# Low framerate when my line is fading away?

**URL:** <https://discourse.processing.org/t/low-framerate-when-my-line-is-fading-away/6582>\
**Category:** Libraries\
**Created:** [December 13, 2018, 11:20pm UTC](https://discourse.processing.org/t/low-framerate-when-my-line-is-fading-away/6582 "2018-12-13T23:20:24Z")\
**Posts on this page:** 1\
**Showing post:** 11

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**Author:** ![neilcsmith](https://yyz2.discourse-cdn.com/flex036/user_avatar/discourse.processing.org/neilcsmith/32/144_2.png) [@neilcsmith](https://discourse.processing.org/u/neilcsmith)\
**Post date:** [December 14, 2018, 12:49pm UTC](https://discourse.processing.org/t/low-framerate-when-my-line-is-fading-away/6582/11 "2018-12-14T12:49:22Z")

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So at some point Processing has been “fixed” to add rather than multiply the alpha channel. The previous behaviour didn’t work anything like multiply blending should, but was useful for masking like this. Now it fulfils neither function correctly! 😖

Assuming you change to create a P2D offscreen, this also works -

```auto
p.beginDraw();
p.blendMode(MULTIPLY);
((PGraphicsOpenGL)p).pgl.blendFunc(PGL.ZERO, PGL.SRC_COLOR);
p.noStroke();
p.fill(255, 230);
p.rect(0, 0, p.width, p.height);
p.stroke(255);

```

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