# OgreImageResampler.h

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    00001 /*
    00002 -----------------------------------------------------------------------------
    00003 This source file is part of OGRE
    00004     (Object-oriented Graphics Rendering Engine)
    00005 For the latest info, see http://www.ogre3d.org/
    00006
    00007 Copyright (c) 2000-2006 Torus Knot Software Ltd
    00008 Also see acknowledgements in Readme.html
    00009
    00010 This program is free software; you can redistribute it and/or modify it under
    00011 the terms of the GNU Lesser General Public License as published by the Free Software
    00012 Foundation; either version 2 of the License, or (at your option) any later
    00013 version.
    00014
    00015 This program is distributed in the hope that it will be useful, but WITHOUT
    00016 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
    00017 FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details.
    00018
    00019 You should have received a copy of the GNU Lesser General Public License along with
    00020 this program; if not, write to the Free Software Foundation, Inc., 59 Temple
    00021 Place - Suite 330, Boston, MA 02111-1307, USA, or go to
    00022 http://www.gnu.org/copyleft/lesser.txt.
    00023
    00024 You may alternatively use this source under the terms of a specific version of
    00025 the OGRE Unrestricted License provided you have obtained such a license from
    00026 Torus Knot Software Ltd.
    00027 -----------------------------------------------------------------------------
    00028 */
    00029 #ifndef OGREIMAGERESAMPLER_H
    00030 #define OGREIMAGERESAMPLER_H
    00031
    00032 #include <algorithm>
    00033
    00034 // this file is inlined into OgreImage.cpp!
    00035 // do not include anywhere else.
    00036 namespace Ogre {
    00037
    00038 // variable name hints:
    00039 // sx_48 = 16/48-bit fixed-point x-position in source
    00040 // stepx = difference between adjacent sx_48 values
    00041 // sx1 = lower-bound integer x-position in source
    00042 // sx2 = upper-bound integer x-position in source
    00043 // sxf = fractional weight beween sx1 and sx2
    00044 // x,y,z = location of output pixel in destination
    00045
    00046 // nearest-neighbor resampler, does not convert formats.
    00047 // templated on bytes-per-pixel to allow compiler optimizations, such
    00048 // as simplifying memcpy() and replacing multiplies with bitshifts
    00049 template<unsigned int elemsize> struct NearestResampler {
    00050     static void scale(const PixelBox& src, const PixelBox& dst) {
    00051         // assert(src.format == dst.format);
    00052
    00053         // srcdata stays at beginning, pdst is a moving pointer
    00054         uchar* srcdata = (uchar*)src.data;
    00055         uchar* pdst = (uchar*)dst.data;
    00056
    00057         // sx_48,sy_48,sz_48 represent current position in source
    00058         // using 16/48-bit fixed precision, incremented by steps
    00059         uint64 stepx = ((uint64)src.getWidth() << 48) / dst.getWidth();
    00060         uint64 stepy = ((uint64)src.getHeight() << 48) / dst.getHeight();
    00061         uint64 stepz = ((uint64)src.getDepth() << 48) / dst.getDepth();
    00062
    00063         // note: ((stepz>>1) - 1) is an extra half-step increment to adjust
    00064         // for the center of the destination pixel, not the top-left corner
    00065         uint64 sz_48 = (stepz >> 1) - 1;
    00066         for (size_t z = dst.front; z < dst.back; z++, sz_48 += stepz) {
    00067             size_t srczoff = (size_t)(sz_48 >> 48) * src.slicePitch;
    00068
    00069             uint64 sy_48 = (stepy >> 1) - 1;
    00070             for (size_t y = dst.top; y < dst.bottom; y++, sy_48 += stepy) {
    00071                 size_t srcyoff = (size_t)(sy_48 >> 48) * src.rowPitch;
    00072
    00073                 uint64 sx_48 = (stepx >> 1) - 1;
    00074                 for (size_t x = dst.left; x < dst.right; x++, sx_48 += stepx) {
    00075                     uchar* psrc = srcdata +
    00076                         elemsize*((size_t)(sx_48 >> 48) + srcyoff + srczoff);
    00077                     memcpy(pdst, psrc, elemsize);
