anime.h => pnm work

src/pnm.cpp

+#include "pnm.h"
+#include <iostream>
+
+// pnm
+// The PNM format is just an abstraction of the PBM, PGM, and PPM formats. I.e. the name "PNM" refers collectively to PBM, PGM, and PPM.
+// pam has the advanced header
+
+RGBAPNMObject * readPPM(const char* fileName) {
+    RGBAPNMObject *data=new RGBAPNMObject;
+    // open the file to read just the header reading
+    FILE* fr = fopen(fileName, "r");
+    if (!fr) {
+        std::cout << "Can't open " << fileName << std::endl;
+        return nullptr;
+    }
+
+    // formatted read of header
+    char fileType[11];
+    fscanf(fr, "%9s", fileType);
+    data->magicNum=fileType;
+
+    std::cout << "fileType:" << fileType << std::endl;
+    
+    unsigned char bits = 0;
+
+    // check to see if it's a PPM image file
+    if (strncmp(fileType, "P4" , 2) == 0) {
+        bits = 1; // PBM
+    } else if (strncmp(fileType, "P5" , 2) == 0) {
+        bits = 8; // PGM
+    } else if (strncmp(fileType, "P6" , 2) == 0) {
+        bits = 24; // PPM
+    } else if (strncmp(fileType, "P8" , 2) == 0) {
+        bits = 32; // PPM
+    }
+    std::cout << "bits:" << bits << std::endl;
+
+    // read the rest of header
+    unsigned int width, height;
+    fscanf(fr, "%u\n %u\n", &width, &height);
+    data->width = width;
+    data->height = height;
+    
+
+    // read maximum
+    data->maxColVal = 255; // just set a default
+    if (bits != 1) {
+        unsigned int maximum;
+        fscanf(fr, "%u\n", &maximum);
+        data->maxColVal = height;
+    }
+    int size = width * height;
+    if (bits != 1) {
+        size *= bits/8;
+    }
+
+    // allocate array for pixels
+    char* pixels = new char[size];
+
+    // unformatted read of binary pixel data
+    fread(pixels, sizeof(int), size, fr);
+    data->m_Ptr = pixels;
+
+    // close file
+    fclose(fr);
+
+    // return the array
+    return data;
+} // end of readPPM
+
+void writePBM4(const char *filename, const RGBAPNMObject &data) {
+  FILE *fp = fopen(filename, "wb"); /* b - binary mode */
+  fprintf(fp, "P6\n%d %d\n255\n", data.width, data.height);
+  for (int j = 0; j < data.height; ++j) {
+    for (int i = 0; i < data.width; ++i) {
+      static unsigned char color[1];
+      unsigned int pos = ((i * 4) + (j * 4 * 1024));
+      //color[0] = data.m_Ptr[pos + 0];  /* red */
+      //color[1] = data.m_Ptr[pos + 1];  /* green */
+      //color[2] = data.m_Ptr[pos + 2];  /* blue */
+      color[0] = data.m_Ptr[pos + 3];  /* alpha */
+      fwrite(color, 1, 1, fp);
+    }
+  }
+  fclose(fp);
+}
+
+void writePGM5(const char *filename, const RGBAPNMObject &data) {
+  FILE *fp = fopen(filename, "wb"); /* b - binary mode */
+  fprintf(fp, "P5\n%d %d\n255\n", data.width, data.height);
+  for (int j = 0; j < data.height; ++j) {
+    for (int i = 0; i < data.width; ++i) {
+      static unsigned char color[1];
+      unsigned int pos = ((i * 4) + (j * 4 * 1024));
+      color[0] = data.m_Ptr[pos + 0];  /* red */
+      //color[1] = data.m_Ptr[pos + 1];  /* green */
+      //color[2] = data.m_Ptr[pos + 2];  /* blue */
+      //color[3] = data.m_Ptr[pos + 3];  /* alpha */
+      fwrite(color, 1, 1, fp);
+    }
+  }
+  fclose(fp);
+}
+
+void writePPM6(const char *filename, const RGBAPNMObject &data) {
+  FILE *fp = fopen(filename, "wb"); /* b - binary mode */
+  fprintf(fp, "P6\n%d %d\n255\n", data.width, data.height);
+  for (int j = 0; j < data.height; ++j) {
+    for (int i = 0; i < data.width; ++i) {
+      static unsigned char color[3];
+      unsigned int pos = ((i * 4) + (j * 4 * 1024));
+      color[0] = data.m_Ptr[pos + 0];  /* red */
+      color[1] = data.m_Ptr[pos + 1];  /* green */
+      color[2] = data.m_Ptr[pos + 2];  /* blue */
+      //color[3] = data.m_Ptr[pos + 3];  /* alpha */
+      fwrite(color, 1, 3, fp);
+    }
+  }
+  fclose(fp);
+}
+
+void writePPM8(const char *filename, const RGBAPNMObject &data) {
+  FILE *fp = fopen(filename, "wb"); /* b - binary mode */
+  fprintf(fp, "P8\n%d %d\n255\n", data.width, data.height);
+  for (int j = 0; j < data.height; ++j) {
+    for (int i = 0; i < data.width; ++i) {
+      static unsigned char color[4];
+      unsigned int pos = ((i * 4) + (j * 4 * 1024));
+      color[0] = data.m_Ptr[pos + 0];  /* red */
+      color[1] = data.m_Ptr[pos + 1];  /* green */
+      color[2] = data.m_Ptr[pos + 2];  /* blue */
+      color[3] = data.m_Ptr[pos + 3];  /* alpha */
+      fwrite(color, 1, 4, fp);
+    }
+  }
+  fclose(fp);
+}

src/pnm.h

+#include <string>
+
+// this structure expects RGBA
+struct RGBAPNMObject {
+  std::string magicNum;
+  int width, height, maxColVal;
+  char * m_Ptr;
+};
+
+RGBAPNMObject * readPPM(const char* fileName);
+void writePBM4(const char *filename, const RGBAPNMObject &data);
+void writePGM5(const char *filename, const RGBAPNMObject &data);
+void writePPM6(const char *filename, const RGBAPNMObject &data);
+void writePPM8(const char *filename, const RGBAPNMObject &data);