Initial commit.

Framework/external/embree/tutorials/common/image/ppm.cpp

@@ -0,0 +1,117 @@
+// Copyright 2009-2021 Intel Corporation
+// SPDX-License-Identifier: Apache-2.0
+
+#include "image.h"
+
+#include <iostream>
+#include <cstring>
+#include <cstdio>
+#include <fstream>
+
+namespace embree
+{
+  static void skipSpacesAndComments(std::fstream& file)
+  {
+    while (true)
+    {
+      if  (isspace(file.peek())) {
+        file.ignore();
+      } else  if (file.peek() == '#') {
+        std::string line; std::getline(file,line);
+      } else break;
+    }
+  }
+
+  /*! read PPM file from disk */
+  Ref<Image> loadPPM(const FileName& fileName)
+  {
+    /* open file for reading */
+    std::fstream file;
+    file.exceptions (std::fstream::failbit | std::fstream::badbit);
+    file.open (fileName.c_str(), std::fstream::in | std::fstream::binary);
+
+    /* read file type */
+    char cty[2]; file.read(cty,2);
+    skipSpacesAndComments(file);
+    std::string type(cty,2);
+
+    /* read width, height, and maximum color value */
+    int width; file >> width;
+    skipSpacesAndComments(file);
+    int height; file >> height;
+    skipSpacesAndComments(file);
+    int maxColor; file >> maxColor;
+    if (maxColor <= 0) THROW_RUNTIME_ERROR("Invalid maxColor value in PPM file");
+    float rcpMaxColor = 1.0f/float(maxColor);
+    file.ignore(); // skip space or return
+
+    /* create image and fill with data */
+    Ref<Image> img = new Image4uc(width,height,fileName);
+
+    /* image in text format */
+    if (type == "P3")
+    {
+      int r, g, b;
+      for (ssize_t y=0; y<height; y++) {
+        for (ssize_t x=0; x<width; x++) {
+          file >> r; file >> g; file >> b;
+          img->set(x,y,Color4(float(r)*rcpMaxColor,float(g)*rcpMaxColor,float(b)*rcpMaxColor,1.0f));
+        }
+      }
+    }
+
+    /* image in binary format 8 bit */
+    else if (type == "P6" && maxColor <= 255)
+    {
+      unsigned char rgb[3];
+      for (ssize_t y=0; y<height; y++) {
+        for (ssize_t x=0; x<width; x++) {
+          file.read((char*)rgb,sizeof(rgb));
+          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 (type == "P6" && maxColor <= 65535)
+    {
+      unsigned short rgb[3];
+      for (ssize_t y=0; y<height; y++) {
+        for (ssize_t x=0; x<width; x++) {
+          file.read((char*)rgb,sizeof(rgb));
+          img->set(x,y,Color4(float(rgb[0])*rcpMaxColor,float(rgb[1])*rcpMaxColor,float(rgb[2])*rcpMaxColor,1.0f));
+        }
+      }
+    }
+
+    /* invalid magic value */
+    else {
+      THROW_RUNTIME_ERROR("Invalid magic value in PPM file");
+    }
+    return img;
+  }
+
+  /*! store PPM file to disk */
+  void storePPM(const Ref<Image>& img, const FileName& fileName)
+  {
+    /* open file for writing */
+    std::fstream file;
+    file.exceptions (std::fstream::failbit | std::fstream::badbit);
+    file.open (fileName.c_str(), std::fstream::out | std::fstream::binary);
+
+    /* write file header */
+    file << "P6" << std::endl;
+    file << img->width << " " << img->height << std::endl;
+    file << 255 << std::endl;
+
+    /* write image */
+    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);
+        file << (unsigned char)(clamp(c.r)*255.0f);
+        file << (unsigned char)(clamp(c.g)*255.0f);
+        file << (unsigned char)(clamp(c.b)*255.0f);
+      }
+    }
+  }
+}