General Lua Discussion Thread [Not For Help]

[Nielkie]

To advocate PGE Lua, I decided to benchmark it against other Luaplayer version to see how it compares in terms of speed. First benchmark is blitting speed. I'll do a font, sprite and maby a memory one later.

Enjoy:





As expected, PGE Lua is more than 4 times as fast as standard Luaplayer. Interestingly, LuaPlayerHM7 was only marginally faster than (the infamously slow) Luaplayer 0.20, even though it is meant to be based on the graphics code of Luaplayer 0.16.

Anyway, for those interested, 4 tests were run each, and results averaged between them (didn't really have much of an effect, as each test was usually within 0.01 seconds of each other)

Code used:
For LuaplayerHM, Luaplayer 0.16 and Luaplayer 0.20:

ITERATIONS = 100
SPRITECOUNT = 1000

SCREENWIDTH = 480
SCREENHEIGHT = 272

black = Color.new(0,0,0)
white = Color.new(255,255,255)

math.randomseed(os.time())

sprites = {img = Image.load("asprite.png")}
for i=1, SPRITECOUNT do
	sprites[i] = {x = math.random(SCREENWIDTH),y = math.random(SCREENHEIGHT), mx = math.random(-6,6) / 3, my = math.random(-6,6) / 3}
end

starttime = os.clock()

for j = 1, ITERATIONS do
	screen:clear(white)
	for i,sprite in ipairs(sprites) do
		sprites[i].x,sprites[i].y = sprites[i].x + sprites[i].mx, sprites[i].y + sprites[i].my
		if sprite.x < 0 or sprite.y > SCREENWIDTH then
			sprites[i].mx = -sprites[i].mx
		end
		if sprite.y < 0 or sprite.y > SCREENHEIGHT then
			sprites[i].my = -sprites[i].my
		end
		
		screen:blit(sprite.x,sprite.y, sprites.img)
	end
	
	screen.flip()
end

endtime = os.clock()

screen:clear(black)
screen:print(10, 10, endtime - starttime, white)

screen.waitVblankStart()
screen.flip()

while true do
	pad = Controls.read()
	--System.sleep(500)
	screen.waitVblankStart(30)
	
	if pad:start() then break end
end

For LuaPlayer HMv2:

ITERATIONS = 100
SPRITECOUNT = 1000

SCREENWIDTH = 480
SCREENHEIGHT = 272

white = Color.new(255,255,255,255)
black = Color.new(0,0,0,255)

math.randomseed(os.time())

sprites = {img = Image.load("asprite.png", 1)}
for i=1, SPRITECOUNT do
	sprites[i] = {x = math.random(SCREENWIDTH),y = math.random(SCREENHEIGHT), mx = math.random(-6,6) / 3, my = math.random(-6,6) / 3}
end

screen.init()

starttime = os.clock()
for j = 1, ITERATIONS do
	screen.startDraw()
	screen.clear(white)

	for i,sprite in ipairs(sprites) do
		sprites[i].x,sprites[i].y = sprites[i].x + sprites[i].mx, sprites[i].y + sprites[i].my
		if sprite.x < 0 or sprite.y > SCREENWIDTH then
			sprites[i].mx = -sprites[i].mx
		end
		if sprite.y < 0 or sprite.y > SCREENHEIGHT then
			sprites[i].my = -sprites[i].my
		end
		
		Image.blit(sprite.x,sprite.y, sprites.img)
	end
	
	screen.endDraw()
	screen.flipscreen()
end

endtime = os.clock()

screen.startDraw()

screen.print(10, 10, tostring(endtime - starttime), 1, white, black)

screen.endDraw()
screen.flipscreen()

while not Controls.read():start() do
end

And for PGE Lua:

ITERATIONS = 100
SPRITECOUNT = 1000

SCREENWIDTH = 480
SCREENHEIGHT = 272

white = pgeGfx.createcolor(255, 255, 255)
black = pgeGfx.createcolor(0, 0, 0)

monaco8 = pgeFont.load("monaco.ttf", 9, PGE_VRAM)

math.randomseed(os.time())

sprites = {img = pgeTexture.load("asprite.png",PGE_VRAM)}
for i=1, SPRITECOUNT do
	sprites[i] = {x = math.random(SCREENWIDTH),y = math.random(SCREENHEIGHT), mx = math.random(-6,6) / 3, my = math.random(-6,6) / 3}
end

pgeGfx.startdrawing()
sprites.img:activate()
pgeGfx.enddrawing()

starttime = os.clock()

for j = 1, ITERATIONS do
	pgeGfx.startdrawing()
	pgeGfx.clearscreen(white)

	for i,sprite in ipairs(sprites) do
		sprites[i].x,sprites[i].y = sprites[i].x + sprites[i].mx, sprites[i].y + sprites[i].my
		if sprite.x < 0 or sprite.y > SCREENWIDTH then
			sprites[i].mx = -sprites[i].mx
		end
		if sprite.y < 0 or sprite.y > SCREENHEIGHT then
			sprites[i].my = -sprites[i].my
		end
		
