CUGL 2.0
Cornell University Game Library
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#include <CUPoly2.h>
Public Member Functions | |
Poly2 () | |
Poly2 (const std::vector< Vec2 > &vertices) | |
Poly2 (const std::vector< Vec2 > &vertices, const std::vector< Uint32 > &indices) | |
Poly2 (const std::vector< float > &vertices) | |
Poly2 (const std::vector< float > &vertices, const std::vector< Uint32 > &indices) | |
Poly2 (const float *vertices, size_t vertsize) | |
Poly2 (const float *vertices, size_t vertsize, const Uint32 *indices, size_t indxsize) | |
Poly2 (const Poly2 &poly) | |
Poly2 (Poly2 &&poly) | |
Poly2 (const Rect rect, bool solid=true) | |
~Poly2 () | |
Poly2 & | operator= (const Poly2 &other) |
Poly2 & | operator= (Poly2 &&other) |
Poly2 & | operator= (const Rect rect) |
Poly2 & | set (const std::vector< Vec2 > &vertices) |
Poly2 & | set (const std::vector< Vec2 > &vertices, const std::vector< Uint32 > &indices) |
Poly2 & | set (const std::vector< float > &vertices) |
Poly2 & | set (const std::vector< float > &vertices, const std::vector< Uint32 > &indices) |
Poly2 & | set (const Vec2 *vertices, size_t vertsize) |
Poly2 & | set (const float *vertices, size_t vertsize) |
Poly2 & | set (const Vec2 *vertices, size_t vertsize, const Uint32 *indices, size_t indxsize) |
Poly2 & | set (const float *vertices, size_t vertsize, const Uint32 *indices, size_t indxsize) |
Poly2 & | set (const Poly2 &poly) |
Poly2 & | set (const Rect rect, bool solid=true) |
Poly2 & | setIndices (const std::vector< Uint32 > &indices) |
Poly2 & | setIndices (const Uint32 *indices, size_t indxsize) |
Poly2 & | clear () |
size_t | size () const |
size_t | indexSize () const |
Vec2 & | at (int index) |
const std::vector< Vec2 > & | vertices () const |
std::vector< Vec2 > & | vertices () |
const std::vector< Uint32 > & | indices () const |
std::vector< Uint32 > & | indices () |
const Rect | getBounds () const |
Geometry | getGeometry () const |
void | setGeometry (Geometry geom) |
Poly2 & | operator*= (float scale) |
Poly2 & | operator*= (const Vec2 scale) |
Poly2 & | operator*= (const Affine2 &transform) |
Poly2 & | operator*= (const Mat4 &transform) |
Poly2 & | operator/= (float scale) |
Poly2 & | operator/= (const Vec2 scale) |
Poly2 & | operator+= (float offset) |
Poly2 & | operator+= (const Vec2 offset) |
Poly2 & | operator-= (float offset) |
Poly2 & | operator-= (const Vec2 offset) |
Poly2 | operator* (float scale) const |
Poly2 | operator* (const Vec2 scale) const |
Poly2 | operator* (const Affine2 &transform) const |
Poly2 | operator* (const Mat4 &transform) const |
Poly2 | operator/ (float scale) const |
Poly2 | operator/ (const Vec2 scale) const |
Poly2 | operator+ (float offset) const |
Poly2 | operator+ (const Vec2 offset) const |
Poly2 | operator- (float offset) |
Poly2 | operator- (const Vec2 offset) |
std::vector< Vec2 > | convexHull () const |
bool | contains (Vec2 point, bool implicit=false) const |
bool | contains (float x, float y, bool implicit=false) const |
bool | incident (Vec2 point, float err=CU_MATH_EPSILON) const |
bool | incident (float x, float y, float err=CU_MATH_EPSILON) const |
int | orientation () const |
void | reverse () |
std::string | toString (bool verbose=false) const |
operator std::string () const | |
operator Rect () const | |
Static Public Member Functions | |
static int | orientation (Vec2 a, Vec2 b, Vec2 c) |
Friends | |
class | PolyFactory |
class | PolySplineFactory |
class | SimpleTriangulator |
class | ComplexTriangulator |
class | SimpleExtruder |
class | ComplexExtruder |
class | PathSmoother |
Poly2 | operator* (float scale, const Poly2 &poly) |
Poly2 | operator* (const Vec2 scale, const Poly2 &poly) |
Class to represent a simple polygon.
