dawn-cmake/examples/glTFViewer/Camera.inl

68 lines
2.2 KiB
C++

// Copyright 2017 The NXT Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
class Camera {
public:
Camera()
: _azimuth(glm::radians(45.f)),
_altitude(glm::radians(30.f)),
_radius(10.f),
_center(0, 0, 0),
_dirty(true) {
recalculate();
}
void rotate(float dAzimuth, float dAltitude) {
_dirty = true;
_azimuth = glm::mod(_azimuth + dAzimuth, glm::radians(360.f));
_altitude = glm::clamp(_altitude + dAltitude, glm::radians(-89.f), glm::radians(89.f));
}
void pan(float dX, float dY) {
recalculate();
glm::vec3 vX = glm::normalize(glm::cross(-_eyeDir, glm::vec3(0, 1, 0)));
glm::vec3 vY = glm::normalize(glm::cross(_eyeDir, vX));
_center += vX * dX * _radius + vY * dY * _radius;
}
void zoom(float factor) {
_dirty = true;
_radius = _radius * glm::exp(-factor);
}
glm::mat4 view() {
if (_dirty) {
recalculate();
}
return _view;
}
private:
void recalculate() {
glm::vec4 eye4 = glm::vec4(1, 0, 0, 1);
eye4 = glm::rotate(glm::mat4(), _altitude, glm::vec3(0, 0, 1)) * eye4;
eye4 = glm::rotate(glm::mat4(), _azimuth, glm::vec3(0, 1, 0)) * eye4;
_eyeDir = glm::vec3(eye4);
_view = glm::lookAt(_center + _eyeDir * _radius, _center, glm::vec3(0, 1, 0));
_dirty = false;
}
float _azimuth;
float _altitude;
float _radius;
glm::vec3 _center;
glm::vec3 _eyeDir;
bool _dirty;
glm::mat4 _view;
};