| // Copyright 2017 The Fuchsia Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #ifndef LIB_ESCHER_GEOMETRY_TRANSFORM_H_ |
| #define LIB_ESCHER_GEOMETRY_TRANSFORM_H_ |
| |
| #include "lib/escher/geometry/types.h" |
| #include "lib/escher/util/debug_print.h" |
| |
| namespace escher { |
| |
| // |Transform| defines an affine transformation that is easier to work with |
| // than a general 4x4 matrix. Rotation and scaling occur around an anchor |
| // point; translation is applied after rotation and scaling. |
| struct Transform { |
| vec3 translation; |
| vec3 scale = vec3(1, 1, 1); |
| quat rotation; |
| vec3 anchor; |
| |
| // Allow static_cast<mat4>(*this). |
| explicit operator mat4() const; |
| |
| Transform(vec3 translation, vec3 scale = vec3(1, 1, 1), |
| quat rotation = quat(), vec3 anchor = vec3(0, 0, 0)) |
| : translation(translation), |
| scale(scale), |
| rotation(rotation), |
| anchor(anchor) {} |
| |
| Transform(vec3 translation, vec3 scale, float rotation_radians, |
| vec3 rotation_axis, vec3 anchor = vec3(0, 0, 0)) |
| : Transform(translation, scale, |
| glm::angleAxis(rotation_radians, rotation_axis), anchor) { |
| FXL_DCHECK(std::abs(1.f - glm::dot(rotation_axis, rotation_axis)) < |
| kEpsilon); |
| } |
| |
| Transform() : scale(vec3(1, 1, 1)) {} |
| |
| bool IsIdentity() const { |
| return translation == vec3() && scale == vec3(1, 1, 1) && |
| rotation == quat() && anchor == vec3(); |
| } |
| }; |
| |
| // Debugging. |
| ESCHER_DEBUG_PRINTABLE(Transform); |
| |
| } // namespace escher |
| |
| #endif // LIB_ESCHER_GEOMETRY_TRANSFORM_H_ |