    00078                     pdst += elemsize;
    00079                 }
    00080                 pdst += elemsize*dst.getRowSkip();
    00081             }
    00082             pdst += elemsize*dst.getSliceSkip();
    00083         }
    00084     }
    00085 };
    00086
    00087
    00088 // default floating-point linear resampler, does format conversion
    00089 struct LinearResampler {
    00090     static void scale(const PixelBox& src, const PixelBox& dst) {
    00091         size_t srcelemsize = PixelUtil::getNumElemBytes(src.format);
    00092         size_t dstelemsize = PixelUtil::getNumElemBytes(dst.format);
    00093
    00094         // srcdata stays at beginning, pdst is a moving pointer
    00095         uchar* srcdata = (uchar*)src.data;
    00096         uchar* pdst = (uchar*)dst.data;
    00097
    00098         // sx_48,sy_48,sz_48 represent current position in source
    00099         // using 16/48-bit fixed precision, incremented by steps
    00100         uint64 stepx = ((uint64)src.getWidth() << 48) / dst.getWidth();
    00101         uint64 stepy = ((uint64)src.getHeight() << 48) / dst.getHeight();
    00102         uint64 stepz = ((uint64)src.getDepth() << 48) / dst.getDepth();
    00103
    00104         // temp is 16/16 bit fixed precision, used to adjust a source
    00105         // coordinate (x, y, or z) backwards by half a pixel so that the
    00106         // integer bits represent the first sample (eg, sx1) and the
    00107         // fractional bits are the blend weight of the second sample
    00108         unsigned int temp;
    00109
    00110         // note: ((stepz>>1) - 1) is an extra half-step increment to adjust
    00111         // for the center of the destination pixel, not the top-left corner
    00112         uint64 sz_48 = (stepz >> 1) - 1;
    00113         for (size_t z = dst.front; z < dst.back; z++, sz_48+=stepz) {
    00114             temp = sz_48 >> 32;
    00115             temp = (temp > 0x8000)? temp - 0x8000 : 0;
    00116             size_t sz1 = temp >> 16;                 // src z, sample #1
    00117             size_t sz2 = std::min(sz1+1,src.getDepth()-1);// src z, sample #2
    00118             float szf = (temp & 0xFFFF) / 65536.f; // weight of sample #2
    00119
    00120             uint64 sy_48 = (stepy >> 1) - 1;
    00121             for (size_t y = dst.top; y < dst.bottom; y++, sy_48+=stepy) {
    00122                 temp = sy_48 >> 32;
    00123                 temp = (temp > 0x8000)? temp - 0x8000 : 0;
    00124                 size_t sy1 = temp >> 16;                    // src y #1
    00125                 size_t sy2 = std::min(sy1+1,src.getHeight()-1);// src y #2
    00126                 float syf = (temp & 0xFFFF) / 65536.f; // weight of #2
    00127
    00128                 uint64 sx_48 = (stepx >> 1) - 1;
    00129                 for (size_t x = dst.left; x < dst.right; x++, sx_48+=stepx) {
    00130                     temp = sx_48 >> 32;
    00131                     temp = (temp > 0x8000)? temp - 0x8000 : 0;
    00132                     size_t sx1 = temp >> 16;                    // src x #1
    00133                     size_t sx2 = std::min(sx1+1,src.getWidth()-1);// src x #2
    00134                     float sxf = (temp & 0xFFFF) / 65536.f; // weight of #2
    00135
    00136                     ColourValue x1y1z1, x2y1z1, x1y2z1, x2y2z1;
    00137                     ColourValue x1y1z2, x2y1z2, x1y2z2, x2y2z2;
    00138
    00139 #define UNPACK(dst,x,y,z) PixelUtil::unpackColour(&dst, src.format, \
    00140     srcdata + srcelemsize*((x)+(y)*src.rowPitch+(z)*src.slicePitch))
    00141
    00142                     UNPACK(x1y1z1,sx1,sy1,sz1); UNPACK(x2y1z1,sx2,sy1,sz1);
    00143                     UNPACK(x1y2z1,sx1,sy2,sz1); UNPACK(x2y2z1,sx2,sy2,sz1);
    00144                     UNPACK(x1y1z2,sx1,sy1,sz2); UNPACK(x2y1z2,sx2,sy1,sz2);
    00145                     UNPACK(x1y2z2,sx1,sy2,sz2); UNPACK(x2y2z2,sx2,sy2,sz2);
    00146 #undef UNPACK
    00147
    00148                     ColourValue accum =
    00149                         x1y1z1 * ((1.0f - sxf)*(1.0f - syf)*(1.0f - szf)) +
    00150                         x2y1z1 * (        sxf *(1.0f - syf)*(1.0f - szf)) +
