# 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 // define uint64 type
    00039 #if OGRE_COMPILER == OGRE_COMPILER_MSVC
    00040 typedef unsigned __int64 uint64;
    00041 #else
    00042 typedef unsigned long long uint64;
    00043 #endif
    00044
    00045 // variable name hints:
    00046 // sx_48 = 16/48-bit fixed-point x-position in source
    00047 // stepx = difference between adjacent sx_48 values
    00048 // sx1 = lower-bound integer x-position in source
    00049 // sx2 = upper-bound integer x-position in source
    00050 // sxf = fractional weight beween sx1 and sx2
    00051 // x,y,z = location of output pixel in destination
    00052
    00053 // nearest-neighbor resampler, does not convert formats.
    00054 // templated on bytes-per-pixel to allow compiler optimizations, such
    00055 // as simplifying memcpy() and replacing multiplies with bitshifts
    00056 template<unsigned int elemsize> struct NearestResampler {
    00057     static void scale(const PixelBox& src, const PixelBox& dst) {
    00058         // assert(src.format == dst.format);
    00059
    00060         // srcdata stays at beginning, pdst is a moving pointer
    00061         uchar* srcdata = (uchar*)src.data;
    00062         uchar* pdst = (uchar*)dst.data;
    00063
    00064         // sx_48,sy_48,sz_48 represent current position in source
    00065         // using 16/48-bit fixed precision, incremented by steps
    00066         uint64 stepx = ((uint64)src.getWidth() << 48) / dst.getWidth();
    00067         uint64 stepy = ((uint64)src.getHeight() << 48) / dst.getHeight();
    00068         uint64 stepz = ((uint64)src.getDepth() << 48) / dst.getDepth();
    00069
    00070         // note: ((stepz>>1) - 1) is an extra half-step increment to adjust
    00071         // for the center of the destination pixel, not the top-left corner
    00072         uint64 sz_48 = (stepz >> 1) - 1;
    00073         for (size_t z = dst.front; z < dst.back; z++, sz_48 += stepz) {
    00074             size_t srczoff = (size_t)(sz_48 >> 48) * src.slicePitch;
    00075
    00076             uint64 sy_48 = (stepy >> 1) - 1;
    00077             for (size_t y = dst.top; y < dst.bottom; y++, sy_48 += stepy) {
    00078                 size_t srcyoff = (size_t)(sy_48 >> 48) * src.rowPitch;
    00079
    00080                 uint64 sx_48 = (stepx >> 1) - 1;
    00081                 for (size_t x = dst.left; x < dst.right; x++, sx_48 += stepx) {
    00082                     uchar* psrc = srcdata +
    00083                         elemsize*((size_t)(sx_48 >> 48) + srcyoff + srczoff);
    00084                     memcpy(pdst, psrc, elemsize);
    00085                     pdst += elemsize;
    00086                 }
    00087                 pdst += elemsize*dst.getRowSkip();
    00088             }
    00089             pdst += elemsize*dst.getSliceSkip();
    00090         }
    00091     }
    00092 };
    00093
    00094
    00095 // default floating-point linear resampler, does format conversion
    00096 struct LinearResampler {
    00097     static void scale(const PixelBox& src, const PixelBox& dst) {
    00098         size_t srcelemsize = PixelUtil::getNumElemBytes(src.format);
    00099         size_t dstelemsize = PixelUtil::getNumElemBytes(dst.format);
    00100
    00101         // srcdata stays at beginning, pdst is a moving pointer
    00102         uchar* srcdata = (uchar*)src.data;
    00103         uchar* pdst = (uchar*)dst.data;
    00104
    00105         // sx_48,sy_48,sz_48 represent current position in source
    00106         // using 16/48-bit fixed precision, incremented by steps
    00107         uint64 stepx = ((uint64)src.getWidth() << 48) / dst.getWidth();
    00108         uint64 stepy = ((uint64)src.getHeight() << 48) / dst.getHeight();
    00109         uint64 stepz = ((uint64)src.getDepth() << 48) / dst.getDepth();
    00110
    00111         // temp is 16/16 bit fixed precision, used to adjust a source
