OpenGL Insights

210 II Rendering Techniques

value to a framebuffer attachment.

2

Then, the second pass computes the contrast

of the current pixel by comparing the pixel’s brightness with the brightness of the

5 × 5 neighboring pixels. If this contrast is above a predefined threshold, its position,

CoC size, and average color are appended to a buffer. During the third pass, a blur-

based depth of field is computed with one of the previous methods, e.g., Gaussian

blur. Finally, a fourth pass splats textured quads at the bokeh positions that were

appended to the buffer in the second pass.

In order to maintain high performance, it is crucial to avoid CPU/GPU syn-

chronizatio ...