The document discusses different techniques for line clipping, including:
1. The Cohen-Sutherland line clipping algorithm which divides the screen into 9 regions and clips lines based on which regions their endpoints fall into.
2. Midpoint subdivision is an alternative that recursively divides lines at the midpoint until they can be fully classified.
3. Intersection calculations determine where lines intersect clipping boundaries.
Polygon clipping extends these ideas, testing vertex pairs and either outputting intersections or vertices as needed to clip the polygon shape.
The Lian-Barsky algorithm is a line clipping algorithm. This algorithm is more efficient than Cohen–Sutherland line clipping algorithm and can be extended to 3-Dimensional clipping. This algorithm is considered to be the faster parametric line-clipping algorithm. The following concepts are used in this clipping:
The parametric equation of the line.
The inequalities describing the range of the clipping window which is used to determine the intersections between the line and the clip window.
Sutherland hodgman polygon clipping algorithmTawfiq Ahmed
Sutherland Hodgman polygon clipping algorithm is a very simple clipping algorithm to understand. I hope my slide will help you guys.
-Thanks
Tawfiq Ahmed
Ever been troubled by the blinking sign and didn’t know what to do?
Here’s a handy guide to dashboard symbols so that you’ll never be confused again!
Save them for later and save the trouble!
Why Is Your BMW X3 Hood Not Responding To Release CommandsDart Auto
Experiencing difficulty opening your BMW X3's hood? This guide explores potential issues like mechanical obstruction, hood release mechanism failure, electrical problems, and emergency release malfunctions. Troubleshooting tips include basic checks, clearing obstructions, applying pressure, and using the emergency release.
The Lian-Barsky algorithm is a line clipping algorithm. This algorithm is more efficient than Cohen–Sutherland line clipping algorithm and can be extended to 3-Dimensional clipping. This algorithm is considered to be the faster parametric line-clipping algorithm. The following concepts are used in this clipping:
The parametric equation of the line.
The inequalities describing the range of the clipping window which is used to determine the intersections between the line and the clip window.
Sutherland hodgman polygon clipping algorithmTawfiq Ahmed
Sutherland Hodgman polygon clipping algorithm is a very simple clipping algorithm to understand. I hope my slide will help you guys.
-Thanks
Tawfiq Ahmed
Ever been troubled by the blinking sign and didn’t know what to do?
Here’s a handy guide to dashboard symbols so that you’ll never be confused again!
Save them for later and save the trouble!
Why Is Your BMW X3 Hood Not Responding To Release CommandsDart Auto
Experiencing difficulty opening your BMW X3's hood? This guide explores potential issues like mechanical obstruction, hood release mechanism failure, electrical problems, and emergency release malfunctions. Troubleshooting tips include basic checks, clearing obstructions, applying pressure, and using the emergency release.
What Exactly Is The Common Rail Direct Injection System & How Does It WorkMotor Cars International
Learn about Common Rail Direct Injection (CRDi) - the revolutionary technology that has made diesel engines more efficient. Explore its workings, advantages like enhanced fuel efficiency and increased power output, along with drawbacks such as complexity and higher initial cost. Compare CRDi with traditional diesel engines and discover why it's the preferred choice for modern engines.
In this presentation, we have discussed a very important feature of BMW X5 cars… the Comfort Access. Things that can significantly limit its functionality. And things that you can try to restore the functionality of such a convenient feature of your vehicle.
What Does the PARKTRONIC Inoperative, See Owner's Manual Message Mean for You...Autohaus Service and Sales
Learn what "PARKTRONIC Inoperative, See Owner's Manual" means for your Mercedes-Benz. This message indicates a malfunction in the parking assistance system, potentially due to sensor issues or electrical faults. Prompt attention is crucial to ensure safety and functionality. Follow steps outlined for diagnosis and repair in the owner's manual.
Fleet management these days is next to impossible without connected vehicle solutions. Why? Well, fleet trackers and accompanying connected vehicle management solutions tend to offer quite a few hard-to-ignore benefits to fleet managers and businesses alike. Let’s check them out!
"Trans Failsafe Prog" on your BMW X5 indicates potential transmission issues requiring immediate action. This safety feature activates in response to abnormalities like low fluid levels, leaks, faulty sensors, electrical or mechanical failures, and overheating.
5 Warning Signs Your BMW's Intelligent Battery Sensor Needs AttentionBertini's German Motors
IBS monitors and manages your BMW’s battery performance. If it malfunctions, you will have to deal with an array of electrical issues in your vehicle. Recognize warning signs like dimming headlights, frequent battery replacements, and electrical malfunctions to address potential IBS issues promptly.
