' imgput() ... draw flip, transpose, 90/180 degree rotation.
' by counting_pine
' https://www.freebasic.net/forum/viewtopic.php?t=12074

#ifndef __IMGPUT__
#define __IMGPUT__

#include "crt.bi"

enum IMGPUT_TRANSFORM
    TRANSFORM_HFLIP      = 1
    TRANSFORM_VFLIP      = 2
    TRANSFORM_D1FLIP     = 4
    TRANSFORM_R90        = TRANSFORM_HFLIP or TRANSFORM_D1FLIP
    TRANSFORM_R180       = TRANSFORM_HFLIP or TRANSFORM_VFLIP
    TRANSFORM_R270       = TRANSFORM_VFLIP or TRANSFORM_D1FLIP
    TRANSFORM_D2FLIP     = TRANSFORM_R180  or TRANSFORM_D1FLIP
    TRANSFORM_NONE       = 0
end enum


sub imgput overload( _
      byval srcImg as any ptr, _
      byval dstImg as any ptr = 0, _
      byval x as integer = 0, byval y as integer = 0 )

    dim as integer srcWidth, srcHeight, srcBypp, srcPitch
    dim as integer dstWidth, dstHeight, dstBypp, dstPitch

    dim as integer srcXLow, srcXUpp, srcYLow, srcYUpp
    dim as integer dstXLow, dstXUpp, dstYLow, dstYUpp

    dim as any ptr srcPData, spr
    dim as any ptr dstPData, dpr

    dim as integer screenDest = 0
    dim as integer rowBytes

    if imageinfo( srcImg, srcWidth, srcHeight, srcBypp, srcPitch, srcPData ) then exit sub
    if dstImg <> 0 then
        if imageinfo( dstImg, dstWidth, dstHeight, dstBypp, dstPitch, dstPData ) then exit sub
    else
        dstPData = screenptr: if dstPData = 0 then exit sub
        screeninfo( dstWidth, dstHeight, , dstBypp, dstPitch )
        screenDest = 1
    end if

    if srcBypp <> dstBypp then exit sub

    srcXLow = 0: srcXUpp = srcWidth - 1
    srcYLow = 0: srcYUpp = srcHeight - 1


    '' clipping
    dstXLow = x: dstXUpp = x + srcXUpp - srcXLow
    dstYLow = y: dstYUpp = y + srcYUpp - srcYLow

    if dstXLow < 0 then srcXLow -= dstXLow: dstXLow = 0
    if dstYLow < 0 then srcYLow -= dstYLow: dstYLow = 0

    if dstXUpp >= dstWidth  then srcXUpp += dstWidth-1  - dstXUpp: dstXUpp = dstWidth-1
    if dstYUpp >= dstHeight then srcYUpp += dstHeight-1 - dstYUpp: dstYUpp = dstHeight-1


    '' find starting corner addresses
    spr = srcPData + srcYLow * srcPitch + srcXLow * srcBypp
    dpr = dstPData + dstYLow * dstPitch + dstXLow * dstBypp


    '' put image
#macro PUT_ROWS()
    rowBytes = srcBypp * (srcXUpp - srcXLow + 1)
    for y = srcYLow to srcYUpp
        memcpy( dpr, spr, rowBytes )
        spr += srcPitch
        dpr += dstPitch
    next y
#endmacro

    if screenDest then screenlock
    PUT_ROWS()
    if screenDest then screenunlock

end sub

sub imgput overload( _
      byval srcImg as any ptr, _
      byval dstImg as any ptr = 0, _
      byval x as integer = 0, byval y as integer = 0, _
      byval transform as IMGPUT_TRANSFORM )

    dim as integer srcWidth, srcHeight, srcBypp, srcPitch
    dim as integer dstWidth, dstHeight, dstBypp, dstPitch

    dim as integer srcXLow, srcXUpp, srcYLow, srcYUpp, srcDx, srcDy
    dim as integer dstXLow, dstXUpp, dstYLow, dstYUpp, dstDx, dstDy