This class is intended to represent any polygon (including non-convex polygons). that does not have self-interections (as these can cause serious problems with the mathematics). Most polygons are simple, meaning that they have no holes. However, this class does support complex polygons with holes, provided that the polygon is not implicit and has an corresponding mesh.
To define a mesh, the user should provide a set of indices which will be used in rendering. These indices can either represent a triangulation of the polygon, or they can represent a traversal (for a wireframe). The semantics of these indices is provided by the associated value. This class performs no verification. It will not check that a mesh is in proper form, nor will it search for holes or self-intersections. These are the responsibility of the programmer.
Generating indices for a Poly2 can be nontrivial. While this class has standard constructors, allowing the programmer full control, most Poly2 objects are created through alternate means. For simple shapes, like lines, triangles, and ellipses, this class has several static constructors.
For more complex shapes, we have several Poly2 factories. These factories allow for delegating index computation to a separate thread, if it takes too long. These factories are as follows:
SimpleTriangulator: This is a simple earclipping-triangulator for tesselating simple, solid polygons (e.g. no holes or self-intersections).
ComplexTriangulator: This is a Delaunay Triangular that gives a more uniform triangulation in accordance to the Vornoi diagram. It also allows you to create 2d meshes while holes inside of them.
PolyFactory: This is a tool is used to generate several basic path shapes, such as rounded rectangles or arcs. It also allows you construct wireframe traversals of existing polygons.
PolySplineFactory: This is a tool is used to generate a Poly2 object from a Cubic Bezier curve.
SimpleExtruder: This is a tool can take a path polygon and convert it into a solid polygon. This solid polygon is the same as the path, except that the path now has a width and a mitre at the joints. It is fast, but has graphical limitations.
ComplexExtruder: Like SimpleExtruder, this is a tool can take a path polygon and convert it into a solid polygon. It is incredibly versatile and works in all instances. However, it is extremely slow (in the 10s of milliseconds) and is unsuitable for calcuations at framerate.
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Creates an empty polygon.
The created polygon has no vertices and no triangulation. The bounding box is trivial.
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Creates a polygon with the given vertices
The new polygon has no indices and the geometry is IMPLICIT
.
vertices | The vector of vertices (as Vec2) in this polygon |
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Creates a polygon with the given vertices and indices.
A valid list of indices must only refer to vertices in the vertex array. That is, the indices should all be non-negative, and each value should be less than the number of vertices.
The index geometry will be assigned via Geometry#categorize.
vertices | The vector of vertices (as Vec2) in this polygon |
indices | The vector of indices for the rendering |
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Creates a polygon with the given vertices
The new polygon has no indices.
The float array should have an even number of elements. The number of vertices is half of the size of the array. For each value ii, 2*ii and 2*ii+1 are the coordinates of a single vertex.
The new polygon has no indices and the geometry is IMPLICIT
.
vertices | The vector of vertices (as floats) in this polygon |
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Creates a polygon with the given vertices and indices.
The float array should have an even number of elements. The number of vertices is half of the size of the array. For each value ii, 2*ii and 2*ii+1 are the coordinates of a single vertex.
A valid list of indices must only refer to vertices in the vertex array. That is, the indices should all be non-negative, and each value should be less than the number of vertices.
The index geometry will be assigned via Geometry#categorize.
vertices | The vector of vertices (as floats) in this polygon |
indices | The vector of indices for the rendering |
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Creates a polygon with the given vertices
The new polygon has no indices and the geometry is IMPLICIT
.
vertices | The array of vertices (as Vec2) in this polygon |
vertsize | The number of elements to use from vertices |
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Creates a polygon with the given vertices and indices.
A valid list of indices must only refer to vertices in the vertex array. That is, the indices should all be non-negative, and each value should be less than the number of vertices.
The index geometry will be assigned via Geometry#categorize.
vertices | The array of vertices (as Vec2) in this polygon |
vertsize | The number of elements to use from vertices |
indices | The array of indices for the rendering |
indxsize | The number of elements to use for the indices |
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Creates a copy of the given polygon.
