deleted in favor of frisian's suggestion in the next post.
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Bresenham3D

 Posts: 3589
 Joined: Jan 01, 2009 7:03
 Location: Australia
Bresenham3D
Last edited by BasicCoder2 on Sep 14, 2017 20:52, edited 1 time in total.
Re: Bresenham3D
BasicCoder2
Your program contains for i as integer = 0 to l that should be for i = 0 to l. The i in for i as integer = 0 to l is a different one then the one in dim as integer i.
Here is a other Bresenham in 3D that is much simpler. You should have a look there, it's a simple clear page with simple listings in C.
Regards.
[Edit] corrected a typo in the link.
Your program contains for i as integer = 0 to l that should be for i = 0 to l. The i in for i as integer = 0 to l is a different one then the one in dim as integer i.
Here is a other Bresenham in 3D that is much simpler. You should have a look there, it's a simple clear page with simple listings in C.
Code: Select all
ScreenRes 500, 500, 32
Color RGB(0, 0, 0), RGB(255, 255, 255) : Cls
Sub SETXYZ(x As Integer, y As Integer, z As Integer, cc As ULong)
'circle ((x+z\2)+250,(yz\2)+250),3,cc
PSet ((x+z\2)+250,(yz\2)+250),cc
End Sub
Sub Br_line_3d(x0 As Integer, y0 As Integer, z0 As Integer, x1 As Integer, y1 As Integer, z1 As Integer, Col As ULong)
Dim As Integer dx = Abs(x1  x0), sx = IIf(x0 < x1, 1, 1)
Dim As Integer dy = Abs(y1  y0), sy = IIf(y0 < y1, 1, 1)
Dim As Integer dz = Abs(z1  z0), sz = IIf(z0 < z1, 1, 1)
Dim As Integer dm = IIf(dx > dy, dx, dy)
dm = IIf(dz > dm, dz, dm)
Dim As Integer i = dm ' maximum difference
x1 = dm \ 2 : y1 = dm \ 2 : z1 = dm \ 2 ' error offset
Do
SETXYZ(x0, y0, z0, col)
If i = 0 Then Exit Do
i = 1
x1 = dx : If x1 < 0 Then x1 += dm : x0 += sx
y1 = dy : If y1 < 0 Then y1 += dm : y0 += sy
z1 = dz : If z1 < 0 Then z1 += dm : z0 += sz
Loop
End Sub
'draw x,y,z axis
Br_line_3d(250,0,0,250,0,0,RGB(255,0,0))
Br_line_3d(0,250,0,0,250,0,RGB(0,255,0))
Br_line_3d(0,0,250,0,0,250,RGB(0,0,255))
'draw triangle
Br_line_3d( 0, 100, 0, 0, 0, 100, RGB(255,0,255))
Br_line_3d( 0, 0, 100, 100, 0, 0, RGB(255,0,255))
Br_line_3d(100, 0, 0, 0, 100, 0, RGB(255,0,255))
Sleep
End
Regards.
[Edit] corrected a typo in the link.

 Posts: 3589
 Joined: Jan 01, 2009 7:03
 Location: Australia
Re: Bresenham3D
Thank you for your input and the link.
I noticed two of the triangle's sides were unconnected dots which was of concern.
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I noticed two of the triangle's sides were unconnected dots which was of concern.
.

 Posts: 3589
 Joined: Jan 01, 2009 7:03
 Location: Australia
Re: Bresenham3D
Changed the SETXYZ to display the isometric coordinates that I had been using in some computer game isometric displays.
It also now uses a POINT3D type.
There is still something wrong in the Bresenham3D algorithm in that some lines are not made up of connected pixels.
It also now uses a POINT3D type.
There is still something wrong in the Bresenham3D algorithm in that some lines are not made up of connected pixels.
Code: Select all
'http://members.chello.at/~easyfilter/bresenham.html
ScreenRes 500, 500, 32
Color RGB(0, 0, 0), RGB(255, 255, 255) : Cls
type POINT3D
as integer x
as integer y
as integer z
as ulong c 'color of point
end type
sub setXYZ(pt as POINT3D)
dim as single tempX,tempY,tempZ
tempX = pt.x  pt.z
tempY = (pt.x + pt.z) / 2
tempZ = pt.y
pset (tempX+250,(tempZtempY)+250),pt.c
'circle (tempX+250,(tempZtempY)+250),1,cc,,,,f
end sub
Sub Br_line_3d(pt0 as POINT3D, pt1 as POINT3D)
Dim As Integer dx = Abs(pt1.x  pt0.x), sx = IIf(pt0.x < pt1.x, 1, 1)
Dim As Integer dy = Abs(pt1.y  pt0.y), sy = IIf(pt0.y < pt1.y, 1, 1)
Dim As Integer dz = Abs(pt1.z  pt0.z), sz = IIf(pt0.z < pt1.z, 1, 1)
Dim As Integer dm = IIf(dx > dy, dx, dy)
dm = IIf(dz > dm, dz, dm)
Dim As Integer i = dm ' maximum difference
pt1.x = dm \ 2 : pt1.y = dm \ 2 : pt1.z = dm \ 2 ' error offset
Do
SETXYZ(pt0)
If i = 0 Then Exit Do
i = 1
pt1.x = dx : If pt1.x < 0 Then pt1.x += dm : pt0.x += sx
pt1.y = dy : If pt1.y < 0 Then pt1.y += dm : pt0.y += sy
pt1.z = dz : If pt1.z < 0 Then pt1.z += dm : pt0.z += sz
Loop
End Sub
dim as POINT3D pt0,pt1
'draw x,y,z axis
pt0.c = rgb(255,0,0)
pt0.x = 250
pt0.y = 0
pt0.z = 0
pt1.x = 250
pt1.y = 0
pt1.z = 0
Br_line_3d(pt0,pt1)
pt0.c = rgb(0,255,0)
pt0.x = 0
pt0.y = 250
pt0.z = 0
pt1.x = 0
pt1.y = 250
pt1.z = 0
Br_line_3d(pt0,pt1)
pt0.c = rgb(0,0,255)
pt0.x = 0
pt0.y = 0
pt0.z = 250
pt1.x = 0
pt1.y = 0
pt1.z = 250
Br_line_3d(pt0,pt1)
'draw triangle
pt0.c = rgb(255,0,255)
pt0.x = 0
pt0.y = 100
pt0.z = 0
pt1.x = 0
pt1.y = 0
pt1.z = 100
Br_line_3d(pt0,pt1)
pt0.c = rgb(255,0,255)
pt0.x = 0
pt0.y = 0
pt0.z = 100
pt1.x = 100
pt1.y = 0
pt1.z = 0
Br_line_3d(pt0,pt1)
pt0.c = rgb(255,0,255)
pt0.x = 100
pt0.y = 0
pt0.z = 0
pt1.x = 0
pt1.y = 100
pt1.z = 0
Br_line_3d(pt0,pt1)
Sleep
End
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