    00151                         x1y2z1 * ((1.0f - sxf)*        syf *(1.0f - szf)) +
    00152                         x2y2z1 * (        sxf *        syf *(1.0f - szf)) +
    00153                         x1y1z2 * ((1.0f - sxf)*(1.0f - syf)*        szf ) +
    00154                         x2y1z2 * (        sxf *(1.0f - syf)*        szf ) +
    00155                         x1y2z2 * ((1.0f - sxf)*        syf *        szf ) +
    00156                         x2y2z2 * (        sxf *        syf *        szf );
    00157
    00158                     PixelUtil::packColour(accum, dst.format, pdst);
    00159
    00160                     pdst += dstelemsize;
    00161                 }
    00162                 pdst += dstelemsize*dst.getRowSkip();
    00163             }
    00164             pdst += dstelemsize*dst.getSliceSkip();
    00165         }
    00166     }
    00167 };
    00168
    00169
    00170 // float32 linear resampler, converts FLOAT32_RGB/FLOAT32_RGBA only.
    00171 // avoids overhead of pixel unpack/repack function calls
    00172 struct LinearResampler_Float32 {
    00173     static void scale(const PixelBox& src, const PixelBox& dst) {
    00174         size_t srcchannels = PixelUtil::getNumElemBytes(src.format) / sizeof(float);
    00175         size_t dstchannels = PixelUtil::getNumElemBytes(dst.format) / sizeof(float);
    00176         // assert(srcchannels == 3 || srcchannels == 4);
    00177         // assert(dstchannels == 3 || dstchannels == 4);
    00178
    00179         // srcdata stays at beginning, pdst is a moving pointer
    00180         float* srcdata = (float*)src.data;
    00181         float* pdst = (float*)dst.data;
    00182
    00183         // sx_48,sy_48,sz_48 represent current position in source
    00184         // using 16/48-bit fixed precision, incremented by steps
    00185         uint64 stepx = ((uint64)src.getWidth() << 48) / dst.getWidth();
    00186         uint64 stepy = ((uint64)src.getHeight() << 48) / dst.getHeight();
    00187         uint64 stepz = ((uint64)src.getDepth() << 48) / dst.getDepth();
    00188
    00189         // temp is 16/16 bit fixed precision, used to adjust a source
    00190         // coordinate (x, y, or z) backwards by half a pixel so that the
    00191         // integer bits represent the first sample (eg, sx1) and the
    00192         // fractional bits are the blend weight of the second sample
    00193         unsigned int temp;
    00194
    00195         // note: ((stepz>>1) - 1) is an extra half-step increment to adjust
    00196         // for the center of the destination pixel, not the top-left corner
    00197         uint64 sz_48 = (stepz >> 1) - 1;
    00198         for (size_t z = dst.front; z < dst.back; z++, sz_48+=stepz) {
    00199             temp = sz_48 >> 32;
    00200             temp = (temp > 0x8000)? temp - 0x8000 : 0;
    00201             size_t sz1 = temp >> 16;                 // src z, sample #1
    00202             size_t sz2 = std::min(sz1+1,src.getDepth()-1);// src z, sample #2
    00203             float szf = (temp & 0xFFFF) / 65536.f; // weight of sample #2
    00204
    00205             uint64 sy_48 = (stepy >> 1) - 1;
    00206             for (size_t y = dst.top; y < dst.bottom; y++, sy_48+=stepy) {
    00207                 temp = sy_48 >> 32;
    00208                 temp = (temp > 0x8000)? temp - 0x8000 : 0;
    00209                 size_t sy1 = temp >> 16;                    // src y #1
    00210                 size_t sy2 = std::min(sy1+1,src.getHeight()-1);// src y #2
    00211                 float syf = (temp & 0xFFFF) / 65536.f; // weight of #2
    00212
    00213                 uint64 sx_48 = (stepx >> 1) - 1;
    00214                 for (size_t x = dst.left; x < dst.right; x++, sx_48+=stepx) {
    00215                     temp = sx_48 >> 32;
    00216                     temp = (temp > 0x8000)? temp - 0x8000 : 0;
    00217                     size_t sx1 = temp >> 16;                    // src x #1
    00218                     size_t sx2 = std::min(sx1+1,src.getWidth()-1);// src x #2
    00219                     float sxf = (temp & 0xFFFF) / 65536.f; // weight of #2
    00220
    00221                     // process R,G,B,A simultaneously for cache coherence?
