StackOverflow2013

Note that there are some explanatory texts on larger screens.

plurals

POGLES20 Texture Not Working on Some Devices
text
Body
copied!<p>I have tried to add a fairly simple extension on top of <a href="http://developer.android.com/training/graphics/opengl/index.html" rel="nofollow">Android's example OpenGL 2.0 project</a> in order to add texturing to basic shapes. This <strong>seems</strong> pretty straightforward, but on certain devices (Samsung Nexus S, LG Optimus 3D, Samsung Galaxy S) the texture just does not render. </p> <p><em>This is actually a problem that I am having on a much larger project, but I was able to reproduce the issue with the simple project below in the hope that someone here has an idea of where my code presents issues, or how to specifically architect GL textures for these devices (maybe there are issues with the devices).</em></p> <p>To give an idea of how this object is used: In the GLSurfaceView.Renderer's <code>onSurfaceCreated</code> method I am instantiating a <code>Square()</code> object and in the <code>onDrawFrame</code> method I am calling Square's <code>draw()</code> method. However, all of the relevant code to dealing with textures should appear in this Square class which is almost exactly identical to Google's own example.</p> <p>Many thanks in advance to anyone who takes a crack at this. </p> <pre><code>class Square { private final String vertexShaderCode = // This matrix member variable provides a hook to manipulate // the coordinates of the objects that use this vertex shader "uniform mat4 uMVPMatrix;" + "attribute vec4 vPosition;" + "attribute vec2 a_TexCoordinate;" + "varying vec2 v_TexCoordinate;" + "void main() {" + // the matrix must be included as a modifier of gl_Position " gl_Position = vPosition * uMVPMatrix;" + " v_TexCoordinate = a_TexCoordinate;" + "}"; private final String fragmentShaderCode = "precision mediump float;" + "uniform sampler2D u_Texture;" + "varying vec2 v_TexCoordinate;" + "void main() {" + " gl_FragColor = texture2D(u_Texture, v_TexCoordinate);" + "}"; private final FloatBuffer vertexBuffer; private final FloatBuffer textureBuffer; private final ShortBuffer drawListBuffer; private final int mProgram; private int mPositionHandle; private int mColorHandle; private int mMVPMatrixHandle; // number of coordinates per vertex in this array static final int COORDS_PER_VERTEX = 3; static float squareCoords[] = { -0.5f, 0.5f, 0.0f, // top left -0.5f, -0.5f, 0.0f, // bottom left 0.5f, -0.5f, 0.0f, // bottom right 0.5f, 0.5f, 0.0f }; // top right final float[] previewTextureCoordinateData = { 0.0f, 1.0f, 0.0f, 0.0f, 1.0f, 1.0f, 1.0f, 0.0f }; private int textureDataHandle; private int textureUniformHandle; private int textureCoordinateHandle; private final short drawOrder[] = { 0, 1, 2, 0, 2, 3 }; // order to draw vertices private final int vertexStride = COORDS_PER_VERTEX * 4; // 4 bytes per vertex // Set color with red, green, blue and alpha (opacity) values float color[] = { 0.2f, 0.709803922f, 0.898039216f, 1.0f }; private int loadTexture(final Context context, final int resourceId) { final int[] textureHandle = new int[1]; GLES20.glGenTextures(1, textureHandle, 0); if (textureHandle[0] != 0) { final BitmapFactory.Options options = new BitmapFactory.Options(); options.inScaled = false; // No pre-scaling // Read in the resource final Bitmap bitmap = BitmapFactory.decodeResource(context.getResources(), resourceId, options); // Bind to the texture in OpenGL GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, textureHandle[0]); // Set filtering 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); // Load the bitmap into the bound texture. GLUtils.texImage2D(GLES20.GL_TEXTURE_2D, 0, bitmap, 0); // Recycle the bitmap, since its data has been loaded into OpenGL. bitmap.recycle(); } if (textureHandle[0] == 0) { throw new RuntimeException("Error loading texture."); } return textureHandle[0]; } public Square(Context context) { // initialize vertex byte buffer for shape coordinates ByteBuffer bb = ByteBuffer.allocateDirect( // (# of coordinate values * 4 bytes per float) squareCoords.length * 4); bb.order(ByteOrder.nativeOrder()); vertexBuffer = bb.asFloatBuffer(); vertexBuffer.put(squareCoords); vertexBuffer.position(0); // initialize byte buffer for the draw list ByteBuffer dlb = ByteBuffer.allocateDirect( // (# of coordinate values * 2 bytes per short) drawOrder.length * 2); dlb.order(ByteOrder.nativeOrder()); drawListBuffer = dlb.asShortBuffer(); drawListBuffer.put(drawOrder); drawListBuffer.position(0); ByteBuffer texCoordinates = ByteBuffer.allocateDirect(previewTextureCoordinateData.length * 4); texCoordinates.order(ByteOrder.nativeOrder()); textureBuffer = texCoordinates.asFloatBuffer(); textureBuffer.put(previewTextureCoordinateData); textureBuffer.position(0); // prepare shaders and OpenGL program int vertexShader = MyGLRenderer.loadShader(GLES20.GL_VERTEX_SHADER, vertexShaderCode); int fragmentShader = MyGLRenderer.loadShader(GLES20.GL_FRAGMENT_SHADER, fragmentShaderCode); textureDataHandle = loadTexture(context, R.drawable.color_texture); mProgram = GLES20.glCreateProgram(); // create empty OpenGL Program GLES20.glAttachShader(mProgram, vertexShader); // add the vertex shader to program GLES20.glAttachShader(mProgram, fragmentShader); // add the fragment shader to program GLES20.glLinkProgram(mProgram); // create OpenGL program executables } 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); textureCoordinateHandle = GLES20.glGetAttribLocation(mProgram, "a_TexCoordinate"); GLES20.glVertexAttribPointer(textureCoordinateHandle, 2, GLES20.GL_FLOAT, false, 0, textureBuffer); GLES20.glEnableVertexAttribArray(textureCoordinateHandle); textureUniformHandle = GLES20.glGetUniformLocation(mProgram, "u_Texture"); MyGLRenderer.checkGlError("glGetUniformLocation"); GLES20.glActiveTexture(GLES20.GL_TEXTURE0); GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, textureDataHandle); GLES20.glUniform1i(textureUniformHandle, 0); // get handle to shape's transformation matrix mMVPMatrixHandle = GLES20.glGetUniformLocation(mProgram, "uMVPMatrix"); MyGLRenderer.checkGlError("glGetUniformLocation"); // Apply the projection and view transformation GLES20.glUniformMatrix4fv(mMVPMatrixHandle, 1, false, mvpMatrix, 0); MyGLRenderer.checkGlError("glUniformMatrix4fv"); // Draw the square GLES20.glDrawElements(GLES20.GL_TRIANGLES, drawOrder.length, GLES20.GL_UNSIGNED_SHORT, drawListBuffer); // Disable vertex array GLES20.glDisableVertexAttribArray(mPositionHandle); } } </code></pre>

Querying!

Guidance

An individual column

Larger individual text columns get their own page to allow for proper reading.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload