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igl/external/embree/tutorials/common/image/ppm.cpp
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Executable File

// ======================================================================== //
// Copyright 2009-2014 Intel Corporation //
// //
// Licensed under the Apache License, Version 2.0 (the "License"); //
// you may not use this file except in compliance with the License. //
// You may obtain a copy of the License at //
// //
// http://www.apache.org/licenses/LICENSE-2.0 //
// //
// Unless required by applicable law or agreed to in writing, software //
// distributed under the License is distributed on an "AS IS" BASIS, //
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. //
// See the License for the specific language governing permissions and //
// limitations under the License. //
// ======================================================================== //
#include "image/image.h"
#include <iostream>
#include <cstring>
#include <cstdio>
namespace embree
{
/*! read a single comment line starting with #, or read a space */
static bool readCommentLine(FILE* file)
{
int c = fgetc(file);
if (isspace(c)) return true;
if (c != '#') {
ungetc(c, file);
return false;
}
char line[1024];
if(fgets(line, sizeof(line), file) == NULL)
THROW_RUNTIME_ERROR("Error reading PPM file!");
return true;
}
/*! read PPM file from disk */
Ref<Image> loadPPM(const FileName& fileName)
{
/* open PPM file */
FILE* file = fopen(fileName.c_str(), "rb");
if (!file) THROW_RUNTIME_ERROR("cannot open " + fileName.str());
/* read file type */
char type[8];
if (fscanf(file, "%7s", type) != 1)
THROW_RUNTIME_ERROR("Error reading " + fileName.str());
/* skip comment lines */
while (readCommentLine(file)) {};
/* read width, height, and maximal color value */
int width, height, maxColor;
if (fscanf(file, "%i %i %i", &width, &height, &maxColor) != 3)
THROW_RUNTIME_ERROR("Error reading " + fileName.str());
float rcpMaxColor = 1.0f/float(maxColor);
/* get return or space */
fgetc(file);
/* create image and fill with data */
Ref<Image> img = new Image4c(width,height,fileName);
/* image in text format */
if (!strcmp(type, "P3"))
{
int r, g, b;
for (ssize_t y=0; y<height; y++) {
for (ssize_t x=0; x<width; x++) {
if (fscanf(file, "%i %i %i", &r, &g, &b) != 3)
THROW_RUNTIME_ERROR("Error reading " + fileName.str());
img->set(x,y,Color4(float(r)*rcpMaxColor,float(g)*rcpMaxColor,float(b)*rcpMaxColor,1.0f));
}
}
}
/* image in binary format 8 bit */
else if (!strcmp(type, "P6") && maxColor <= 255)
{
unsigned char rgb[3];
for (ssize_t y=0; y<height; y++) {
for (ssize_t x=0; x<width; x++) {
if (fread(rgb,sizeof(rgb),1,file) != 1)
THROW_RUNTIME_ERROR("Error reading " + fileName.str());
img->set(x,y,Color4(float(rgb[0])*rcpMaxColor,float(rgb[1])*rcpMaxColor,float(rgb[2])*rcpMaxColor,1.0f));
}
}
}
/* image in binary format 16 bit */
else if (!strcmp(type, "P6"))
{
unsigned short rgb[3];
for (ssize_t y=0; y<height; y++) {
for (ssize_t x=0; x<width; x++) {
if (fread(rgb,sizeof(rgb),1,file) != 1)
THROW_RUNTIME_ERROR("Error reading " + fileName.str());
img->set(x,y,Color4(float(rgb[0])*rcpMaxColor,float(rgb[1])*rcpMaxColor,float(rgb[2])*rcpMaxColor,1.0f));
}
}
}
/* invalid magic value */
else {
fclose(file);
THROW_RUNTIME_ERROR("Invalid magic value in PPM file");
}
fclose(file);
return img;
}
/*! store PPM file to disk */
void storePPM(const Ref<Image>& img, const FileName& fileName)
{
FILE* file = fopen(fileName.c_str(), "wb");
if (!file) THROW_RUNTIME_ERROR("cannot open file " + fileName.str());
fprintf(file,"P6\n%i %i\n255\n", int(img->width), int(img->height));
for (size_t y=0; y<img->height; y++) {
for (size_t x=0; x<img->width; x++) {
const Color4 c = img->get(x,y);
fputc((unsigned char)(clamp(c.r)*255.0f), file);
fputc((unsigned char)(clamp(c.g)*255.0f), file);
fputc((unsigned char)(clamp(c.b)*255.0f), file);
}
}
fclose(file);
}
}