    00112         // coordinate (x, y, or z) backwards by half a pixel so that the
    00113         // integer bits represent the first sample (eg, sx1) and the
    00114         // fractional bits are the blend weight of the second sample
    00115         unsigned int temp;
    00116
    00117         // note: ((stepz>>1) - 1) is an extra half-step increment to adjust
    00118         // for the center of the destination pixel, not the top-left corner
    00119         uint64 sz_48 = (stepz >> 1) - 1;
    00120         for (size_t z = dst.front; z < dst.back; z++, sz_48+=stepz) {
    00121             temp = sz_48 >> 32;
    00122             temp = (temp > 0x8000)? temp - 0x8000 : 0;
    00123             size_t sz1 = temp >> 16;                 // src z, sample #1
    00124             size_t sz2 = std::min(sz1+1,src.getDepth()-1);// src z, sample #2
    00125             float szf = (temp & 0xFFFF) / 65536.f; // weight of sample #2
    00126
    00127             uint64 sy_48 = (stepy >> 1) - 1;
    00128             for (size_t y = dst.top; y < dst.bottom; y++, sy_48+=stepy) {
    00129                 temp = sy_48 >> 32;
    00130                 temp = (temp > 0x8000)? temp - 0x8000 : 0;
    00131                 size_t sy1 = temp >> 16;                    // src y #1
    00132                 size_t sy2 = std::min(sy1+1,src.getHeight()-1);// src y #2
    00133                 float syf = (temp & 0xFFFF) / 65536.f; // weight of #2
    00134
    00135                 uint64 sx_48 = (stepx >> 1) - 1;
    00136                 for (size_t x = dst.left; x < dst.right; x++, sx_48+=stepx) {
    00137                     temp = sx_48 >> 32;
    00138                     temp = (temp > 0x8000)? temp - 0x8000 : 0;
    00139                     size_t sx1 = temp >> 16;                    // src x #1
    00140                     size_t sx2 = std::min(sx1+1,src.getWidth()-1);// src x #2
    00141                     float sxf = (temp & 0xFFFF) / 65536.f; // weight of #2
    00142
    00143                     ColourValue x1y1z1, x2y1z1, x1y2z1, x2y2z1;
    00144                     ColourValue x1y1z2, x2y1z2, x1y2z2, x2y2z2;
    00145
    00146 #define UNPACK(dst,x,y,z) PixelUtil::unpackColour(&dst, src.format, \
    00147     srcdata + srcelemsize*((x)+(y)*src.rowPitch+(z)*src.slicePitch))
    00148
    00149                     UNPACK(x1y1z1,sx1,sy1,sz1); UNPACK(x2y1z1,sx2,sy1,sz1);
    00150                     UNPACK(x1y2z1,sx1,sy2,sz1); UNPACK(x2y2z1,sx2,sy2,sz1);
    00151                     UNPACK(x1y1z2,sx1,sy1,sz2); UNPACK(x2y1z2,sx2,sy1,sz2);
    00152                     UNPACK(x1y2z2,sx1,sy2,sz2); UNPACK(x2y2z2,sx2,sy2,sz2);
    00153 #undef UNPACK
    00154
    00155                     ColourValue accum =
    00156                         x1y1z1 * ((1.0f - sxf)*(1.0f - syf)*(1.0f - szf)) +
    00157                         x2y1z1 * (        sxf *(1.0f - syf)*(1.0f - szf)) +
    00158                         x1y2z1 * ((1.0f - sxf)*        syf *(1.0f - szf)) +
    00159                         x2y2z1 * (        sxf *        syf *(1.0f - szf)) +
    00160                         x1y1z2 * ((1.0f - sxf)*(1.0f - syf)*        szf ) +
    00161                         x2y1z2 * (        sxf *(1.0f - syf)*        szf ) +
    00162                         x1y2z2 * ((1.0f - sxf)*        syf *        szf ) +
    00163                         x2y2z2 * (        sxf *        syf *        szf );
    00164
    00165                     PixelUtil::packColour(accum, dst.format, pdst);
    00166
    00167                     pdst += dstelemsize;
    00168                 }
    00169                 pdst += dstelemsize*dst.getRowSkip();
    00170             }
    00171             pdst += dstelemsize*dst.getSliceSkip();
    00172         }
    00173     }
    00174 };
    00175
    00176
    00177 // float32 linear resampler, converts FLOAT32_RGB/FLOAT32_RGBA only.
