy Nexus I see only 'white box'.
I have tried to change size of texture to power of 2(512 x 512) but it not helpes.
In Square class add function:
public boolean isNPOTSupported(GL10 gl) {
String extensions = gl.glGetString(GL10.GL_EXTENSIONS);
return extensions.indexOf("GL_OES_texture_npot") != -1;
}
And when you Generate textures, add this:
final boolean isNPOTSupported = isNPOTSupported(gl);
if(isNPOTSupported) {
gl.glGenTextures(mImageEntityList.size(), textures, 0);
}else{
for(int i = 0; i < mImageEntityList.size(); i++){
gl.glGenTextures(1, textures, i);
}
}
Instead this:
gl.glGenTextures(mImageEntityList.size(), textures, 0);
I am trying to understand the concept of texture mapping. I tried to map a texture onto a square ( made up of 2 triangles ). However only the top left pixel of the image is rendered onto the square completely. Why does this happen? I have seen another post with the same issue .. but that solution doesnt work for me
Initial Setup
gl.glDisable(GL10.GL_DITHER); //Disable dithering ( NEW )
gl.glEnable(GL10.GL_TEXTURE_2D); //Enable Texture Mapping
gl.glShadeModel(GL10.GL_SMOOTH); //Enable Smooth Shading
gl.glClearColor(0.0f, 0.0f, 0.0f, 0.5f); //Black Background
gl.glClearDepthf(1.0f); //Depth Buffer Setup
gl.glEnable(GL10.GL_DEPTH_TEST); //Enables Depth Testing
gl.glDepthFunc(GL10.GL_LEQUAL); //The Type Of Depth Testing To Do
vertex coords -
private float[] _vertices = {0.0f, 0.0f,0.0f, 1.0f,
60.0f, 0.0f, 0.0f, 1.0f,
0.0f, 60.0f, 0.0f, 1.0f,
60.0f, 60.0f, 0.0f, 1.0f};
texture coords -
private float _texCoords[] = {0.0f, 1.0f,
1.0f, 1.0f,
0.0f, 0.0f,
1.0f, 0.0f };
Load texture method -
public void loadGLTexture(GL10 gl, Context context) {
//Get the texture from the Android resource directory
InputStream is = context.getResources().openRawResource(com.mhoapps.bugswatter.R.drawable.crate);
Bitmap bitmap = null;
try {
//BitmapFactory is an Android graphics utility for images
bitmap = BitmapFactory.decodeStream(is);
} finally {
//Always clear and close
try {
is.close();
is = null;
} catch (IOException e) {
}
}
// Generate one texture pointer...
gl.glGenTextures(1, _textures, 0);
int mTextureId = _textures[0];
// ...and bind it to our array
gl.glBindTexture(GL10.GL_TEXTURE_2D, mTextureId);
// Create Nearest Filtered Texture
gl.glTexParameterf(GL10.GL_TEXTURE_2D, GL10.GL_TEXTURE_MIN_FILTER,
GL10.GL_LINEAR);
gl.glTexParameterf(GL10.GL_TEXTURE_2D, GL10.GL_TEXTURE_MAG_FILTER,
GL10.GL_LINEAR);
// Use the Android GLUtils to specify a two-dimensional texture image
// from our bitmap
GLUtils.texImage2D(GL10.GL_TEXTURE_2D, 0, bitmap, 0); //Clean up
bitmap.recycle();
}
Finally the draw method
public void draw(GL10 gl) {
//Bind the texture according to the set texture filter
//gl.glLoadIdentity();
gl.glTranslatef(0.0f, 0.0f, -3.0f);
gl.glEnable(GL10.GL_TEXTURE_COORD_ARRAY);
gl.glBindTexture(GL10.GL_TEXTURE_2D, _textures[0]);
gl.glEnableClientState(GL10.GL_VERTEX_ARRAY);
gl.glVertexPointer(4, GL10.GL_FLOAT, 0, _currentVertexBuffer);
gl.glTexCoordPointer(2, GL10.GL_FLOAT, 0, _bugTexBuffer1);
gl.glDrawArrays(GL10.GL_TRIANGLE_STRIP, 0, 4);
gl.glDisableClientState(GL10.GL_VERTEX_ARRAY);
gl.glDisableClientState(GL10.GL_TEXTURE_COORD_ARRAY);
}
Are you specifying your texture coordinates? It sounds like you aren't, and they are just defaulting to (0, 0). Another options is the texture matrix - are you setting that to all zeroes?
