The point array classes consist of TGPointArray and TGRPointArray. These are lowlevel classes that do not perform any computation, but store and manipulate linear arrays of 2-D ordered points.
Descriptions for these classes are summarized here for your convenience while reading this manual. Refer to the online Class and Member Function descriptions for detailed information on these classes and their functions.
Points
The TGPoint class defines (x, y) coordinates that represent a point or vector on the 2D coordinate plane. The TGRPoint class defines (x,y, w) coordinate values that represent a homogeneous (rational) point or vector on the 2D coordinate plane. The TGPoint and TGRPoint member functions are shown in Table 1.
|
Points |
TGPoint | CrossProduct | SetVectorAngle | VectorAngle |
| DotProduct | SetVectorLength | VectorLength | ||
| Interpolate | SetPolarCoordinates | |||
| TGRPoint | DivW | DropW |
Point arrays
TGPointArray handles arrays of TGPoints and is the basis for TGPolyline and TGPolygon. TGRPointArray handles arrays of TGRPoints and is the basis for TGCurve and TGLoop). The point array member functions are summarized in Table 2.
.
|
Point arrays |
TGPointArray and | GetBounds | Resize | |
| TGRPointArray | GetNumberofPoints | SetPoint | ||
| GetPoint | Swap |
TGInfiniteLine classes define geometric calculations that involve lines, axes, and vectors. They are used in design and computeraided design (CAD) applications where infinite construction lines relate one piece of geometry to another. TGInfiniteLine member functions are summarized in Table 3.
Infinite line
The TGInfiniteLine class represents an infinitely long directional line with a direction vector and a base point that defines a point on the line. The line extends to infinity in both directions, but the actual direction is determined by the direction vector.
|
Infinite lines |
TGInfiniteLine | AngleBetween | GetDirection | Reverse |
| Clip | Intersects | ReverseDirection | ||
| Distance | Intersection | SetBasePoint | ||
| Evaluate | Parallel | SetDirection | ||
| EvaluateAtX | Perpendicular | TransformBy | ||
| EvaluateAtY | Projection | |||
| GetBasePoint | Reflection |
Rectangle
The TGRect class defines an axisaligned rectangle that is defined by the coordinate points for the topleft corner and the bottomright corner. The topleft corner consists of the minimum x and y coordinates. The bottomright corner consists of the maximum x and y coordinates. TGRect can be passed to a TGrafPort for rendering. The TGRect member functions are summarized in Table 4.
|
Rectangles |
TGRect | Contains | GetRightLine | Pin |
| EqualSize | GetHeight | MapRect | ||
| ExtendTo | GetWidth | SetCenter | ||
| GetCenter | GetSize | Set | ||
| GetTopLeft | Inset | SetSize |
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