Both the vertices and the indices are copied.No references to the original polygon are kept.
poly | The polygon to copy |
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Creates a copy with the resource of the given polygon.
poly | The polygon to take from |
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Creates a polygon for the given rectangle.
The polygon will have four vertices, one for each corner of the rectangle. This optional argument (which is true by default) will initialize the indices with a triangulation of the rectangle. In other words, the geometry will be SOLID
. This is faster than using one of the more heavy-weight triangulators.
If solid is false, it will still generate indices, but will have CLOSED
geometry instead.
rect | The rectangle to copy |
solid | Whether to treat this rectangle as a solid polygon |
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Deletes the given polygon, freeing all resources.
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Returns a reference to the attribute at the given index.
This accessor will allow you to change the (singular) vertex. It is intended to allow minor distortions to the polygon without changing the underlying mesh.
index | The attribute index |
Poly2& cugl::Poly2::clear | ( | ) |
Clears the contents of this polygon and sets the geometry to IMPLICIT
bool cugl::Poly2::contains | ( | float | x, |
float | y, | ||
bool | implicit = false |
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) | const |
Returns true if this polygon contains the given point.
This method returns false is the geometry is POINTS
. If the geometry is SOLID
, it checks for containment within the associated triangle mesh. Otherwise, it uses an even-odd crossing rule on the polygon edges (either explicit or implicit) to determine containment.
If the value implicit is true, it will treat the polygon implicitly, even if it has a mesh (and no matter the geometry).
Containment is not strict. Points on the boundary are contained within this polygon.
x | The x-coordinate to test |
y | The y-coordinate to test |
implicit | Whether to ignore indices and use even-odd on vertices |
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Returns true if this polygon contains the given point.
This method returns false is the geometry is POINTS
. If the geometry is SOLID
, it checks for containment within the associated triangle mesh. Otherwise, it uses an even-odd crossing rule on the polygon edges (either explicit or implicit) to determine containment.
If the value implicit is true, it will treat the polygon implicitly, even if it has a mesh (and no matter the geometry).
Containment is not strict. Points on the boundary are contained within this polygon.
point | The point to test |
implicit | Whether to ignore indices and use even-odd on vertices |
std::vector<Vec2> cugl::Poly2::convexHull | ( | ) | const |
Returns the set of points forming the convex hull of this polygon.
The returned set of points is guaranteed to be a counter-clockwise traversal of the hull.
The points on the convex hull define the "border" of the shape. In addition to minimizing the number of vertices, this is useful for determining whether or not a point lies on the boundary.
This implementation is adapted from the example at
http://www.geeksforgeeks.org/convex-hull-set-2-graham-scan/
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Returns the bounding box for the polygon
The bounding box is the minimal rectangle that contains all of the vertices in this polygon. It is recomputed whenever the vertices are set.
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Returns the geometry of this polygon.
The type determines the proper form of the indices.
If the geometry is SOLID
, the number of indices should be a multiple of 3. Each triplet should define a triangle over the vertices.
If the geometry is PATH
, the number of indices should be a multiple of 2. Each pair should define a line segment over the vertices.
If the polygon is IMPLICIT
, the index list should be empty.
bool cugl::Poly2::incident | ( | float | x, |
float | y, | ||
float | err = CU_MATH_EPSILON |
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) | const |
Returns true if the given point is on the boundary of this polygon.
This method generates uses Geometry to determine the boundaries. For `POINTS, it returns true if point is with margin of error of a vertex. For all other shapes it returns true if it is within margin of error of a line segment.
x | The x-coordinate to test |
y | The y-coordinate to test |
err | The distance tolerance |
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Returns true if the given point is on the boundary of this polygon.
This method generates uses Geometry to determine the boundaries. For `POINTS, it returns true if point is with margin of error of a vertex. For all other shapes it returns true if it is within margin of error of a line segment.
point | The point to check |
err | The distance tolerance |
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Returns the number of indices in a polygon.
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Returns a reference to list of indices.
This accessor will not permit any changes to the index array. To change the array, you must change the polygon via a set() method.
This non-const version of the method is used by triangulators.
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Returns a reference to list of indices.