I'm new to OpenGL and I'm developing an Augmented-reality application for Android.
Until now, I was drawing white squares, perpendicular to the camera, pointing the user to the direction where a "Point of interest" would be.
Now, I'm trying to show some text into the squares.
I've read a lot and it seems that creating a texture with the text is the most direct and easiest approach, so I'm creating the textures as soon as I get data of the Points of interest and stick them to their squares. For that, I use bitmaps.
Let's see some code. Within my onDrawFrame method, I do something like this:
public void onDrawFrame(GL10 gl) {
// Get sensors matrix
...
//Clear Screen And Depth Buffer
gl.glClear(GL10.GL_COLOR_BUFFER_BIT | GL10.GL_DEPTH_BUFFER_BIT);
// Load remapped matrix
gl.glMatrixMode(GL10.GL_MODELVIEW);
// List of Points of interest (modified when some data is downloaded)
synchronized (poiList) {
if(mNewData){ // True if new data has been dowloaded)
if(textures != null) // Delete old textures
gl.glDeleteTextures(textures.length, textures, 0);
textures = loadGLTexture(gl, soapPoiList.getPoiList());
mNewData = false;
}
int i = 0;
// Iterate the list
for (PointOfInterest c : poiList) {
gl.glLoadIdentity();
gl.glLoadMatrixf(remappedRotationMatrix, 0);
// Get bearing
...
// Place polygon in the right place
gl.glRotatef(-bearing, 0, 0, 1);
gl.glTranslatef(0, ICONS_SIZE_RATIO, 0);
// Actually draws the polygon with text
c.draw(gl, textures[i]);
i++;
}
}
}
Where loadGLTextures is:
protected int[] loadGLTexture(GL10 gl, List<PointOfInterest> l){
int res[] = new int[l.size()];
gl.glGenTextures(res.length, res, 0);
int i = 0;
for(PointOfInterest p : l) {
Bitmap bitmap = Bitmap.createBitmap(256, 256, Bitmap.Config.RGB_565);
bitmap.eraseColor(Color.BLACK);
Canvas canvas = new Canvas(bitmap);
Paint textPaint = new Paint();
textPaint.setTextSize(35);
textPaint.setFakeBoldText(true);
textPaint.setAntiAlias(true);
textPaint.setARGB(255, 255, 255, 255);
// Draw the text centered
canvas.drawText(Float.toString(p.getDinstanceToOrigin()) + " m.", 10,35, textPaint);
// Bind the texture to our array
gl.glBindTexture(GL10.GL_TEXTURE_2D, res[i]);
// Create Nearest Filtered Texture
gl.glTexParameterf(GL10.GL_TEXTURE_2D, GL10.GL_TEXTURE_MIN_FILTER, GL10.GL_LINEAR);
gl.glTexParameterf(GL10.GL_TEXTURE_2D, GL10.GL_TEXTURE_MAG_FILTER, GL10.GL_LINEAR);
gl.glTexParameterf(GL10.GL_TEXTURE_2D, GL10.GL_TEXTURE_WRAP_S, GL10.GL_CLAMP_TO_EDGE);
gl.glTexParameterf(GL10.GL_TEXTURE_2D, GL10.GL_TEXTURE_WRAP_T, GL10.GL_CLAMP_TO_EDGE);
GLUtils.texImage2D(GL10.GL_TEXTURE_2D, 0, bitmap, 0);
bitmap.recycle();
i++;
}
return res;
}
It basically creates a bitmap for each Point of Interest, and generate a texture with it. The texture will be applied over a white square later, as it is shown in this class:
public class PointOfInterest {
// MEMBERS ----------------------------------------------------------------
....
....