		sprites.img:draw(sprite.x,sprite.y)
	end
	
	pgeGfx.enddrawing()
	pgeGfx.swapbuffers(false)
end

endtime = os.clock()

pgeGfx.startdrawing()
monaco8:activate()
pgeGfx.enddrawing()

while pge.running() do
	pgeControls.update()
	
	if pgeControls.held(PGE_CTRL_START) then break end

	pgeGfx.clearscreen()
	
	monaco8:print(10, 10, white, tostring(endtime - starttime))
	
	pgeGfx.enddrawing()
	
	pgeGfx.swapbuffers()
end

Sprites:
For Alpha tests:

And for Non-Alpha tests:

[Insert_Witty_Name]

Thanks for that test Nielkie

That PGE Lua test isn't as optimised as it could be:

ITERATIONS = 100
SPRITECOUNT = 1000

SCREENWIDTH = 480
SCREENHEIGHT = 272

white = pgeGfx.createcolor(255, 255, 255)
black = pgeGfx.createcolor(0, 0, 0)

monaco8 = pgeFont.load("monaco.ttf", 9, PGE_VRAM)

if not monaco8 then
	error("Failed to load font.")
end

math.randomseed(os.time())

-- Changed from PGE_RAM to PGE_VRAM
sprites = {img = pgeTexture.load("asprite.png",PGE_VRAM)}
for i=1, SPRITECOUNT do
	sprites[i] = {x = math.random(SCREENWIDTH),y = math.random(SCREENHEIGHT), mx = math.random(-6,6) / 3, my = math.random(-6,6) / 3}
end

starttime = os.clock()

 -- Moved this line out of the loop, texture only needs activating once, even for multiple blits.
pgeGfx.startdrawing()
sprites.img:activate()
pgeGfx.enddrawing()

for j = 1, ITERATIONS do
	pgeGfx.startdrawing()
	pgeGfx.clearscreen(white)
	
	for i,sprite in ipairs(sprites) do
		sprites[i].x,sprites[i].y = sprites[i].x + sprites[i].mx, sprites[i].y + sprites[i].my
		if sprite.x < 0 or sprite.y > SCREENWIDTH then
			sprites[i].mx = -sprites[i].mx
		end
		if sprite.y < 0 or sprite.y > SCREENHEIGHT then
			sprites[i].my = -sprites[i].my
		end
		
		sprites.img:draw(sprite.x,sprite.y)
	end
	
	pgeGfx.enddrawing()
	pgeGfx.swapbuffers(false) -- Added the false to not wait for vblank
end

endtime = os.clock()

while pge.running() do
	pgeControls.update()
	
	if pgeControls.held(PGE_CTRL_START) then break end

	pgeGfx.clearscreen()
	
	monaco8:activate()
	monaco8:print(10, 10, white, tostring(endtime - starttime))
	
	pgeGfx.enddrawing()
	
	pgeGfx.swapbuffers()
end

I've commented the three changes I made.

[Nielkie]

Oh right, thanks. I'll re-run the tests tomorrow.
Any reason textures are activated every loop in the examples? What does "activating" a texture actually do?

[Insert_Witty_Name]

Note that I just edited the optimised code, the texure:activate() call must be within a startdrawing() and enddrawing() block.

Activating a texture uploads it to the GE so that it can be used for texturing. Whether you're drawing once or a thousand times, it only needs doing once.

Note that activating a font or a texture both use the same space, so if you activate a font at any time, the texture that was activated previously will be replaced with the font and vice versa.

Hope that makes sense.

[Nielkie]

That makes more sense, thanks again.

[TurtlesPwn]

I'm not doubting that the PGELua is much faster or that the original test was not as optimized as it could have been, but I will argue that the regular lua test was also far from perfectly optimized. I doubt the possible changes would make a significant difference, but it would certainly show up at least after the decimal.

Perhaps tests with a simple Gu.blit function might also help show whether the GU is worth using for small sprites or not? I've found that for > 5-10 sprites all which are small (<64x64) using a simple Gu.blit function with Gu.SPRITES, the Gu begins making up for its lost time starting and ending.

 
function Gu.blit(x,y,img)
	local w = img:width()
	local h = img:height()
	Gu.enable(Gu.TEXTURE_2D) 
	Gu.texImage(img)
	Gum.drawArray(Gu.SPRITES, Gu.TEXTURE_32BITF+Gu.VERTEX_32BITF+Gu.TRANSFORM_2D,{{0,0,x,y,0},{w,h,w+x,h+y,0}})
end

Also, is there a reason the PGE function names (pgeModule.functionname) doesn't follow the standard rule for capitalization of function names in lua (pgeModule.functionName)?

[Insert_Witty_Name]

The naming scheme is currently under review.

