the following might be good for people like me struggling with the basics...
Code: Select all
; purebasic survival guide (http://www.xs4all.nl/~bluez)
; graphics 1: bitmaps, blockcopy, winapi
; 31.10.2003 ejn (blueznl)
;
; this code shows some alternatives for the build in commands of purebasic, using:
;
; getdc_()
; loadimage()
; createcompatiblebitmap_()
; loadimage_()
; createcompatibledc_()
; selectobject_()
; deletedc_()
; releasedc_()
;
; plgblt_() is an api call that can transform and rotate objects (as a variation of
; bitblt), it does not run on all variations of windows
;
; note: plgblt doesn't directly output on screen, unless the debugger is switched off (!)
; however it can be used using an intermediate step
;
main_whnd = OpenWindow(0,200,100,660,500,"Test",#PB_Window_SystemMenu)
main_dc = GetDC_(WindowID(0))
;
; creating your own device independent bitmap
;
; note: creating a bitmap with the wrong number of colours (aka. not compatible / identical
; with current screen) doesn't display it when using DrawImage()
;
; bitmap_hnd.l = createbitmap_(10,10,1,32,0)
;
; or use a compatible bitmap
;
; bitmap_hnd.l = createcompatiblebitmap_(main_hdc,10,10)
;
; or load a bitmap (which, funny enough, doesn't have to be compatible) appearently the
; bitmap and / or structure generated is not identical to a createbitmap_() yet no dc
; is given during the call, so how does windows know how to (re)format the image? i'm missing
; something here... but it works anyway :-)
;
; bitmap_hnd.l = LoadImage_(0,"..\_projects\zm24.bmp",#IMAGE_BITMAP,0,0,#LR_LOADFROMFILE|#LR_CREATEDIBSECTION)
;
; but let's stick to the regular purebasic loadimage command :-)
;
bitmap1_hnd.l = LoadImage(0,"1.bmp")
bitmap_w = ImageWidth(0)
bitmap_h = ImageHeight(0)
;
bitmap2_hnd = CreateImage(1,bitmap_w,bitmap_h)
;
; structure needed for plgblt_()
;
Structure corners
x1.l ; left upper corner
y1.l
x2.l ; right upper corner
y2.l
x3.l ; left lower corner
y3.l
EndStructure
;
new.corners
new\x1 = bitmap_w
new\y1 = 0
new\x2 = bitmap_w
new\y2 = bitmap_h
new\x3 = 0
new\y3 = 0
;
; create device contexts (placeholders) and select images into them
;
source_dc = CreateCompatibleDC_(main_dc)
SelectObject_(source_dc,bitmap1_hnd)
dest_dc = CreateCompatibleDC_(main_dc)
SelectObject_(dest_dc,bitmap2_hnd)
;
;
; plgblt allows rotation and transformation
;
; PlgBlt_(dest_dc,@new\x1,source_dc,0,0,bitmap_w,bitmap_h,0,0,0)
;
; bitblt is a block copy but with a parameter that affects how the copy is handled
;
BitBlt_(dest_dc,0,0,bitmap_w,bitmap_h,source_dc,0,0,#SRCCOPY)
;
;
DeleteDC_(source_dc)
DeleteDC_(dest_dc)
;
; draw the results (from bitmap 2) into the screen
;
; UseWindow(0)
; StartDrawing(WindowOutput())
; DrawImage(bitmap2_hnd,10,10)
; StopDrawing()
;
; you could do it with bitblt as well...
;
; UseWindow(0)
; dest_dc = StartDrawing(WindowOutput())
; source_dc = CreateCompatibleDC_(main_dc)
; SelectObject_(source_dc,bitmap2_hnd)
; BitBlt_(dest_dc,10,10,bitmap_w,bitmap_h,source_dc,0,0,#SRCCOPY)
; deletedc_(source_dc)
; StopDrawing()
;
; however, drawing directly on screen means it's not protected, and can be overwritten
; so either copy it back using bitblt on every redraw or using a callback, or...
; use an imagegadget
;
ImageGadget(0,10,10,bitmap_w,bitmap_h,bitmap2_hnd)
;
Repeat
Until WaitWindowEvent() = #PB_Event_CloseWindow
;
FreeGadget(0)
ReleaseDC_(main_whnd,main_dc)
