# 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) 2000-2005 The OGRE Team
    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 */
    00025 #ifndef OGREIMAGERESAMPLER_H
    00026 #define OGREIMAGERESAMPLER_H
    00027
    00028 #include <algorithm>
    00029
    00030 // this file is inlined into OgreImage.cpp!
    00031 // do not include anywhere else.
    00032 namespace Ogre {
    00033
    00034 // define uint64 type
    00035 #if OGRE_COMPILER == OGRE_COMPILER_MSVC
    00036 typedef unsigned __int64 uint64;
    00037 #else
    00038 typedef unsigned long long uint64;
    00039 #endif
    00040
    00041 // variable name hints:
    00042 // sx_48 = 16/48-bit fixed-point x-position in source
    00043 // stepx = difference between adjacent sx_48 values
    00044 // sx1 = lower-bound integer x-position in source
    00045 // sx2 = upper-bound integer x-position in source
    00046 // sxf = fractional weight beween sx1 and sx2
    00047 // x,y,z = location of output pixel in destination
    00048
    00049 // nearest-neighbor resampler, does not convert formats.
    00050 // templated on bytes-per-pixel to allow compiler optimizations, such
    00051 // as simplifying memcpy() and replacing multiplies with bitshifts
    00052 template<unsigned int elemsize> struct NearestResampler {
    00053     static void scale(const PixelBox& src, const PixelBox& dst) {
    00054         // assert(src.format == dst.format);
    00055
    00056         // srcdata stays at beginning, pdst is a moving pointer
    00057         uchar* srcdata = (uchar*)src.data;
    00058         uchar* pdst = (uchar*)dst.data;
    00059
    00060         // sx_48,sy_48,sz_48 represent current position in source
    00061         // using 16/48-bit fixed precision, incremented by steps
    00062         uint64 stepx = ((uint64)src.getWidth() << 48) / dst.getWidth();
    00063         uint64 stepy = ((uint64)src.getHeight() << 48) / dst.getHeight();
    00064         uint64 stepz = ((uint64)src.getDepth() << 48) / dst.getDepth();
    00065
    00066         // note: ((stepz>>1) - 1) is an extra half-step increment to adjust
    00067         // for the center of the destination pixel, not the top-left corner
    00068         uint64 sz_48 = (stepz >> 1) - 1;
    00069         for (size_t z = dst.front; z < dst.back; z++, sz_48 += stepz) {
    00070             size_t srczoff = (size_t)(sz_48 >> 48) * src.slicePitch;
    00071
    00072             uint64 sy_48 = (stepy >> 1) - 1;
    00073             for (size_t y = dst.top; y < dst.bottom; y++, sy_48 += stepy) {
    00074                 size_t srcyoff = (size_t)(sy_48 >> 48) * src.rowPitch;
    00075
    00076                 uint64 sx_48 = (stepx >> 1) - 1;
    00077                 for (size_t x = dst.left; x < dst.right; x++, sx_48 += stepx) {
    00078                     uchar* psrc = srcdata +
    00079                         elemsize*((size_t)(sx_48 >> 48) + srcyoff + srczoff);
    00080                     memcpy(pdst, psrc, elemsize);
    00081                     pdst += elemsize;
    00082                 }
    00083                 pdst += elemsize*dst.getRowSkip();
    00084             }
    00085             pdst += elemsize*dst.getSliceSkip();
    00086         }
    00087     }
    00088 };
    00089
    00090
    00091 // default floating-point linear resampler, does format conversion
    00092 struct LinearResampler {
    00093     static void scale(const PixelBox& src, const PixelBox& dst) {
    00094         size_t srcelemsize = PixelUtil::getNumElemBytes(src.format);
    00095         size_t dstelemsize = PixelUtil::getNumElemBytes(dst.format);
    00096
    00097         // srcdata stays at beginning, pdst is a moving pointer
    00098         uchar* srcdata = (uchar*)src.data;
    00099         uchar* pdst = (uchar*)dst.data;
    00100
    00101         // sx_48,sy_48,sz_48 represent current position in source
    00102         // using 16/48-bit fixed precision, incremented by steps
    00103         uint64 stepx = ((uint64)src.getWidth() << 48) / dst.getWidth();
    00104         uint64 stepy = ((uint64)src.getHeight() << 48) / dst.getHeight();
