OpenGL ES2:在片段着色器中使用Mali的多个纹理

Question

我目前正在尝试让多个纹理在android上工作(使用一个碎片着色器)。它在我的Nexus4上运行良好，但在我测试过的所有三星设备上，它根本不显示矩形。问题似乎是texture2d在片段着色器代码中被调用了两次：

precision mediump float;                
uniform sampler2D uTexture;
uniform sampler2D refractTexture;       
varying vec2 vTexCoordinate;
varying vec2 vRefTexCoordinate;

void main() {
    vec2 scaleVec = vec2(0.05, 0.05);
    vec4 bumpTex = 2.0 * texture2D(refractTexture, vRefTexCoordinate) - 1.0;
    vec2 refCoords = vTexCoordinate.xy + bumpTex.xy * scaleVec;

    gl_FragColor = texture2D(uTexture, refCoords);
}

在此着色器中，我使用法线贴图(refractTexture)扭曲纹理(uTexture)。我试过使用正确的(而不是计算出来的) gl_FragColor坐标，一旦我删除了vec4 bumpTex = 2.0 * texture2D(refractTexture, vRefTexCoordinate) - 1.0;，它就会出现在设备上。

任何提示都会有所帮助。

这里请求的是我用来设置纹理的Java代码：

    mTextureUniformHandle = GLES20.glGetUniformLocation(mProgram,
            "uTexture");

    GLES20.glActiveTexture(GLES20.GL_TEXTURE0);

    GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, mTextureDataHandle);

    GLES20.glUniform1i(mTextureUniformHandle, 0);

    if (refractNormal && textureRefBuffer != null) {
        mTextureRefUniHandle = GLES20.glGetUniformLocation(mProgram,
                "refractTexture");

        GLES20.glActiveTexture(GLES20.GL_TEXTURE1);

        GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, mTextureRefDataHandle);

        GLES20.glUniform1i(mTextureRefUniHandle, 1);

        mTextureRefCoordinateHandle = GLES20.glGetAttribLocation(mProgram,
                "aRefTexCoordinate");

        GLES20.glVertexAttribPointer(mTextureRefCoordinateHandle,
                mTextureCoordinateDataSize, GLES20.GL_FLOAT, false, 0,
                textureRefBuffer);
        GLES20.glEnableVertexAttribArray(mTextureRefCoordinateHandle);

    }

    mTextureCoordinateHandle = GLES20.glGetAttribLocation(mProgram,
            "aTexCoordinate");
    GLES20.glVertexAttribPointer(mTextureCoordinateHandle,
            mTextureCoordinateDataSize, GLES20.GL_FLOAT, false, 0,
            textureBuffer);
    GLES20.glEnableVertexAttribArray(mTextureCoordinateHandle);

顶点着色器的C代码：

        uniform mat4 uMVPMatrix;
        attribute vec4 vPosition;
        attribute vec2 aTexCoordinate;
        attribute vec2 aRefTexCoordinate;
        varying vec2 vTexCoordinate;
        varying vec2 vRefTexCoordinate;

        void main() {         
            vTexCoordinate = aTexCoordinate;
            vRefTexCoordinate = aRefTexCoordinate;
            gl_Position =   uMVPMatrix*vPosition;
        }

Answer 1

我建议我在ARM论坛上寻求帮助，在那里有人向我索要一个示例项目。我沉重地剥离了我所拥有的，并对其进行了测试。令人惊讶的是，它在S3上运行没有问题，我在上面测试了它。我试图通过从我的原始项目中复制代码来查找问题，最终我将着色器从小项目复制到原始项目中，并以某种方式完成了这项工作。我真的不知道到底是什么导致了这个问题，但下面是为我工作的着色器代码：

        precision mediump float;
        uniform vec4 vColor;
        uniform sampler2D uTexture;
        uniform sampler2D refractTexture;   
        varying vec2 vTexCoordinate;
        varying vec2 vRefTexCoordinate;                     

        void main() {   

            vec2 scaleVec = vec2(0.05, 0.05);
            vec4 bumpTex = 2.0 * texture2D(refractTexture, vRefTexCoordinate) - 1.0;
            vec2 refCoords = vTexCoordinate.xy + bumpTex.xy * scaleVec;     
            gl_FragColor = texture2D(uTexture, refCoords);

        }

和顶点着色器：

        uniform mat4 uMVPMatrix;
        attribute vec4 vPosition;
        attribute vec2 aTexCoordinate;
        attribute vec2 aRefTexCoordinate;
        varying vec2 vTexCoordinate;
        varying vec2 vRefTexCoordinate;

        void main() {         
            vTexCoordinate = aTexCoordinate;
            vRefTexCoordinate = aRefTexCoordinate;
            gl_Position =   uMVPMatrix*vPosition;

        }