1 #define SET_GET_FLOAT_PROPERTY(name) \
 2     void Set##name##(float v)\
 3     {\
 4         m_##name## = v;\
 5     }\
 6     float Get##name##() const\
 7     {\
 8         return m_##name##;\
 9     }
10
11 #define PI 3.14159265f
12
13 // --------------------------------------------------------------------------------------
14
15 class DiscreteEquation
16 {
17 public:
18     DiscreteEquation()
19     {
20         m_StartX = 0.0f;
21         m_StartY = 0.0f;
22
23         m_ParamA = 0.0f;
24         m_ParamB = 0.0f;
25         m_ParamC = 0.0f;
26         m_ParamD = 0.0f;
27         m_ParamE = 0.0f;
28     }
29
30     // 求迭代值
31     virtual void IterateValue(float y, float z, float& outY, float& outZ) const = NULL;
32
33     // 计算点集的Z轴坐标
34     static void CalculatePointsZ(void* curveVerticesPtr, unsigned int stride, unsigned int count, float minZ, float maxZ)
35     {
36         char* zPtr = (char*)curveVerticesPtr + 2*sizeof(float);
37         float zStep = (maxZ - minZ)/(count - 1);
38
39         for (unsigned int i = 0; i < count; i++)
40         {
41             *(float*)zPtr = minZ + i*zStep;
42             zPtr += stride;
43         }
44     }
45
46     // 计算点集的Y轴与X轴坐标
47     virtual void CalculatePointsXY(void* curveVerticesPtr, unsigned int stride, unsigned int count)
48     {
49         char* xPtr = (char*)curveVerticesPtr;
50         char* yPtr = (char*)curveVerticesPtr + sizeof(float);
51
52         float y, x;
53         float nx, ny;
54
55         x = m_StartX;
56         y = m_StartY;
57
58         for (unsigned int i = 0; i < count; i++)
59         {
60             *(float*)xPtr = x;
61             *(float*)yPtr = y;
62
63             IterateValue(x, y, nx, ny);
64
65             x = nx;
66             y = ny;
67
68             xPtr += stride;
69             yPtr += stride;
70         }
71     }
72
73     SET_GET_FLOAT_PROPERTY(StartX);
74     SET_GET_FLOAT_PROPERTY(StartY);
75
76     SET_GET_FLOAT_PROPERTY(ParamA);
77     SET_GET_FLOAT_PROPERTY(ParamB);
78     SET_GET_FLOAT_PROPERTY(ParamC);
79     SET_GET_FLOAT_PROPERTY(ParamD);
80     SET_GET_FLOAT_PROPERTY(ParamE);
81
82     virtual bool IsValidParamA() const {return false;}
83     virtual bool IsValidParamB() const {return false;}
84     virtual bool IsValidParamC() const {return false;}
85     virtual bool IsValidParamD() const {return false;}
86     virtual bool IsValidParamE() const {return false;}
87
88 protected:
89     float m_StartX;
90     float m_StartY;
91
92     float m_ParamA;
93     float m_ParamB;
94     float m_ParamC;
95     float m_ParamD;
96     float m_ParamE;
97 };