    00105         uint64 stepz = ((uint64)src.getDepth() << 48) / dst.getDepth();
    00106
    00107         // temp is 16/16 bit fixed precision, used to adjust a source
    00108         // coordinate (x, y, or z) backwards by half a pixel so that the
    00109         // integer bits represent the first sample (eg, sx1) and the
    00110         // fractional bits are the blend weight of the second sample
    00111         unsigned int temp;
    00112
    00113         // note: ((stepz>>1) - 1) is an extra half-step increment to adjust
    00114         // for the center of the destination pixel, not the top-left corner
    00115         uint64 sz_48 = (stepz >> 1) - 1;
    00116         for (size_t z = dst.front; z < dst.back; z++, sz_48+=stepz) {
    00117             temp = sz_48 >> 32;
    00118             temp = (temp > 0x8000)? temp - 0x8000 : 0;
    00119             size_t sz1 = temp >> 16;                 // src z, sample #1
    00120             size_t sz2 = std::min(sz1+1,src.getDepth()-1);// src z, sample #2
    00121             float szf = (temp & 0xFFFF) / 65536.f; // weight of sample #2
    00122
    00123             uint64 sy_48 = (stepy >> 1) - 1;
    00124             for (size_t y = dst.top; y < dst.bottom; y++, sy_48+=stepy) {
    00125                 temp = sy_48 >> 32;
    00126                 temp = (temp > 0x8000)? temp - 0x8000 : 0;
    00127                 size_t sy1 = temp >> 16;                    // src y #1
    00128                 size_t sy2 = std::min(sy1+1,src.getHeight()-1);// src y #2
    00129                 float syf = (temp & 0xFFFF) / 65536.f; // weight of #2
    00130
    00131                 uint64 sx_48 = (stepx >> 1) - 1;
    00132                 for (size_t x = dst.left; x < dst.right; x++, sx_48+=stepx) {
    00133                     temp = sx_48 >> 32;
    00134                     temp = (temp > 0x8000)? temp - 0x8000 : 0;
    00135                     size_t sx1 = temp >> 16;                    // src x #1
    00136                     size_t sx2 = std::min(sx1+1,src.getWidth()-1);// src x #2
    00137                     float sxf = (temp & 0xFFFF) / 65536.f; // weight of #2
    00138
    00139                     ColourValue x1y1z1, x2y1z1, x1y2z1, x2y2z1;
    00140                     ColourValue x1y1z2, x2y1z2, x1y2z2, x2y2z2;
    00141
    00142 #define UNPACK(dst,x,y,z) PixelUtil::unpackColour(&dst, src.format, \
    00143     srcdata + srcelemsize*((x)+(y)*src.rowPitch+(z)*src.slicePitch))
    00144
    00145                     UNPACK(x1y1z1,sx1,sy1,sz1); UNPACK(x2y1z1,sx2,sy1,sz1);
    00146                     UNPACK(x1y2z1,sx1,sy2,sz1); UNPACK(x2y2z1,sx2,sy2,sz1);
    00147                     UNPACK(x1y1z2,sx1,sy1,sz2); UNPACK(x2y1z2,sx2,sy1,sz2);
    00148                     UNPACK(x1y2z2,sx1,sy2,sz2); UNPACK(x2y2z2,sx2,sy2,sz2);
    00149 #undef UNPACK
    00150
    00151                     ColourValue accum =
    00152                         x1y1z1 * ((1.0f - sxf)*(1.0f - syf)*(1.0f - szf)) +
    00153                         x2y1z1 * (        sxf *(1.0f - syf)*(1.0f - szf)) +
    00154                         x1y2z1 * ((1.0f - sxf)*        syf *(1.0f - szf)) +
    00155                         x2y2z1 * (        sxf *        syf *(1.0f - szf)) +
    00156                         x1y1z2 * ((1.0f - sxf)*(1.0f - syf)*        szf ) +
    00157                         x2y1z2 * (        sxf *(1.0f - syf)*        szf ) +
    00158                         x1y2z2 * ((1.0f - sxf)*        syf *        szf ) +
    00159                         x2y2z2 * (        sxf *        syf *        szf );
    00160
    00161                     PixelUtil::packColour(accum, dst.format, pdst);
    00162
    00163                     pdst += dstelemsize;
    00164                 }
    00165                 pdst += dstelemsize*dst.getRowSkip();
    00166             }
    00167             pdst += dstelemsize*dst.getSliceSkip();
    00168         }
    00169     }
    00170 };
    00171
    00172
    00173 // float32 linear resampler, converts FLOAT32_RGB/FLOAT32_RGBA only.
