Tweet
Hi Paul,
I found some old code you wrote to rotate an image. It was short and sweet which is why I am bit embarassed that I cannot convert it for my needs. Your code is below. I basically need to rotate a portion of an image within a larger image.
The total image is just an rgbtriple that is 320x240. I want to rotate a box in the center of that image around its own center within the larger image. This box is 176 pixels on each side. Its upper left coordinate is then 44,16 and its lower right is 220,192.
I am trying to understand how you picked your constants and after trying several variations I thought I would just ask if you had any suggestions.
I found some old code you wrote to rotate an image. It was short and sweet which is why I am bit embarassed that I cannot convert it for my needs. Your code is below. I basically need to rotate a portion of an image within a larger image.
The total image is just an rgbtriple that is 320x240. I want to rotate a box in the center of that image around its own center within the larger image. This box is 176 pixels on each side. Its upper left coordinate is then 44,16 and its lower right is 220,192.
I am trying to understand how you picked your constants and after trying several variations I thought I would just ask if you had any suggestions.
Code:
#COMPILE EXE
#DIM ALL
%xWindowSize = 480
%yWindowSize = 480
%xRotateOffset=140
%yRotateOffset=140
FUNCTION PBMAIN () AS LONG
LOCAL hInitialBMP,hWindow, hThread AS DWORD
LOCAL InitialBMPstring, RotatedBMPstring AS STRING
LOCAL x,y,a,xSize,ySize,t1,t2, Oldx,Oldy, QuitAll, lResult AS LONG
LOCAL Angle,sina, cosa AS EXT
LOCAL file AS STRING
LOCAL initial(), rotated() AS LONG
file$="rose.bmp"
x = FREEFILE
OPEN file$ FOR BINARY AS x
GET #x, 19, xSize
GET #x, 23, ySize
CLOSE x
GRAPHIC WINDOW "Rotation test",200,200, %xWindowSize,%yWindowSize TO hWindow
GRAPHIC ATTACH hWindow,0
GRAPHIC GET BITS TO RotatedBMPstring
GRAPHIC DETACH
GRAPHIC BITMAP LOAD file$, xSize&, ySize& TO hInitialBMP
GRAPHIC ATTACH hInitialBMP,0
GRAPHIC GET BITS TO InitialBMPstring
GRAPHIC DETACH
THREAD CREATE RedrawGraphics (hWindow) TO hThread
DIM initial&(1 TO xSize&,1 TO ySize&) AT STRPTR(InitialBMPstring)+8
DIM rotated&(1 TO %xWindowSize,1 TO %yWindowSize) AT STRPTR(RotatedBMPstring)+8
LOCAL tc, ts AS EXT
t1&=TIMER*100
DO
FOR a& = 0 TO 360 'degrees
angle##=a&/(180/3.141592653589)
cosa=COS(angle##)
sina=SIN(angle##)
FOR x&=1 TO %xWindowSize
tc = (x& - %xRotateOffset) *cosa + %xRotateOffset -40
ts = -(x& - %xRotateOffset)*sina + %yRotateOffset -70
FOR y& = 1 TO %yWindowSize
oldx& =tc + (y& - %yRotateOffset)*sina
oldy& =(y& - %yRotateOffset) *cosa + ts
IF oldx&>0 AND oldx& < xSize& AND oldy&>0 AND oldy&< ySize& THEN
Rotated&(x&,y&) = Initial&(oldx& ,oldy&)
ELSE
Rotated&(x&,y&) = %WHITE
END IF
NEXT
NEXT
SLEEP 500
GRAPHIC ATTACH hWindow,0 ,REDRAW
GRAPHIC SET BITS RotatedBMPstring
GRAPHIC DETACH
SLEEP 0
NEXT
LOOP
t2&=TIMER*100
'PRINT "Time Taken = "(t2&-t1&)/100
'PRINT "Frames per second ="; 360/((t2&-t1&)/100 )
QuitAll& =1
THREAD CLOSE hThread TO lResult
MSGBOX "dfg"
END FUNCTION
'This is a flag intended to cause all otherwise non-terminating threads to quit
GLOBAL QuitAll&
'This routine and the main program must use GRAPHIC ATTACH WindowID,0,REDRAW but the main program shouldn't
'issue a GRAPHIC REDRAW command in normal use. Leave that up to this thread.
FUNCTION RedrawGraphics(BYVAL WinID AS DWORD) AS DWORD
GRAPHIC ATTACH WinID,0,REDRAW
DO
GRAPHIC REDRAW
SLEEP 1
LOOP UNTIL QuitAll&
END FUNCTION
Comment