Paste image on image with alpha using memblocks help

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Mobiius

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Posted: 13th Feb 2018 11:17 Edited at: 13th Feb 2018 11:18

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Hello, I have some code I copied from the forums a while back to paste one image onto another image using memblocks, but it doesn't seem to take alpha values into account.

Does anyone have "teh coadz" to do this, or know how to alter what I have to take alpha into account.

Here is the non-alpha version I have. (If you wrote it, then thanks, and who are you?!)

function pastetoimage(sourceimage as integer, destimage as integer, xoffset as integer, yoffset as integer)
    newimageblock = creatememblockfromimage(destimage)
    smallimageblock = CreateMemblockFromImage(sourceimage)
    swidth = GetMemblockInt(smallimageblock, 0)
    sheight = GetMemblockInt(smallimageblock, 4)
    dwidth = GetMemblockInt(newimageblock,0)
    xoff=xoffset*4
    yoff=yoffset*dwidth*4
    for y = 0 to sheight-1
        dlin=dwidth*y*4
        CopyMemblock(smallimageblock,newimageblock,(y*swidth*4)+12,xoff+yoff+dlin+12,swidth*4)
    next y
    newimage = CreateImageFromMemblock(newimageblock)
    DeleteMemblock(newimageblock)
    Deletememblock(smallimageblock)
endfunction newimage
 
function createblankimage(swidth as integer, sheight as integer)
    newblock = CreateMemblock((swidth*sheight*4)+12)
    SetMemblockInt(newblock,0,swidth)
    Setmemblockint(newblock,4,sheight)
    SetMemblockInt(newblock,8,32)
    newimage = CreateImageFromMemblock(newblock)
    DeleteMemblock(newblock)
endfunction newimage

+ Code Snippet

function pastetoimage(sourceimage as integer, destimage as integer, xoffset as integer, yoffset as integer)
    newimageblock = creatememblockfromimage(destimage)
    smallimageblock = CreateMemblockFromImage(sourceimage)
    swidth = GetMemblockInt(smallimageblock, 0)
    sheight = GetMemblockInt(smallimageblock, 4)
    dwidth = GetMemblockInt(newimageblock,0)
    xoff=xoffset*4
    yoff=yoffset*dwidth*4
    for y = 0 to sheight-1
        dlin=dwidth*y*4
        CopyMemblock(smallimageblock,newimageblock,(y*swidth*4)+12,xoff+yoff+dlin+12,swidth*4)
    next y
    newimage = CreateImageFromMemblock(newimageblock)
    DeleteMemblock(newimageblock)
    Deletememblock(smallimageblock)
endfunction newimage
 
function createblankimage(swidth as integer, sheight as integer)
    newblock = CreateMemblock((swidth*sheight*4)+12)
    SetMemblockInt(newblock,0,swidth)
    Setmemblockint(newblock,4,sheight)
    SetMemblockInt(newblock,8,32)
    newimage = CreateImageFromMemblock(newblock)
    DeleteMemblock(newblock)
endfunction newimage

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Scraggle

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Posted: 13th Feb 2018 15:47 Edited at: 13th Feb 2018 16:38

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Hey, I'm pretty sure there's something like that in my 'image functions' library. See my signature.
I'll check later when I'm back at my PC but I think I covered that.

[Edit]
OK, I checked and it looks like I didn't include that.
Not to worry here it is. Well two versions actually. The first one uses sprites and GetImage() and the second uses memblocks.

function CombineImages(img1, img2)
	spr1 = CreateSprite(img1)
	spr2 = CreateSprite(img2)
	w =  GetSpriteWidth(spr1)
	h = GetSpriteHeight(spr2)
	SetSpriteDepth(spr1, 0)
	SetSpriteDepth(spr2, 0)

ClearScreen()
    SetSpritePosition(spr1, 0, 0)
    SetSpritePosition(spr2, 0, 0)
   	DrawSprite(spr1)
   	DrawSprite(spr2)
   	
    ret = GetImage(0, 0, w, h)

DeleteSprite(spr1)
    DeleteSprite(spr2)
endfunction ret

function CombineImagesMB(img1, img2)
	w = GetImageWidth(img1)
	h = GetImageHeight(img1)
	img3 = CopyImage(img2, 0, 0, GetImageWidth(img2), GetImageHeight(img2))
	mb1 = CreateMemblockFromImage(img1)
	ResizeImage(img3, w, h)
	mb2 = CreateMemblockFromImage(img3)
	mb3 = CreateMemblockEmptyImage(w, h)
	for k = 12 to GetMemblockSize(mb1)-12 step 4
		r1 = GetMemblockByte(mb1, k)
		g1 = GetMemblockByte(mb1, k+1)
		b1 = GetMemblockByte(mb1, k+2)
		a1 = GetMemblockByte(mb1, k+3)
		r2 = GetMemblockByte(mb2, k)
		g2 = GetMemblockByte(mb2, k+1)
		b2 = GetMemblockByte(mb2, k+2)
		a2 = GetMemblockByte(mb2, k+3)

