android - 黑屏而不是多纹理

Question

我已经单独检查了纹理，它们工作正常。每个纹理都是 128*128 像素，我在摩托罗拉 MILESTONE 手机上工作，并测试了所有基本示例(从线到立方体贴图)，在多纹理处理时卡住了长方形。

如果我不绑定(bind)任何一个纹理，着色器运行良好，但问题始于两个用于多纹理的纹理。

private float[] myRotateMatrix = new float[16];
private float[] myViewMatrix = new float[16];
private float[] myProjectionMatrix = new float[16];
private float[] myMVPMatrix = new float[16];
private int aPositionLocation;
private int uMVPLocation;
private int aTextureCoordLocation;
private FloatBuffer rectangleVFB;
private ShortBuffer rectangleISB;
private FloatBuffer textureCFB;
private int program;
private int textureId1;
private int textureId2;
private int uSampler1Location;
private int uSampler2Location;

private void initShapes()  {
    float[] rectangleVFA = {-1,-1,0,  1,-1,0,  1,1,0, -1,1,0};
    short[] rectangleISA = {0,1,2,  0,3,2};
    float[] textureCFA = {0,0,  1,0,  1,1, 0,1};

    ByteBuffer rectangleVBB = ByteBuffer.allocateDirect(rectangleVFA.length * 4);
    rectangleVBB.order(ByteOrder.nativeOrder());
    rectangleVFB = rectangleVBB.asFloatBuffer();
    rectangleVFB.put(rectangleVFA);
    rectangleVFB.position(0);

    ByteBuffer rectangleIBB = ByteBuffer.allocateDirect(rectangleISA.length * 2);
    rectangleIBB.order(ByteOrder.nativeOrder());
    rectangleISB = rectangleIBB.asShortBuffer();
    rectangleISB.put(rectangleISA);
    rectangleISB.position(0);

    ByteBuffer textureCBB = ByteBuffer.allocateDirect(textureCFA.length * 4);
    textureCBB.order(ByteOrder.nativeOrder());
    textureCFB = textureCBB.asFloatBuffer();
    textureCFB.put(textureCFA);
    textureCFB.position(0);
}

public void onSurfaceChanged(GL10 gl, int width, int height)  {
    GLES20.glViewport(0, 0, width, height);
    checkError("glViewport");
    float ratio = (float) width / height;
    Matrix.setLookAtM(myViewMatrix, 0, 0, 0, 6, 0, 0, 0, 0, 1, 0);
    Matrix.frustumM(myProjectionMatrix, 0, -ratio, ratio, -1, 1, 3, 7);

    aPositionLocation = GLES20.glGetAttribLocation(program, "aPosition");
    checkError("glGetAttribLocation");

    uMVPLocation = GLES20.glGetUniformLocation(program, "uMVP");
    checkError("glGetUniformLocation");

    aTextureCoordLocation = GLES20.glGetAttribLocation(program, "aTextureCoord");
    checkError("glGetAttribLocation");

    uSampler1Location = GLES20.glGetUniformLocation(program, "uSampler1");
    checkError("glGetUniformLocation");

    uSampler2Location = GLES20.glGetUniformLocation(program, "uSampler2");
    checkError("glGetUniformLocation");

    int[] textures = new int[2];

    GLES20.glGenTextures(2, textures, 0);
    checkError("glGenTextures");

    textureId1 = textures[0];
    textureId2 = textures[1];

    GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, textureId1);
    checkError("glBindTexture");

    InputStream is1 = context.getResources().openRawResource(R.drawable.brick1);
    Bitmap img1;
    try  {
        img1 = BitmapFactory.decodeStream(is1);
    }finally  {
        try {
            is1.close();
        }catch (IOException ioe) {
        }
    }
    GLUtils.texImage2D(GLES20.GL_TEXTURE_2D, 0, img1, 0);

    GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, textureId2);
    checkError("glBindTexture");

    InputStream is2 = context.getResources().openRawResource(R.drawable.brick2);
    Bitmap img2;
    try  {
        img2 = BitmapFactory.decodeStream(is2);
    }finally  {
        try  {
            is2.close();
        }catch (IOException ioe) {
        }
    }
    GLUtils.texImage2D(GLES20.GL_TEXTURE_2D, 0, img2, 0);

    GLES20.glPixelStorei(GLES20.GL_UNPACK_ALIGNMENT, 1);
    GLES20.glTexParameterf(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_MIN_FILTER, GLES20.GL_LINEAR);
    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);
}

public void onDrawFrame(GL10 gl)  {
    GLES20.glClear(GLES20.GL_COLOR_BUFFER_BIT | GLES20.GL_DEPTH_BUFFER_BIT);
    checkError("glClear");

    GLES20.glUseProgram(program);
    checkError("glUseProgram");

    GLES20.glActiveTexture(GLES20.GL_TEXTURE0);
    checkError("glActiveTexture");
    GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, textureId1);
    checkError("glBindTexture");

    GLES20.glUniform1i(uSampler1Location, 0);
    checkError("glUniform1i");

    GLES20.glActiveTexture(GLES20.GL_TEXTURE1);
    checkError("glActiveTexture");
    GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, textureId2);
    checkError("glBindTexture");

    GLES20.glUniform1i(uSampler2Location, 1);
    checkError("glUniform1i");

    Matrix.setIdentityM(myRotateMatrix, 0);
    Matrix.rotateM(myRotateMatrix, 0, touchX, 0, 1, 0);
    Matrix.rotateM(myRotateMatrix, 0, touchY, 1, 0, 0);
    Matrix.multiplyMM(myMVPMatrix, 0, myViewMatrix, 0, myRotateMatrix, 0);
    Matrix.multiplyMM(myMVPMatrix, 0, myProjectionMatrix, 0, myMVPMatrix, 0);

    GLES20.glVertexAttribPointer(aPositionLocation, 3, GLES20.GL_FLOAT, false, 12, rectangleVFB);
    checkError("glVertexAttribPointer");

    GLES20.glEnableVertexAttribArray(aPositionLocation);
    checkError("glEnableVertexAttribArray");

    GLES20.glVertexAttribPointer(aTextureCoordLocation, 2, GLES20.GL_FLOAT, false, 8, textureCFB);
    checkError("glVertexAttribPointer");

    GLES20.glEnableVertexAttribArray(aTextureCoordLocation);
    checkError("glEnableVertexAttribArray");

    GLES20.glUniformMatrix4fv(uMVPLocation, 1, false, myMVPMatrix, 0);
    checkError("glUniformMatrix4fv");

    GLES20.glDrawElements(GLES20.GL_TRIANGLES, 6, GLES20.GL_UNSIGNED_SHORT, rectangleISB);
    checkError("glDrawElements");
}

Answer 1

在 OpenGL ES 2.0 中，在每次调用 glBindTexture 之后和 texImage2D 之前，必须单独指定该纹理的参数。

因此，如果有 2 个纹理(如在多纹理中)，则纹理 1 和 2 各需要 4 个 glTexParameterf，总共 8 个。