如何使用GPUImageLibrary"减去"滤色器？

Question

目前BlendModes(减去,排除等)使用LauncherImage作为掩码.我可以将这些BlendModes应用于ColorMatrix吗？

我正在使用GPUImageLibrary:

colorMatrix[
    0.393, 0.7689999, 0.18899999, 0, 0,
    0.349, 0.6859999, 0.16799999, 0, 0,
    0.272, 0.5339999, 0.13099999, 0, 0,
    0,     0,         0,          1, 0];

SubtractBlendFilter.java

public class GPUImageSubtractBlendFilter extends GPUImageTwoInputFilter {
    public static final String SUBTRACT_BLEND_FRAGMENT_SHADER = "varying highp vec2 textureCoordinate;\n" +
            " varying highp vec2 textureCoordinate2;\n" +
            "\n" +
            " uniform sampler2D inputImageTexture;\n" +
            " uniform sampler2D inputImageTexture2;\n" +
            " \n" +
            " void main()\n" +
            " {\n" +
            "   lowp vec4 textureColor = texture2D(inputImageTexture, textureCoordinate);\n" +
            "   lowp vec4 textureColor2 = texture2D(inputImageTexture2, textureCoordinate2);\n" +
            "\n" +
            "   gl_FragColor = vec4(textureColor.rgb - textureColor2.rgb, textureColor.a);\n" +
            " }";

    public GPUImageSubtractBlendFilter() {
        super(SUBTRACT_BLEND_FRAGMENT_SHADER);
    }
}

GPUIMageTwoInputFilter.java

public class GPUImageTwoInputFilter extends GPUImageFilter {
    private static final String VERTEX_SHADER = "attribute vec4 position;\n" +
            "attribute vec4 inputTextureCoordinate;\n" +
            "attribute vec4 inputTextureCoordinate2;\n" +
            " \n" +
            "varying vec2 textureCoordinate;\n" +
            "varying vec2 textureCoordinate2;\n" +
            " \n" +
            "void main()\n" +
            "{\n" +
            "    gl_Position = position;\n" +
            "    textureCoordinate = inputTextureCoordinate.xy;\n" +
            "    textureCoordinate2 = inputTextureCoordinate2.xy;\n" +
            "}";

    public int mFilterSecondTextureCoordinateAttribute;
    public int mFilterInputTextureUniform2;
    public int mFilterSourceTexture2 = OpenGlUtils.NO_TEXTURE;
    private ByteBuffer mTexture2CoordinatesBuffer;
    private Bitmap mBitmap;

    public GPUImageTwoInputFilter(String fragmentShader) {
        this(VERTEX_SHADER, fragmentShader);
    }

    public GPUImageTwoInputFilter(String vertexShader, String fragmentShader) {
        super(vertexShader, fragmentShader);
        setRotation(Rotation.NORMAL, false, false);
    }

    @Override
    public void onInit() {
        super.onInit();

        mFilterSecondTextureCoordinateAttribute = GLES20.glGetAttribLocation(getProgram(), "inputTextureCoordinate2");
        mFilterInputTextureUniform2 = GLES20.glGetUniformLocation(getProgram(), "inputImageTexture2"); // This does assume a name of "inputImageTexture2" for second input texture in the fragment shader
        GLES20.glEnableVertexAttribArray(mFilterSecondTextureCoordinateAttribute);

        if (mBitmap != null&&!mBitmap.isRecycled()) {
            setBitmap(mBitmap);
        }
    }

    public void setBitmap(final Bitmap bitmap) {
        if (bitmap != null && bitmap.isRecycled()) {
            return;
        }
        mBitmap = bitmap;
        if (mBitmap == null) {
            return;
        }
        runOnDraw(new Runnable() {
            public void run() {
                if (mFilterSourceTexture2 == OpenGlUtils.NO_TEXTURE) {
                    if (bitmap == null || bitmap.isRecycled()) {
                        return;
                    }
                    GLES20.glActiveTexture(GLES20.GL_TEXTURE3);
                    mFilterSourceTexture2 = OpenGlUtils.loadTexture(bitmap, OpenGlUtils.NO_TEXTURE, false);
                }
            }
        });
    }

    public Bitmap getBitmap() {
        return mBitmap;
    }

    public void recycleBitmap() {
        if (mBitmap != null && !mBitmap.isRecycled()) {
            mBitmap.recycle();
            mBitmap = null;
        }
    }

    public void onDestroy() {
        super.onDestroy();
        GLES20.glDeleteTextures(1, new int[]{
                mFilterSourceTexture2
        }, 0);
        mFilterSourceTexture2 = OpenGlUtils.NO_TEXTURE;
    }

    @Override
    protected void onDrawArraysPre() {
        GLES20.glEnableVertexAttribArray(mFilterSecondTextureCoordinateAttribute);
        GLES20.glActiveTexture(GLES20.GL_TEXTURE3);
        GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, mFilterSourceTexture2);
        GLES20.glUniform1i(mFilterInputTextureUniform2, 3);

        mTexture2CoordinatesBuffer.position(0);
        GLES20.glVertexAttribPointer(mFilterSecondTextureCoordinateAttribute, 2, GLES20.GL_FLOAT, false, 0, mTexture2CoordinatesBuffer);
    }

    public void setRotation(final Rotation rotation, final boolean flipHorizontal, final boolean flipVertical) {
        float[] buffer = TextureRotationUtil.getRotation(rotation, flipHorizontal, flipVertical);

        ByteBuffer bBuffer = ByteBuffer.allocateDirect(32).order(ByteOrder.nativeOrder());
        FloatBuffer fBuffer = bBuffer.asFloatBuffer();
        fBuffer.put(buffer);
        fBuffer.flip();

        mTexture2CoordinatesBuffer = bBuffer;
    }
}

我猜它涉及用String SUBTRACT_BLEND_GRAGMENT_SHADER&改变一些东西String VERTEX_SHADER .

Answer 1

颜色矩阵是将某些像素的新颜色分量值定义为同一像素当前颜色分量的线性函数的实体。即颜色矩阵转换的唯一输入是像素，应转换哪些颜色。无法让其他像素参与此类转换。无论它们是来自另一幅图像的像素还是变换后像素的邻居——这是不可能的。