𝘼𝙣𝙩𝙞𝙦𝙪𝙚 𝙋𝙡𝙖𝙨𝙩𝙞𝙘 𝙏𝙧𝙖𝙙𝙚𝙧𝙨 𝙞𝙨 𝙫𝙚𝙧𝙮 𝙛𝙖𝙢𝙤𝙪𝙨 𝙛𝙤𝙧 𝙢𝙖𝙣𝙪𝙛𝙖𝙘𝙩𝙪𝙧𝙞𝙣𝙜 𝙩𝙝𝙚𝙞𝙧 𝙥𝙧𝙤𝙙𝙪𝙘𝙩𝙨. 𝙒𝙚 𝙝𝙖𝙫𝙚 𝙖𝙡𝙡 𝙩𝙝𝙚 𝙥𝙡𝙖𝙨𝙩𝙞𝙘 𝙜𝙧𝙖𝙣𝙪𝙡𝙚𝙨 𝙪𝙨𝙚𝙙 𝙞𝙣 𝙖𝙪𝙩𝙤𝙢𝙤𝙩𝙞𝙫𝙚 𝙖𝙣𝙙 𝙖𝙪𝙩𝙤 𝙥𝙖𝙧𝙩𝙨 𝙖𝙣𝙙 𝙖𝙡𝙡 𝙩𝙝𝙚 𝙛𝙖𝙢𝙤𝙪𝙨 𝙘𝙤𝙢𝙥𝙖𝙣𝙞𝙚𝙨 𝙗𝙪𝙮 𝙩𝙝𝙚 𝙜𝙧𝙖𝙣𝙪𝙡𝙚𝙨 𝙛𝙧𝙤𝙢 𝙪𝙨.
Over the 10 years, we have gained a strong foothold in the market due to our range's high quality, competitive prices, and time-lined delivery schedules.
Things to remember while upgrading the brakes of your carjennifermiller8137
Upgrading the brakes of your car? Keep these things in mind before doing so. Additionally, start using an OBD 2 GPS tracker so that you never miss a vehicle maintenance appointment. On top of this, a car GPS tracker will also let you master good driving habits that will let you increase the operational life of your car’s brakes.
Comprehensive program for Agricultural Finance, the Automotive Sector, and Empowerment . We will define the full scope and provide a detailed two-week plan for identifying strategic partners in each area within Limpopo, including target areas.:
1. Agricultural : Supporting Primary and Secondary Agriculture
• Scope: Provide support solutions to enhance agricultural productivity and sustainability.
• Target Areas: Polokwane, Tzaneen, Thohoyandou, Makhado, and Giyani.
2. Automotive Sector: Partnerships with Mechanics and Panel Beater Shops
• Scope: Develop collaborations with automotive service providers to improve service quality and business operations.
• Target Areas: Polokwane, Lephalale, Mokopane, Phalaborwa, and Bela-Bela.
3. Empowerment : Focusing on Women Empowerment
• Scope: Provide business support support and training to women-owned businesses, promoting economic inclusion.
• Target Areas: Polokwane, Thohoyandou, Musina, Burgersfort, and Louis Trichardt.
We will also prioritize Industrial Economic Zone areas and their priorities.
Sign up on https://profilesmes.online/welcome/
To be eligible:
1. You must have a registered business and operate in Limpopo
2. Generate revenue
3. Sectors : Agriculture ( primary and secondary) and Automative
Women and Youth are encouraged to apply even if you don't fall in those sectors.
Symptoms like intermittent starting and key recognition errors signal potential problems with your Mercedes’ EIS. Use diagnostic steps like error code checks and spare key tests. Professional diagnosis and solutions like EIS replacement ensure safe driving. Consult a qualified technician for accurate diagnosis and repair.
Core technology of Hyundai Motor Group's EV platform 'E-GMP'Hyundai Motor Group
What’s the force behind Hyundai Motor Group's EV performance and quality?
Maximized driving performance and quick charging time through high-density battery pack and fast charging technology and applicable to various vehicle types!
Discover more about Hyundai Motor Group’s EV platform ‘E-GMP’!
1. Different cases for Line Clipping
1. Both endpoints of the line lie with in the clipping area. This means that the
line is included completely in the clipping area, so that the whole line must be
drawn.
Clip
rectangle
B
A
B
A
1
2. Conti….
3. Both end points are located outside the clipping area and the line do not intersect the
clipping area. In the case , the line lies completely outside the clipping area and can be
neglected for the scene.
4. Both endpoints are located outside the clipping area and the line intersect the clipping
area. The two intersection points of the line with the clipping are must be determined.
