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bufferDescriptor.h
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24 
25 #ifndef OPENSUBDIV3_OSD_BUFFER_DESCRIPTOR_H
26 #define OPENSUBDIV3_OSD_BUFFER_DESCRIPTOR_H
27 
28 #include "../version.h"
29 #include <string.h>
30 
31 namespace OpenSubdiv {
32 namespace OPENSUBDIV_VERSION {
33 
34 namespace Osd {
35 
46 
47 // example:
48 // n
49 // -----+----------------------------------------+-------------------------
50 // | vertex 0 |
51 // -----+----------------------------------------+-------------------------
52 // | X Y Z R G B A Xu Yu Zu Xv Yv Zv |
53 // -----+----------------------------------------+-------------------------
54 // <------------- stride = 13 -------------->
55 //
56 // - XYZ (offset = n+0, length = 3, stride = 13)
57 // - RGBA (offset = n+3, length = 4, stride = 13)
58 // - uTangent (offset = n+7, length = 3, stride = 13)
59 // - vTangent (offset = n+10, length = 3, stride = 13)
60 //
62 
64  BufferDescriptor() : offset(0), length(0), stride(0) { }
65 
67  BufferDescriptor(int o, int l, int s) : offset(o), length(l), stride(s) { }
68 
70  int GetLocalOffset() const {
71  return stride > 0 ? offset % stride : 0;
72  }
73 
75  bool IsValid() const {
76  return ((length > 0) &&
77  (length <= stride - GetLocalOffset()));
78  }
79 
81  void Reset() {
82  offset = length = stride = 0;
83  }
84 
86  bool operator == (BufferDescriptor const &other) const {
87  return (offset == other.offset &&
88  length == other.length &&
89  stride == other.stride);
90  }
91 
93  bool operator != (BufferDescriptor const &other) const {
94  return !(this->operator==(other));
95  }
96 
98  int offset;
100  int length;
102  int stride;
103 };
104 
105 } // end namespace Osd
106 
107 } // end namespace OPENSUBDIV_VERSION
108 using namespace OPENSUBDIV_VERSION;
109 
110 } // end namespace OpenSubdiv
111 
112 #endif // OPENSUBDIV3_OSD_BUFFER_DESCRIPTOR_H
BufferDescriptor is a struct which describes buffer elements in interleaved data buffers. Almost all Osd Evaluator APIs take BufferDescriptors along with device-specific buffer objects.
BufferDescriptor(int o, int l, int s)
Constructor.
bool IsValid() const
True if the descriptor values are internally consistent.
bool operator==(BufferDescriptor const &other) const
True if the descriptors are identical.
void Reset()
Resets the descriptor to default.
int GetLocalOffset() const
Returns the relative offset within a stride.
bool operator!=(BufferDescriptor const &other) const
True if the descriptors are not identical.