- float x = look_dir.y*up_dir.z-look_dir.z*up_dir.y;
- float y = look_dir.z*up_dir.x-look_dir.x*up_dir.z;
- float z = look_dir.x*up_dir.y-look_dir.y*up_dir.x;
- float len = sqrt(x*x+y*y+z*z);
- double mdata[16];
-
- mdata[0] = x/len;
- mdata[4] = y/len;
- mdata[8] = z/len;
-
- mdata[1] = mdata[4]*look_dir.z-mdata[8]*look_dir.y;
- mdata[5] = mdata[8]*look_dir.x-mdata[0]*look_dir.z;
- mdata[9] = mdata[0]*look_dir.y-mdata[4]*look_dir.x;
-
- mdata[2] = -look_dir.x;
- mdata[6] = -look_dir.y;
- mdata[10] = -look_dir.z;
-
- mdata[12] = -position.x*mdata[0]-position.y*mdata[4]-position.z*mdata[8];
- mdata[13] = -position.x*mdata[1]-position.y*mdata[5]-position.z*mdata[9];
- mdata[14] = -position.x*mdata[2]-position.y*mdata[6]-position.z*mdata[10];
-
- mdata[3] = 0;
- mdata[7] = 0;
- mdata[11] = 0;
- mdata[15] = 1;
-
- matrix = mdata;
+ Vector3 right_dir = normalize(cross(look_dir, up_dir));
+ Vector4 columns[4];
+ columns[0] = Vector4(right_dir, 0.0f);
+ columns[1] = Vector4(cross(right_dir, look_dir), 0.0f);
+ columns[2] = Vector4(-look_dir, 0.0f);
+ columns[3] = Vector4(position, 1.0f);
+ object_matrix = Matrix::from_columns(columns);
+ view_matrix = invert(object_matrix);