下面的代码使用八面体作为起始3D形状(我在网上找到它),经过一些调整后我仍然无法使其工作。
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <stddef.h> /* must include for the offsetof macro */
#include <GL/glew.h>
#include <GL/glfw.h>
#include <glm/glm.hpp>
#include <glm/gtc/matrix_transform.hpp>
#include <glm/gtc/type_ptr.hpp>
#include <stdlib.h>
#include <vector>
#include <iostream>
using namespace std;
struct XYZ {
GLdouble x;
GLdouble y;
GLdouble z;
};
struct FACET3 {
XYZ p1;
XYZ p2;
XYZ p3;
};
void Normalise(XYZ *p_input)
{
double magnitude = 0;
magnitude = sqrt((p_input.x * p_input.x )+ (p_input.y * p_input.y) + (p_input.z * p_input.z));
p_input.x = p_input.x / magnitude;
p_input.y = p_input.y / magnitude;
p_input.z = p_input.z / magnitude;
}
int CreateNSphere(FACET3 *f,int iterations)
{
int i,it;
double a;
XYZ p[6] = {0,0,1, 0,0,-1, -1,-1,0, 1,-1,0, 1,1,0, -1,1,0};
XYZ pa,pb,pc;
int nt = 0,ntold;
/* Create the level 0 object */
a = 1 / sqrt(2.0);
for (i=0;i<6;i++) {
p[i].x *= a;
p[i].y *= a;
}
f[0].p1 = p[0]; f[0].p2 = p[3]; f[0].p3 = p[4];
f[1].p1 = p[0]; f[1].p2 = p[4]; f[1].p3 = p[5];
f[2].p1 = p[0]; f[2].p2 = p[5]; f[2].p3 = p[2];
f[3].p1 = p[0]; f[3].p2 = p[2]; f[3].p3 = p[3];
f[4].p1 = p[1]; f[4].p2 = p[4]; f[4].p3 = p[3];
f[5].p1 = p[1]; f[5].p2 = p[5]; f[5].p3 = p[4];
f[6].p1 = p[1]; f[6].p2 = p[2]; f[6].p3 = p[5];
f[7].p1 = p[1]; f[7].p2 = p[3]; f[7].p3 = p[2];
nt = 8;
if (iterations < 1)
return(nt);
/* Bisect each edge and move to the surface of a unit sphere */
for (it=0;it<iterations;it++) {
ntold = nt;
for (i=0;i<ntold;i++) {
pa.x = (f[i].p1.x + f[i].p2.x) / 2;
pa.y = (f[i].p1.y + f[i].p2.y) / 2;
pa.z = (f[i].p1.z + f[i].p2.z) / 2;
pb.x = (f[i].p2.x + f[i].p3.x) / 2;
pb.y = (f[i].p2.y + f[i].p3.y) / 2;
pb.z = (f[i].p2.z + f[i].p3.z) / 2;
pc.x = (f[i].p3.x + f[i].p1.x) / 2;
pc.y = (f[i].p3.y + f[i].p1.y) / 2;
pc.z = (f[i].p3.z + f[i].p1.z) / 2;
Normalise(&pa);
Normalise(&pb);
Normalise(&pc);
f[nt].p1 = f[i].p1; f[nt].p2 = pa; f[nt].p3 = pc; nt++;
f[nt].p1 = pa; f[nt].p2 = f[i].p2; f[nt].p3 = pb; nt++;
f[nt].p1 = pb; f[nt].p2 = f[i].p3; f[nt].p3 = pc; nt++;
f[i].p1 = pa;
f[i].p2 = pb;
f[i].p3 = pc;
}
}
return(nt);
}
int main()
{
FACET3 *facet;
int facets = CreateNSphere(facet, 2);
printf(" Result: %d", facets);
}
我正在尝试运行此代码。我基本上试图从八面体生成球体的坐标。但是当我使用g ++编译它时,我得到了这个:
sphere_model.cpp:32:28: error: request for member ‘x’ in ‘p_input’, which is of non-class type ‘XYZ*’
sphere_model.cpp:32:40: error: request for member ‘x’ in ‘p_input’, which is of non-class type ‘XYZ*’
sphere_model.cpp:32:54: error: request for member ‘y’ in ‘p_input’, which is of non-class type ‘XYZ*’
sphere_model.cpp:32:66: error: request for member ‘y’ in ‘p_input’, which is of non-class type ‘XYZ*’
sphere_model.cpp:32:80: error: request for member ‘z’ in ‘p_input’, which is of non-class type ‘XYZ*’
sphere_model.cpp:32:92: error: request for member ‘z’ in ‘p_input’, which is of non-class type ‘XYZ*’
sphere_model.cpp:33:10: error: request for member ‘x’ in ‘p_input’, which is of non-class type ‘XYZ*’
sphere_model.cpp:33:22: error: request for member ‘x’ in ‘p_input’, which is of non-class type ‘XYZ*’
sphere_model.cpp:34:10: error: request for member ‘y’ in ‘p_input’, which is of non-class type ‘XYZ*’
sphere_model.cpp:34:22: error: request for member ‘y’ in ‘p_input’, which is of non-class type ‘XYZ*’
sphere_model.cpp:35:10: error: request for member ‘z’ in ‘p_input’, which is of non-class type ‘XYZ*’
sphere_model.cpp:35:22: error: request for member ‘z’ in ‘p_input’, which is of non-class type ‘XYZ*’
为什么?
答案 0 :(得分:5)
p_input
是指针,您应该使用->
运算符而不是.
答案 1 :(得分:2)
这是对您的第二个问题的回答,您已将其作为评论发布。
函数CreateNSphere
假定它传递了一个包含8个FACET3对象的数组。在main()中,您需要初始化facet
,或者将其创建为数组实例而不是指针。这些都可以起作用:
FACET3 facet[8];
int facets = CreateNSphere(facet, 2);
或
FACET3 *facet = new FACET3[8];
int facets = CreateNSphere(facet, 2);