    00222                     float accum[4] = { 0.0f, 0.0f, 0.0f, 0.0f };
    00223
    00224 #define ACCUM3(x,y,z,factor) \
    00225     { float f = factor; \
    00226     size_t off = (x+y*src.rowPitch+z*src.slicePitch)*srcchannels; \
    00227     accum[0]+=srcdata[off+0]*f; accum[1]+=srcdata[off+1]*f; \
    00228     accum[2]+=srcdata[off+2]*f; }
    00229
    00230 #define ACCUM4(x,y,z,factor) \
    00231     { float f = factor; \
    00232     size_t off = (x+y*src.rowPitch+z*src.slicePitch)*srcchannels; \
    00233     accum[0]+=srcdata[off+0]*f; accum[1]+=srcdata[off+1]*f; \
    00234     accum[2]+=srcdata[off+2]*f; accum[3]+=srcdata[off+3]*f; }
    00235
    00236                     if (srcchannels == 3 || dstchannels == 3) {
    00237                         // RGB, no alpha
    00238                         ACCUM3(sx1,sy1,sz1,(1.0f-sxf)*(1.0f-syf)*(1.0f-szf));
    00239                         ACCUM3(sx2,sy1,sz1,      sxf *(1.0f-syf)*(1.0f-szf));
    00240                         ACCUM3(sx1,sy2,sz1,(1.0f-sxf)*      syf *(1.0f-szf));
    00241                         ACCUM3(sx2,sy2,sz1,      sxf *      syf *(1.0f-szf));
    00242                         ACCUM3(sx1,sy1,sz2,(1.0f-sxf)*(1.0f-syf)*      szf );
    00243                         ACCUM3(sx2,sy1,sz2,      sxf *(1.0f-syf)*      szf );
    00244                         ACCUM3(sx1,sy2,sz2,(1.0f-sxf)*      syf *      szf );
    00245                         ACCUM3(sx2,sy2,sz2,      sxf *      syf *      szf );
    00246                         accum[3] = 1.0f;
    00247                     } else {
    00248                         // RGBA
    00249                         ACCUM4(sx1,sy1,sz1,(1.0f-sxf)*(1.0f-syf)*(1.0f-szf));
    00250                         ACCUM4(sx2,sy1,sz1,      sxf *(1.0f-syf)*(1.0f-szf));
    00251                         ACCUM4(sx1,sy2,sz1,(1.0f-sxf)*      syf *(1.0f-szf));
    00252                         ACCUM4(sx2,sy2,sz1,      sxf *      syf *(1.0f-szf));
    00253                         ACCUM4(sx1,sy1,sz2,(1.0f-sxf)*(1.0f-syf)*      szf );
    00254                         ACCUM4(sx2,sy1,sz2,      sxf *(1.0f-syf)*      szf );
    00255                         ACCUM4(sx1,sy2,sz2,(1.0f-sxf)*      syf *      szf );
    00256                         ACCUM4(sx2,sy2,sz2,      sxf *      syf *      szf );
    00257                     }
    00258
    00259                     memcpy(pdst, accum, sizeof(float)*dstchannels);
    00260
    00261 #undef ACCUM3
    00262 #undef ACCUM4
    00263
    00264                     pdst += dstchannels;
    00265                 }
    00266                 pdst += dstchannels*dst.getRowSkip();
    00267             }
    00268             pdst += dstchannels*dst.getSliceSkip();
    00269         }
    00270     }
    00271 };
    00272
    00273
    00274
    00275 // byte linear resampler, does not do any format conversions.
