ImfEnvmap.cpp 7.21 KB
Newer Older
wester committed
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328
///////////////////////////////////////////////////////////////////////////
//
// 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.
//
///////////////////////////////////////////////////////////////////////////


//-----------------------------------------------------------------------------
//
//	Environment maps
//
//-----------------------------------------------------------------------------

#include <ImfEnvmap.h>
#include "ImathFun.h"
#include <algorithm>
#include <math.h>

using namespace std;
using namespace Imath;

namespace Imf {
namespace LatLongMap {

V2f
latLong (const V3f &dir)
{
    float r = sqrt (dir.z * dir.z + dir.x * dir.x);

    float latitude = (r < abs (dir.y))?
             acos (r / dir.length()) * sign (dir.y):
             asin (dir.y / dir.length());

    float longitude = (dir.z == 0 && dir.x == 0)? 0: atan2 (dir.x, dir.z);

    return V2f (latitude, longitude);
}


V2f
latLong (const Box2i &dataWindow, const V2f &pixelPosition)
{
    float latitude, longitude;

    if (dataWindow.max.y > dataWindow.min.y)
    {
    latitude = -M_PI *
          ((pixelPosition.y  - dataWindow.min.y) /
           (dataWindow.max.y - dataWindow.min.y) - 0.5f);
    }
    else
    {
    latitude = 0;
    }

    if (dataWindow.max.x > dataWindow.min.x)
    {
    longitude = -2 * M_PI *
           ((pixelPosition.x  - dataWindow.min.x) /
            (dataWindow.max.x - dataWindow.min.x) - 0.5f);
    }
    else
    {
    longitude = 0;
    }

    return V2f (latitude, longitude);
}


V2f
pixelPosition (const Box2i &dataWindow, const V2f &latLong)
{
    float x = latLong.y / (-2 * M_PI) + 0.5f;
    float y = latLong.x / -M_PI + 0.5f;

    return V2f (x * (dataWindow.max.x - dataWindow.min.x) + dataWindow.min.x,
        y * (dataWindow.max.y - dataWindow.min.y) + dataWindow.min.y);
}


V2f
pixelPosition (const Box2i &dataWindow, const V3f &direction)
{
    return pixelPosition (dataWindow, latLong (direction));
}


V3f
direction (const Box2i &dataWindow, const V2f &pixelPosition)
{
    V2f ll = latLong (dataWindow, pixelPosition);

    return V3f (sin (ll.y) * cos (ll.x),
        sin (ll.x),
        cos (ll.y) * cos (ll.x));
}

} // namespace LatLongMap


namespace CubeMap {

int
sizeOfFace (const Box2i &dataWindow)
{
    return min ((dataWindow.max.x - dataWindow.min.x + 1),
        (dataWindow.max.y - dataWindow.min.y + 1) / 6);
}


Box2i
dataWindowForFace (CubeMapFace face, const Box2i &dataWindow)
{
    int sof = sizeOfFace (dataWindow);
    Box2i dwf;

    dwf.min.x = 0;
    dwf.min.y = int (face) * sof;

    dwf.max.x = dwf.min.x + sof - 1;
    dwf.max.y = dwf.min.y + sof - 1;

    return dwf;
}


V2f
pixelPosition (CubeMapFace face, const Box2i &dataWindow, V2f positionInFace)
{
    Box2i dwf = dataWindowForFace (face, dataWindow);
    V2f pos (0, 0);

    switch (face)
    {
      case CUBEFACE_POS_X:

    pos.x = dwf.min.x + positionInFace.y;
    pos.y = dwf.max.y - positionInFace.x;
    break;

      case CUBEFACE_NEG_X:

    pos.x = dwf.max.x - positionInFace.y;
    pos.y = dwf.max.y - positionInFace.x;
    break;

      case CUBEFACE_POS_Y:

    pos.x = dwf.min.x + positionInFace.x;
    pos.y = dwf.max.y - positionInFace.y;
    break;

      case CUBEFACE_NEG_Y:

    pos.x = dwf.min.x + positionInFace.x;
    pos.y = dwf.min.y + positionInFace.y;
    break;

      case CUBEFACE_POS_Z:

    pos.x = dwf.max.x - positionInFace.x;
    pos.y = dwf.max.y - positionInFace.y;
    break;

      case CUBEFACE_NEG_Z:

    pos.x = dwf.min.x + positionInFace.x;
    pos.y = dwf.max.y - positionInFace.y;
    break;
    }

    return pos;
}


void
faceAndPixelPosition (const V3f &direction,
              const Box2i &dataWindow,
              CubeMapFace &face,
              V2f &pif)
{
    int sof = sizeOfFace (dataWindow);
    float absx = abs (direction.x);
    float absy = abs (direction.y);
    float absz = abs (direction.z);

    if (absx >= absy && absx >= absz)
    {
    if (absx == 0)
    {
        //
        // Special case - direction is (0, 0, 0)
        //

        face = CUBEFACE_POS_X;
        pif = V2f (0, 0);
        return;
    }

    pif.x = (direction.y / absx + 1) / 2 * (sof - 1);
    pif.y = (direction.z / absx + 1) / 2 * (sof - 1);

    if (direction.x > 0)
        face = CUBEFACE_POS_X;
    else
        face = CUBEFACE_NEG_X;
    }
    else if (absy >= absz)
    {
    pif.x = (direction.x / absy + 1) / 2 * (sof - 1);
    pif.y = (direction.z / absy + 1) / 2 * (sof - 1);

    if (direction.y > 0)
        face = CUBEFACE_POS_Y;
    else
        face = CUBEFACE_NEG_Y;
    }
    else
    {
    pif.x = (direction.x / absz + 1) / 2 * (sof - 1);
    pif.y = (direction.y / absz + 1) / 2 * (sof - 1);

    if (direction.z > 0)
        face = CUBEFACE_POS_Z;
    else
        face = CUBEFACE_NEG_Z;
    }
}


V3f
direction (CubeMapFace face, const Box2i &dataWindow, const V2f &positionInFace)
{
    int sof = sizeOfFace (dataWindow);

    V2f pos;

    if (sof > 1)
    {
    pos = V2f (positionInFace.x / (sof - 1) * 2 - 1,
           positionInFace.y / (sof - 1) * 2 - 1);
    }
    else
    {
    pos = V2f (0, 0);
    }

    V3f dir (1, 0, 0);

    switch (face)
    {
      case CUBEFACE_POS_X:

    dir.x = 1;
    dir.y = pos.x;
    dir.z = pos.y;
    break;

      case CUBEFACE_NEG_X:

    dir.x = -1;
    dir.y = pos.x;
    dir.z = pos.y;
    break;

      case CUBEFACE_POS_Y:

    dir.x = pos.x;
    dir.y = 1;
    dir.z = pos.y;
    break;

      case CUBEFACE_NEG_Y:

    dir.x = pos.x;
    dir.y = -1;
    dir.z = pos.y;
    break;

      case CUBEFACE_POS_Z:

    dir.x = pos.x;
    dir.y = pos.y;
    dir.z = 1;
    break;

      case CUBEFACE_NEG_Z:

    dir.x = pos.x;
    dir.y = pos.y;
    dir.z = -1;
    break;
    }

    return dir;
}

} // namespace CubeMap
} // namespace Imf