    00178 // avoids overhead of pixel unpack/repack function calls
    00179 struct LinearResampler_Float32 {
    00180     static void scale(const PixelBox& src, const PixelBox& dst) {
    00181         size_t srcchannels = PixelUtil::getNumElemBytes(src.format) / sizeof(float);
    00182         size_t dstchannels = PixelUtil::getNumElemBytes(dst.format) / sizeof(float);
    00183         // assert(srcchannels == 3 || srcchannels == 4);
    00184         // assert(dstchannels == 3 || dstchannels == 4);
    00185
    00186         // srcdata stays at beginning, pdst is a moving pointer
    00187         float* srcdata = (float*)src.data;
    00188         float* pdst = (float*)dst.data;
    00189
    00190         // sx_48,sy_48,sz_48 represent current position in source
    00191         // using 16/48-bit fixed precision, incremented by steps
    00192         uint64 stepx = ((uint64)src.getWidth() << 48) / dst.getWidth();
    00193         uint64 stepy = ((uint64)src.getHeight() << 48) / dst.getHeight();
    00194         uint64 stepz = ((uint64)src.getDepth() << 48) / dst.getDepth();
    00195
    00196         // temp is 16/16 bit fixed precision, used to adjust a source
    00197         // coordinate (x, y, or z) backwards by half a pixel so that the
    00198         // integer bits represent the first sample (eg, sx1) and the
    00199         // fractional bits are the blend weight of the second sample
    00200         unsigned int temp;
    00201
    00202         // note: ((stepz>>1) - 1) is an extra half-step increment to adjust
    00203         // for the center of the destination pixel, not the top-left corner
    00204         uint64 sz_48 = (stepz >> 1) - 1;
    00205         for (size_t z = dst.front; z < dst.back; z++, sz_48+=stepz) {
    00206             temp = sz_48 >> 32;
    00207             temp = (temp > 0x8000)? temp - 0x8000 : 0;
    00208             size_t sz1 = temp >> 16;                 // src z, sample #1
    00209             size_t sz2 = std::min(sz1+1,src.getDepth()-1);// src z, sample #2
    00210             float szf = (temp & 0xFFFF) / 65536.f; // weight of sample #2
    00211
    00212             uint64 sy_48 = (stepy >> 1) - 1;
    00213             for (size_t y = dst.top; y < dst.bottom; y++, sy_48+=stepy) {
    00214                 temp = sy_48 >> 32;
    00215                 temp = (temp > 0x8000)? temp - 0x8000 : 0;
    00216                 size_t sy1 = temp >> 16;                    // src y #1
    00217                 size_t sy2 = std::min(sy1+1,src.getHeight()-1);// src y #2
    00218                 float syf = (temp & 0xFFFF) / 65536.f; // weight of #2
    00219
    00220                 uint64 sx_48 = (stepx >> 1) - 1;
    00221                 for (size_t x = dst.left; x < dst.right; x++, sx_48+=stepx) {
    00222                     temp = sx_48 >> 32;
    00223                     temp = (temp > 0x8000)? temp - 0x8000 : 0;
    00224                     size_t sx1 = temp >> 16;                    // src x #1
    00225                     size_t sx2 = std::min(sx1+1,src.getWidth()-1);// src x #2
    00226                     float sxf = (temp & 0xFFFF) / 65536.f; // weight of #2
    00227
    00228                     // process R,G,B,A simultaneously for cache coherence?