This accessor will not permit any changes to the index array. To change the array, you must change the polygon via a set() method.
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Cast from Poly to a string.
Returns a new polygon by transforming all of the vertices of this polygon.
Note: This method does not modify the polygon.
transform | The affine transform |
Returns a new polygon by transforming all of the vertices of this polygon.
The vertices are transformed as points. The z-value is 0.
Note: This method does not modify the polygon.
transform | The transform matrix |
Returns a new polygon by scaling the vertices non-uniformly.
The vertices are scaled from the origin of the coordinate space. This means that if the origin is not in the interior of this polygon, the polygon will be effectively translated by the scaling.
Note: This method does not modify the polygon.
scale | The non-uniform scaling factor |
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Returns a new polygon by scaling the vertices uniformly.
The vertices are scaled from the origin of the coordinate space. This means that if the origin is not in the interior of this polygon, the polygon will be effectively translated by the scaling.
Note: This method does not modify the polygon.
scale | The uniform scaling factor |
Transforms all of the vertices of this polygon.
transform | The affine transform |
Transforms all of the vertices of this polygon.
The vertices are transformed as points. The z-value is 0.
transform | The transform matrix |
Nonuniformly scales all of the vertices of this polygon.
The vertices are scaled from the origin of the coordinate space. This means that if the origin is not in the interior of this polygon, the polygon will be effectively translated by the scaling.
scale | The non-uniform scaling factor |
Poly2& cugl::Poly2::operator*= | ( | float | scale | ) |
Uniformly scales all of the vertices of this polygon.
The vertices are scaled from the origin of the coordinate space. This means that if the origin is not in the interior of this polygon, the polygon will be effectively translated by the scaling.
scale | The uniform scaling factor |
Returns a new polygon by translating the vertices non-uniformly.
Note: This method does not modify the polygon.
offset | The non-uniform translation amount |
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Returns a new polygon by translating the vertices uniformly.
Note: This method does not modify the polygon.
offset | The uniform translation amount |
Non-uniformly translates all of the vertices of this polygon.
offset | The non-uniform translation amount |
Poly2& cugl::Poly2::operator+= | ( | float | offset | ) |
Uniformly translates all of the vertices of this polygon.
offset | The uniform translation amount |
Returns a new polygon by translating the vertices non-uniformly.
Note: This method does not modify the polygon.
offset | The inverse of the non-uniform translation amount |
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Returns a new polygon by translating the vertices uniformly.
Note: This method does not modify the polygon.
offset | The inverse of the uniform translation amount |
Non-uniformly translates all of the vertices of this polygon.
offset | The inverse of the non-uniform translation amount |
Poly2& cugl::Poly2::operator-= | ( | float | offset | ) |
Uniformly translates all of the vertices of this polygon.
offset | The inverse of the uniform translation amount |
Returns a new polygon by scaling the vertices non-uniformly.
The vertices are scaled from the origin of the coordinate space. This means that if the origin is not in the interior of this polygon, the polygon will be effectively translated by the scaling.
Note: This method does not modify the polygon.
scale | The inverse of the non-uniform scaling factor |
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Returns a new polygon by scaling the vertices uniformly.
The vertices are scaled from the origin of the coordinate space. This means that if the origin is not in the interior of this polygon, the polygon will be effectively translated by the scaling.
Note: This method does not modify the polygon.
scale | The inverse of the uniform scaling factor |
Nonuniformly scales all of the vertices of this polygon.
The vertices are scaled from the origin of the coordinate space. This means that if the origin is not in the interior of this polygon, the polygon will be effectively translated by the scaling.
scale | The inverse of the non-uniform scaling factor |
Poly2& cugl::Poly2::operator/= | ( | float | scale | ) |
Uniformly scales all of the vertices of this polygon.
The vertices are scaled from the origin of the coordinate space. This means that if the origin is not in the interior of this polygon, the polygon will be effectively translated by the scaling.
scale | The inverse of the uniform scaling factor |
Sets this polygon to be a copy of the given one.
All of the contents are copied, so that this polygon does not hold any references to elements of the other polygon. This method returns a reference to this polygon for chaining.
other | The polygon to copy |
Sets this polygon to be a copy of the given rectangle.
