Shadow Not visible

Blitz3D Forums/Blitz3D Beginners Area/Shadow Not visible

_PJ_	(Posted 2016) [#1]

I'm sturggling to understand why the 'dropshadow' image idoesn't appear to be visible.

I've checked the following:

AMBIENT_R,G,B etc. values
Creation of Image
Drawing X Y Location
Width & Height dimensions of Image
Call to DrawImage actually processed

All of which are valid and correct.

Theonly thing I can think of, then, is the actual image itself is somehow transparent (alpha'd pixels maybe?)

However in the creation function:


Function him_UI_CreateGadgetDropShadow(n_W,n_H)
	Local Image=CreateImage(n_W,n_H)
	Local Buffer=ImageBuffer(Image)
	Local X
	Local Y
	
	Local Pixel=n_COL_RGBa(cm_EDT_AMBIENT_R,cm_EDT_AMBIENT_G,cm_EDT_AMBIENT_B,0)
	
	LockBuffer Buffer
	For Y=0 To n_H-1
		For X=1 To n_W-1
			WritePixelFast X,Y,Pixel,Buffer
		Next
	Next
	UnlockBuffer
	BufferDirty Buffer
	
	DebugLog("UI (Create Gadget DropShadow): Dropshadow Image created 0x"+Hex(Image))
	
	Return Image
End Function

I have tried changing Pixel to -1, -255, 256 ,255, 65535 and 16777215 all to no avail.
I also tried adding a MaskImage line to ensure that this was set to completely different colour

Here's the actual drawing routine. This definitely runs:

[code]

Function v_UI_DisplayButtonGadgets()
Local o.T_UI_ButtonGadget
Local Frame=cm_UI_STATE_NORMAL
go_UI_CURRENT_MOUSEOVER=Null

For o=Each T_UI_ButtonGadget
If (Not(nb_UI_GetButtonStateHidden(o)))

If (nb_UI_GetButtonStateEnabled(o))
If (nb_UI_GetButtonMouseOver(o))
go_UI_CURRENT_MOUSEOVER=o
Frame=cm_UI_STATE_MOUSEOVER
Else
Frame=nb_UI_GetButtonStateActive(o)
End If
Else
Frame=cm_UI_STATE_DISABLED
End If

DrawImage o\yhim_ButtonGadget_DropShadow,o\yn_ButtonGadget_X-(cn_UI_DROPSHADOW_OFFSET*0.5),o\yn_ButtonGadget_Y+cn_UI_DROPSHADOW_OFFSET
DrawImage o\yhim_ButtonGadget_ImageHandle,o\yn_ButtonGadget_X,o\yn_ButtonGadget_Y,Frame
End If
Next
End Function
[\code]

_PJ_	(Posted 2016) [#2]

!

Apparently, it was because I didn't include the Buffer parameter for UnLockBuffer

Once this was changed to UnLockBuffer Buffer
everything worked as expected.

Floyd

(Posted 2016) [#3]

That's a sneaky one. You specified the buffer in the WritePixelFast command and never used SetBuffer to change the default. Thus UnlockBuffer with no buffer specified was still referring to something other than the image buffer, probably the back buffer.

_PJ_	(Posted 2016) [#4]

Yep, that's exactly what was happening.