# Command: LockBuffer

LockBuffer buffer Definition:

Locks a buffer for high speed pixel operations.

Parameter Description:

buffer = any valid screen/image buffer (optional)

Command Description:

After you use LockBuffer on a buffer, the only graphics commands you can use are the read/write pixel commands ReadPixel, WritePixel, ReadPixelFast, WritePixelFast, CopyPixelFast, and CopyPixel. You must UnlockBuffer before using other graphics commands. The buffer parameter isn't required. If omitted, the default buffer set with SetBuffer will be used. See the other commands for more information.

Example:

; High Speed Graphics Commands
Graphics 640,480,16
; Draw a bunch of crap on the screen
For t= 1 To 1000
Color Rnd(255),Rnd(255),Rnd(255)
Rect Rnd(640),Rnd(480),Rnd(150),Rnd(150),Rnd(1)
Next
Delay 3000
; Copy the top half of the screen over the bottom half
; using fast pixels and locked buffers
For x = 1 To 640
For y = 1 To 240
LockBuffer FrontBuffer()
WritePixelFast x,y+241,ReadPixelFast(x,y)
UnlockBuffer FrontBuffer()
Next
Next
Delay 3000
; Draw the left half of the screen over the right half
; using the slower direct pixel access
For x = 1 To 320
For y = 1 To 480
WritePixel x+320,y,ReadPixel(x,y)
Next
Next

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