Only the part of the line between these two intersection points should be drawn.
C
D’
B
A
G’
H'
Clip
rectangle
B
A
D
D’
C
G’
H'
G
H
I’
I
J’
J
E
F
2
3. COHEN-SUTHERLAND LINE CLIPPING
ALGORITHM
This algorithm divides a 2D space into 9parts,of which only the middle part is
visible.
Cohen- Sutherland subdivision line clipping algorithm was developed by Dan
Cohen and lvan Sutherland. This method is used:
i. To save a line segment.
ii. To discard line segment or,
iii. To divide the line according to window co- ordinate.
Cohen Sutherland performs line clipping in two phases:
Phase1: Find visibility of line.
Phase2: clip the line falling in category 3 (candidate for Clipping).
3
4. COHEN-SUTHERLAND LINE
CLIPPING ALGORITHM
Following rules are used for clipping by Cohen-Sutherland line clipping algorithm:
Visible : Any lines that are completely contained within the window boundaries have a
region code of 0000 for both endpoints, and we trivially accept these lines . For example,
Line segment P1P2 is visible in the figure.
Invisible : Any lines that have a 1 in the same bit position in the region code for each
endpoints are completely outside the clipping rectangle and the line segment is invisible ,
Ad we trivially reject these lines. We would discard the line that has a region code of 0001
For one endpoint and a code of 0101 for the other endpoint. Both end points of the line are
Left of the clipping rectangle , as indicated by the 1 in the first position of each region code.
4
5. Cont…….
window
ywmax
ywmin
xwmin xwmax
y
LEFT RIGHT
TOP
BOTTOM
x
1001
0001
0101
1000
0010
0100
1010
0110
P8
P7
0000
P1
P2
P3
P4
P6
P5
Figure :Cohen- Sutherland clipping techniques
Clipping Candidate or indeterminate : A line segment is said to be indeterminate
If the bitwise logical AND of the region codes of the end points is equal to(0000).
For example: line segment P3P4 having endpoint codes(0100) and (0010) and P7P8 having endpoints
Codes (0010) and (1000) in the figure. These line segments may or may not process the window
Boundaries as line segment P7P8 is invisible but line segment P3P4 is partially visible and must be
Clipped.
5
6. COHEN-SUTHERLAND LINE
CLIPPING ALGORITHM
Advantage and Disadvantages:
Will do unnecessary clipping.
Not the most efficient.
Clipping and testing are done in fixed order.
Easy to program.
Efficient when most of lines to be clipped are either rejected or
accepted.
6
7. Intersection, Calculation and
Clipping
Line that can not be identified as completely inside a clip window by
these test are checked for intersection with the window boundaries.We
begin the clipping process for a line by comparing an outside endpoint
to a window boundary to determine how much of the line can be
discard . Then the remaining part of the line is checked against the
other boundaries,and we continue until either the line is totally discard
or a section is found inside the window.We set up our algorithm to
check line endpoints against clipping boundaries in the order
left,right,bottom,top.
TO ilustrate the specific step in clipping line against rectangular
boundary using the Cohen-Suterland algorithm,We show the linein
figure could be processed.
7
8. Starting with the bottom endpoints of the line from p1 to p2, we check p1
against the left right bottom boundaries in turn and find that this point is
below the window. We then find the intersection point p1’ with the window
boundary and discard the line section from p1 to p1’.The line now be reduced to
the section from p1’ to p2.
Since P2 is outside the clip window. We check these end points against the
boundary. find that it is to the left of the window. Intersection point p2’ is
calculated . But this point is outside the window. So the final intersection
calculation is p2” and the line from P1’ to p2” is saved. This complete
processing for these line . So we save this part and go on to the next line.
Point P3 is the next line is to the left of the clipping window, so we
determine the intersection point P3 and eliminate the line from P3 to P3’.By
checking region code for the line section from P3’ to P4. We find the remainder
of the line is below the clip window and can be discarded also.
Intersection Calculation and Clipping
8
9. Intersection Calculation and Clipping
window
xwmin xwmax
y
TOP
BOTTOM
x
1001
0001
0101
1000
0010
0100
1010
0110
0000
ywmax
ywmin
LEFT RIGHT
P2
P2’
P2”
P1’
P1
P3’
P3
P4
Figure : lines extending from one coordinate region to another may pass through the
Clip window, or they may intersect clipping boundaries without entering the window.
9
10. Intersection and calculation
clipping
Q.Intersection point with a clipping boundary can be
calculated using the slope intersect for the line of
equation.
