Question

我正在制作Android应用以拍摄照片并使用过滤器。过滤器由android.media.effect包提供。要使用滤镜，我必须在GL曲面上绘制位图。

当我绘制它时，会裁剪位图。第一个截图是我拍照时的情况。第二个是当我在表面上绘制它时。

我对OpenGl了解不多，但我花了很多时间来搜索问题，但我仍然没有解决方案。我把我的代码放在下面，我伸出手指，也许有人有解决方案。

非常感谢您阅读。

意图的输入：

public class PhotoEditor extends AppCompatActivity {

private GLSurfaceView surface;
private Bitmap bmp;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_photo_editor);

    Intent i = getIntent();
    Uri uri = Uri.parse("file://" + i.getStringExtra("photo_uri"));

    try {
        bmp = MediaStore.Images.Media.getBitmap(getContentResolver(), uri);
    } catch (IOException e) {
        Log.d("photoapp", "Impossible de charger la photo.");

        return;
    }

    surface = (GLSurfaceView) findViewById(R.id.glSurface);;
    surface.setEGLContextClientVersion(2);
    surface.setRenderer(new EffectsRenderer(this, bmp));
    surface.setRenderMode(GLSurfaceView.RENDERMODE_WHEN_DIRTY);
}}

渲染器：

public class EffectsRenderer implements GLSurfaceView.Renderer {

private Bitmap bmp;
private int width, height;

private int textures[] = new int[2];
private Square square;

private EffectContext effectContext;
private Effect effect;

public EffectsRenderer(Context context, Bitmap bmp) {
    super();
    this.bmp = bmp;
    width = bmp.getWidth();
    height = bmp.getHeight();
    Log.d("photoapp", "width : " + width);
    Log.d("photoapp", "height : " + height);
}

@Override
public void onSurfaceCreated(GL10 gl, EGLConfig config) {

}

@Override
public void onSurfaceChanged(GL10 gl, int width, int height) {
    GLES20.glViewport(0,0,width, height);
    GLES20.glClearColor(0,0,0,1);
    generateSquare();
}

@Override
public void onDrawFrame(GL10 gl) {
    if(null == effectContext) {
        effectContext = EffectContext.createWithCurrentGlContext();
    }

    if(null != effect){
        effect.release();
    }

    grayScaleEffect();

    square.draw(textures[1]);
}

private void grayScaleEffect(){
    EffectFactory factory = effectContext.getFactory();
    effect = factory.createEffect(EffectFactory.EFFECT_GRAYSCALE);
    effect.apply(textures[0], width, height, textures[1]);
}

private void generateSquare(){
    GLES20.glGenTextures(2, textures, 0);
    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);
    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, bmp, 0);
    square = new Square();
}}

方形类：

public class Square {

private float[] vertices = {
        -1f, -1f,
        1f, -1f,
        -1f, 1f,
        1f, 1f
};

private float[] textureVertices = {
        0f, 1f,
        1f, 1f,
        0f, 0f,
        1f, 0f
};

private final String vertexShaderCode =
        "attribute vec4 aPosition;" +
                "attribute vec2 aTexPosition;" +
                "varying vec2 vTexPosition;" +
                "void main() {" +
                "  gl_Position = aPosition;" +
                "  vTexPosition = aTexPosition;" +
                "}";

private final String fragmentShaderCode =
        "precision mediump float;" +
                "uniform sampler2D uTexture;" +
                "varying vec2 vTexPosition;" +
                "void main() {" +
                "  gl_FragColor = texture2D(uTexture, vTexPosition);" +
                "}";

private FloatBuffer verticesBuffer;
private FloatBuffer textureBuffer;

private int vertexShader;
private int fragmentShader;
private int program;

public Square() {
    initializeBuffers();
    initializeProgram();
}

private void initializeBuffers() {
    ByteBuffer buff = ByteBuffer.allocateDirect(vertices.length * 4);
    buff.order(ByteOrder.nativeOrder());
    verticesBuffer = buff.asFloatBuffer();
    verticesBuffer.put(vertices);
    verticesBuffer.position(0);

    buff = ByteBuffer.allocateDirect(textureVertices.length * 4);
    buff.order(ByteOrder.nativeOrder());
    textureBuffer = buff.asFloatBuffer();
    textureBuffer.put(textureVertices);
    textureBuffer.position(0);
}

private void initializeProgram() {
    vertexShader = GLES20.glCreateShader(GLES20.GL_VERTEX_SHADER);
    GLES20.glShaderSource(vertexShader, vertexShaderCode);
    GLES20.glCompileShader(vertexShader);

    fragmentShader = GLES20.glCreateShader(GLES20.GL_FRAGMENT_SHADER);
    GLES20.glShaderSource(fragmentShader, fragmentShaderCode);
    GLES20.glCompileShader(fragmentShader);

    program = GLES20.glCreateProgram();
    GLES20.glAttachShader(program, vertexShader);
    GLES20.glAttachShader(program, fragmentShader);

    GLES20.glLinkProgram(program);
}

public void draw(int texture) {
    GLES20.glBindFramebuffer(GLES20.GL_FRAMEBUFFER, 0);
    GLES20.glUseProgram(program);
    GLES20.glDisable(GLES20.GL_BLEND);

    int positionHandle = GLES20.glGetAttribLocation(program, "aPosition");
    int textureHandle = GLES20.glGetUniformLocation(program, "uTexture");
    int texturePositionHandle = GLES20.glGetAttribLocation(program, "aTexPosition");

    GLES20.glVertexAttribPointer(texturePositionHandle, 2, GLES20.GL_FLOAT, false, 0, textureBuffer);
    GLES20.glEnableVertexAttribArray(texturePositionHandle);

    GLES20.glActiveTexture(GLES20.GL_TEXTURE0);
    GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, texture);
    GLES20.glUniform1i(textureHandle, 0);

    GLES20.glVertexAttribPointer(positionHandle, 2, GLES20.GL_FLOAT, false, 0, verticesBuffer);
    GLES20.glEnableVertexAttribArray(positionHandle);

    GLES20.glClear(GLES20.GL_COLOR_BUFFER_BIT);
    GLES20.glDrawArrays(GLES20.GL_TRIANGLE_STRIP, 0, 4);
}}

OpenGL ES绘制位图

0 个答案: