image4: complete command-line option parsing

ray4/src/image4.cpp

@@ -32,7 +32,7 @@
 using namespace std;
 
 
-//==================================================================================================
+//__________________________________________________________________________________________________
 // Information Text Definitions
 
 static auto version = L"image4 0.0.0 | 2024-10-31 | https://github.com/hollasch/ray4/tree/master/image4";
@@ -82,28 +82,30 @@ options.
         If a horizontalCount is specified, then each row will have the specified number of
     thumbnails, sized to fit, with as tall a result as needed to display all slices.
 
--c, --crop <minX>,<minY>-<maxX>,<maxY>
+-c, --crop <xMin>,<yMin>-<xMax>,<yMax>
     Output images may be optionally cropped to the specified region. If specified, all images will
     be similarly cropped.
 )";
+
 //__________________________________________________________________________________________________
 
 struct Parameters {
-    bool    printHelp {false};
-    wstring imageCubeFilename;
-    bool    printFileInfo {false};
-    wstring outputFilePattern;
-    int     sliceStart{0};
-    int     sliceEnd{-1};
-    int     sliceStep{1};
-    bool    showTiled{false};
-    int     tiledPixelWidth{0};
-    int     tiledHorizontalCount{0};
-    int     cropXMin{0};
-    int     cropXMax{-1};
-    int     cropYMin{0};
-    int     cropYMax{-1};
+    bool    printHelp{false};         // Print help and version information.
+    wstring imageCubeFilename;        // Input image cube file name
+    bool    printFileInfo{false};     // Print information about the image cube file.
+    wstring outputFilePattern;        // Output image file name pattern
+    int     sliceStart{0};            // First slice to output
+    int     sliceEnd{-1};             // Last output slice. -1 indicates last slice
+    int     sliceStep{1};             // Step size between slices
+    bool    showTiled{false};         // Generate a tiled contact sheet of thumbnails.
+    int     tiledPixelWidth{0};       // Width in pixels of tiled contact sheet
+    int     tiledHorizontalCount{0};  // Number of thumbnails per row in tiled contact sheet
+    int     cropXMin{0};              // Minimum X coordinate for cropped output images
+    int     cropXMax{-1};             // Maximum X coordinate for cropped output images
+    int     cropYMin{0};              // Minimum Y coordinate for cropped output images 
+    int     cropYMax{-1};             // Maximum Y coordinate for cropped output images
 };
+
 //__________________________________________________________________________________________________
 
 enum class OptionType {
@@ -137,9 +139,11 @@ static vector<OptionInfo> optionInfo = {
     {OptionType::Tiled,          L't', L"tiled",  true},
     {OptionType::Crop,           L'c', L"crop",   true},
 };
+
 //__________________________________________________________________________________________________
 
 const OptionInfo& getOptionInfo(wchar_t *arg) {
+    // Given a command-line option, return the corresponding OptionInfo structure.
 
     if (arg[0] == L'/' && arg[1] == L'?')
         return optionInfo[1];
@@ -159,46 +163,142 @@ const OptionInfo& getOptionInfo(wchar_t *arg) {
 
     return optionInfo[0];
 }
+
+//__________________________________________________________________________________________________
+
+std::pair<wchar_t*, int> readInteger (wchar_t* str) {
+    // Reads the integer from the string. Returns a pair containing the pointer to the remainder of
+    // the string, and the integer value.
+
+    auto *ptr = str;
+    bool negate = *ptr == L'-';
+    if (negate) ++ptr;
+
+    int value = 0;
+    for (; isdigit(*ptr);  ++ptr)
+        value = (10 * value) + (*ptr - L'0');
+
+    return { ptr, negate ? -value : value };
+}
+
 //__________________________________________________________________________________________________
 
 bool parseOptionValueSlice (Parameters &params, wchar_t* value) {
-    // Parse the slice option string. Format is '<start>[-<end>][x<stepSize>]'.
+    // Parse the --slice option string. Format is '<start>[-<end>][x<stepSize>]'.
+
+    const auto optionValue = value;
+
+    if (!isdigit(*value)) {
+        wcerr << "image4: Invalid slice start (" << optionValue << ").\n";
+        return false;
+    }
+
+    std::tie(value, params.sliceStart) = readInteger(value);
 
-    if (atoi
+    if (*value == '-') {
+        ++value;
+        if (!isdigit(*value)) {
+            wcerr << "image4: Invalid slice end (" << optionValue << ").\n";
+            return false;
+        }
+        std::tie(value, params.sliceEnd) = readInteger(value);
+    }
+
+    if (*value == 'x') {
+        ++value;
+        if (!isdigit(*value)) {
+            wcerr << "image4: Invalid slice step (" << optionValue << ").\n";
+            return false;
+        }
+        std::tie(value, params.sliceStep) = readInteger(value);
+    }
+
+    if (*value) {
+        wcerr << "image4: Invalid slice option value (" << optionValue << ").\n";
+        return false;
+    }
 
-    params.sliceStart = 1;
-    params.sliceEnd = -1;
-    params.sliceStep = -1;
     return true;
 }
+
 //__________________________________________________________________________________________________
 
 bool parseOptionValueTiled (Parameters &params, wchar_t* value) {
-    params.showTiled = true;
-    params.tiledPixelWidth = -1;
-    params.tiledHorizontalCount = -1;
+    // Parse the --tiled option string. Format is '<pixelWidth>[x<horizontalCount]'.
+
+    const auto optionValue = value;
+
+    if (!isdigit(*value)) {
+        wcerr << "image4: Invalid tiled pixel width (" << optionValue << ").\n";
+        return false;
+    }
+
+    std::tie(value, params.tiledPixelWidth) = readInteger(value);
+
+    if (*value == 'x') {
+        ++value;
+        if (!isdigit(*value)) {
+            wcerr << "image4: Invalid tiled horizontal count (" << optionValue << ").\n";
+            return false;
+        }
+        std::tie(value, params.tiledHorizontalCount) = readInteger(value);
+    }
+
+    if (*value) {
+        wcerr << "image4: Invalid tiled option value (" << optionValue << ").\n";
+        return false;
+    }
+
     return true;
 }
+
 //__________________________________________________________________________________________________
 
 bool parseOptionValueCrop (Parameters &params, wchar_t* value) {
-    params.cropXMin = 0;
-    params.cropYMin = 0;
-    params.cropYMax = -1;
-    params.cropYMin = -1;
+    // Parse the --crop option string. Format is '<xMin>,<yMin>-<xMax>,<yMax>'.
+
+    const auto optionValue = value;
+
+    if (!isdigit(*value)) {
+        wcerr << "image4: Invalid crop X minimum (" << optionValue << ").\n";
+        return false;
+    }
+    std::tie(value, params.cropXMin) = readInteger(value);
+
+    if (*value != ',' || !isdigit(*++value)) {
+        wcerr << "image4: Invalid crop option value (" << optionValue << ").\n";
+        return false;
+    }
+    std::tie(value, params.cropYMin) = readInteger(value);
+
+    if (*value != '-' || !isdigit(*++value)) {
+        wcerr << "image4: Invalid crop option value (" << optionValue << ").\n";
+        return false;
+    }
+    std::tie(value, params.cropXMax) = readInteger(value);
+
+    if (*value != ',' || !isdigit(*++value)) {
+        wcerr << "image4: Invalid crop option value (" << optionValue << ").\n";
+        return false;
+    }
+    std::tie(value, params.cropYMax) = readInteger(value);
+
+    if (*value) {
+        wcerr << "image4: Invalid tiled option value (" << optionValue << ").\n";
+        return false;
+    }
+
     return true;
 }
+
 //__________________________________________________________________________________________________
 
 bool processParameters (Parameters &params, int argc, wchar_t *argv[]) {
     // Process the command-line options and load results into the given Parameters object. Returns
     // true on success, false on error.
 
-    wcout << "\nArguments:\n";
     for (auto argi = 1;  argi < argc;  ++argi) {
         auto *arg = argv[argi];
-        wcout << argi << ": " << arg << '\n';
-
         auto optionInfo = getOptionInfo(arg);
         wchar_t *optionValue = nullptr;
 
@@ -261,6 +361,7 @@ bool processParameters (Parameters &params, int argc, wchar_t *argv[]) {
 
     return true;
 }
+
 //__________________________________________________________________________________________________
 
 int wmain(int argc, wchar_t *argv[]) {
@@ -269,6 +370,17 @@ int wmain(int argc, wchar_t *argv[]) {
     if (!processParameters(params, argc, argv))
         return 1;
 
+    if (params.printHelp) {
+        wcout << usage;
+        wcout << version;
+        return 0;
+    }
+
+    if (params.imageCubeFilename.empty()) {
+        wcerr << "image4: Missing input image file name.\n";
+        return 1;
+    }
+
     wcout << "\nCommand-line parameters:\n";
     wcout << "    printHelp: " << (params.printHelp ? "true\n" : "false\n");
     wcout << "    imageCubeFilename: '" << params.imageCubeFilename << "'\n";