add lab3

lab3/grid2DIO.cpp

@@ -0,0 +1,224 @@
+// Functions to read/write a 2D grid of 3D points.
+
+#include "grid2DIO.h"
+
+#include <fstream>
+#include <iostream>
+#include <sstream>
+#include <stdexcept>
+#include <string>
+
+const std::string GRID2D_POINTS3D_HEADER = "GRID2D_OF_POINTS3D";
+
+
+// ********************************************************************************
+// Internal helpers
+// ********************************************************************************
+
+/// Trim leading and trailing whitespace from s.
+static std::string Trim(const std::string& s) {
+    const std::string whitespace = " \t\r\n";
+    size_t start = s.find_first_not_of(whitespace);
+    if (start == std::string::npos) { return ""; }
+    size_t end = s.find_last_not_of(whitespace);
+    return s.substr(start, end - start + 1);
+}
+
+
+/// Throw a read error with two descriptive lines.
+static void RaiseReadErrorII(int iline,
+                              const std::string& error_line1,
+                              const std::string& error_line2)
+{
+    throw std::runtime_error(
+        "Error reading line " + std::to_string(iline) + ": " +
+        error_line1 + "\n    " + error_line2);
+}
+
+
+// ********************************************************************************
+// Read/Write helper predicates
+// ********************************************************************************
+
+bool IsHeader(const std::string& line) {
+    return Trim(line) == GRID2D_POINTS3D_HEADER;
+}
+
+
+bool IsCommentOrBlankLine(const std::string& line) {
+    std::string s = Trim(line);
+    if (s.empty()) { return true; }
+    if (s[0] == '#') { return true; }
+    return false;
+}
+
+
+// ********************************************************************************
+// Read functions
+// ********************************************************************************
+
+void ReadGrid2DPoints3D(std::istream& infile, GRID2D_POINTS3D& grid2D) {
+    // Read coordinates of point [i,j] in grid.
+    int i = 0, j = 0, iline = 1;
+    std::string line;
+
+    while (std::getline(infile, line)) {
+        std::string trimmed = Trim(line);
+
+        if (iline == 1) {
+            if (!IsHeader(trimmed)) {
+                RaiseReadErrorII(1,
+                    "Incorrect file header.",
+                    "Expected header: " + GRID2D_POINTS3D_HEADER);
+            }
+        }
+        else if (!IsCommentOrBlankLine(trimmed)) {
+            if (!grid2D.AreDimensionsSet()) {
+                std::istringstream iss(trimmed);
+                int n, m;
+                if (!(iss >> n >> m)) {
+                    RaiseReadErrorII(iline,
+                        "Incorrect grid dimensions.",
+                        "Expecting two integers for grid dimensions.");
+                }
+                std::string extra;
+                if (iss >> extra) {
+                    RaiseReadErrorII(iline,
+                        "Incorrect grid dimensions.",
+                        "Expecting two integers for grid dimensions.");
+                }
+                grid2D.SetDimensions(n, m);
+            }
+            else {
+                std::istringstream iss(trimmed);
+                double x, y, z;
+                if (!(iss >> x >> y >> z)) {
+                    RaiseReadErrorII(iline,
+                        "Error reading point coordinates.",
+                        "Expecting three float coordinates for each point.");
+                }
+
+                if (i >= grid2D.NumRows()) {
+                    std::cerr << "Warning: More than "
+                              << grid2D.NumRows() << " x "
+                              << grid2D.NumCols()
+                              << " points in file.\n";
+                    std::cerr << "Skipping remaining points after line "
+                              << iline << ".\n";
+                    break;
+                }
+
+                grid2D.SetCoord(i, j, x, y, z);
+
+                j++;
+                if (j >= grid2D.NumCols()) {
+                    j = 0;
+                    i++;
+                }
+            }
+        }
+
+        iline++;
+    }
+
+    if (i < grid2D.NumRows()) {
+        throw std::runtime_error(
+            "Too few points in file. Expected coordinates of " +
+            std::to_string(grid2D.NumPoints()) + " points.\n" +
+            "    Found coordinates of  " +
+            std::to_string(i * grid2D.NumCols() + j) + " points.\n" +
+            "    First missing point: [" +
+            std::to_string(i) + "," + std::to_string(j) + "].");
+    }
+}
+
+
+void OpenReadGrid2DPoints3D(const std::string& filename,
+                              GRID2D_POINTS3D& grid2D)
+{
+    try {
+        std::ifstream infile(filename);
+        if (!infile.is_open()) {
+            std::cerr << "Input file " << filename << " not found.\n";
+            throw std::runtime_error(
+                "Input file " + filename + " not found.");
+        }
+        ReadGrid2DPoints3D(infile, grid2D);
+    }
+    catch (const std::out_of_range& e) {
+        std::cerr << "Error reading file " << filename
+                  << ".\n " << e.what() << "\n";
+        throw;
+    }
+    catch (const std::runtime_error& e) {
+        std::cerr << "Error reading file " << filename
+                  << ".\n " << e.what() << "\n";
+        throw;
+    }
+    catch (const std::exception& e) {
+        std::cerr << "Error reading file " << filename
+                  << ".\n " << e.what() << "\n";
+        throw;
+    }
+}
+
+
+// ********************************************************************************
+// Write functions
+// ********************************************************************************
+
+void WriteGrid2DPoints3D(std::ostream& outfile,
+                          const GRID2D_POINTS3D& grid2D,
+                          const std::vector<std::string>& comment_list)
+{
+    // Write header
+    outfile << GRID2D_POINTS3D_HEADER << "\n";
+
+    // Write dimensions
+    outfile << grid2D.NumRows() << " " << grid2D.NumCols() << "\n";
+
+    // Write comments
+    for (const auto& comment : comment_list) {
+        outfile << "# " << comment << "\n";
+    }
+
+    // Write point coordinates
+    for (int irow = 0; irow < grid2D.NumRows(); irow++) {
+        for (int icol = 0; icol < grid2D.NumCols(); icol++) {
+            auto c = grid2D.Coord(irow, icol);
+            outfile << c[0] << " " << c[1] << " " << c[2] << "\n";
+        }
+    }
+}
+
+
+void OpenWriteGrid2DPoints3D(const std::string& filename,
+                               const GRID2D_POINTS3D& grid2D,
+                               const std::vector<std::string>& comment_list)
+{
+    try {
+        std::ofstream outfile(filename);
+        if (!outfile.is_open()) {
+            std::cerr << "Cannot open file " << filename
+                      << " for writing.\n";
+            throw std::runtime_error(
+                "Cannot open file " + filename + " for writing.");
+        }
+        WriteGrid2DPoints3D(outfile, grid2D, comment_list);
+    }
+    catch (const std::out_of_range& e) {
+        std::cerr << "Error writing file " << filename
+                  << ".\n " << e.what() << "\n";
+        throw;
+    }
+    catch (const std::runtime_error& e) {
+        std::cerr << "Error writing file " << filename
+                  << ".\n " << e.what() << "\n";
+        throw;
+    }
+    catch (const std::exception& e) {
+        std::cerr << "Error writing file " << filename
+                  << ".\n " << e.what() << "\n";
+        throw;
+    }
+}