assimp/port/dAssimp/assimp/camera.d

/*
---------------------------------------------------------------------------
Open Asset Import Library (ASSIMP)
---------------------------------------------------------------------------

Copyright (c) 2006-2020, ASSIMP Development Team

All rights reserved.

Redistribution and use of this software in source and binary forms,
with or without modification, are permitted provided that the following
conditions are met:

 * Redistributions of source code must retain the above
  copyright notice, this list of conditions and the
  following disclaimer.

 * Redistributions in binary form must reproduce the above
  copyright notice, this list of conditions and the
  following disclaimer in the documentation and/or other
  materials provided with the distribution.

 * Neither the name of the ASSIMP team, nor the names of its
  contributors may be used to endorse or promote products
  derived from this software without specific prior
  written permission of the ASSIMP Development Team.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
---------------------------------------------------------------------------
*/

/**
 * Contains the data structure which is used to store the imported information
 * about the virtual cameras in the scene.
 */
module assimp.camera;

import assimp.math;
import assimp.types;

extern ( C ) {
   /**
    * Helper structure to describe a virtual camera.
    *
    * Cameras have a representation in the node graph and can be animated.
    * An important aspect is that the camera itself is also part of the
    * scenegraph. This means, any values such as the look-at vector are not
    * absolute, they're <em>relative</em> to the coordinate system defined
    * by the node which corresponds to the camera. This allows for camera
    * animations. Static cameras parameters like the look-at or up vectors are
    * usually specified directly in the class members, but beware, they could
    * also be encoded in the node transformation. The following (pseudo)code
    * sample shows how to do it.
    *
    * Examples:
    * ---
    * // Get the camera matrix for a camera at a specific time
    * // if the node hierarchy for the camera does not contain
    * // at least one animated node this is a static computation
    * get-camera-matrix (node sceneRoot, camera cam) : matrix
    * {
    *    node   cnd = find-node-for-camera(cam)
    *    matrix cmt = identity()
    *
    *    // as usual - get the absolute camera transformation for this frame
    *    for each node nd in hierarchy from sceneRoot to cnd
    *      matrix cur
    *      if (is-animated(nd))
    *         cur = eval-animation(nd)
    *      else cur = nd->mTransformation;
    *      cmt = mult-matrices( cmt, cur )
    *    end for
    *
    *    // now multiply with the camera's own local transform
    *    cam = mult-matrices (cam, get-camera-matrix(cmt) )
    * }
    * ---
    *
    * Note: Some file formats (such as 3DS, ASE) export a "target point" – the
    *    point the camera is looking at (it can even be animated). Assimp
    *    writes the target point as a subnode of the camera's main node, called
    *    "<camName>.Target". However, this is just additional information; the
    *    transformation applied to the main camera node already makes the
    *    camera face the right direction.
    */
   struct aiCamera {
      /**
       * The name of the camera.
       *
       * There must be a node in the scenegraph with the same name. This node
       * specifies the position of the camera in the scene hierarchy and can
       * be animated.
       */
      aiString mName;


      /**
       * Position of the camera relative to the coordinate space defined by the
       * corresponding node.
       *
       * The default value is 0|0|0.
       */
      aiVector3D mPosition;

      /**
       * Up vector of the camera coordinate system relative to the
       * coordinate space defined by the corresponding node.
       *
       * The right vector of the camera coordinate system is the cross
       * product of the up and lookAt vectors.
       *
       * The default value is 0|1|0. The vector may be normalized, but it
       * needn't.
       */
      aiVector3D mUp;

      /**
       * Look-at vector of the camera coordinate system relative to the
       * coordinate space defined by the corresponding node.
       *
       * This is the viewing direction of the user.
       *
       * The default value is 0|0|1. The vector may be normalized, but it
       * needn't.
       */
      aiVector3D mLookAt;


      /**
       * Half horizontal field of view angle, in radians.
       *
       * The field of view angle is the angle between the center line of the
       * screen and the left or right border.
       *
       * The default value is PI/4.
       */
      float mHorizontalFOV;

      /**
       * Distance of the near clipping plane from the camera.
       *
       * The value may not be 0.f (for arithmetic reasons to prevent
       * a division through zero).
       *
       * The default value is 0.1f.
       */
      float mClipPlaneNear;

      /**
       * Distance of the far clipping plane from the camera.
       *
       * The far clipping plane must, of course, be further away than the
       * near clipping plane. The ratio between the near and the far plane
       * should not be too large (between 1000-10000 should be ok) to avoid
       * floating-point inaccuracies which could lead to z-fighting.
       *
       * The default value is 1000.f.
       */
      float mClipPlaneFar;

      /**
       * Screen aspect ratio.
       *
       * This is the ration between the width and the height of the
       * screen. Typical values are 4/3, 1/2 or 1/1. This value is
       * 0 if the aspect ratio is not defined in the source file.
       *
       * 0 is also the default value.
       */
      float mAspect;
   }
}