3D-effects

[Semen Matusovski]

I want to draw 3D-border for non-rectangle figure.
Just now I do following. I select white, insideframe pen and execute PolyPoligon.
Then, using the same points, select grey Pen and by PolyLine change right and down border.
After this it's necessary to make offset 1 pixel and to draw black line around right and down parts.
For horizontal and vertical lines - no problems. But with rounded/diagonal lines occurs troubles.
I understand, that it possible to create Poligon from vertical and horizontal lines only (with step 1-2 pixels).
But could be exist better solution ?

[Scott Hauser]

Hi Semen,
Perhaps PolyBezier could be adapted to your border function.

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[Semen Matusovski]

Thanks, Scott, for you reply, but I can't imagine, how to use it.
I have a line (x1, y1) - (x2, y2) and want to draw (x1, y1 + 1) - (x2, y2 + 1) so, that to have delta y = 1 pixel for each point.
Which control points I should pass to PolyBezier ?

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[Scott Hauser]

hi semen,

>>i have a line (x1, y1) - (x2, y2) and want to draw (x1, y1 + 1) - (x2, y2 + 1)
>>so, that to have delta y = 1 pixel for each point.

>>which control points i should pass to polybezier ?

the win32 help file defines:

bezier spline

"an irregular curve defined by four points: two endpoints and two control points.
the endpoints determine where the curve begins and ends. the control points determine
the shape of the curve; however, unlike the endpoints, the control points do not
intersect the curve."

i am only guessing here because i have not used polybezier. i presume it is some
form of a cubic spline equation. you need to pass data points in two diminsions.

for example: we have two line segments that will be joined by a bezier curve.
where line segment 1 = (x1, y1) to (x2, y2)
where line segment 2 = (x3, y3) to (x4, y4)


(x1, y1) (x2, y2)
'*----------------------------*..+ <--- control points in this area?
' .
' *(x3, y3)
' |
' |
' |
' |
' |
' *(x4, y4)

the start point would probably be (x2, y2)
the end point would probably be (x3, y3)

since the control points determine the shape of the curve, i suspect they might be
somewhere at or near the corner junction of the two line segments (represented by the plus sign.)

dave navarro wrote a sample using polybezierto and lance converted it to pbcc. it is called "cool.bas"

also the following link may be of use

http://www.powerbasic.com/support/pb...ead.php?t=2072

scott

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[Scott Hauser]

forgot about [ code ]

<font face="courier new, courier" size="3"><pre>
hi semen,

>>i have a line (x1, y1) - (x2, y2) and want to draw (x1, y1 + 1) - (x2, y2 + 1)
>>so, that to have delta y = 1 pixel for each point.

>>which control points i should pass to polybezier ?

the win32 help file defines:

bezier spline

"an irregular curve defined by four points: two endpoints and two control points.
the endpoints determine where the curve begins and ends. the control points determine
the shape of the curve; however, unlike the endpoints, the control points do not
intersect the curve."

i am only guessing here because i have not used polybezier. i presume it is some
form of a cubic spline equation. you need to pass data points in two diminsions.

for example: we have two line segments that will be joined by a bezier curve.
where line segment 1 = (x1, y1) to (x2, y2)
where line segment 2 = (x3, y3) to (x4, y4)


(x1, y1) (x2, y2)
'*----------------------------*..+ <--- control points in this area?
' .
' *(x3, y3)
' |
' |
' |
' |
' |
' *(x4, y4)

the start point would probably be (x2, y2)
the end point would probably be (x3, y3)

since the control points determine the shape of the curve, i suspect they might be
somewhere at or near the corner junction of the two line segments (represented by the plus sign.)

dave navarro wrote a sample using polybezierto and lance converted it to pbcc. it is called "cool.bas"

also the following link may be of use

http://www.powerbasic.com/support/pb...ead.php?t=2072

scott
[/CODE]

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