pc# = GetMemblockByte(mb2, k+3) / 255.0
		SetMemblockByte(mb3, k, r1*(1-pc#)+r2*pc#)
		SetMemblockByte(mb3, k+1, g1*(1-pc#)+g2*pc#)
		SetMemblockByte(mb3, k+2, b1*(1-pc#)+b2*pc#)
		SetMemblockByte(mb3, k+3, a1*(1-pc#)+a2*pc#)
		
	next k
	ret = CreateImageFromMemblock(mb3)
	DeleteMemblock(mb1)
	DeleteMemblock(mb2)
	DeleteMemblock(mb3)
	DeleteImage(img3)
endfunction ret

+ Code Snippet

function CombineImages(img1, img2)
	spr1 = CreateSprite(img1)
	spr2 = CreateSprite(img2)
	w =  GetSpriteWidth(spr1)
	h = GetSpriteHeight(spr2)
	SetSpriteDepth(spr1, 0)
	SetSpriteDepth(spr2, 0)

    ClearScreen()
    SetSpritePosition(spr1, 0, 0)
    SetSpritePosition(spr2, 0, 0)
   	DrawSprite(spr1)
   	DrawSprite(spr2)
   	
    ret = GetImage(0, 0, w, h)

    DeleteSprite(spr1)
    DeleteSprite(spr2)
endfunction ret


function CombineImagesMB(img1, img2)
	w = GetImageWidth(img1)
	h = GetImageHeight(img1)
	img3 = CopyImage(img2, 0, 0, GetImageWidth(img2), GetImageHeight(img2))
	mb1 = CreateMemblockFromImage(img1)
	ResizeImage(img3, w, h)
	mb2 = CreateMemblockFromImage(img3)
	mb3 = CreateMemblockEmptyImage(w, h)
	for k = 12 to GetMemblockSize(mb1)-12 step 4
		r1 = GetMemblockByte(mb1, k)
		g1 = GetMemblockByte(mb1, k+1)
		b1 = GetMemblockByte(mb1, k+2)
		a1 = GetMemblockByte(mb1, k+3)
		r2 = GetMemblockByte(mb2, k)
		g2 = GetMemblockByte(mb2, k+1)
		b2 = GetMemblockByte(mb2, k+2)
		a2 = GetMemblockByte(mb2, k+3)

		pc# = GetMemblockByte(mb2, k+3) / 255.0
		SetMemblockByte(mb3, k, r1*(1-pc#)+r2*pc#)
		SetMemblockByte(mb3, k+1, g1*(1-pc#)+g2*pc#)
		SetMemblockByte(mb3, k+2, b1*(1-pc#)+b2*pc#)
		SetMemblockByte(mb3, k+3, a1*(1-pc#)+a2*pc#)
		
	next k
	ret = CreateImageFromMemblock(mb3)
	DeleteMemblock(mb1)
	DeleteMemblock(mb2)
	DeleteMemblock(mb3)
	DeleteImage(img3)
endfunction ret

And if you don't have the rest of my image functions included then you'll also need this function:

+ Code Snippet

/**********		CreateMemblockEmptyImage(w, h)   **************************

Description:	Creates a new memblock ready to create an image and
				populates the header of the memblock with the dimensions.

Parameters:		w - The width of the image
				h - The height of the image

Returns:		mb - The memblock ID of the newly created memblock
*/
function CreateMemblockEmptyImage(w, h)
	mb = CreateMemblock(w*h*4+12)
	SetMemblockInt(mb, 0, w)
	SetMemblockInt(mb, 4, h)
	SetMemblockInt(mb, 8, 32)
endfunction mb

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Mobiius

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Posted: 13th Feb 2018 17:16

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Quote: "Hey, I'm pretty sure there's something like that in my 'image functions' library."

There very well may be, , but the code I already had is missing the 'MyResize' function.

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Scraggle

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Posted: 13th Feb 2018 17:20

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Oh?
here it is:

+ Code Snippet

function myResizeImage( Image, Width, Height )
	s = CreateSprite( image )
	SetSpriteSize( s, Width, Height )
	SetSpritePosition( s, 0, 0 )
	Render()
	i = GetImage( 0, 0, Width, Height )
	DeleteSprite( s )
endfunction i

That was just a quick fix before the (now standard) ResizeImage()

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Additional Image Functions (9 sprite slicing etc.)
Additional String Functions
XML read, write, parse
Black theme for Geeny
RGB->HSV->RGB
SpriteSheet XML Control

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Mobiius

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Joined: 27th Feb 2003

Location: The Cold North