Получите копию java-кода android.opengl.matrix из здесь .Затем измените синтаксис с Java на C, и все готово.Вот код, который я использовал для моего собственного проекта.Это не полный набор функций матрицы Opengl.
#include <stdlib.h>
#include <math.h>
#define PI 3.1415926f
#define normalize(x, y, z) \
{ \
float norm = 1.0f / sqrt(x*x+y*y+z*z); \
x *= norm; y *= norm; z *= norm; \
}
#define I(_i, _j) ((_j)+4*(_i))
void matrixSetIdentityM(float *m)
{
memset((void*)m, 0, 16*sizeof(float));
m[0] = m[5] = m[10] = m[15] = 1.0f;
}
void matrixSetRotateM(float *m, float a, float x, float y, float z)
{
float s, c;
memset((void*)m, 0, 15*sizeof(float));
m[15] = 1.0f;
a *= PI/180.0f;
s = sin(a);
c = cos(a);
if (1.0f == x && 0.0f == y && 0.0f == z) {
m[5] = c; m[10] = c;
m[6] = s; m[9] = -s;
m[0] = 1;
} else if (0.0f == x && 1.0f == y && 0.0f == z) {
m[0] = c; m[10] = c;
m[8] = s; m[2] = -s;
m[5] = 1;
} else if (0.0f == x && 0.0f == y && 1.0f == z) {
m[0] = c; m[5] = c;
m[1] = s; m[4] = -s;
m[10] = 1;
} else {
normalize(x, y, z);
float nc = 1.0f - c;
float xy = x * y;
float yz = y * z;
float zx = z * x;
float xs = x * s;
float ys = y * s;
float zs = z * s;
m[ 0] = x*x*nc + c;
m[ 4] = xy*nc - zs;
m[ 8] = zx*nc + ys;
m[ 1] = xy*nc + zs;
m[ 5] = y*y*nc + c;
m[ 9] = yz*nc - xs;
m[ 2] = zx*nc - ys;
m[ 6] = yz*nc + xs;
m[10] = z*z*nc + c;
}
}
void matrixMultiplyMM(float *m, float *lhs, float *rhs)
{
float t[16];
for (int i = 0; i < 4; i++) {
register const float rhs_i0 = rhs[I(i, 0)];
register float ri0 = lhs[ I(0,0) ] * rhs_i0;
register float ri1 = lhs[ I(0,1) ] * rhs_i0;
register float ri2 = lhs[ I(0,2) ] * rhs_i0;
register float ri3 = lhs[ I(0,3) ] * rhs_i0;
for (int j = 1; j < 4; j++) {
register const float rhs_ij = rhs[ I(i,j) ];
ri0 += lhs[ I(j,0) ] * rhs_ij;
ri1 += lhs[ I(j,1) ] * rhs_ij;
ri2 += lhs[ I(j,2) ] * rhs_ij;
ri3 += lhs[ I(j,3) ] * rhs_ij;
}
t[ I(i,0) ] = ri0;
t[ I(i,1) ] = ri1;
t[ I(i,2) ] = ri2;
t[ I(i,3) ] = ri3;
}
memcpy(m, t, sizeof(t));
}
void matrixScaleM(float *m, float x, float y, float z)
{
for (int i = 0; i < 4; i++)
{
m[i] *= x; m[4+i] *=y; m[8+i] *= z;
}
}
void matrixTranslateM(float *m, float x, float y, float z)
{
for (int i = 0; i < 4; i++)
{
m[12+i] += m[i]*x + m[4+i]*y + m[8+i]*z;
}
}
void matrixRotateM(float *m, float a, float x, float y, float z)
{
float rot[16], res[16];
matrixSetRotateM(rot, a, x, y, z);
matrixMultiplyMM(res, m, rot);
memcpy(m, res, 16*sizeof(float));
}
void matrixLookAtM(float *m,
float eyeX, float eyeY, float eyeZ,
float cenX, float cenY, float cenZ,
float upX, float upY, float upZ)
{
float fx = cenX - eyeX;
float fy = cenY - eyeY;
float fz = cenZ - eyeZ;
normalize(fx, fy, fz);
float sx = fy * upZ - fz * upY;
float sy = fz * upX - fx * upZ;
float sz = fx * upY - fy * upX;
normalize(sx, sy, sz);
float ux = sy * fz - sz * fy;
float uy = sz * fx - sx * fz;
float uz = sx * fy - sy * fx;
m[ 0] = sx;
m[ 1] = ux;
m[ 2] = -fx;
m[ 3] = 0.0f;
m[ 4] = sy;
m[ 5] = uy;
m[ 6] = -fy;
m[ 7] = 0.0f;
m[ 8] = sz;
m[ 9] = uz;
m[10] = -fz;
m[11] = 0.0f;
m[12] = 0.0f;
m[13] = 0.0f;
m[14] = 0.0f;
m[15] = 1.0f;
matrixTranslateM(m, -eyeX, -eyeY, -eyeZ);
}
void matrixFrustumM(float *m, float left, float right, float bottom, float top, float near, float far)
{
float r_width = 1.0f / (right - left);
float r_height = 1.0f / (top - bottom);
float r_depth = 1.0f / (near - far);
float x = 2.0f * (near * r_width);
float y = 2.0f * (near * r_height);
float A = 2.0f * ((right+left) * r_width);
float B = (top + bottom) * r_height;
float C = (far + near) * r_depth;
float D = 2.0f * (far * near * r_depth);
memset((void*)m, 0, 16*sizeof(float));
m[ 0] = x;
m[ 5] = y;
m[ 8] = A;
m[ 9] = B;
m[10] = C;
m[14] = D;
m[11] = -1.0f;
}