From Igor Kravtchenko, new HDR plugin.

src/osgPlugins/hdr/hdrloader.cpp

@@ -0,0 +1,233 @@
+/*
+*
+* Copyright (C) 2004 Mekensleep
+*
+*    Mekensleep
+*    24 rue vieille du temple
+*    75004 Paris
+*       licensing@mekensleep.com
+*
+* This library is free software; you can redistribute it and/or
+* modify it under the terms of the GNU Lesser General Public
+* License as published by the Free Software Foundation; either
+* version 2.1 of the License, or (at your option) any later version.
+*
+* This library is distributed in the hope that it will be useful,
+* but WITHOUT ANY WARRANTY; without even the implied warranty of
+* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+* Lesser General Public License for more details.
+*
+* You should have received a copy of the GNU Lesser General Public
+* License along with this library; if not, write to the Free Software
+* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307  USA
+*
+* Author:
+*  Igor Kravtchenko <igor@obraz.net>
+*
+*/
+
+#include "hdrloader.h"
+
+#include <math.h>
+#include <memory.h>
+#include <stdio.h>
+
+typedef unsigned char RGBE[4];
+#define R            0
+#define G            1
+#define B            2
+#define E            3
+
+#define  MINELEN    8                // minimum scanline length for encoding
+#define  MAXELEN    0x7fff            // maximum scanline length for encoding
+
+static void workOnRGBE(RGBE *scan, int len, float *cols);
+static bool decrunch(RGBE *scanline, int len, FILE *file);
+static bool oldDecrunch(RGBE *scanline, int len, FILE *file);
+
+bool HDRLoader::isHDRFile(const char *_fileName)
+{
+    FILE *file;
+    file = fopen(_fileName, "rb");
+    if (!file)
+        return false;
+
+    char str[10];
+    fread(str, 10, 1, file);
+    fclose(file);
+
+    if (memcmp(str, "#?RADIANCE", 10) && memcmp(str, "#?RGBE", 6))
+        return false;
+
+    return true;
+}
+
+bool HDRLoader::load(const char *_fileName, HDRLoaderResult &_res)
+{
+    int i;
+    char str[200];
+    FILE *file;
+
+    file = fopen(_fileName, "rb");
+    if (!file)
+        return false;
+
+    fread(str, 10, 1, file);
+    if (memcmp(str, "#?RADIANCE", 10)) {
+        fseek(file, 0, SEEK_SET);
+        fread(str, 6, 1, file);
+        if (memcmp(str, "#?RGBE", 6)) {
+            fclose(file);
+            return false;
+        }
+    }
+    fseek(file, 1, SEEK_CUR);
+
+    char cmd[2000];
+    i = 0;
+    char c = 0, oldc;
+    while(true) {
+        oldc = c;
+        c = fgetc(file);
+        if (c == 0xa && oldc == 0xa)
+            break;
+        cmd[i++] = c;
+    }
+
+    char reso[2000];
+    i = 0;
+    while(true) {
+        c = fgetc(file);
+        reso[i++] = c;
+        if (c == 0xa)
+            break;
+    }
+
+    int w, h;
+    if (!sscanf(reso, "-Y %ld +X %ld", &h, &w)) {
+        fclose(file);
+        return false;
+    }
+
+    _res.width = w;
+    _res.height = h;
+
+    float *cols = new float[w * h * 3];
+    _res.cols = cols;
+
+    RGBE *scanline = new RGBE[w];
+    if (!scanline) {
+        fclose(file);
+        return false;
+    }
+
+    // convert image
+    cols += (h-1) * w * 3;
+    for (int y = h - 1; y >= 0; y--) {
+        if (decrunch(scanline, w, file) == false)
+            break;
+        workOnRGBE(scanline, w, cols);
+        cols -= w * 3;
+    }
+
+    delete [] scanline;
+    fclose(file);
+
+    return true;
+}
+
+float convertComponent(int _expo, int _val)
+{
+    float v = _val / 256.0f;
+    float d = powf(2, _expo);
+    return v * d;
+}
+
+void workOnRGBE(RGBE *_scan, int _len, float *_cols)
+{
+    int ii = 0;
+    while (_len-- > 0) {
+        int expo = _scan[0][E] - 128;
+        _cols[0] = convertComponent(expo, _scan[0][R]);
+        _cols[1] = convertComponent(expo, _scan[0][G]);
+        _cols[2] = convertComponent(expo, _scan[0][B]);
+        _cols += 3;
+        _scan++;
+        ii++;
+    }
+}
+
+bool decrunch(RGBE *_scanline, int _len, FILE *_file)
+{
+    int  i, j;
+
+    if (_len < MINELEN || _len > MAXELEN)
+        return oldDecrunch(_scanline, _len, _file);
+
+    i = fgetc(_file);
+    if (i != 2) {
+        fseek(_file, -1, SEEK_CUR);
+        return oldDecrunch(_scanline, _len, _file);
+    }
+
+    _scanline[0][G] = fgetc(_file);
+    _scanline[0][B] = fgetc(_file);
+    i = fgetc(_file);
+
+    if (_scanline[0][G] != 2 || _scanline[0][B] & 128) {
+        _scanline[0][R] = 2;
+        _scanline[0][E] = i;
+        return oldDecrunch(_scanline + 1, _len - 1, _file);
+    }
+
+    // read each component
+    for (i = 0; i < 4; i++) {
+        for (j = 0; j < _len; ) {
+            unsigned char code = fgetc(_file);
+            if (code > 128) { // run
+                code &= 127;
+                unsigned char val = fgetc(_file);
+                while (code--)
+                    _scanline[j++][i] = val;
+            }
+            else  {    // non-run
+                while(code--)
+                    _scanline[j++][i] = fgetc(_file);
+            }
+        }
+    }
+
+    return feof(_file) ? false : true;
+}
+
+bool oldDecrunch(RGBE *_scanline, int _len, FILE *_file)
+{
+    int i;
+    int rshift = 0;
+
+    while (_len > 0) {
+        _scanline[0][R] = fgetc(_file);
+        _scanline[0][G] = fgetc(_file);
+        _scanline[0][B] = fgetc(_file);
+        _scanline[0][E] = fgetc(_file);
+        if (feof(_file))
+            return false;
+
+        if (_scanline[0][R] == 1 &&
+            _scanline[0][G] == 1 &&
+            _scanline[0][B] == 1) {
+                for (i = _scanline[0][E] << rshift; i > 0; i--) {
+                    memcpy(&_scanline[0][0], &_scanline[-1][0], 4);
+                    _scanline++;
+                    _len--;
+                }
+                rshift += 8;
+            }
+        else {
+            _scanline++;
+            _len--;
+            rshift = 0;
+        }
+    }
+    return true;
+}