ios - 旋转GPUImageTiltShiftFilter-GPUImage

Question

我想要一个非水平的GPUImageTiltShiftFilter旋转。我想将其旋转到任意旋转角度。我还希望过滤器速度快，可以使用带有UIRotationGestureRecongizer的UI旋转它。

我该怎么做呢？

Answer 1

啊，想通了!

代替修改GPUImageTiltShiftFilter，创建一个新的GPUImageFilterGroup作为GPUImageGaussianSelectiveBlurFilter的修改版本以添加旋转。

我补充说:

   uniform highp float rotation;

在kGPUImageSMTiltShiftFragmentShaderString中，然后将distanceFromCenter线添加到GPUImageGaussianSelectiveBlurFilter的主行中，以将GPUImageGaussianSelectiveBlurFilter旋转为倾斜移位:

 void main()
{
   lowp vec4 sharpImageColor = texture2D(inputImageTexture, textureCoordinate);
   lowp vec4 blurredImageColor = texture2D(inputImageTexture2, textureCoordinate2);

   highp vec2 textureCoordinateToUse = vec2(textureCoordinate2.x, (textureCoordinate2.y * aspectRatio + 0.5 - 0.5 * aspectRatio));

   highp float distanceFromCenter = abs((textureCoordinate2.x - excludeCirclePoint.x) * aspectRatio*cos(rotation) + (textureCoordinate2.y-excludeCirclePoint.y)*sin(rotation));

   gl_FragColor = mix(sharpImageColor, blurredImageColor, smoothstep(excludeCircleRadius - excludeBlurSize, excludeCircleRadius, distanceFromCenter));
 }