See the thread(s) on luaplayer.org forums.

[TurtlesPwn]

Yes, I've seen and posted in that thread, but that is simply discussing the pge and module parts - the function names (createcolor,startdrawing ,clearscreen) etc are not capitalized following the standard lua convention of capitalizing the first letter of each additional word after the first.

[Insert_Witty_Name]

That part is not conventional Lua.

It's what Lua Player does, but not Lua.

[TurtlesPwn]

Ah, true, now that I think about it. But why not keep it similar to how the current luaplayer does things?

[Insert_Witty_Name]

Because PGE Lua is not Lua Player.

They share absolutely 0 code.

It's better to stick to the base language rather than what people may be used to with something that implements that language.

[dan369]

Ummmhhh, this thread hasn't really been used in a while but i'd like to ask 1 question: What has been the best Lua game made??
taking in to account the code efficiency and gameplay.

[eldiablov]

Something by youresam or TacticalPenguin.

I would go with wedgeracer and/or lua modeller 3d.

[TurtlesPwn]

"lua modeller 3d."
That's not a game and was a mere 300 lines of code.

If you're going by efficiency and how much the PSP is having to do to run the game, definitely Wedge Racer - play music, render walls and spaceships, do lots of math, and send data back and forth online - at 60 frames per second

If you go by gameplay, probably Luamines and some stiff competition from the project I'm working on at the moment.

[eldiablov]

Originally Posted by TurtlesPwn

"lua modeller 3d."
That's not a game and was a mere 300 lines of code.

Which leads me to believe it is efficient. By the way I knew it wasn't a game.

[TurtlesPwn]

I suppose so, but all it is doing is rendering some 3d stuff and then messing with some tables and numbers when some buttons are pressed. I'm sure it could be dropped to 200 lines or less.

Also, http://psp.metaclassofnil.com/crystalise/

Heavily rewritten luaplayer, the performance can't be wowed at because it uses OGL for the graphics and thus is much faster than luaplayer, but it is done with lua on the PSP with some of the same parts as the luaplayer we know today.

[dan369]

Question: Is there a good example of physics in lua?
Also is 'Jumping' a form of VERY simple physics?

[_df_]

I would precalc a sin table for things like jumping physics. google sin/cos lookup tables or something. that should give you what you need. Jumping is physics, its a sin wave. rapid rise, level off, descend.

[TurtlesPwn]

math.sincache = {}
for i = 1, 180 do --don't need to go into then negatives if it's just for jumping up
	math.sincache[i] = math.sin(i)
end


	if jumpingTime >= 1 then
		playerY = onFlatGroundY + math.sincache[jumpingTime]
		if jumpingTime < 180 then
			jumpingTime = jumpingTime + jumpingTimeIncrement
			if jumpingTime > 180 then
				jumpingTime = 0
			end
		end
	elseif pad:cross() and not oldpad:cross() then
		jumpingTime = 1
	end

general idea. very pseudocodeish

[dan369]

Ok, thanks That gives me the general idea

[yaustar]

Look at the jumping code from here: Lua Code Snippets I did a while back...

[dan369]

Originally Posted by yaustar

Look at the jumping code from here: Lua Code Snippets I did a while back...

That actually what i've been looking at, and for once after about 5-10 minutes i understood How it works.
They Only question on that Is The Bool_UpLastState, are they there to stop Double jumping? Why didn't you just use oldpad?

[yaustar]

They are there for the same reason as people use oldpad. At the time, I wasn't sure what the function calls for reading control input was doing under the hood.

The double jumping bug is still there is due to the code checking for a vertical velocity of 0 for being on the ground.

[xXChromeXx]

It is basically an idea for a Shell that comes with the most popular Lua Games and can Launch them. Therefore it takes your favorite lua games and organizes them into 1 compact EBOOT. The Shell will be able to do other things such as USB connect and Play MP3s.

[Davee]

There is already sooo many shells. There has to be one that does this already.

[TurtlesPwn]

I've toyed around with making a "lua arcade" system before with a bunch of games and an interface to connect to a server to download more. i made it work and all but I never made it fancy or worth releasing. a similar system would probably be better because a generic shell in lua is not worth making

[xXChromeXx]

Originally Posted by TurtlesPwn

I've toyed around with making a "lua arcade" system before with a bunch of games and an interface to connect to a server to download more. i made it work and all but I never made it fancy or worth releasing. a similar system would probably be better because a generic shell in lua is not worth making

So maybe an arcade with a bunch of games. Sounds better

[TurtlesPwn]

and the downloadable part, thats what makes it worthwhile over lowser

[xXChromeXx]

Originally Posted by TurtlesPwn

and the downloadable part, thats what makes it worthwhile over lowser

To add downloads would I need to make my own website and host my files there?

[Moose]

Originally Posted by xXChromeXx

To add downloads would I need to make my own website and host my files there?

That would be the best way to go about it, yes.