    00276 // only handles pixel formats that use 1 byte per color channel.
    00277 // 2D only; punts 3D pixelboxes to default LinearResampler (slow).
    00278 // templated on bytes-per-pixel to allow compiler optimizations, such
    00279 // as unrolling loops and replacing multiplies with bitshifts
    00280 template<unsigned int channels> struct LinearResampler_Byte {
    00281     static void scale(const PixelBox& src, const PixelBox& dst) {
    00282         // assert(src.format == dst.format);
    00283
    00284         // only optimized for 2D
    00285         if (src.getDepth() > 1 || dst.getDepth() > 1) {
    00286             LinearResampler::scale(src, dst);
    00287             return;
    00288         }
    00289
    00290         // srcdata stays at beginning of slice, pdst is a moving pointer
    00291         uchar* srcdata = (uchar*)src.data;
    00292         uchar* pdst = (uchar*)dst.data;
    00293
    00294         // sx_48,sy_48 represent current position in source
    00295         // using 16/48-bit fixed precision, incremented by steps
    00296         uint64 stepx = ((uint64)src.getWidth() << 48) / dst.getWidth();
    00297         uint64 stepy = ((uint64)src.getHeight() << 48) / dst.getHeight();
    00298
    00299         // bottom 28 bits of temp are 16/12 bit fixed precision, used to
    00300         // adjust a source coordinate backwards by half a pixel so that the
    00301         // integer bits represent the first sample (eg, sx1) and the
    00302         // fractional bits are the blend weight of the second sample
    00303         unsigned int temp;
    00304
    00305         uint64 sy_48 = (stepy >> 1) - 1;
    00306         for (size_t y = dst.top; y < dst.bottom; y++, sy_48+=stepy) {
    00307             temp = sy_48 >> 36;
    00308             temp = (temp > 0x800)? temp - 0x800: 0;
    00309             unsigned int syf = temp & 0xFFF;
    00310             size_t sy1 = temp >> 12;
    00311             size_t sy2 = std::min(sy1+1, src.bottom-src.top-1);
    00312             size_t syoff1 = sy1 * src.rowPitch;
    00313             size_t syoff2 = sy2 * src.rowPitch;
    00314
    00315             uint64 sx_48 = (stepx >> 1) - 1;
    00316             for (size_t x = dst.left; x < dst.right; x++, sx_48+=stepx) {
    00317                 temp = sx_48 >> 36;
    00318                 temp = (temp > 0x800)? temp - 0x800 : 0;
    00319                 unsigned int sxf = temp & 0xFFF;
    00320                 size_t sx1 = temp >> 12;
    00321                 size_t sx2 = std::min(sx1+1, src.right-src.left-1);
    00322
    00323                 unsigned int sxfsyf = sxf*syf;
    00324                 for (unsigned int k = 0; k < channels; k++) {
    00325                     unsigned int accum =
    00326                         srcdata[(sx1 + syoff1)*channels+k]*(0x1000000-(sxf<<12)-(syf<<12)+sxfsyf) +
    00327                         srcdata[(sx2 + syoff1)*channels+k]*((sxf<<12)-sxfsyf) +
    00328                         srcdata[(sx1 + syoff2)*channels+k]*((syf<<12)-sxfsyf) +
    00329                         srcdata[(sx2 + syoff2)*channels+k]*sxfsyf;
    00330                     // accum is computed using 8/24-bit fixed-point math
    00331                     // (maximum is 0xFF000000; rounding will not cause overflow)
    00332                     *pdst++ = (accum + 0x800000) >> 24;
    00333                 }
    00334             }
    00335             pdst += channels*dst.getRowSkip();
    00336         }
    00337     }
    00338 };
    00339
    00340 }
    00341
    00342 #endif

Copyright © 2008 Torus Knot Software Ltd
This work is licensed under a Creative Commons Attribution-ShareAlike 2.5 License.
Last modified Sat Apr 11 13:46:40 2009