--- /dev/null
+///////////////////////////////////////////////////////////////////////////
+//
+// Copyright (c) 2004, Industrial Light & Magic, a division of Lucas
+// Digital Ltd. LLC
+//
+// All rights reserved.
+//
+// Redistribution and use 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 Industrial Light & Magic nor the names of
+// its contributors may be used to endorse or promote products derived
+// from this software without specific prior written permission.
+//
+// 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.
+//
+///////////////////////////////////////////////////////////////////////////
+
+
+#ifndef INCLUDED_IMF_ENVMAP_H
+#define INCLUDED_IMF_ENVMAP_H
+
+//-----------------------------------------------------------------------------
+//
+// Environment maps
+//
+// Environment maps define a mapping from 3D directions to 2D
+// pixel space locations. Environment maps are typically used
+// in 3D rendering, for effects such as quickly approximating
+// how shiny surfaces reflect their environment.
+//
+// Environment maps can be stored in scanline-based or in tiled
+// OpenEXR files. The fact that an image is an environment map
+// is indicated by the presence of an EnvmapAttribute whose name
+// is "envmap". (Convenience functions to access this attribute
+// are defined in header file ImfStandardAttributes.h.)
+// The attribute's value defines the mapping from 3D directions
+// to 2D pixel space locations.
+//
+// This header file defines the set of possible EnvmapAttribute
+// values.
+//
+// For each possible EnvmapAttribute value, this header file also
+// defines a set of convienience functions to convert between 3D
+// directions and 2D pixel locations.
+//
+// Most of the convenience functions defined below require a
+// dataWindow parameter. For scanline-based images, and for
+// tiled images with level mode ONE_LEVEL, the dataWindow
+// parameter should be set to the image's data window, as
+// defined in the image header. For tiled images with level
+// mode MIPMAP_LEVELS or RIPMAP_LEVELS, the data window of the
+// image level that is being accessed should be used instead.
+// (See the dataWindowForLevel() methods in ImfTiledInputFile.h
+// and ImfTiledOutputFile.h.)
+//
+//-----------------------------------------------------------------------------
+
+#include "ImathBox.h"
+
+namespace Imf {
+
+//--------------------------------
+// Supported environment map types
+//--------------------------------
+
+enum Envmap
+{
+ ENVMAP_LATLONG = 0, // Latitude-longitude environment map
+ ENVMAP_CUBE = 1, // Cube map
+
+ NUM_ENVMAPTYPES // Number of different environment map types
+};
+
+
+//-------------------------------------------------------------------------
+// Latitude-Longitude Map:
+//
+// The environment is projected onto the image using polar coordinates
+// (latitude and longitude). A pixel's x coordinate corresponds to
+// its longitude, and the y coordinate corresponds to its latitude.
+// Pixel (dataWindow.min.x, dataWindow.min.y) has latitude +pi/2 and
+// longitude +pi; pixel (dataWindow.max.x, dataWindow.max.y) has
+// latitude -pi/2 and longitude -pi.
+//
+// In 3D space, latitudes -pi/2 and +pi/2 correspond to the negative and
+// positive y direction. Latitude 0, longitude 0 points into positive
+// z direction; and latitude 0, longitude pi/2 points into positive x
+// direction.
+//
+// The size of the data window should be 2*N by N pixels (width by height),
+// where N can be any integer greater than 0.
+//-------------------------------------------------------------------------
+
+namespace LatLongMap
+{
+ //----------------------------------------------------
+ // Convert a 3D direction to a 2D vector whose x and y
+ // components represent the corresponding latitude
+ // and longitude.
+ //----------------------------------------------------
+
+ Imath::V2f latLong (const Imath::V3f &direction);
+
+
+ //--------------------------------------------------------
+ // Convert the position of a pixel to a 2D vector whose
+ // x and y components represent the corresponding latitude
+ // and longitude.
+ //--------------------------------------------------------
+
+ Imath::V2f latLong (const Imath::Box2i &dataWindow,
+ const Imath::V2f &pixelPosition);
+
+
+ //-------------------------------------------------------------
+ // Convert a 2D vector, whose x and y components represent
+ // longitude and latitude, into a corresponding pixel position.
+ //-------------------------------------------------------------
+
+ Imath::V2f pixelPosition (const Imath::Box2i &dataWindow,
+ const Imath::V2f &latLong);
+
+
+ //-----------------------------------------------------
+ // Convert a 3D direction vector into a corresponding
+ // pixel position. pixelPosition(dw,dir) is equivalent
+ // to pixelPosition(dw,latLong(dw,dir)).
+ //-----------------------------------------------------
+
+ Imath::V2f pixelPosition (const Imath::Box2i &dataWindow,
+ const Imath::V3f &direction);
+
+
+ //--------------------------------------------------------
+ // Convert the position of a pixel in a latitude-longitude
+ // map into a corresponding 3D direction.
+ //--------------------------------------------------------
+
+ Imath::V3f direction (const Imath::Box2i &dataWindow,
+ const Imath::V2f &pixelPosition);
+}
+
+
+//--------------------------------------------------------------
+// Cube Map:
+//
+// The environment is projected onto the six faces of an
+// axis-aligned cube. The cube's faces are then arranged
+// in a 2D image as shown below.
+//
+// 2-----------3
+// / /|
+// / / | Y
+// / / | |
+// 6-----------7 | |
+// | | | |
+// | | | |
+// | 0 | 1 *------- X
+// | | / /
+// | | / /
+// | |/ /
+// 4-----------5 Z
+//
+// dataWindow.min
+// /
+// /
+// +-----------+
+// |3 Y 7|
+// | | |
+// | | |
+// | ---+---Z | +X face
+// | | |
+// | | |
+// |1 5|
+// +-----------+
+// |6 Y 2|
+// | | |
+// | | |
+// | Z---+--- | -X face
+// | | |
+// | | |
+// |4 0|
+// +-----------+
+// |6 Z 7|
+// | | |
+// | | |
+// | ---+---X | +Y face
+// | | |
+// | | |
+// |2 3|
+// +-----------+
+// |0 1|
+// | | |
+// | | |
+// | ---+---X | -Y face
+// | | |
+// | | |
+// |4 Z 5|
+// +-----------+
+// |7 Y 6|
+// | | |
+// | | |
+// | X---+--- | +Z face
+// | | |
+// | | |
+// |5 4|
+// +-----------+
+// |2 Y 3|
+// | | |
+// | | |
+// | ---+---X | -Z face
+// | | |
+// | | |
+// |0 1|
+// +-----------+
+// /
+// /
+// dataWindow.max
+//
+// The size of the data window should be N by 6*N pixels
+// (width by height), where N can be any integer greater
+// than 0.
+//
+//--------------------------------------------------------------
+
+//------------------------------------
+// Names for the six faces of the cube
+//------------------------------------
+
+enum CubeMapFace
+{
+ CUBEFACE_POS_X, // +X face
+ CUBEFACE_NEG_X, // -X face
+ CUBEFACE_POS_Y, // +Y face
+ CUBEFACE_NEG_Y, // -Y face
+ CUBEFACE_POS_Z, // +Z face
+ CUBEFACE_NEG_Z, // -Z face
+};
+
+namespace CubeMap
+{
+ //---------------------------------------------
+ // Width and height of a cube's face, in pixels
+ //---------------------------------------------
+
+ int sizeOfFace (const Imath::Box2i &dataWindow);
+
+
+ //------------------------------------------
+ // Compute the region in the environment map
+ // that is covered by the specified face.
+ //------------------------------------------
+
+ Imath::Box2i dataWindowForFace (CubeMapFace face,
+ const Imath::Box2i &dataWindow);
+
+
+ //----------------------------------------------------
+ // Convert the coordinates of a pixel within a face
+ // [in the range from (0,0) to (s-1,s-1), where
+ // s == sizeOfFace(dataWindow)] to pixel coordinates
+ // in the environment map.
+ //----------------------------------------------------
+
+ Imath::V2f pixelPosition (CubeMapFace face,
+ const Imath::Box2i &dataWindow,
+ Imath::V2f positionInFace);
+
+
+ //--------------------------------------------------------------
+ // Convert a 3D direction into a cube face, and a pixel position
+ // within that face.
+ //
+ // If you have a 3D direction, dir, the following code fragment
+ // finds the position, pos, of the corresponding pixel in an
+ // environment map with data window dw:
+ //
+ // CubeMapFace f;
+ // V2f pif, pos;
+ //
+ // faceAndPixelPosition (dir, dw, f, pif);
+ // pos = pixelPosition (f, dw, pif);
+ //
+ //--------------------------------------------------------------
+
+ void faceAndPixelPosition (const Imath::V3f &direction,
+ const Imath::Box2i &dataWindow,
+ CubeMapFace &face,
+ Imath::V2f &positionInFace);
+
+
+ // --------------------------------------------------------
+ // Given a cube face and a pixel position within that face,
+ // compute the corresponding 3D direction.
+ // --------------------------------------------------------
+
+ Imath::V3f direction (CubeMapFace face,
+ const Imath::Box2i &dataWindow,
+ const Imath::V2f &positionInFace);
+}
+
+
+} // namespace Imf
+
+#endif
projects / opencv / blobdiff