X min=2,X max=8, y min=2 y max=8
EF:E(3,10) & F(6,12)
GH:G(4,1) &H (10,6)
Formula:
M=Y2-Y1/X2-X1
Xi=X1+1/m(Yi-Y1)
Where the x value is set to either Xmin or to a x max
Yi=Y1+m(Xi-X1)
10
11. Mid point subdivision algorithm
This method divide the line into three category:
I. Category 1: Visible line
II. Category 2: not visible line
III. Category 3: candidate for Clipping.
An alternative way to process a line in category 3 is based on binary
search.The line is divided at its midpointsinto two shorter line segments.
Each line in a category three is divided again into shorter segments and
categorized.This bisection and categorization process continue until eavh
line segment that spans across a window boundary reaches a threshold for
line size and all other segments are either in a category 1 (visible) or in
category 2 (Not visible.)
11
12. Mid-point subdivision algorithm
The mid points coordinates are (x m, y m) of a line joining the points(X1,Y1)and (X2,Y2)
are given by:
X m= X1+X2/2 and
Y M= Y1+Y2/2 Q
P
6
7
8
5
1
I1
I2
2
4
3
Figure: illustrates how midpoint subdivision is used to zoom in onto the two Intersection points I1 and I2 with 10 bisection.
12
13. Comparison b/w Cohen-Sutherland and Mid-point subdivision clipping Algorithm
• Midpoint subdivision algorithm is a special case of Cohen-sutherland algorithm,
where the intersection is not computed by equation solving. It is computed by a
midpoint approximation method, which is suitable for hardware and it is very
fast and efficient.
• The maximum time is consume in the clipping process is to do intersection calculation
with the window boundaries.
• The Cohen-sutherland algorithm reduces these calculation by first discarding that lines
those can be trivially accepted or rejected.
13
14. Polygon Clipping
The simplest curve is a line segment or simply a line. A sequence of line where the
following line starts where the previous one ends is called a polyline. If the last line
segment of the polyline ends where the first line segment started, the polyline is called
a polygon. A polygon is defined by n number of sides in the polygon. We can divide
polygon into two classes.
A convex polygon is a polygon such that for any two points inside the polygon , all
the point of the line segment connecting them are also inside the polygon. A triangle
is always a convex one.
Polygon
Convex
Polygon
Concave
Polygon
P
Q
14
15. Conti…
A Concave polygon is one which is not convex.. A polygon is said to be a concave
if the line joining any two interior points of the polygon does not lies completely
inside the polygon.
There are four possible cases when processes vertices in sequence around the
parameter of the polygon. As each pair of adjacent polygon vertices is passed to a
window boundary clipper. We make the following test.
P
Q
15
16. Conti…
Case 1: If the first vertex is outside the window boundary and second vertex
is inside the window boundary then both the intersection point of a polygon
edge with the window boundary and second vertex are added to the output
vertex list.
Case 2: If both input vertices are inside the window boundary. Only the
second vertex is added to the Vertex list
Case3: If the first vertex is inside the window boundary and the second
vertex is outside the window boundary then only the edge intersection with the
window boundary is added to the output vertex list.
Case 4: If both the input vertices are outside the window boundary then
nothing is save to the output list.
16
17. SUTHERLAND AND HODGEMAN
ALGORITHM(Polygon clipping)
Polygon clipping is a process of clipping a polygon by considering
the edge of that as different line segments. If a polygon is clipped
against a rectangular window then it is possible that we get various
unconnected edges of a polygon. To get a closed polygon of unconnected
edges we connect theses edges along the side of a clipping window to
form a closed polygon.
The Sutherland –Hodgeman polygon clipping algorithm clips polygon
against convex clipping windows. The Sutherland Hodgeman Polygon
clipping algorithm may produce connecting lines that were not in the
original polygon. When the subject polygon is concave theses connecting
lines may be undesirable artifacts.
There are four situation to save vertices in output vertex list.
17
18. Conti……
1. If the first vertex is outside the window boundary and second vertex is inside the
window boundary then both the intersection point of a polygon edge with the
window boundary and second vertex are added to the output vertex list.Ex:save v1’,v2.
POLYGON
WINDOW(W)
2. If both input vertices are inside the window boundary. Only the second vertex is
added to the Vertex list
POLYGON
WINDOW(w)
V1
V1’
V2
V1
V2
18
19. Cont…..
3. If the first vertex is inside the window boundary and the second vertex is
outside the window boundary then only the edge intersection with the
window boundary is added to the output vertex list.Ex: v1’, v1.
POLYGON
WINDOW(W)
4. If both the input vertices are outside the window boundary then nothing is
save to the output list.
POLYGON
WINDOW(W)
’
V2
V1
V2
V1’
V1
19