ray4: convert all command argument processing

- Camel case renaming in random locations.
- Got rid of some defines.
- No longer read from stdin by default.
- Add double-dash options.
- Delete aspect ratio parameters.
- Scan range replaced with option to select single Z slice.
- Upgraded parameter processing code.
- Replace global header struct with main-local instance.
- Keep parameters in main-local instance, pass as function argument. No
  more global parameters struct.

ray4/src/r4_image.h

@@ -63,15 +63,15 @@
 
 // Macro Definitions
 
-#define R4_IMAGE_ID   0x52617934L       // 'Ray4'
+const uint32_t ray4FormatMagic = 0x52617934L;  // 'Ray4'
 
 
 // Structure Definitions
 
 struct ImageHeader_1 {
     unsigned long  magic;         // Magic Number = R4_IMAGE_ID
     unsigned char  version;       // Image File Version Number = 1
-    unsigned char  bitsperpixel;  // Number of Bits per Pixel
+    unsigned char  bitsPerPixel;  // Number of Bits per Pixel
     unsigned short aspect[3];     // Aspect Ratios [X,Y,Z]
     unsigned short start[3];      // Starting Image Pixels for [X,Y,Z]
     unsigned short end[3];        // Ending Image Pixels for [X,Y,Z]

ray4/src/r4_io.cpp

@@ -44,7 +44,7 @@ FILE *outstream = nullptr;  // Output Stream
 void CloseInput () {
     // Closes the input stream.
 
-    if (!infile || (*infile == 0) || (!instream))
+    if (!instream)
         return;
     fclose (instream);
     instream = nullptr;
@@ -89,27 +89,23 @@ void UnreadChar (int c) {
 
 //__________________________________________________________________________________________________
 
-void OpenInput () {
+void OpenInput (const char* fileName) {
     // This subroutine opens the input file. If no filename was given in the command-line arguments,
     // we'll use the standard input stream.
 
-    if (!infile || (*infile == 0))
-        instream = stdin;
-    else if (! (instream = fopen (infile, "r")))
-        Halt ("Open failed on input file (%s).", infile);
+    instream = fopen (fileName, "r");
+    if (!instream)
+        Halt ("Open failed on input file (%s).", fileName);
 }
 
 //__________________________________________________________________________________________________
 
-void OpenOutput () {
+void OpenOutput (const char* fileName) {
     // This subroutine opens the output file.
 
-    if (!outfile || (*outfile == 0))
-        Halt ("No output file specified.");
-
-    outstream = fopen (outfile, "wb");
+    outstream = fopen (fileName, "wb");
     if (!outstream)
-        Halt ("Open failed on output file (%s).", outfile);
+        Halt ("Open failed on output file (%s).", fileName);
 }
 
 //__________________________________________________________________________________________________