Matrix CPP类

#include "Matrix.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 Matrix() //{ // //} // //void ~Matrix() //{ // //} void Matrix::matrixSetIdentityM(float *m) { memset((void*)m, 0, 16*sizeof(float)); m[0] = m[5] = m[10] = m[15] = 1.0f; } void Matrix::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 Matrix::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 Matrix::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 Matrix::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 Matrix::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 Matrix::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 Matrix::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; }