// OpenGL necessary variables
/** The buffer holding the vertices */
private FloatBuffer vertexBuffer;
/** The initial vertex definition */
private float vertices[] = {
-1.0f, 0.0f, -1.0f, //Bottom Left V1
-1.0f, 0.0f, 1.0f, //Top Left V2
1.0f, 0.0f, -1.0f, //Bottom Right V3
1.0f, 0.0f, 1.0f, //Top Right V4
};
private FloatBuffer textureBuffer;
private float texture[] = {
0.0f, 0.0f, // V1
1.0f, 0.0f, // V3
0.0f, 1.0f, // V2
1.0f, 1.0f // V4
};
// CONSTRUCTORS -----------------------------------------------------------
public PointOfInterest(Location originLocation){
currentLocation = originLocation;
mPoiLocation = new Location(LocationManager.GPS_PROVIDER);
ByteBuffer byteBuf = ByteBuffer.allocateDirect(vertices.length * 4);
byteBuf.order(ByteOrder.nativeOrder());
vertexBuffer = byteBuf.asFloatBuffer();
vertexBuffer.put(vertices);
vertexBuffer.position(0);
byteBuf = ByteBuffer.allocateDirect(texture.length * 4);
byteBuf.order(ByteOrder.nativeOrder());
textureBuffer = byteBuf.asFloatBuffer();
textureBuffer.put(texture);
textureBuffer.position(0);
}
// PUBLIC METHODS ---------------------------------------------------------
public void draw(GL10 gl, int textureId){
// Bind the previously generated texture
gl.glBindTexture(GL10.GL_TEXTURE_2D, textureId);
// Point to our buffers
gl.glEnableClientState(GL10.GL_VERTEX_ARRAY);
gl.glEnableClientState(GL10.GL_TEXTURE_COORD_ARRAY);
// set the colour for the square
//gl.glColor4f(0.0f, 0.1f, 0.0f, 0.5f);
//Set the face rotation
gl.glFrontFace(GL10.GL_CW);
//Point to our vertex buffer
gl.glVertexPointer(3, GL10.GL_FLOAT, 0, vertexBuffer);
gl.glTexCoordPointer(2, GL10.GL_FLOAT, 0, textureBuffer);
//Draw the vertices as triangle strip
gl.glDrawArrays(GL10.GL_TRIANGLE_STRIP, 0, vertices.length / 3);
//Disable the client state before leaving
gl.glDisableClientState(GL10.GL_VERTEX_ARRAY);
gl.glDisableClientState(GL10.GL_TEXTURE_COORD_ARRAY);
}
....
....
}
I have tried to map the texture as it is taught here and here with no success. I really don't know what to do to get some letters drawn on the squares and am really lost here... Maybe the text is being drawn on the other face of the square, maybe the textures are not being generated... I don't know.
Any kind of help would be very appreciated.
Okay, I had forgotten to enable texture mapping. You can do that within any method that uses the GL10 object. I prefer to do it within the draw method of my objects, so any other object is not affected by the texture. It's as simple as this (just changed 2 lines, the ones that say NEW!!):
public void draw(GL10 gl, int textureId){
gl.glEnable(GL10.GL_TEXTURE_2D); //NEW !!! Enable Texture Mapping
// Bind the previously generated texture
gl.glBindTexture(GL10.GL_TEXTURE_2D, textureId);
// Point to our buffers
gl.glEnableClientState(GL10.GL_VERTEX_ARRAY);
gl.glEnableClientState(GL10.GL_TEXTURE_COORD_ARRAY);
// set the colour for the square
//gl.glColor4f(0.0f, 0.1f, 0.0f, 0.5f);
//Set the face rotation
gl.glFrontFace(GL10.GL_CW);
//Point to our vertex buffer
gl.glVertexPointer(3, GL10.GL_FLOAT, 0, vertexBuffer);
gl.glTexCoordPointer(2, GL10.GL_FLOAT, 0, textureBuffer);
//Draw the vertices as triangle strip
gl.glDrawArrays(GL10.GL_TRIANGLE_STRIP, 0, vertices.length / 3);
//Disable the client state before leaving
gl.glDisableClientState(GL10.GL_VERTEX_ARRAY);
gl.glDisableClientState(GL10.GL_TEXTURE_COORD_ARRAY);
gl.glDisable(GL10.GL_TEXTURE_2D); ////NEW !!! Disable texture mapping
}
I have an android application that is drawing a 800*480 image on the screen. My phone is also 800*480 px. The phone is able to do the drawing in about 25 ms. Every few seconds i want to transition to another image which is also 800*480 by fading the alpha of the first image and increasing the alpha of the second image. While doing this the drawable.draw(canvas) call takes about 75 ms.
