【发布时间】：2012-09-23 20:38:09
【问题描述】：
我已经在 Android 上使用 OPENGL 库完成了一个 3d 立方体，立方体工作得很好，但是要在立方体上打印的图像没有显示...
这是我的渲染代码（java 类）：
public class GLRenderEx implements Renderer {
private GLCube cube;
Context c;
public GLRenderEx(Context c) {
cube = new GLCube();
this.c = c;
}
@Override
public void onDrawFrame(GL10 gl) {
gl.glDisable(GL10.GL_DITHER);
gl.glClear(GL10.GL_COLOR_BUFFER_BIT | GL10.GL_DEPTH_BUFFER_BIT);
gl.glMatrixMode(GL10.GL_MODELVIEW);
gl.glLoadIdentity();
GLU.gluLookAt(gl, 0, 0, -3, 0, 0, 0, 0, 2, 0);
long time = SystemClock.uptimeMillis() % 4000L;
float angle = .090f * ((int) time);
gl.glRotatef(angle, 2, 4, 3);
cube.draw(gl);
}
@Override
public void onSurfaceChanged(GL10 gl, int width, int height) {
// TODO Auto-generated method stub
gl.glViewport(0, 0, width, height);
float ratio = (float) width / height;
gl.glMatrixMode(GL10.GL_PROJECTION);
gl.glLoadIdentity();
gl.glFrustumf(-ratio, ratio, -1, 1, 1, 25);
}
@Override
public void onSurfaceCreated(GL10 gl, EGLConfig egl) {
gl.glDisable(GL10.GL_DITHER);
gl.glHint(GL10.GL_PERSPECTIVE_CORRECTION_HINT, GL10.GL_FASTEST);
gl.glClearColor(0f, 0f, 0f, 1);
gl.glClearDepthf(1f);
}
}
这是我的立方体的代码：
public class GLCube {
/** The buffer holding the vertices */
private FloatBuffer vertexBuffer;
/** The buffer holding the texture coordinates */
private FloatBuffer textureBuffer;
/** The buffer holding the indices */
private ByteBuffer indexBuffer;
/** Our texture pointer */
private int[] textures = new int[1];
/**
* The initial vertex definition
*
* Note that each face is defined, even if indices are available, because of
* the texturing we want to achieve
*/
private float vertices[] = {
// Vertices according to faces
-1.0f,
-1.0f,
1.0f, // Vertex 0
1.0f,
-1.0f,
1.0f, // v1
-1.0f,
1.0f,
1.0f, // v2
1.0f,
1.0f,
1.0f, // v3
1.0f,
-1.0f,
1.0f, // ...
1.0f, -1.0f, -1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, -1.0f,
1.0f, -1.0f, -1.0f, -1.0f, -1.0f, -1.0f, 1.0f, 1.0f, -1.0f, -1.0f,
1.0f, -1.0f,
-1.0f, -1.0f, -1.0f, -1.0f, -1.0f, 1.0f, -1.0f, 1.0f, -1.0f, -1.0f,
1.0f, 1.0f,
-1.0f, -1.0f, -1.0f, 1.0f, -1.0f, -1.0f, -1.0f, -1.0f, 1.0f, 1.0f,
-1.0f, 1.0f,
-1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, -1.0f, 1.0f, -1.0f, 1.0f,
1.0f, -1.0f, };
/** The initial texture coordinates (u, v) */
private float texture[] = {
// Mapping coordinates for the vertices
0.0f, 0.0f, 0.0f, 1.0f, 1.0f, 0.0f, 1.0f, 1.0f,
0.0f, 0.0f, 0.0f, 1.0f, 1.0f, 0.0f, 1.0f, 1.0f,
0.0f, 0.0f, 0.0f, 1.0f, 1.0f, 0.0f, 1.0f, 1.0f,
0.0f, 0.0f, 0.0f, 1.0f, 1.0f, 0.0f, 1.0f, 1.0f,
0.0f, 0.0f, 0.0f, 1.0f, 1.0f, 0.0f, 1.0f, 1.0f,
0.0f, 0.0f, 0.0f, 1.0f, 1.0f, 0.0f, 1.0f, 1.0f,
};
/** The initial indices definition */
private byte indices[] = {
// Faces definition
0, 1, 3, 0, 3,
2, // Face front
4, 5, 7, 4, 7,
6, // Face right
8, 9, 11, 8, 11,
10, // ...
12, 13, 15, 12, 15, 14, 16, 17, 19, 16, 19, 18, 20, 21, 23, 20, 23,
22, };
/**
* The Cube constructor.
*
* Initiate the buffers.
*/
public GLCube() {
//
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);
//
indexBuffer = ByteBuffer.allocateDirect(indices.length);
indexBuffer.put(indices);
indexBuffer.position(0);
}
/**
* The object own drawing function. Called from the renderer to redraw this
* instance with possible changes in values.
*
* @param gl
* - The GL Context
*/
public void draw(GL10 gl) {
// Bind our only previously generated texture in this case
gl.glBindTexture(GL10.GL_TEXTURE_2D, textures[0]);
gl.glEnable(GL10.GL_TEXTURE_2D);
// Point to our buffers
gl.glEnableClientState(GL10.GL_VERTEX_ARRAY);
gl.glEnableClientState(GL10.GL_TEXTURE_COORD_ARRAY);
// Set the face rotation
gl.glFrontFace(GL10.GL_CCW);
// Enable the vertex and texture state
gl.glVertexPointer(3, GL10.GL_FLOAT, 0, vertexBuffer);
gl.glTexCoordPointer(2, GL10.GL_FLOAT, 0, textureBuffer);
// Draw the vertices as triangles, based on the Index Buffer information
gl.glDrawElements(GL10.GL_TRIANGLES, indices.length,
GL10.GL_UNSIGNED_BYTE, indexBuffer);
// Disable the client state before leaving
gl.glDisableClientState(GL10.GL_VERTEX_ARRAY);
gl.glDisableClientState(GL10.GL_TEXTURE_COORD_ARRAY);
}
/**
* Load the textures
*
* @param gl
* - The GL Context
* @param context
* - The Activity context
*/
public void loadGLTexture(GL10 gl, Context context) {
// Get the texture from the Android resource directory
InputStream is = context.getResources().openRawResource(
R.drawable.ic_launcher);
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);
// ...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);
// Different possible texture parameters, e.g. GL10.GL_CLAMP_TO_EDGE
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);
// 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();
}
}
为什么我的代码上的位图没有显示在立方体中？？！！
谢谢。
【问题讨论】：
-
您似乎在设置中忘记了
glActiveTexture( GL_TEXTURE0 )。
标签： java android opengl-es bitmap cube