The polygon will have four vertices, one for each corner of the rectangle. In addition, this assignment will initialize the indices with a simple triangulation of the rectangle. The geometry will be SOLID
.
rect | The rectangle to copy |
Sets this polygon to be have the resources of the given one.
other | The polygon to take from |
int cugl::Poly2::orientation | ( | ) | const |
Returns -1, 0, or 1 indicating the polygon orientation.
If the method returns -1, this is a counter-clockwise polygon. If 1, it is a clockwise polygon. If 0, that means it is undefined. The orientation of an IMPLICIT
polygon is always defined as long as it has at least three vertices. Polygons with POINTS
geometry never have a defined orientation.
For polygons with PATH
geometry, the orientation is determined by following the path. However, if the path is disconnected, this could result in more than one orientation, making the orientation undefined.
For polygons with SOLID
geometry, the orientiation is that of the triangles in the triangle mesh. However, if this value is not uniform (some triangles have one orientation and others do not), then this orientation is undefined.
Returns -1, 0, or 1 indicating the orientation of a -> b -> c
If the function returns -1, this is a counter-clockwise turn. If 1, it is a clockwise turn. If 0, it is colinear.
a | The first point |
b | The second point |
c | The third point |
void cugl::Poly2::reverse | ( | ) |
Reverses the orientation of this polygon.
If the polygon orientation is undefined, then this method does nothing. Otherwise, it reorders either the vertices or the mesh indices to reverse the orientation. Which one is resorted (vertices or indices) is undefined.
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Sets the polygon to have the given vertices.
The float array should have an even number of elements. The number of vertices is half of the size of the array. For each value ii, 2*ii and 2*ii+1 are the coordinates of a single vertex.
The resulting polygon has no indices and the geometry is IMPLICIT
.
This method returns a reference to this polygon for chaining.
vertices | The array of vertices (as floats) in this polygon |
vertsize | The number of elements to use from vertices |
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Sets the polygon to have the given vertices and indices.
The float array should have an even number of elements. The number of vertices is half of the size of the array. For each value ii, 2*ii and 2*ii+1 are the coordinates of a single vertex.
A valid list of indices must only refer to vertices in the vertex array. That is, the indices should all be non-negative, and each value should be less than the number of vertices.
The index geometry will be assigned via Geometry#categorize. This method returns a reference to this polygon for chaining.
vertices | The array of vertices (as floats) in this polygon |
vertsize | The number of elements to use from vertices |
indices | The array of indices for the rendering |
indxsize | The number of elements to use for the indices |
Sets this polygon to be a copy of the given one.
All of the contents are copied, so that this polygon does not hold any references to elements of the other polygon. This method returns a reference to this polygon for chaining.
This method returns a reference to this polygon for chaining.
poly | The polygon to copy |
Sets the polygon to represent the given rectangle.
The polygon will have four vertices, one for each corner of the rectangle. This optional argument (which is true by default) will initialize the indices with a triangulation of the rectangle. In other words, the geometry will be SOLID
. This is faster than using one of the more heavy-weight triangulators.
If solid is false, it will still generate indices, but will have CLOSED
geometry instead.
rect | The rectangle to copy |
solid | Whether to treat this rectangle as a solid polygon |
Poly2& cugl::Poly2::set | ( | const std::vector< float > & | vertices | ) |
Sets the polygon to have the given vertices
The float array should have an even number of elements. The number of vertices is half of the size of the array. For each value ii, 2*ii and 2*ii+1 are the coordinates of a single vertex.
The resulting polygon has no indices and the geometry is IMPLICIT
.
This method returns a reference to this polygon for chaining.
vertices | The vector of vertices (as floats) in this polygon |
Poly2& cugl::Poly2::set | ( | const std::vector< float > & | vertices, |
const std::vector< Uint32 > & | indices | ||
) |
Sets a polygon to have the given vertices and indices.
The float array should have an even number of elements. The number of vertices is half of the size of the array. For each value ii, 2*ii and 2*ii+1 are the coordinates of a single vertex.
A valid list of indices must only refer to vertices in the vertex array. That is, the indices should all be non-negative, and each value should be less than the number of vertices.
The index geometry will be assigned via Geometry#categorize.
