RodBird
Nov 25, 2015
Stefan's Advanced Polygon API Demos
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StPendl Stefan's Advanced Polygon API Demos | Array of Structures | String Hack
Array of Structures
Currently there are two ways to handle an array of structures.1) using direct memory access. This is the regular way, but involves using API functions.
'draw_polygon.bas
'Author: Stefan Pendl
'Date: 30.01.06
'
' draw polygon thru user defined points
' minimum number of points is 3
'
' left mouse button to set ponts
' right mouse button to daw poly
nomainwin
polyDrawn = 0
ptSize = 4
ptColor$ = "red"
polySize = 1
polyColor$ = "black"
fillColor$ = "green"
polyFillColor$ = "blue"
gbWidth = 300
gbHeight = 300
if gbWidth > DisplayWidth - 30 then gbWidth = DisplayWidth - 30
if gbHeight > DisplayHeight - 90 then gbHeight = DisplayHeight - 90
WindowWidth = gbWidth + 30
WindowHeight = gbHeight + 90
UpperLeftX = int((DisplayWidth-WindowWidth)/2)
UpperLeftY = int((DisplayHeight-WindowHeight)/2)
graphicbox #1.gb, 10, 10, gbWidth, gbHeight
button #1.draw, "Draw Poly", [drawPoly], ul, 10, gbHeight + 20, 60, 20
stylebits #1.ptnum, _SS_RIGHT, 0, 0, 0
statictext #1.ptnum, "0", 80, gbHeight + 20, 15, 15
statictext #1.pt, "Points selected", 100, gbHeight + 20, 100, 15
statictext #1.ptx, "X:", 200, gbHeight + 20, 10, 15
stylebits #1.ptxpos, _SS_RIGHT, 0, 0, 0
statictext #1.ptxpos, "000", 215, gbHeight + 20, 20, 15
statictext #1.pty, "Y:", 200, gbHeight + 40, 10, 15
stylebits #1.ptypos, _SS_RIGHT, 0, 0, 0
statictext #1.ptypos, "000", 215, gbHeight + 40, 20, 15
open "Polygon" for window_nf as #1
#1 "trapclose [quit]"
#1.draw "!disable"
#1.gb "down;fill ";fillColor$;";flush"
#1.gb "size "; ptSize
#1.gb "color "; ptColor$
#1.gb "backcolor "; polyFillColor$
#1.gb "when mouseMove [updatePos]"
#1.gb "when leftButtonUp [drawPoint]"
#1.gb "when rightButtonUp [drawPoly]"
h=hwnd(#1.gb) 'window handle
'get device context for window:
calldll #user32, "GetDC",_
h as ulong,_
hdc as ulong
cursor crosshair
wait
[updatePos]
#1.ptxpos MouseX
#1.ptypos MouseY
wait
[drawPoint]
if polyDrawn = 1 then
#1.gb "cls;fill "; fillColor$; ";flush blank"
polyDrawn = 0
Points$ = ""
ptNum = 0
end if
Points$ = Points$; MouseX; " "; MouseY; " "
#1.gb "set "; MouseX; " "; MouseY
ptNum = ptNum + 1
#1.ptnum ptNum
if ptNum = 3 then #1.draw "!enable"
wait
[drawPoly]
if ptNum < 3 then wait
#1.draw "!disable"
#1.gb "size "; polySize
#1.gb "color "; polyColor$
STRUCT PolyPoints,_
x as long,_
y as long
PolyPointsLen = len(PolyPoints.struct)
cbBuf = PolyPointsLen * ptNum
uFlags = _LMEM_MOVEABLE or _LMEM_ZEROINIT
CallDll #kernel32, "LocalAlloc", _
uFlags as ulong, _
cbBuf as ulong, _
hMem as ulong
CallDll #kernel32, "LocalLock", _
hMem as ulong, _
PolyPointsArray as ulong
BufferPointer = PolyPointsArray
'The STRUCT must be filled before it can be used in an api call:
for count = 1 to ptNum * 2 step 2
PolyPoints.x.struct = val(word$(Points$, count))
PolyPoints.y.struct = val(word$(Points$, count + 1))
calldll #kernel32, "RtlMoveMemory", _
BufferPointer as ulong, _
PolyPoints as struct,_
PolyPointsLen as ulong, _
result as void
BufferPointer = BufferPointer + PolyPointsLen
next
calldll #gdi32, "Polygon",_
hdc as ulong,_ 'device context of window or control
PolyPointsArray as ulong,_ 'memory address of array of points
ptNum as ulong,_ 'number of x,y pairs in array
result as boolean
#1.gb "getbmp pix 0 0 ";gbWidth; " "; gbHeight