    00174 // avoids overhead of pixel unpack/repack function calls
    00175 struct LinearResampler_Float32 {
    00176     static void scale(const PixelBox& src, const PixelBox& dst) {
    00177         size_t srcchannels = PixelUtil::getNumElemBytes(src.format) / sizeof(float);
    00178         size_t dstchannels = PixelUtil::getNumElemBytes(dst.format) / sizeof(float);
    00179         // assert(srcchannels == 3 || srcchannels == 4);
    00180         // assert(dstchannels == 3 || dstchannels == 4);
    00181
    00182         // srcdata stays at beginning, pdst is a moving pointer
    00183         float* srcdata = (float*)src.data;
    00184         float* pdst = (float*)dst.data;
    00185
    00186         // sx_48,sy_48,sz_48 represent current position in source
    00187         // using 16/48-bit fixed precision, incremented by steps
    00188         uint64 stepx = ((uint64)src.getWidth() << 48) / dst.getWidth();
    00189         uint64 stepy = ((uint64)src.getHeight() << 48) / dst.getHeight();
    00190         uint64 stepz = ((uint64)src.getDepth() << 48) / dst.getDepth();
    00191
    00192         // temp is 16/16 bit fixed precision, used to adjust a source
    00193         // coordinate (x, y, or z) backwards by half a pixel so that the
    00194         // integer bits represent the first sample (eg, sx1) and the
    00195         // fractional bits are the blend weight of the second sample
    00196         unsigned int temp;
    00197
    00198         // note: ((stepz>>1) - 1) is an extra half-step increment to adjust
    00199         // for the center of the destination pixel, not the top-left corner
    00200         uint64 sz_48 = (stepz >> 1) - 1;
    00201         for (size_t z = dst.front; z < dst.back; z++, sz_48+=stepz) {
    00202             temp = sz_48 >> 32;
    00203             temp = (temp > 0x8000)? temp - 0x8000 : 0;
    00204             size_t sz1 = temp >> 16;                 // src z, sample #1
    00205             size_t sz2 = std::min(sz1+1,src.getDepth()-1);// src z, sample #2
    00206             float szf = (temp & 0xFFFF) / 65536.f; // weight of sample #2
    00207
    00208             uint64 sy_48 = (stepy >> 1) - 1;
    00209             for (size_t y = dst.top; y < dst.bottom; y++, sy_48+=stepy) {
    00210                 temp = sy_48 >> 32;
    00211                 temp = (temp > 0x8000)? temp - 0x8000 : 0;
    00212                 size_t sy1 = temp >> 16;                    // src y #1
    00213                 size_t sy2 = std::min(sy1+1,src.getHeight()-1);// src y #2
    00214                 float syf = (temp & 0xFFFF) / 65536.f; // weight of #2
    00215
    00216                 uint64 sx_48 = (stepx >> 1) - 1;
    00217                 for (size_t x = dst.left; x < dst.right; x++, sx_48+=stepx) {
    00218                     temp = sx_48 >> 32;
    00219                     temp = (temp > 0x8000)? temp - 0x8000 : 0;
    00220                     size_t sx1 = temp >> 16;                    // src x #1
    00221                     size_t sx2 = std::min(sx1+1,src.getWidth()-1);// src x #2
    00222                     float sxf = (temp & 0xFFFF) / 65536.f; // weight of #2
    00223
    00224                     // process R,G,B,A simultaneously for cache coherence?
