OpenGL动效滤镜，其最主要的因素，是将时间因素传递进去再做一系列的滤镜变化处理。
首先我们来看时间因素怎么传递进去，其代码：
//使用program
glUseProgram(self.program);
//绑定buffer
glBindBuffer(GL_ARRAY_BUFFER, self.vertexBuffer);
// 传入时间
CGFloat currentTime = self.displayLink.timestamp - self.startTimeInterval;
GLuint time = glGetUniformLocation(self.program, "Time");
glUniform1f(time, currentTime);
这样就可以将外部时间传递给片元着色器进去计算处理，根据时间作出相应的改变
其主要滤镜表达有，缩放，灵魂出窍，抖动，闪白，毛刺，幻觉
灵魂出窍动画效果：
灵魂出窍代码实现：
floatduration =0.7;
floatmaxAlpha =0.4;
floatmaxScale =1.8;
floatprogress =mod(Time, duration) / duration;// 0~1
floatalpha = maxAlpha * (1.0- progress);
floatscale =1.0+ (maxScale -1.0) * progress;
floatweakX =0.5+ (TextureCoordsVarying.x -0.5) / scale;
floatweakY =0.5+ (TextureCoordsVarying.y -0.5) / scale;
vec2weakTextureCoords =vec2(weakX, weakY);
vec4weakMask =texture2D(Texture, weakTextureCoords);
vec4mask =texture2D(Texture, TextureCoordsVarying);
gl_FragColor= mask * (1.0- alpha) + weakMask * alpha;