    00229                     float accum[4] = { 0.0f, 0.0f, 0.0f, 0.0f };
    00230
    00231 #define ACCUM3(x,y,z,factor) \
    00232     { float f = factor; \
    00233     size_t off = (x+y*src.rowPitch+z*src.slicePitch)*srcchannels; \
    00234     accum[0]+=srcdata[off+0]*f; accum[1]+=srcdata[off+1]*f; \
    00235     accum[2]+=srcdata[off+2]*f; }
    00236
    00237 #define ACCUM4(x,y,z,factor) \
    00238     { float f = factor; \
    00239     size_t off = (x+y*src.rowPitch+z*src.slicePitch)*srcchannels; \
    00240     accum[0]+=srcdata[off+0]*f; accum[1]+=srcdata[off+1]*f; \
    00241     accum[2]+=srcdata[off+2]*f; accum[3]+=srcdata[off+3]*f; }
    00242
    00243                     if (srcchannels == 3 || dstchannels == 3) {
    00244                         // RGB, no alpha
    00245                         ACCUM3(sx1,sy1,sz1,(1.0f-sxf)*(1.0f-syf)*(1.0f-szf));
    00246                         ACCUM3(sx2,sy1,sz1,      sxf *(1.0f-syf)*(1.0f-szf));
    00247                         ACCUM3(sx1,sy2,sz1,(1.0f-sxf)*      syf *(1.0f-szf));
    00248                         ACCUM3(sx2,sy2,sz1,      sxf *      syf *(1.0f-szf));
    00249                         ACCUM3(sx1,sy1,sz2,(1.0f-sxf)*(1.0f-syf)*      szf );
    00250                         ACCUM3(sx2,sy1,sz2,      sxf *(1.0f-syf)*      szf );
    00251                         ACCUM3(sx1,sy2,sz2,(1.0f-sxf)*      syf *      szf );
    00252                         ACCUM3(sx2,sy2,sz2,      sxf *      syf *      szf );
    00253                         accum[3] = 1.0f;
    00254                     } else {
    00255                         // RGBA
    00256                         ACCUM4(sx1,sy1,sz1,(1.0f-sxf)*(1.0f-syf)*(1.0f-szf));
    00257                         ACCUM4(sx2,sy1,sz1,      sxf *(1.0f-syf)*(1.0f-szf));
    00258                         ACCUM4(sx1,sy2,sz1,(1.0f-sxf)*      syf *(1.0f-szf));
    00259                         ACCUM4(sx2,sy2,sz1,      sxf *      syf *(1.0f-szf));
    00260                         ACCUM4(sx1,sy1,sz2,(1.0f-sxf)*(1.0f-syf)*      szf );
    00261                         ACCUM4(sx2,sy1,sz2,      sxf *(1.0f-syf)*      szf );
    00262                         ACCUM4(sx1,sy2,sz2,(1.0f-sxf)*      syf *      szf );
    00263                         ACCUM4(sx2,sy2,sz2,      sxf *      syf *      szf );
    00264                     }
    00265
    00266                     memcpy(pdst, accum, sizeof(float)*dstchannels);
    00267
    00268 #undef ACCUM3
    00269 #undef ACCUM4
    00270
    00271                     pdst += dstchannels;
    00272                 }
    00273                 pdst += dstchannels*dst.getRowSkip();
    00274             }
    00275             pdst += dstchannels*dst.getSliceSkip();
    00276         }
    00277     }
    00278 };
    00279
    00280
    00281
    00282 // byte linear resampler, does not do any format conversions.
    00283 // only handles pixel formats that use 1 byte per color channel.
