Panda3D

eggTriangleStrip.cxx
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1 /**
2 * PANDA 3D SOFTWARE
3 * Copyright (c) Carnegie Mellon University. All rights reserved.
4 *
5 * All use of this software is subject to the terms of the revised BSD
6 * license. You should have received a copy of this license along
7 * with this source code in a file named "LICENSE."
8 *
9 * @file eggTriangleStrip.cxx
10 * @author drose
11 * @date 2005-03-13
12 */
13
14 #include "eggTriangleStrip.h"
15 #include "eggGroupNode.h"
16 #include "eggPolygon.h"
17 #include "indent.h"
18
19 TypeHandle EggTriangleStrip::_type_handle;
20
21 /**
22 *
23 */
24 EggTriangleStrip::
25 ~EggTriangleStrip() {
26 clear();
27 }
28
29 /**
30 * Makes a copy of this object.
31 */
32 EggTriangleStrip *EggTriangleStrip::
33 make_copy() const {
34 return new EggTriangleStrip(*this);
35 }
36
37 /**
38 * Writes the triangle strip to the indicated output stream in Egg format.
39 */
40 void EggTriangleStrip::
41 write(std::ostream &out, int indent_level) const {
42 write_header(out, indent_level, "<TriangleStrip>");
43 write_body(out, indent_level+2);
44 indent(out, indent_level) << "}\n";
45 }
46
47 /**
48 * Returns the number of initial vertices that are not used in defining any
49 * component; the first component is defined by the (n + 1)th vertex, and then
50 * a new component at each vertex thereafter.
51 */
52 int EggTriangleStrip::
53 get_num_lead_vertices() const {
54 return 2;
55 }
56
57 /**
58 * Fills the container up with EggPolygons that represent the component
59 * triangles of this triangle strip.
60 *
61 * It is assumed that the EggTriangleStrip is not already a child of any other
62 * group when this function is called.
63 *
64 * Returns true if the triangulation is successful, or false if there was some
65 * error (in which case the container may contain some partial triangulation).
66 */
67 bool EggTriangleStrip::
68 do_triangulate(EggGroupNode *container) const {
69 if (size() < 3) {
70 return false;
71 }
72 const_iterator vi = begin();
73 EggVertex *v0 = (*vi);
74 ++vi;
75 EggVertex *v1 = (*vi);
76 ++vi;
77 bool reversed = false;
78
79 for (int i = 0; i < (int)size() - 2; i++) {
80 PT(EggPolygon) poly = new EggPolygon;
81 poly->copy_attributes(*this);
82 const EggAttributes *attrib = get_component(i);
83 if (attrib->has_color()) {
84 poly->set_color(attrib->get_color());
85 }
86 if (attrib->has_normal()) {
87 poly->set_normal(attrib->get_normal());
88 }
89
90 if (reversed) {
91 poly->add_vertex(v1);
92 poly->add_vertex(v0);
93 reversed = false;
94 } else {
95 poly->add_vertex(v0);
96 poly->add_vertex(v1);
97 reversed = true;
98 }
99 poly->add_vertex(*vi);
100 v0 = v1;
101 v1 = *vi;
102 container->add_child(poly);
103 ++vi;
104 }
105
106 return true;
107 }
EggAttributes
The set of attributes that may be applied to vertices as well as polygons, such as surface normal and...
Definition: eggAttributes.h:33
EggAttributes::get_color
LColor get_color() const
Returns the color set on this particular attribute.
Definition: eggAttributes.I:91
EggCompositePrimitive::get_component
get_component
Returns the attributes for the nth component triangle.
Definition: eggCompositePrimitive.h:38
EggGroupNode
A base class for nodes in the hierarchy that are not leaf nodes.
Definition: eggGroupNode.h:46
EggGroupNode::add_child
EggNode * add_child(EggNode *node)
Adds the indicated child to the group and returns it.
Definition: eggGroupNode.cxx:243
EggNamedObject::write_header
void write_header(std::ostream &out, int indent_level, const char *egg_keyword) const
Writes the first line of the egg object, e.g.
Definition: eggNamedObject.cxx:39
EggPolygon
A single polygon.
Definition: eggPolygon.h:24
EggPrimitive::copy_attributes
void copy_attributes(const EggAttributes &other)
Copies the rendering attributes from the indicated primitive.
Definition: eggPrimitive.cxx:265
EggPrimitive::clear
void clear()
Removes all of the vertices from the primitive.
Definition: eggPrimitive.I:352
EggTriangleStrip
A connected strip of triangles.
Definition: eggTriangleStrip.h:25
EggTriangleStrip::make_copy
virtual EggTriangleStrip * make_copy() const override
Makes a copy of this object.
Definition: eggTriangleStrip.cxx:33
EggTriangleStrip::write
virtual void write(std::ostream &out, int indent_level) const override
Writes the triangle strip to the indicated output stream in Egg format.
Definition: eggTriangleStrip.cxx:41
EggVertex
Any one-, two-, three-, or four-component vertex, possibly with attributes such as a normal.
Definition: eggVertex.h:39
TypeHandle
TypeHandle is the identifier used to differentiate C++ class types.
Definition: typeHandle.h:81
eggGroupNode.h
PANDA 3D SOFTWARE Copyright (c) Carnegie Mellon University.
eggPolygon.h
PANDA 3D SOFTWARE Copyright (c) Carnegie Mellon University.
eggTriangleStrip.h
PANDA 3D SOFTWARE Copyright (c) Carnegie Mellon University.
indent
std::ostream & indent(std::ostream &out, int indent_level)
A handy function for doing text formatting.
Definition: indent.cxx:20
indent.h
PANDA 3D SOFTWARE Copyright (c) Carnegie Mellon University.