#1.gb "delsegment Polygon;drawbmp pix 0 0;flush Polygon"
#1.gb "size "; ptSize
#1.gb "color "; ptColor$
polyDrawn = 1
' free PolyPointsArray memory
calldll #kernel32, "LocalFree", _
hMem as ulong, _
result as ulong
wait
[quit]
calldll #user32, "ReleaseDC",_
h as ulong,_
hdc as ulong,_
ret as long
close #1
end
String Hack
This one is based on an easter egg of LB, where a structure is basically handled like a string, since you use the LEN() function to get the size of the structure in LB.'draw_poly.bas
'Author: Stefan Pendl
'Date: 08.07.08
'
' draw polygon thru user defined points
' minimum number of points is 3
'
' left mouse button to set ponts
' right mouse button to daw poly
nomainwin
polyDrawn = 0
ptSize = 4
ptColor$ = "red"
polySize = 1
polyColor$ = "black"
fillColor$ = "green"
polyFillColor$ = "blue"
gbWidth = 300
gbHeight = 300
if gbWidth > DisplayWidth - 30 then gbWidth = DisplayWidth - 30
if gbHeight > DisplayHeight - 90 then gbHeight = DisplayHeight - 90
WindowWidth = gbWidth + 30
WindowHeight = gbHeight + 90
UpperLeftX = int((DisplayWidth-WindowWidth)/2)
UpperLeftY = int((DisplayHeight-WindowHeight)/2)
graphicbox #1.gb, 10, 10, gbWidth, gbHeight
button #1.draw, "Draw Poly", [drawPoly], ul, 10, gbHeight + 20, 60, 20
stylebits #1.ptnum, _SS_RIGHT, 0, 0, 0
statictext #1.ptnum, "0", 80, gbHeight + 20, 15, 15
statictext #1.pt, "Points selected", 100, gbHeight + 20, 100, 15
statictext #1.ptx, "X:", 200, gbHeight + 20, 10, 15
stylebits #1.ptxpos, _SS_RIGHT, 0, 0, 0
statictext #1.ptxpos, "000", 215, gbHeight + 20, 20, 15
statictext #1.pty, "Y:", 200, gbHeight + 40, 10, 15
stylebits #1.ptypos, _SS_RIGHT, 0, 0, 0
statictext #1.ptypos, "000", 215, gbHeight + 40, 20, 15
open "Polygon" for window_nf as #1
#1 "trapclose [quit]"
#1.draw "!disable"
#1.gb "down;fill ";fillColor$;";flush"
#1.gb "size "; ptSize
#1.gb "color "; ptColor$
#1.gb "backcolor "; polyFillColor$
#1.gb "when mouseMove [updatePos]"
#1.gb "when leftButtonUp [drawPoint]"
#1.gb "when rightButtonUp [drawPoly]"
h=hwnd(#1.gb) 'window handle
'get device context for window:
calldll #user32, "GetDC",_
h as ulong,_
hdc as ulong
cursor crosshair
wait
[updatePos]
#1.ptxpos MouseX
#1.ptypos MouseY
wait
[drawPoint]
if polyDrawn = 1 then
#1.gb "cls;fill "; fillColor$; ";flush blank"
polyDrawn = 0
Points$ = ""
ptNum = 0
end if
Points$ = Points$; MouseX; " "; MouseY; " "
#1.gb "set "; MouseX; " "; MouseY
ptNum = ptNum + 1
#1.ptnum ptNum
if ptNum = 3 then #1.draw "!enable"
wait
[drawPoly]
if ptNum < 3 then wait
#1.draw "!disable"
#1.gb "size "; polySize
#1.gb "color "; polyColor$
STRUCT PolyPoints,_
x as long,_
y as long
PolyPointsArray$ = ""
'The STRUCT must be filled before it can be used in an api call:
for count = 1 to ptNum * 2 step 2
PolyPoints.x.struct = val(word$(Points$, count))
PolyPoints.y.struct = val(word$(Points$, count + 1))
PolyPointsArray$ = PolyPointsArray$; PolyPoints.struct
next
calldll #gdi32, "Polygon",_
hdc as ulong,_ 'device context of window or control
PolyPointsArray$ as ptr,_ 'memory address of array of points
ptNum as ulong,_ 'number of x,y pairs in array
result asbooleanlong
#1.gb "getbmp pix 0 0 ";gbWidth; " "; gbHeight
#1.gb "delsegment Polygon;drawbmp pix 0 0;flush Polygon"
#1.gb "size "; ptSize
#1.gb "color "; ptColor$
polyDrawn = 1
wait
[quit]
calldll #user32, "ReleaseDC",_
h as ulong,_
hdc as ulong,_
ret as long
close #1
end
Stefan's Advanced Polygon API Demos | Array of Structures | String Hack