# Horizontal wall clipping

**URL:** <https://discourse.processing.org/t/horizontal-wall-clipping/29226>\
**Category:** Processing\
**Created:** [April 8, 2021, 3:58pm UTC](https://discourse.processing.org/t/horizontal-wall-clipping/29226 "2021-04-08T15:58:01Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![davejr17](https://avatars.discourse-cdn.com/v4/letter/d/96bed5/32.png) [@davejr17](https://discourse.processing.org/u/davejr17)\
**Post date:** [April 8, 2021, 3:58pm UTC](https://discourse.processing.org/t/horizontal-wall-clipping/29226/1 "2021-04-08T15:58:01Z")

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![image](https://canada1.discourse-cdn.com/flex036/uploads/processingfoundation1/original/2X/e/e82b6bcfd29d0283cebc3acbd774ec861f956ba1.png)

I was wondering how you would go about coding this horizontal wall clipping  
this is from [https://fabiensanglard.net/gebbdoom.pdf](https://fabiensanglard.net/gebbdoom.pdf) on page 212.  
having it so it only draws on the screen where it hasn’t already been drawn but only taking into account the x-axis as shown in the picture.