CreateImage

CreateImage( width,height[,frames,flags] )

Parameters:

width - width of the new image (or its frames)
height - height of the new image
frames - optional number of frames (assumed to be a single frame)
flags - optional image flags

Description:

Sometimes you want to create a completely new graphic on the fly (using other images, drawing commands, etc.) instead of loading one. This command will let you create a new image with a single frame or multiple frames for animation. You specify the width, height, and optional number of frames. The example should be pretty self-explainatory.

The optional flags parameter can be one of:

1 : managed (image is frequently drawn but seldom modified)
2 : dynamic (image is frequently drawn and modified - this is the default)
4 : scratch (image is seldom drawn or modified)

Dynamic images are the default.

Dynamic images are the fastest, but can be 'lost' when the display mode changes. This means the
contents of the image will be scrambled, and you will need to restore the image content. If you
are frequently redrawing the image contents, this isn't really a problem. If not, you should use
managed images!

Scratch images are slow all round but consume no videomemory. These are good for things like title
pages and 'temporary work' images.

Note that canvas buffers and back buffers should be considered 'dynamic'.

See also: LoadImage, DrawImage, SaveImage, Graphics.

Example:

; CreateImage/TileImage/ImageBuffer example

; Again, we'll use globals even tho we don't need them here
; One variable for the graphic we'll create, one for a timer
Global gfxStarfield, tmrScreen

; Declare graphic mode
Graphics 640,480,16

; Create a blank image that is 32 pixels wide and 32 high with 10 frames of  32x32
gfxStarfield=CreateImage(32,32,10)

; loop through each frame of the graphic we just made
For t = 0 To 9
; Set the drawing buffer to the graphic frame so we can write on it
SetBuffer ImageBuffer(gfxStarfield,t)
; put 50 stars in the frame at random locations
For y = 1 To 50
Plot Rnd(32),Rnd(32)
Next
Next

; Double buffer mode for smooth screen drawing
SetBuffer BackBuffer()

; Loop until ESC is pressed
While Not KeyHit(1)

; Only update the screen every 300 milliseconds. Change 300 for faster or
; slower screen updates
If MilliSecs() > tmrScreen+300 Then 
Cls ; clear the screen

; Tile the screen with a random frame from our new graphic starting at
; x=0 and y=0 location.
TileImage gfxStarfield,0,0,Rnd(9)
Flip ; Flip the screen into view
tmrScreen=MilliSecs() ; reset the time
End If
Wend

Comments

TAS	(Posted 1+ years ago)

The default option flag may have been changed to 2 (dynamic) with version 1.38. If you have a problem with blank/black images after alt-tabing or after being gone for while use;
hand=createimage(w,h,1,1)
in place of
hand=createimage(w,h)

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