Files
qglengine/core/hdr.cpp
2020-08-25 21:57:31 +03:00

126 lines
3.6 KiB
C++

/*
QGL HDR
Ivan Pelipenko peri4ko@yandex.ru
This program 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 3 of the License, or
(at your option) any later version.
This program 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 program. If not, see <http://www.gnu.org/licenses/>.
*/
#include "hdr_p.h"
#include "qmath.h"
#define RGBE_DATA_RED 2
#define RGBE_DATA_GREEN 1
#define RGBE_DATA_BLUE 0
/* number of floats per pixel */
#define RGBE_DATA_SIZE 3
void rgbe2float(float *red, float *green, float *blue, uchar rgbe[4]) {
float f;
if (rgbe[3]) {
f = static_cast<float>(ldexp(1.0,rgbe[3]-(int)(128+8)));
*red = rgbe[0] * f;
*green = rgbe[1] * f;
*blue = rgbe[2] * f;
}
else
*red = *green = *blue = 0.0;
}
/* simple read routine. will not correctly handle run length encoding */
bool RGBE_ReadPixels(QDataStream * fp, float * data, int numpixels) {
uchar rgbe[4];
while(numpixels-- > 0) {
if (fp->readRawData((char*)rgbe, sizeof(rgbe)) < 1)
return false;
rgbe2float(&data[RGBE_DATA_RED], &data[RGBE_DATA_GREEN], &data[RGBE_DATA_BLUE],rgbe);
data += RGBE_DATA_SIZE;
}
return true;
}
bool RGBE_ReadPixels_RLE(QDataStream * fp, float * data, int scanline_width, int num_scanlines) {
uchar rgbe[4], *ptr, *ptr_end;
int i, count;
uchar buf[2];
QByteArray scanline_buffer;
if ((scanline_width < 8)||(scanline_width > 0x7fff))
/* run length encoding is not allowed so read flat*/
return RGBE_ReadPixels(fp,data,scanline_width*num_scanlines);
scanline_buffer.resize(4*scanline_width);
/* read in each successive scanline */
while(num_scanlines > 0) {
if (fp->readRawData((char*)rgbe,sizeof(rgbe)) < 1) {
return false;
}
if ((rgbe[0] != 2)||(rgbe[1] != 2)||(rgbe[2] & 0x80)) {
/* this file is not run length encoded */
rgbe2float(&data[RGBE_DATA_RED],&data[RGBE_DATA_GREEN],&data[RGBE_DATA_BLUE],rgbe);
data += RGBE_DATA_SIZE;
return RGBE_ReadPixels(fp,data,scanline_width*num_scanlines-1);
}
if ((((int)rgbe[2])<<8 | rgbe[3]) != scanline_width) {
return false;
}
ptr = (uchar*)scanline_buffer.data();
/* read each of the four channels for the scanline into the buffer */
for(i=0;i<4;i++) {
ptr_end = (uchar*)scanline_buffer.data() + ((i+1)*scanline_width);
while(ptr < ptr_end) {
if (fp->readRawData((char*)buf,sizeof(buf[0])*2) < 1) {
return false;
}
if (buf[0] > 128) {
/* a run of the same value */
count = buf[0]-128;
if ((count == 0)||(count > ptr_end - ptr)) {
return false;
}
while(count-- > 0)
*ptr++ = buf[1];
}
else {
/* a non-run */
count = buf[0];
if ((count == 0)||(count > ptr_end - ptr)) {
return false;
}
*ptr++ = buf[1];
if (--count > 0) {
if (fp->readRawData((char*)ptr,sizeof(*ptr)*count) < 1) {
return false;
}
ptr += count;
}
}
}
}
/* now convert data from buffer into floats */
for(i=0;i<scanline_width;i++) {
rgbe[0] = scanline_buffer[i];
rgbe[1] = scanline_buffer[i+scanline_width];
rgbe[2] = scanline_buffer[i+2*scanline_width];
rgbe[3] = scanline_buffer[i+3*scanline_width];
rgbe2float(&data[RGBE_DATA_RED],&data[RGBE_DATA_GREEN],
&data[RGBE_DATA_BLUE],rgbe);
data += RGBE_DATA_SIZE;
}
num_scanlines--;
}
return true;
}