big speed hit ...

look at these 2 code, it's the same, only difference is that i copyrect to an imagebuffer instead of the same backbuffer, there's a big speed difference beetween the 2
i wonder why ...
anyone have tips about that ? or it's a bug ?

Graphics 800,600,32,0
Dim x(100),y(100)
For a=0 To 100
x(a)=Rand(800)
y(a)=Rand(400)
Text x(a),y(a),"this is a test"
Next
Repeat
Cls
For t=0 To 100
x(t)=x(t)+Rand(5)-3
y(t)=y(t)+Rand(5)-3
Text x(t),y(t),"this is a test"
Next
For a= 1 To 100
	CopyRect 0,400+a,800,1,0,600-a
Next
Flip
Until KeyDown(1)

And

Graphics 800,600,32,0
miror=CreateImage(800,100)
Dim x(100),y(100)
For a=0 To 100
x(a)=Rand(800)
y(a)=Rand(400)
Text x(a),y(a),"this is a test"
Next
Repeat
Cls
For t=0 To 100
x(t)=x(t)+Rand(5)-3
y(t)=y(t)+Rand(5)-3
Text x(t),y(t),"this is a test"
Next
For a= 1 To 100
	CopyRect 0,400+a,800,1,0,100-a,BackBuffer,ImageBuffer(miror)
Next
DrawImage miror,0,500
Flip
Until KeyDown(1)

anyone have an idea of why such a speed difference ?
i'm using b+ on 1.4 ghz P4, radeon 9600

Obviously you are performing two drawing operations with the second example. One draw to the buffer, one to the screen.

In the first example you are only performing one draw.

Second example will be half as fast.

it's not the reason, it seem that drawing operation to an imagebuffer is wayyyy slower than a drawing operation to mainscreen buffer
as i added in the code the drawimage command to check if it's why i have an as big speed hit

also, note that i do 100 time the copyrect stuff and just 1 more drawing operation in the second example, so the speed hit would be 1 percent more...

Graphics 800,600,32,0
miror=CreateImage(800,100)
Dim x(100),y(100)
For a=0 To 100
x(a)=Rand(800)
y(a)=Rand(400)
Text x(a),y(a),"this is a test"
Next
Repeat
Cls
For t=0 To 100
x(t)=x(t)+Rand(5)-3
y(t)=y(t)+Rand(5)-3
Text x(t),y(t),"this is a test"
Next
DrawImage miror,0,500
For a= 1 To 100
	CopyRect 0,400+a,800,1,0,600-a
Next
Flip
Until KeyDown(1)

miror=CreateImage(800,100,1,2)

See the loadimage docs for new Image flags in BlitzPlus, does the above parameters speed it up?

Sorry, I overlooked the 100 For/Next loop.

uh right skidracer :)
thanks... but i didn't know there's new flags... my fault i had to read more the docs :op

Graphics 800,600,32,0
max=255
Dim x(max),y(max)
For a=0 To max
x(a)=Rand(800)
y(a)=Rand(600)
Next
Repeat
Cls
For t=0 To max
Color t,t,t
x(t)=x(t)+Rand(5)-3
y(t)=y(t)+Rand(5)-3
Text x(t),y(t),t
Next
Color 20,20,40
Rect 0,500,800,100
miror=CreateImage(800,100,1,2)
Stp#=1
For a= 1 To 100
z#=z#+Stp#
	CopyRect 0,400+a,800,1,(100-a)*Cos(z#),100-a,BackBuffer,ImageBuffer(miror)
Next
z#=z#-99*Stp#
DrawImage miror,0,500
FreeImage miror
Flip
Color 255,255,255
Until KeyDown(1)

work better :))
thanks