Common Code Fragments

[Redwolfhome]

Ok this isn´t really a code fragment but its a tip:
If you draw an image with the screen.fillrect memory it takes more memory thanusing an compremize image:
I have tested it with an rectangle in black...

[CrowdAds]

[Habhome]

Originally Posted by Redwolfhome

Ok this isn´t really a code fragment but its a tip:
If you draw an image with the screen.fillrect memory it takes more memory thanusing an compremize image:
I have tested it with an rectangle in black...

So redrawing a 240*400 image takes less than a 240*400 filled square? Sounds odd... Might only be applicable for one colored stuff, had lots of trouble with redrawing to get it smooth in my Paradise Slots where I use images. Though, I use several layers of them..

[Redwolfhome]

I haven´t test it yet, but I have test it with a small 100x100 black image. I have save this image with Photoshop as an compremize image.

[Nohajc]

Because there is still the "draw at negative coordinates" bug which presumably causes the player to shut down, I had an idea to write a function safeDraw which would handle the negative coordinates for you and actually crop the image automatically.

I think it's a good solution when you have lots of moving objects that often slide off the screen and you don't want to make checks every time.

function image:safeDraw(x,y) 
    local l,t=x,y 
    local ox,oy=0,0 
    local crop=false
     
    if x<0 then 
        ox=-x 
        l=0
        crop=true 
    elseif x+self:width()>screen.width() then
        ox=x+self:width()-screen.width()
        crop=true
    end
     
    if y<0 then 
        oy=-y 
        t=0
        crop=true 
    elseif y+self:height()>screen.height() then
        oy=y+self:height()-screen.height()
        crop=true
    end 
    if crop then 
        return self:draw(x,y,l,t,self:width()-ox,self:height()-oy)
    else
        return self:draw(x,y)
    end 
end

So, instead of :draw you can use :safeDraw on every image object, as you please.

[Nohajc]

I had to edit the function a bit, since it was slowing things down and also I did not take to account pictures that are off screen at right or bottom.

So, an updated version above.

[Redwolfhome]

Yes now it works right

[jbob182]

This code is helpfull for realtime saves weather in rpg's,puzzles,fast paced action games
Here is a table to file code:
Right now it will only work with tables in this format: ( i plan on updating my function to handle all types of tables)

example[1].x = 315
example[1].y = 95
example[1].maxx = 21
example[1].maxy = 28

example[2].x = 315
example[2].y = 95
example[2].maxx = 21
example[2].maxy = 28
e.c.t.

tbl= the table you want to save
savename=the name you want your table to be saved as
filename=the file you want to save to
subtables= the number of smaller tables in on section of a table ie: in the example above there is 4

function table_save(tbl,savename,filename,subtables)
	local passes=0
	local charS,charE = "   ","\n"
	file,err = io.open( filename, "w" )
	local tables,lookup = { tbl },{ tbl }
	file:write( savename .. " = {{}")
	for i=2, #tbl do
		file:write(",{}")
	end
	file:write("}")  
	for idx,t in ipairs( tables ) do
		local thandled = {}
		for i,v in ipairs( t ) do
			thandled[i] = true
			if type( v ) == "table" then
				if not lookup[v] then
					table.insert( tables, v )
					lookup[v] = #tables
				end
			else
				local value =  ( type( v ) == "string" and exportstring( v ) ) or tostring( v )
			end
		end
		for i,v in pairs( t ) do
			if (not thandled[i]) then
				if type( i ) == "table" then
					if not lookup[i] then
						table.insert(tables,i)
						lookup[i] = #tables
					end
				else
					passes=passes+1
					currentsubtable=math.ceil(passes/subtables)
							local index = ( type( i ) == "string" and savename.."["..currentsubtable.."]"..".".. i ) or string.format( "[%d]",i )
							-- penguins style table	   

					file:write(index.."=" )
				end
				if type( v ) == "table" then
					if not lookup[v] then
						table.insert( tables,v )
						lookup[v] = #tables
					end
				else
					local value =  ( type( v ) == "string" and exportstring( v ) ) or tostring( v )
					file:write( value..charE )
				end
			end
		end
		file:write(charE )
	end
	file:close()
end

Usage

function table_save(example,"example","save.lua",4)

[jbob182]

Here is a function for on player debugging

function debug_player(functionname)
f,vrf=pcall(functionname)
if not f then
savevariable("ErrorLog.txt",variabletype(vrf))
end
end


function variabletype (o)
if type(o) == "number" then
return tostring(o)
elseif type(o) == "string" then
return string.format("%q", o)
else
return tostring(o)
end
end

function savevariable(file,variable)
Saver= io.open(file,"wb");
Saver:write("\n" .. variable .. "\n");
io.close(Saver);
end

This will output any errors to the ErrorLog.txt file

Usuage:

debug_player(animations)

[jameswalker101]

This is a PSP lua common code snippets page:
http://forums.qj.net/psp-development...-snippets.html
maybe something on here will help coding:-)