Sketch Speed versus Render Quality

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patsharkey

Sketch Speed versus Render Quality

in General Discussion • Other • 2 years ago

I'm building a relatively elaborate sketch consisting of a few hundred shapes (using beginShape/EndShape) with some underlying data structures (objects, arrays, ArrayLists etc.) supported by some mouse-click interaction. It's all in 2D - no fancy 3D. It's now getting sufficiently large that it's running quite slow and the mouse response is a bit sluggish (I'm using a quad Core Intel running Windows 7 64bit). I'm keen to give it to a few people so I'm concerned that it might be slow on other PCs - especially laptops. To speed things up I've removed most of the calculation from repeated traversals through the draw() method and changed as many floats to ints as I can.

I'm using PFont/LoadFont for the text. I am drawing my graphics onto the screen in overlapping layers with some alpha to allow some things to show through but I'm only using two dimensions x and y to locate things on the screen. There is a bit of pushMatrix()/popMatrix() rotation but it's not the bulk of the sketch. I'm using rev 1.2.1.

Using the default renderer it looks beautiful and crisp but it's slow. Switching to openGL makes it look ugly but it runs fantastically fast - the text is smeared, the lines look stippled but the mouse response is great. P3D is both ugly and slow, P2D isn't much better than openGL.

Can anyone recommend either:

1) some guidelines for avoiding ugly openGL artifacts especially for text and lines

2) some hints as to how to render quicker with the default renderer

Many thanks

Pat.

Replies(2)

patsharkey

Re: Sketch Speed versus Render Quality

2 years ago

No one replied to this but for anyone interested I'll just tell you what I've found in the last couple of weeks playing with the code:

basically the openGL renderer behaves in some unexpected ways. I'd been coding a lot of 2D unfilled polygons using beginShape/Vertex/Endshape and I'd assumed that by supplying integer (rather than float) coordinates to Vertex (i.e. integer values of the pixel locations) that this would speed the sketch up. It turns out that using ints doesn't improve the speed much but causes a catastrophic degradation in image quality in the openGL renderer. Switching back to floating point vertices improves the rendering immeasurably. While the result not as good as using the default renderer, it isn't bad at all. I've seen some advice elsewhere in the forums that suggests that, under OpenGL, if you have no other option but to use integer values for vertices (or integers in float format) it is worth dithering the x and y coordinate by +/-0.5 to get the same improvement in quality, I guess this is a manifestation of the same problem.
Text can look really muddy using openGL if you're not careful. The solution mentioned elsewhere in the forums is to use the default textAlign(CENTRE, BASELINE) rather than textAlign(CENTER, CENTER) - however I've independently found that integer values of the x, y coordinates gives sharper text rendering than using floating point values when you're following this advice (which is perverse given the previous point, but never mind).

countrysi..

Re: Sketch Speed versus Render Quality

1 year ago

Hey there. Coming to this discussion way late, but I'm just picking up Processing. I was curious to see if you had learned anything else about improving rendering speed since you first posted this. I have a very complex 3D sketch using fonts drawn to screen, and leveraging other libraries to interact with it, namely ControlP5 and peasycam. Do you know if I instead rendered each frame offscreen and stamped it as an image in the draw() cycle, if that would speed things up?

Thanks!

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