    dim as const integer ptr srcPX1 = @srcXLow, srcPX2 = @srcXUpp
    dim as const integer ptr srcPY1 = @srcYLow, srcPY2 = @srcYUpp

    dim as any ptr srcPData, spr, sp
    dim as any ptr dstPData, dpr, dp

    dim as integer screenDest = 0
    dim as integer rowBytes

    if imageinfo( srcImg, srcWidth, srcHeight, srcBypp, srcPitch, srcPData ) then exit sub
    if dstImg <> 0 then
        if imageinfo( dstImg, dstWidth, dstHeight, dstBypp, dstPitch, dstPData ) then exit sub
    else
        dstPData = screenptr: if dstPData = 0 then exit sub
        screeninfo( dstWidth, dstHeight, , dstBypp, dstPitch )
        screenDest = 1
    end if

    if srcBypp <> dstBypp then exit sub

    srcDx = srcBypp: srcDy = srcPitch
    srcXLow = 0: srcXUpp = srcWidth - 1
    srcYLow = 0: srcYUpp = srcHeight - 1

    dstDx = dstBypp: dstDy = dstPitch


    '' set up transform
    if (transform and TRANSFORM_D1FLIP) then
        swap srcDx, srcDy
        swap srcXLow, srcYLow
        swap srcXUpp, srcYUpp
    end if
    if (transform and TRANSFORM_HFLIP) then srcDx = -srcDx: swap srcPX1, srcPX2
    if (transform and TRANSFORM_VFLIP) then srcDy = -srcDy: swap srcPY1, srcPY2


    '' clipping
    dstXLow = x: dstXUpp = x + srcXUpp - srcXLow
    dstYLow = y: dstYUpp = y + srcYUpp - srcYLow

    if dstXLow < 0 then srcXLow -= dstXLow: dstXLow = 0
    if dstYLow < 0 then srcYLow -= dstYLow: dstYLow = 0

    if dstXUpp >= dstWidth  then srcXUpp += dstWidth-1  - dstXUpp: dstXUpp = dstWidth-1
    if dstYUpp >= dstHeight then srcYUpp += dstHeight-1 - dstYUpp: dstYUpp = dstHeight-1


    '' find starting corner addresses
    spr = srcPData + *srcPY1 * abs(srcDy) + *srcPX1 * abs(srcDx)
    dpr = dstPData + dstYLow * abs(dstDy) + dstXLow * abs(dstDx)


    '' put image
#macro PUT_TYPE( t )
    for y = srcYLow to srcYUpp
        sp = spr
        dp = dpr
        for x = srcXLow to srcXUpp

            *cast( t ptr, dp ) = *cast(t ptr, sp )

            sp += srcDx
            dp += dstDx
        next x
        spr += srcDy
        dpr += dstDy
    next y
#endmacro
    
#macro PUT_ROWS()
    rowBytes = srcBypp * (srcXUpp - srcXLow + 1)
    for y = srcYLow to srcYUpp
        memcpy( dpr, spr, rowBytes )
        spr += srcDy
        dpr += dstDy
    next y
#endmacro

    if screenDest then screenlock
    if srcDx = srcBypp then
        PUT_ROWS()
    else
        select case SrcBypp
        case 1: PUT_TYPE( ubyte )
        case 2: PUT_TYPE( ushort )
        case 4: PUT_TYPE( uinteger )
        end select
    end if
    if screenDest then screenunlock

end sub

sub imgput overload( _
      byval srcImg as any ptr, _
      byval dstImg as any ptr = 0, _
      byval x as integer = 0, byval y as integer = 0, _
      byval transform as integer )

    if transform and -8 then
        select case transform mod 360
        case 0:         transform = TRANSFORM_NONE
        case 90,  -270: transform = TRANSFORM_R90
        case 180, -180: transform = TRANSFORM_R180
        case 270,  -90: transform = TRANSFORM_R270
        end select
    end if

    imgput( srcImg, dstImg, x, y, cast(IMGPUT_TRANSFORM, transform) )

end sub

#endif