This method returns a reference to this polygon for chaining.
vertices | The vector of vertices (as floats) in this polygon |
indices | The vector of indices for the rendering |
Sets the polygon to have the given vertices
The resulting polygon has no indices and the geometry is IMPLICIT
.
This method returns a reference to this polygon for chaining.
vertices | The vector of vertices (as Vec2) in this polygon |
Poly2& cugl::Poly2::set | ( | const std::vector< Vec2 > & | vertices, |
const std::vector< Uint32 > & | indices | ||
) |
Sets the polygon to have the given vertices and indices.
A valid list of indices must only refer to vertices in the vertex array. That is, the indices should all be non-negative, and each value should be less than the number of vertices.
The index geometry will be assigned via Geometry#categorize.
vertices | The vector of vertices (as Vec2) in this polygon |
indices | The vector of indices for the rendering |
Sets the polygon to have the given vertices.
The resulting polygon has no indices and the geometry is IMPLICIT
.
This method returns a reference to this polygon for chaining.
vertices | The array of vertices (as Vec2) in this polygon |
vertsize | The number of elements to use from vertices |
Poly2& cugl::Poly2::set | ( | const Vec2 * | vertices, |
size_t | vertsize, | ||
const Uint32 * | indices, | ||
size_t | indxsize | ||
) |
Sets the polygon to have the given vertices and indices.
A valid list of indices must only refer to vertices in the vertex array. That is, the indices should all be non-negative, and each value should be less than the number of vertices.
The index geometry will be assigned via Geometry#categorize. This method returns a reference to this polygon for chaining.
vertices | The array of vertices (as Vec2) in this polygon |
vertsize | The number of elements to use from vertices |
indices | The array of indices for the rendering |
indxsize | The number of elements to use for the indices |
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Returns the geometry of this polygon.
The type determines the proper form of the indices.
If the geometry is SOLID
, the number of indices should be a multiple of 3. Each triplet should define a triangle over the vertices.
If the geometry is PATH
, the number of indices should be a multiple of 2. Each pair should define a line segment over the vertices.
If the polygon is IMPLICIT
, the index list should be empty.
geom | The geometry of this polygon. |
Poly2& cugl::Poly2::setIndices | ( | const std::vector< Uint32 > & | indices | ) |
Sets the indices for this polygon to the ones given.
A valid list of indices must only refer to vertices in the vertex array. That is, the indices should all be non-negative, and each value should be less than the number of vertices.
The index geometry will be assigned via Geometry#categorize. This method returns a reference to this polygon for chaining.
indices | The vector of indices for the shape |
Poly2& cugl::Poly2::setIndices | ( | const Uint32 * | indices, |
size_t | indxsize | ||
) |
Sets the indices for this polygon to the ones given.
A valid list of indices must only refer to vertices in the vertex array. That is, the indices should all be non-negative, and each value should be less than the number of vertices.
The provided array is copied. The polygon does not retain a reference.
The index geometry will be assigned via Geometry#categorize. This method returns a reference to this polygon for chaining.
indices | The array of indices for the rendering |
indxsize | The number of elements to use for the indices |
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Returns the number of vertices in a polygon.
std::string cugl::Poly2::toString | ( | bool | verbose = false | ) | const |
Returns a string representation of this polygon for debugging purposes.
If verbose is true, the string will include class information. This allows us to unambiguously identify the class.
verbose | Whether to include class information |
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Returns the list of vertices
This accessor will not permit any changes to the vertex array. To change the array, you must change the polygon via a set() method.
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Returns the list of vertices
This accessor will not permit any changes to the vertex array. To change the array, you must change the polygon via a set() method.
Returns a new polygon by scaling the vertices non-uniformly.
The vertices are scaled from the origin of the coordinate space. This means that if the origin is not in the interior of this polygon, the polygon will be effectively translated by the scaling.
scale | The non-uniform scaling factor |
poly | The polygon to scale |
Returns a new polygon by scaling the vertices uniformly.
The vertices are scaled from the origin of the coordinate space. This means that if the origin is not in the interior of this polygon, the polygon will be effectively translated by the scaling.
scale | The uniform scaling factor |
poly | The polygon to scale |