How to rotate square part of a pixmap 45 degrees?

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Abomination (Posted 2008) [#1]

My question is (as the title may suggest); How does one rotate a square part of a pixmap 45 degrees? I would also like to know how to rotate it 315 degrees. So The part can be turned back again. The square would have a width and Height of 64 pixels. I need something like this to create a seamless isometric tile from non tiling images. [EDIT] oh yes; the square to rotate 45 stands on its tip, while the square to be rotated 315 stands on its side. [/EDIT]

Jesse (Posted 2008) [#2]

there is no build in instruction to rotate a Pixmap. you can do it through an image. steps: copy/convert pixmap to image setrotation to 45 draw the image to screen: grab rotated image from screen as pixmap you need to use these commands: loadimage - to convert pixmap to image grabpixmap - to grab the pixmap from the screen

ImaginaryHuman (Posted 2008) [#3]

Also search the forums for the pixmap rotation code that I posted.

Yan (Posted 2008) [#4]

Here's some ancient B2D code, should be easy enough to adapt for your needs...;************************************************************************************************** ;***** Rotazooming - vomit inducing - YAN 2001 ;************************************************************************************************** Graphics 640,480 source_image = LoadImage("phsyc.png") ; a 128x128 pixel image rot_image = CreateImage(160, 160) Dim sint#(359), cost#(359) For t=0 To 359 sint#(t) = Sin(t) cost#(t) = Cos(t) Next SetBuffer BackBuffer() a = 0 : s# = 0 : tx# = 0 : ty# = 0 Repeat fast_rotateflt(source_image, 128, 128, 64, 64, rot_image, 156, 156, cost#(a)*80, sint#(a)*160, a, s#) TileBlock rot_image, tx#, ty# Flip a = (a + 1) Mod 360 s# = Abs(cost#(a)) + 0.4 tx# = cost#(a) * 160 ty# = sint#(a) * 160 Until KeyDown(1) End ; Function fast_rotateflt(src_image, src_w, src_h, src_cx, src_cy, dst_image, dst_w, dst_h, dst_cx, dst_cy, angle, scale#) ;src_w & src_h MUST be powers of 2 : 2,4,8,16,32...etc ducol# = sint#(angle) * (1 / scale#) dvcol# = cost#(angle) * (1 / scale#) durow# = dvcol# dvrow# = -ducol# rowu# = src_cx - ((dst_cx * dvcol#) + (dst_cy * ducol#)) rowv# = src_cy - ((dst_cx * dvrow#) + (dst_cy * durow#)) src_buff = ImageBuffer(src_image) dst_buff = ImageBuffer(dst_image) src_h = src_h - 1 src_w = src_w - 1 dst_h = dst_h - 1 dst_w = dst_w - 1 LockBuffer(ImageBuffer(src_image)) LockBuffer(ImageBuffer(dst_image)) For y=0 To dst_h u# = rowu# v# = rowv# For x=0 To dst_w CopyPixelFast (u# And src_w), (v# And src_h), src_buff, x, y, dst_buff u# = u# + durow# v# = v# + dvrow# Next rowu# = rowu# + ducol# rowv# = rowv# + dvcol# Next UnlockBuffer(ImageBuffer(src_image)) UnlockBuffer(ImageBuffer(dst_image)) End Function ;Original C routine By Steven M Mortimer ; ;void FastRotate( ; WORD *pDstBase, Int dstW, Int dstH, Int dstDelta, ; WORD *pSrcBase, Int srcW, Int srcH, Int srcDelta, ; Float fDstCX, Float fDstCY, ; Float fSrcCX, Float fSrcCY, ; Float fAngle, Float fScale) ;{ ; srcDelta /= sizeof(WORD); ; dstDelta /= sizeof(WORD); ; Float duCol = (Float)Sin(-fAngle) * (1.0f / fScale); ; Float dvCol = (Float)Cos(-fAngle) * (1.0f / fScale); ; Float duRow = dvCol; ; Float dvRow = -duCol; ; Float startingu = fSrcCX - (fDstCX * dvCol + fDstCY * duCol); ; Float startingv = fSrcCY - (fDstCX * dvRow + fDstCY * duRow); ; Float rowu = startingu; ; Float rowv = startingv; ; For(Int y = 0; y < dstH; y++) ; { ; Float u = rowu; ; Float v = rowv; ; ; WORD *pDst = pDstBase + (dstDelta * y); ; For(Int x = 0; x < dstW ; x++) ; { ; WORD *pSrc = pSrcBase + (((Int)u) & srcW-1) + ; ((((Int)v) & srcH-1) * srcDelta ); ; *pDst++ = *pSrc++; ; u += duRow; ; v += dvRow; ; } ; rowu += duCol; ; rowv += dvCol; ; } ;

Abomination (Posted 2008) [#5]

@ Jesse I Forgot to mention that I want to do this in MAxGui, so I suppose I can't do that? @ ImaginaryHuman I tried to follow what was going on in this thread: http://www.blitzbasic.com/Community/posts.php?topic=73042#816898 Don't know if this was the code You mentioned, but I was lost in so many ways, I just gave up. @ Yan Yes; that looks very adaptable. At least I think I can follow the flow. Everybody: Grouphug!

ImaginaryHuman (Posted 2008) [#6]

Yes that's the one.

Jesse (Posted 2008) [#7]

Follow my signature link, I have an antialias pixmap rotating code you can try.

Abomination (Posted 2008) [#8]

Boy! am I out of my element! I think I can understand about a third of all this pixel-juggling. But perhaps that's enough to use some of it for my seamless isometric tile code. Though I wish I could do without rotating the texture, because of the morphing I think will occur when I tilt the seamless tile back on its tip. But I only know how to make a normal tile seamless, not one that's rotated 45 degrees. _____________________________________________________________ "enough!" "let's work!" "where's my thinking cap!" ~it's in the well master~ "how did it get there Thar?" ~I dropped it master~ "did you wear the cap at that time Thar?" ~no master~ "AH!" ________from 'Thar's lonely quest' by Mark Hellmson_________

Jesse (Posted 2008) [#9]

save yourself some head aches and rotate all of your images in a paint program and save them rotated.

Abomination (Posted 2008) [#10]

heh; can't do that! It would make it easier to make it seamless, but the isometric tiles I need, will be not perfectly centered to the texture, but 1 pixel shifted to the right. So I need to be in more control, than I would have to be if they were regular tiles. But no sweat; I think I will get there, If I use the code you suggested as a guideline. ____________________________________________________________ "oh traveler, why are you so sad?" ~I am very tired, for I have walked for three days, without food nor water.~ "but cool water flows under the bridge you crossed and succulent fruit grows in this tree you sit under." ~ah, a tree you say.~ ________from 'Thar's lonely quest' by Mark Hellmson_________