    00225                     float accum[4] = { 0.0f, 0.0f, 0.0f, 0.0f };
    00226
    00227 #define ACCUM3(x,y,z,factor) \
    00228     { float f = factor; \
    00229     size_t off = (x+y*src.rowPitch+z*src.slicePitch)*srcchannels; \
    00230     accum[0]+=srcdata[off+0]*f; accum[1]+=srcdata[off+1]*f; \
    00231     accum[2]+=srcdata[off+2]*f; }
    00232
    00233 #define ACCUM4(x,y,z,factor) \
    00234     { float f = factor; \
    00235     size_t off = (x+y*src.rowPitch+z*src.slicePitch)*srcchannels; \
    00236     accum[0]+=srcdata[off+0]*f; accum[1]+=srcdata[off+1]*f; \
    00237     accum[2]+=srcdata[off+2]*f; accum[3]+=srcdata[off+3]*f; }
    00238
    00239                     if (srcchannels == 3 || dstchannels == 3) {
    00240                         // RGB, no alpha
    00241                         ACCUM3(sx1,sy1,sz1,(1.0f-sxf)*(1.0f-syf)*(1.0f-szf));
    00242                         ACCUM3(sx2,sy1,sz1,      sxf *(1.0f-syf)*(1.0f-szf));
    00243                         ACCUM3(sx1,sy2,sz1,(1.0f-sxf)*      syf *(1.0f-szf));
    00244                         ACCUM3(sx2,sy2,sz1,      sxf *      syf *(1.0f-szf));
    00245                         ACCUM3(sx1,sy1,sz2,(1.0f-sxf)*(1.0f-syf)*      szf );
    00246                         ACCUM3(sx2,sy1,sz2,      sxf *(1.0f-syf)*      szf );
    00247                         ACCUM3(sx1,sy2,sz2,(1.0f-sxf)*      syf *      szf );
    00248                         ACCUM3(sx2,sy2,sz2,      sxf *      syf *      szf );
    00249                         accum[3] = 1.0f;
    00250                     } else {
    00251                         // RGBA
    00252                         ACCUM4(sx1,sy1,sz1,(1.0f-sxf)*(1.0f-syf)*(1.0f-szf));
    00253                         ACCUM4(sx2,sy1,sz1,      sxf *(1.0f-syf)*(1.0f-szf));
    00254                         ACCUM4(sx1,sy2,sz1,(1.0f-sxf)*      syf *(1.0f-szf));
    00255                         ACCUM4(sx2,sy2,sz1,      sxf *      syf *(1.0f-szf));
    00256                         ACCUM4(sx1,sy1,sz2,(1.0f-sxf)*(1.0f-syf)*      szf );
    00257                         ACCUM4(sx2,sy1,sz2,      sxf *(1.0f-syf)*      szf );
    00258                         ACCUM4(sx1,sy2,sz2,(1.0f-sxf)*      syf *      szf );
    00259                         ACCUM4(sx2,sy2,sz2,      sxf *      syf *      szf );
    00260                     }
    00261
    00262                     memcpy(pdst, accum, sizeof(float)*dstchannels);
    00263
    00264 #undef ACCUM3
    00265 #undef ACCUM4
    00266
    00267                     pdst += dstchannels;
    00268                 }
    00269                 pdst += dstchannels*dst.getRowSkip();
    00270             }
    00271             pdst += dstchannels*dst.getSliceSkip();
    00272         }
    00273     }
    00274 };
    00275
    00276
    00277
    00278 // byte linear resampler, does not do any format conversions.