    00284 // 2D only; punts 3D pixelboxes to default LinearResampler (slow).
    00285 // templated on bytes-per-pixel to allow compiler optimizations, such
    00286 // as unrolling loops and replacing multiplies with bitshifts
    00287 template<unsigned int channels> struct LinearResampler_Byte {
    00288     static void scale(const PixelBox& src, const PixelBox& dst) {
    00289         // assert(src.format == dst.format);
    00290
    00291         // only optimized for 2D
    00292         if (src.getDepth() > 1 || dst.getDepth() > 1) {
    00293             LinearResampler::scale(src, dst);
    00294             return;
    00295         }
    00296
    00297         // srcdata stays at beginning of slice, pdst is a moving pointer
    00298         uchar* srcdata = (uchar*)src.data;
    00299         uchar* pdst = (uchar*)dst.data;
    00300
    00301         // sx_48,sy_48 represent current position in source
    00302         // using 16/48-bit fixed precision, incremented by steps
    00303         uint64 stepx = ((uint64)src.getWidth() << 48) / dst.getWidth();
    00304         uint64 stepy = ((uint64)src.getHeight() << 48) / dst.getHeight();
    00305
    00306         // bottom 28 bits of temp are 16/12 bit fixed precision, used to
    00307         // adjust a source coordinate backwards by half a pixel so that the
    00308         // integer bits represent the first sample (eg, sx1) and the
    00309         // fractional bits are the blend weight of the second sample
    00310         unsigned int temp;
    00311
    00312         uint64 sy_48 = (stepy >> 1) - 1;
    00313         for (size_t y = dst.top; y < dst.bottom; y++, sy_48+=stepy) {
    00314             temp = sy_48 >> 36;
    00315             temp = (temp > 0x800)? temp - 0x800: 0;
    00316             unsigned int syf = temp & 0xFFF;
    00317             size_t sy1 = temp >> 12;
    00318             size_t sy2 = std::min(sy1+1, src.bottom-src.top-1);
    00319             size_t syoff1 = sy1 * src.rowPitch;
    00320             size_t syoff2 = sy2 * src.rowPitch;
    00321
    00322             uint64 sx_48 = (stepx >> 1) - 1;
    00323             for (size_t x = dst.left; x < dst.right; x++, sx_48+=stepx) {
    00324                 temp = sx_48 >> 36;
    00325                 temp = (temp > 0x800)? temp - 0x800 : 0;
    00326                 unsigned int sxf = temp & 0xFFF;
    00327                 size_t sx1 = temp >> 12;
    00328                 size_t sx2 = std::min(sx1+1, src.right-src.left-1);
    00329
    00330                 unsigned int sxfsyf = sxf*syf;
    00331                 for (unsigned int k = 0; k < channels; k++) {
    00332                     unsigned int accum =
    00333                         srcdata[(sx1 + syoff1)*channels+k]*(0x1000000-(sxf<<12)-(syf<<12)+sxfsyf) +
    00334                         srcdata[(sx2 + syoff1)*channels+k]*((sxf<<12)-sxfsyf) +
    00335                         srcdata[(sx1 + syoff2)*channels+k]*((syf<<12)-sxfsyf) +
    00336                         srcdata[(sx2 + syoff2)*channels+k]*sxfsyf;
    00337                     // accum is computed using 8/24-bit fixed-point math
    00338                     // (maximum is 0xFF000000; rounding will not cause overflow)
    00339                     *pdst++ = (accum + 0x800000) >> 24;
    00340                 }
    00341             }
    00342             pdst += channels*dst.getRowSkip();
    00343         }
    00344     }
    00345 };
    00346
    00347 }
    00348
    00349 #endif

Copyright © 2000-2005 by The OGRE Team
This work is licensed under a Creative Commons Attribution-ShareAlike 2.5 License.
Last modified Sat May 10 16:24:59 2008