What can i do to reduce the drawing time during the transition phase? I have considered using OPENGL but i cannot figure it out.
Here is a simple example using OpenGL ES 1.0/1.1 and texture to draw bitmap to GLSurfaceView.
private static class BitmapRenderer implements GLSurfaceView.Renderer {
private int[] textures;
private Resources resources;
public BitmapRenderer(Resources resources) {
this.resources = resources;
}
private static final float[] VERTEX_COORDINATES = new float[] {
-1.0f, +1.0f, 0.0f,
+1.0f, +1.0f, 0.0f,
-1.0f, -1.0f, 0.0f,
+1.0f, -1.0f, 0.0f
};
private static final float[] TEXTURE_COORDINATES = new float[] {
0.0f, 0.0f,
1.0f, 0.0f,
0.0f, 1.0f,
1.0f, 1.0f
};
private static final Buffer TEXCOORD_BUFFER = ByteBuffer.allocateDirect(TEXTURE_COORDINATES.length * 4)
.order(ByteOrder.nativeOrder()).asFloatBuffer().put(TEXTURE_COORDINATES).rewind();
private static final Buffer VERTEX_BUFFER = ByteBuffer.allocateDirect(VERTEX_COORDINATES.length * 4)
.order(ByteOrder.nativeOrder()).asFloatBuffer().put(VERTEX_COORDINATES).rewind();
#Override
public void onSurfaceCreated(GL10 gl, EGLConfig config) {
textures = new int[1];
gl.glEnable(GL10.GL_TEXTURE_2D);
gl.glEnableClientState(GL10.GL_VERTEX_ARRAY);
gl.glEnableClientState(GL10.GL_TEXTURE_COORD_ARRAY);
gl.glGenTextures(1, textures, 0);
gl.glBindTexture(GL10.GL_TEXTURE_2D, textures[0]);
gl.glTexParameterf(GL10.GL_TEXTURE_2D, GL10.GL_TEXTURE_MAG_FILTER, GL10.GL_LINEAR);
gl.glTexParameterf(GL10.GL_TEXTURE_2D, GL10.GL_TEXTURE_MIN_FILTER, GL10.GL_LINEAR);
gl.glTexParameterf(GL10.GL_TEXTURE_2D, GL10.GL_TEXTURE_WRAP_S, GL10.GL_CLAMP_TO_EDGE);
gl.glTexParameterf(GL10.GL_TEXTURE_2D, GL10.GL_TEXTURE_WRAP_T, GL10.GL_CLAMP_TO_EDGE);
GLUtils.texImage2D(GL10.GL_TEXTURE_2D, 0, BitmapFactory.decodeResource(resources, R.mipmap.ic_launcher), 0);
}
#Override
public void onSurfaceChanged(GL10 gl, int width, int height) {
gl.glViewport(0, 0, width, height);
}
#Override
public void onDrawFrame(GL10 gl) {
gl.glActiveTexture(GL10.GL_TEXTURE0);
gl.glBindTexture(GL10.GL_TEXTURE_2D, textures[0]);
gl.glVertexPointer(3, GL10.GL_FLOAT, 0, VERTEX_BUFFER);
gl.glTexCoordPointer(2, GL10.GL_FLOAT, 0, TEXCOORD_BUFFER);
gl.glDrawArrays(GL10.GL_TRIANGLE_STRIP, 0, 4);
}
}
Then just use this Renderer in your GLSurfaceView
glSurfaceView.setEGLContextClientVersion(1);
glSurfaceView.setRenderer(new BitmapRenderer(getResources()));
glSurfaceView.setRenderMode(GLSurfaceView.RENDERMODE_WHEN_DIRTY);
Hope it would be helpful.
I had the same problem and found my performance in opengl.
This tutorial got me started: http://obviam.net/index.php/texture-mapping-opengl-android-displaying-images-using-opengl-and-squares/