    00279 // only handles pixel formats that use 1 byte per color channel.
    00280 // 2D only; punts 3D pixelboxes to default LinearResampler (slow).
    00281 // templated on bytes-per-pixel to allow compiler optimizations, such
    00282 // as unrolling loops and replacing multiplies with bitshifts
    00283 template<unsigned int channels> struct LinearResampler_Byte {
    00284     static void scale(const PixelBox& src, const PixelBox& dst) {
    00285         // assert(src.format == dst.format);
    00286
    00287         // only optimized for 2D
    00288         if (src.getDepth() > 1 || dst.getDepth() > 1) {
    00289             LinearResampler::scale(src, dst);
    00290             return;
    00291         }
    00292
    00293         // srcdata stays at beginning of slice, pdst is a moving pointer
    00294         uchar* srcdata = (uchar*)src.data;
    00295         uchar* pdst = (uchar*)dst.data;
    00296
    00297         // sx_48,sy_48 represent current position in source
    00298         // using 16/48-bit fixed precision, incremented by steps
    00299         uint64 stepx = ((uint64)src.getWidth() << 48) / dst.getWidth();
    00300         uint64 stepy = ((uint64)src.getHeight() << 48) / dst.getHeight();
    00301
    00302         // bottom 28 bits of temp are 16/12 bit fixed precision, used to
    00303         // adjust a source coordinate backwards by half a pixel so that the
    00304         // integer bits represent the first sample (eg, sx1) and the
    00305         // fractional bits are the blend weight of the second sample
    00306         unsigned int temp;
    00307
    00308         uint64 sy_48 = (stepy >> 1) - 1;
    00309         for (size_t y = dst.top; y < dst.bottom; y++, sy_48+=stepy) {
    00310             temp = sy_48 >> 36;
    00311             temp = (temp > 0x800)? temp - 0x800: 0;
    00312             unsigned int syf = temp & 0xFFF;
    00313             size_t sy1 = temp >> 12;
    00314             size_t sy2 = std::min(sy1+1, src.bottom-src.top-1);
    00315             size_t syoff1 = sy1 * src.rowPitch;
    00316             size_t syoff2 = sy2 * src.rowPitch;
    00317
    00318             uint64 sx_48 = (stepx >> 1) - 1;
    00319             for (size_t x = dst.left; x < dst.right; x++, sx_48+=stepx) {
    00320                 temp = sx_48 >> 36;
    00321                 temp = (temp > 0x800)? temp - 0x800 : 0;
    00322                 unsigned int sxf = temp & 0xFFF;
    00323                 size_t sx1 = temp >> 12;
    00324                 size_t sx2 = std::min(sx1+1, src.right-src.left-1);
    00325
    00326                 unsigned int sxfsyf = sxf*syf;
    00327                 for (unsigned int k = 0; k < channels; k++) {
    00328                     unsigned int accum =
    00329                         srcdata[(sx1 + syoff1)*channels+k]*(0x1000000-(sxf<<12)-(syf<<12)+sxfsyf) +
    00330                         srcdata[(sx2 + syoff1)*channels+k]*((sxf<<12)-sxfsyf) +
    00331                         srcdata[(sx1 + syoff2)*channels+k]*((syf<<12)-sxfsyf) +
    00332                         srcdata[(sx2 + syoff2)*channels+k]*sxfsyf;
    00333                     // accum is computed using 8/24-bit fixed-point math
    00334                     // (maximum is 0xFF000000; rounding will not cause overflow)
    00335                     *pdst++ = (accum + 0x800000) >> 24;
    00336                 }
    00337             }
    00338             pdst += channels*dst.getRowSkip();
    00339         }
    00340     }
    00341 };
    00342
    00343 }
    00344
    00345 #endif

Copyright © 2000-2005 by The OGRE Team
This work is licensed under a Creative Commons Attribution-ShareAlike 2.5 License.
Last modified Sun Feb 12 12:59:46 2006