High processor usage drawing forms on mouse position

[Petunien]

Hi,

I get a processor usage up to 70% when I draw some forms on the mouse position.
Is there generally a problem with that or am I doing something wrong?

Maybe too much color changes or calculations in the draw commands?

Code: Select all

love.graphics.setColor(0, 200, 0, 100)
love.graphics.circle("fill", love.mouse.getX(), love.mouse.getY(), test1)
	
love.graphics.setColor(test3, test4, 0, 100)
love.graphics.rectangle("fill", love.mouse.getX()-40, love.mouse.getY()-40, test5, test6)
	
love.graphics.setColor(test3, test4, 0)
love.graphics.rectangle("line", love.mouse.getX()-40, love.mouse.getY()-40, test5, test6)
	
love.graphics.setColor(0, 255, 0)
love.graphics.circle("line", love.mouse.getX(), love.mouse.getY(), test2)

"testXYZ" are only integer variables, nothing specially.

[iemfi]

Is that all the code there is? Perhaps the problem is somewhere else?

[Petunien]

When I cut out the mouse specific code, the processor usage is usually at 10-20%, therefore I think, the error is in this piece of code.

[tsturzl]

It seems odd that that would take that much processing, however calling for the mouse coordinates everytime you draw something seems like a waste. Try something like this:

Code: Select all

local x, local y = love.mouse.getPosition( )
love.graphics.setColor(0, 200, 0, 100)
love.graphics.circle("fill", x, y, test1)
   
love.graphics.setColor(test3, test4, 0, 100)
love.graphics.rectangle("fill", x-40, ly-40, test5, test6)
   
love.graphics.setColor(test3, test4, 0)
love.graphics.rectangle("line", x-40, y-40, test5, test6)
   
love.graphics.setColor(0, 255, 0)
love.graphics.circle("line", x, y, test2)

This way you call love.mouse.getPosition() once, then you reuse local variables "x" and "y". This seems slightly less intensive to me. Besides the position of the mouse can't change within the same draw call.

Try this and see if it cuts down your CPU usage, though I still don't see why it takes so much to begin with.

Karmaz?

[Petunien]

Hmm.

I wrote the code in a new gameproject, a new main.lua.

That's all of the code:

Code: Select all

function love.update(dt)

	x, y = love.mouse.getPosition( )
	
	test1 = 100
	test2 = 100
	
	test3 = 0
	test4 = 255
	
	test5 = 80
	test6 = 80

end

function love.draw()

love.graphics.setColor(0, 200, 0, 100)
love.graphics.circle("fill", x, y, test1)
   
love.graphics.setColor(test3, test4, 0, 100)
love.graphics.rectangle("fill", x-40, y-40, test5, test6)
   
love.graphics.setColor(test3, test4, 0)
love.graphics.rectangle("line", x-40, y-40, test5, test6)
   
love.graphics.setColor(0, 255, 0)
love.graphics.circle("line", x, y, test2)

end

When I start this game with LOVE 0.8.0 (pre-release) the cpu usage is about 60%, when I run this with LOVE 0.7.2 is it really low, in the span of 0-20%.
Is this a bug or something like that of LOVE 0.8.0?

I "develop" usually with the latest build, so I don't have to change much on the release.

Edit:
Ok, I think I found the reason:


It's maybe the amount of segments?

Edit²:

No, it isn't. The same with 10 segments. It's because of 0.8.0.

[Boolsheet]

What LÖVE binary are you using? And what framerate do you get with that code in 0.7.2 and 0.8.0?

There's the new smooth-line drawing in 0.8.0, but your system should be able to handle it without any problems. You can disable it with love.graphics.setLineStyle("rough") if you want to test for it.

[Nixola]

LÖVE 0.7.2 also has it

[Petunien]

Without vsync I get in 0.7.2 about 960-999 FPS, in 0.8.0 too.
The cpu usage sway without vsync in the range of 10-30%.

With setting the line-style to "rough" in 0.8.0, the cpu usage sinks down to a normally value.

I think, vsync and "rough" would be the best solution.

But why works it better in 0.7.2 than in 0.8.0, which is a newer version?

[Boolsheet]

But why works it better in 0.7.2 than in 0.8.0, which is a newer version?

The line smoothing in 0.8.0 has a different approach. It does still work on every graphics card with the drawback of some more CPU work. I don't think it should be that noticable unless you're using a slow CPU with software floating point. (If it really is the line smoothing causing the high CPU load)