- 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);
-
- matrix[0] = x/len;
- matrix[4] = y/len;
- matrix[8] = z/len;
-
- matrix[1] = matrix[4]*look_dir.z-matrix[8]*look_dir.y;
- matrix[5] = matrix[8]*look_dir.x-matrix[0]*look_dir.z;
- matrix[9] = matrix[0]*look_dir.y-matrix[4]*look_dir.x;
-
- matrix[2] = -look_dir.x;
- matrix[6] = -look_dir.y;
- matrix[10] = -look_dir.z;
-
- matrix[12] = -position.x*matrix[0]-position.y*matrix[4]-position.z*matrix[8];
- matrix[13] = -position.x*matrix[1]-position.y*matrix[5]-position.z*matrix[9];
- matrix[14] = -position.x*matrix[2]-position.y*matrix[6]-position.z*matrix[10];
+ 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);